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Conserved forage-based systems for backgrounding weaned beef calves

Conserved forage-based systems for backgrounding weaned beef calves † ‡,2 || $ Erin M. Forte, Mary Kimberly Mullenix, Jennifer J. Tucker, Joshua B. Elmore, and Werner G. Bergen † ‡ University of Georgia Extension, Oglethorpe, GA 31068; Department of Animal Sciences, Auburn University, || Auburn, AL 36849; Department of Animal and Dairy Science, University of Georgia, Tifton, GA 31793; and Alabama Cooperative Extension System, Auburn, AL 36849 ABSTRACT: A 45-d backgrounding study was the animals did not differ (P = 0.50 and P = 0.99, conducted to compare animal performance, for- respectively) across treatments. Calf ADG for RB, age nutritive value, digestion dynamics, and diet BH, and CS diets were 0.61, 0.72, and 0.72  kg/d, costs of conserved forage systems for weaned beef respectively, and did not differ across treatments calves. One hundred and eight weaned Angus × (P  =  0.57). Based on these results, these forage Simmental beef calves (initial BW 279 ± 34 kg) were options supported a similar level of gain when used randomly assigned to one of three diets (n = 3 pens/ for backgrounding beef calves. Forage in vitro DM treatment): 1) free-choice annual ryegrass (RB; cv. digestibility differed 48  h after digestion, and BH ‘Marshall’) baleage and 4 kg of a 50/50 mixture of + 50:50 had greater 48-h digestibility than when pelleted soybean hulls and corn gluten feed, 2) free- unsupplemented, which may be related to comple- choice Tifton 85 bermudagrass (BH) and 3 kg of a mentary forage-supplement interactions. In diets 50/50 mixture of pelleted soybean hulls and corn containing RB and CS, digestibility was greater gluten feed, or 3)  free-choice corn silage (CS; cv. with no supplementation at the 48-h time point. Pioneer P1662YHR) and 2  kg of a 85% cracked These data support the observation that supple- corn and 15% cottonseed meal mixture. Diets were mentation type and level influence conserved for - formulated to achieve a target gain of 0.9  kg/d age diet digestibility compared with forage alone. based on the NRC (2000) requirement for a 270 kg The cost of feeding a baleage-based diet in this growing calf. Animal performance (initial BW, final system was higher ($1.37/d) than CS or BH diets BW, and ADG) was measured on days 0 and 45 ($1.02 and $0.95/d, respectively). Results suggest of the study. Forage nutritive value and an in vitro that RB baleage-based diets may support a simi- digestion trial were conducted to evaluate supple- lar level of gain to BH or CS diets in growing beef mentation effects on forage diet digestion dynam- calves, but supplement type, level, and ration costs ics. Data were analyzed using PROC Mixed in SAS should be evaluated when determining cost-effec- 9.4 as a completely randomized design. Pen was the tive backgrounding options in the Southeastern experimental unit. Mean initial and final BW of United States. Key words: annual ryegrass, baleage, bermudagrass, corn silage, coproduct feeds © The Author(s) 2018. Published by Oxford University Press on behalf of the American Society of Animal Science. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com Transl. Anim. Sci. 2018.2:272–279 doi: 10.1093/tas/txy063 Corresponding author: mullemk@auburn.edu This publication was supported by the Alabama Received April 2, 2018. Agricultural Experiment Station and the Alabama Accepted May 20, 2018. Cattlemen’s Association State Beef Checkoff Program. Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 273 INTRODUCTION beef calves and 2) evaluate nutritive value charac- teristics and in vitro digestion dynamics of these There are over 9.8-million head of cattle and systems. calves in the Southeastern United States, with calves being primarily sold at weaning. Depending MATERIALS AND METHODS on cattle market cycles, backgrounding calves for a 45- to 60-d period post weaning may be a profitable alternative. Backgrounding provides an opportu- Animal and Feed Management nity for calf identification, castration and dehorn - A 45-d backgrounding trial was conducted at ing, administration of vaccinations, and training the E.V. Smith Research Center in Shorter, Alabama the animal to eat from feed bunks and drink from from September 15 to October 30, 2015. All proce- a clean water source (Peterson et al., 1989). Avent dures were previously reviewed and approved by the et  al. (2004) suggested that producers might con- Auburn University Institutional Animal Care and sider keeping weaned calves on-farm for a mini- Use Committee (PRN 2015–2710). One hundred mum of 45 d post weaning to take advantage of and eight Angus × Simmental calves were weaned greater seasonal feeder calf prices later in the sea- on September 2, 2015, placed in feeding pens, and son. Midsummer- and fall-weaning programs in given ad libitum access to bermudagrass (BH) hay the Southeastern often coincide with periods of and water. Calves were sorted by sex, weight (initial low-quality forage available for grazing or the fall BW 283  ±  16  kg), age, and randomly assigned to forage production gap in the region. Producers one of three diet treatments on September 8 for a commonly wean and background calves in a drylot 7-d diet acclimation period (n = 9 pens). Nine feed- feeding setting or place calves onto dormant pas- ing pens were used for the study with three pens per tures and feed hay with a supplement and mineral treatment. Twelve calves were allocated per pen (six mix. In either method, conserved forages are the heifers and steers, respectively) to allow for 0.45 m primary forage source in these diets. However, fre- of bunk space per calf. Individual pen space was quent rainfall and high humidity may limit the abil- 2 2 286 m with a 72 m covered loafing area and inline ity for a 3- to 5-d window to adequately cure hay in feed bunks 6.7 m in length. Treatments consisted of the Southeast, which may decrease forage quality three conserved forage diets (% DM basis): 1) Free- due to prolonged harvest frequency between cut- choice annual RB (cv. ‘Marshall’) baleage and 4 kg tings. Alternative harvest methods such as silage of a 50/50 mixture of pelleted soybean hulls and or baleage production require less drying time, corn gluten feed, 2) Free-choice Tifton 85 BH and which may allow for earlier harvests when quality 3  kg of a 50/50 mixture of pelleted soybean hulls is greater and weather conditions are not favorable and corn gluten feed, and 3) Free-choice corn silage for curing. McCormick et  al. (2002) reported that (CS; cv. Pioneer P1662YHR) and 2  kg of a 85% annual ryegrass (RB; Lolium multiflorum ) is one cracked corn and 15% cottonseed meal mixture. of the most successful forage species for making Supplemental feeds were selected to reflect readily baleage in the Southeastern region because of its available feed sources in the Southeast and used to high forage quality, which provides a good environ- develop backgrounding diet systems that are reflec - ment for fermentation when baled between 40% and tive of local industry practice. Diets were formu- 60% moisture. To date, there have been few studies −1 −1 lated to achieve a target gain of 0.9 kg hd d based evaluating the animal performance, forage nutritive on the NRC (2016) requirement for a 270-kg grow- value dynamics, and diet costs of conserved for- ing calf with an expected DMI of 2.5% of BW per age-based diet systems for backgrounding calves in day. Supplemental feed level was determined based the Southeastern United States. This is especially on expected animal nutrient requirements and for- important as forages conserved through ensiling age quality analysis for each treatment. Diets were have been previously shown to result in reduced formulated to be isocaloric, and composition is DMI compared with forage conserved by nonensil- listed in Table 1. Forage was fed in bunk line feed- ing processes (Gordon et al., 1960; Hawkins et al., ers, and 30% excess was added to expected DMI 1970; Bergen, 1972), which may influence feed man - requirements to ensure cattle had ad libitum access agement recommendations during the background- to the forage component of individual diets. Feed ing phase for beef cattle operations. The objectives supplements for each treatment were top-dressed of this study were to 1) provide a system-level com- on forage in the bunk daily. Calves were placed in parison of animal performance and ration costs of pens on day -5 to allow for acclimation to the diet. conserved forage-based diets for backgrounding Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 274 Forte et al. Table 1. Chemical composition of conserved forages and coproduct supplements fed during a 45-d back- grounding trial for weaned beef calves Item RB* CS BH 50/50 SH: CGF 85/15 CC:CSM SE Moisture, % as-fed 59.3 72.0 14.8 9.5 13.1 — Nutrient analysis CP 10.0a 6.9c 9.9b 16.2 13.2 0.35 NDF 56.5b 38.0c 67.0a 51.2 19.4 2.78 ADF 34.9a 19.9b 35.0a 27.9 10.0 2.27 *RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 ber- mudagrass hay harvested on a 4-wk frequency from May through June 2015; 50/50 SH:CGF = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; 85/15 CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. Values reported on a % DM basis. a,b,c Within a row, means without common superscripts differ (P <0.10). Feed was weighed in and out of bunks on a daily study. BH hayfields were fertilized in late April 2015 basis throughout the duration of the feeding trial. with 112-kg N/ha and P and K according to Auburn Estimated forage intake per pen is reported in the University Soil Testing Laboratory recommenda- RESULTS AND DISCUSSION. Cattle had access tions. An additional 112-kg N/ha was applied fol- to water and mineral (Wind and Rain All Season 7 lowing harvest in July. For each forage treatment, Complete, Purina, Shoreview, MN) ad libitum for five core samples were collected from each forage all treatments during the evaluation. Animal BW type weekly throughout the 45-d backgrounding was measured on days -7, 0, 21, and 45 during the period. Samples were composited by forage type backgrounding trial to evaluate BW gain and ADG. and week and transported to the Auburn University Animals were weighed in the morning before being Ruminant Nutrition laboratory for storage prior to fed. Initial BW, final BW, and ADG are reported in nutritive value analysis. Baleage and silage samples Table 3. were freeze-dried using a VirTis Genesis 35L freeze dryer (SP Scientific, Gardiner, NY). Dried samples of all forages were ground to pass a 1-mm screen Forage Management and Laboratory Analysis using a Wiley Mill (Thomas Scientific, Swedesboro, Annual RB was planted on a 6-ha field into pre - NJ) before nutritive value analysis. During the pared seedbed on October 30, 2015. At planting, feeding evaluation, hand-grab samples of baleage, 33-kg N/ha, and P and K were applied according to silage, and hay were taken each day at the morn- recommendations from the Auburn University Soil ing feeding. Samples from each forage type within Testing Laboratory (Mitchell and Huluka, 2017). week were composited and used for laboratory An additional 56-kg N/ha was applied to the area analyses. Forage samples from each week were ana- in late January 2015. Annual RB was harvested as lyzed for concentrations of NDF and ADF accord- baleage in the boot-to-early dough stage on April ing to the procedure described by Van Soest et al. 22, 2015 and allowed to wilt for 24 h to achieve a (1991) using an ANKOM 2000 Automated Fiber moisture level of 40% to 60% prior to baling and Analyzer (ANKOM Technology, Macedon, NY). wrapping. Moisture range of baleage prior to bal- Forage concentration of CP was analyzed accord- ing was determined using a microwave test (Steevens ing to the Kjeldahl procedure (AOAC, 1990) using et al., 1993). Baleage was wrapped using an in-line a FOSS Kjeltec 8200 (FOSS, Eden Prairie, MN). wrapper with six layers of polyethylene plastic with Forage CP was then determined as N × 6.25. a 50% overlap and stored until the time of feeding. Corn was planted on April 1, 2015 and harvested In Vitro DM Digestibility Trial as silage and chopped in the milk stage on July 13, 2015 and stored in polyethylene silo storage bags An in vitro fermentation trial was conducted prior to feeding. CS fertility rates were 200-kg N/ha with each forage type and diet used in the feeding at planting, and P and K applied according to rec- study using 75  mL flasks as described in a proto - ommendations from the Auburn University Soil col by Lourenco et al., 2017. Treatments for the in Testing Laboratory (Mitchell and Huluka, 2017). vitro study included RB, BH, or CS with or without Tifton 85 BH was harvested as hay on a 28-d inter- supplemental feed. Initial sample weight per incu- val for the study from May to July 2015 and stored bation flask was 0.75  g (forage plus supplement). in a pole barn until the start of the backgrounding The amount of each diet added to the incubation Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 275 jars was estimated based on a 272 kg growing steer Nalgene bottles and placed in a freezer (−20 °C) to consuming 2.5% of their BW per day in DM with stop fermentation. Bottles were allowed to thaw at a target ADG of 0.9 kg/d. Supplemental feed type room temperature 3 d later, and diet residues were and amount were representatives of level provided filtered through a Buchner funnel using Whatman to calves in the 45-d feeding trial. Treatments were filter paper (Grade 40)  and a vacuum pump. Diet organized in a 3 × 2 factorial design as three forage residues were placed in a 50 °C forced-air oven to types with or without supplement and are described dry for 48  h. Digestibility at each time point was in Table 2. Diets were subjected to in vitro digestion calculated as the difference between initial sample for seven time points: 0, 3, 6, 12, 18, 24, and 48 h to weight and residual weight. A  NDF analysis was evaluate in vitro DM and NDF digestibility. conducted on sample residue to remove microbial Rumen contents were collected at the Auburn debris and determine in vitro DM digestibility and University College of Veterinary Medicine from a NDF digestibility. cannulated Holstein cow that was offered access to BH hay ad libitum and supplemental feed limit fed Diet Cost Analysis twice a day. This feed consisted of a 15% CP supple- Forage DM cost per ton and daily ration ment consisting of soy hull pellets, corn gluten feed, costs per calf were calculated for each treatment. and whole cottonseed, plus 8 oz of Meagalac (Arm Data from the Alabama Weekly Hay Report and and Hammer Nutrition, Princeton, NJ). Rumen Alabama Weekly Feedstuff Report (USDA AMS, contents were transported to the Auburn University 2018) for the time of the study for each forage and Ruminant Nutrition laboratory in prewarmed supplement were used to determine a ration cost for thermos containers where it was strained through each diet (Table 3) per head per day. cheesecloth to remove particulates. Digestion flasks (75 mL, glass Erlenmeyer flasks) were prepared for the study with 0.75 g of each diet, 16.5 mL of rumen Statistical Analysis fluid, and 33  mL of phosphate-carbonate buffer Data from the feeding trial were evaluated using (pH 6.8; McDougall’s buffer). Each mixture was the PROC MIXED procedure of SAS 9.4. The flushed with CO and sealed with a rubber stopper experiment was a completely randomized design before being placed in a 39 °C water bath incubator with pen as the experimental unit during the 45-d (ThermoFisher Scientific, Waltham, MA) for 48 h. backgrounding study. Diet was considered a fixed Stoppers were retrofitted with a three-way value and effect. The PDIFF option of LSMEANS was used 50  mL syringe and needle to remove gas pressure to separate treatment means, and because of the throughout the study. Each treatment was run in low number of animals, differences were declared duplicate over the respective time points during the when P < 0.10 for all analyses. A first-order autore - 48-h observation period (n  =  84 flasks). Digestion gressive covariance structure was used, and calf sex flasks were removed at the respective time point, was included as a covariate. Regression analysis and contents of the flask were transferred to plastic was performed with in vitro digestibility data to evaluate changes in fermentation metrics over the Table  2. In vitro digestibility trial forage diet incubation times up to 48 h. composition* Treatment Forage (g) Supplemental feed (g) RB 0.75 — Table  3. Animal performance, cost of forage DM CS 0.75 — per metric ton, and daily ration costs for growing BH 0.75 — beef calves from conserved forage diets during a RB + 50:50 0.51 0.24 45-d preconditioning trial CS + CC:CSM 0.63 0.12 BH + 50:50 0.52 0.23 Item RB* CS BH SE Initial BW, kg 287 282 282 8.2 *Diets are based on a 250-kg steer consuming 2.5% BW in DM. Final BW, kg 314 315 314 5.9 Supplemental feed inclusion is estimated based on amount offered to ADG, kg/d 0.61 0.72 0.73 0.12 animals in the 45-d backgrounding trial. Forage DM cost per metric ton 137 160 123 — RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS  =  corn silage harvested in the milk stage; BH  =  Tifton 85 Diet costs ($/head/day) 1.37 1.02 0.95 — bermudagrass hay harvested on a 4-wk frequency from May through June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten *RB  =  annual ryegrass baleage harvested in the boot stage, feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% CS = corn silage harvested in the milk stage, BH = Tifton 85 bermu- mixture of cottonseed meal, respectively. dagrass hay harvested on a 4-wk frequency from May to June 2015. Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 276 Forte et al. RESULTS AND DISCUSSION lower than those reported in other recent evalua- tions, which supports the observation that annual RB in this study was in the dough rather than boot Animal Performance stage of maturity at harvest. Coffey et  al. (2002) performed a 3-yr study providing ad libitum access There were no differences (P  =  0.33) in initial to BH supplemented with grain sorghum for grow- BW, final BW, or ADG of beef calves fed annual ing stocker calves. The authors reported an ADG RB-, CS-, or BH-based rations during the 45-d of 0.71 kg/d across the 3 yr. These data are similar backgrounding trial (Table  3). Gain per day was to those observed in the present study when moder- between 0.61 and 0.73  kg/d for calves consuming ate-quality BH was fed. Based on published trials, the diets evaluated. Estimated forage intake per animal performance from RB may vary, but values pen was 193, 231, and 94  kg/d on an as-fed basis similar to or greater than those of traditional CS- for RB-, CS-, or BH-based rations, respectively, or hay-based diets are commonly observed. across the 45-d feeding period. As a percentage of calf BW during the trial, estimated DMI was 2.5 for RB, 1.8% for CS, and 2.2% for BH, illustrat- Forage Nutritive Value and In Vitro Digestibility ing that intake was equal to or below the formu- Table  1 shows the nutritive value of each of lated intake of 2.5% of BW per day. This level of the forages used in the preconditioning diets in this intake is sufficient to support ADG of 0.7 kg/d for study. Differences were observed in CP, NDF, ADF, growing calves, but diet nutrient density at the lev- and TDN% among forage types (P < 0.10). Forage els of consumption reported was not sufficient to concentration of CP for RB and BH was greater support the target of 0.9 kg/d. As the silage system than CS. This observation fits with expected values had a lower reported DMI, this must be taken into for CS, which commonly range from 6.8% to 9.3% account when making comparative assessments CP (Bal, 2006; Martin et al., 2008). Fiber constitu- between these backgrounding systems. In fer- ents were greater for BH and RB than CS. BH hay mented feeds, the actual availability of feed protein/ and CS quality in this study was similar to those nitrogen to the rumen microbiota is often reduced reported in the literature with a comparable harvest (Bergen et al., 1991). Because of this, a lower DM frequency. Mandebvu et al. (1998) evaluated forage digestibility in ensiled feedstuffs may occur if no nutritive value characteristics of Tifton 85 BH hay protein supplementation is practiced, which has a harvested at 3.5  wk and 7  wk in comparison with depressing effect on observed DMI. Although cot- CS. The authors reported CP values of 15.5% DM tonseed meal was provided as a protein supplement at 3.5  wk and 9.0% DM at 7  wk, although fiber as part of CS-based diets, at the level of intake constituents were greater in their study than those observed, a combination of low protein intake and observed for the 4-wk harvest frequency used in availability may have reduced animal gains in this this trial. Forage CP of CS in their trial was 9.3% system relative to other reported trials. In a 121 DM, which is greater than what was observed in d trial, Young and Kauffman (1978) observed an the present study at 6.9% DM. Lower CP values in ADG for growing calves fed a CS-based diet of the present study may be attributed to differences 1.09 kg/d consuming 2.4% of BW per day in DM. in N fertilization and harvest times between the two When comparing early boot stage cereal rye (Secale studies. McCormick et al. (1998) harvested annual cereale) and RB baleage to late-bloom stage rye RB for baleage in the boot stage and observed and RB baleage, BH baleage, and BH hay, Martin greater CP and digestibility values than were seen et  al. (2015) experienced ADGs lower than those in this study, which is likely attributed to differences observed in the present study at 0.46 kg/d for 60 d in stage of maturity at harvest. Beef producers for growing beef calves when supplemented with a often target daily gains of 0.7 to 0.9 kg in precon- self-limiting molasses-based liquid protein supple- ditioning and stocker systems (Beck et  al., 2013). ment. The authors reported a mean CP of 12.8% The nutritive value of forage reported in this trial and TDN of 64.5% (DM basis) for boot stage rye highlights the need for additional supplementation and RB. However, Hancock (2010) found that beef to be provided if gain is to be achieved for growing replacement heifers fed RB (16.3% CP and 65.9% beef calves, which is illustrated by the level of ani- TDN, respectively) had a greater ADG (0.88 kg/d) mal performance observed in the present study. than those fed BH or RB hay (16.1% and 14.7% In vitro DM digestibility of forage diets CP; 62.9% and 62.4% TDN, respectively). The increased in a quadratic manner with increasing values observed for RB in the present study were Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 277 time of digestion (Figure  1). There were no dif- consistent with those reported in the literature ferences among treatments in IVDMD until the under similar growing conditions (McCormick 48  h after digestion (Table  4; P  =  0.02), which et  al., 1998; Martin et  al., 2008). Overall, forage was attributed to greater variation (mean CV IVDMD reflects moderate-to-high quality forage of 12% across time points) at these time points. used in this study. There were no differences in Supplementation of BH increased IVDMD, NDF digestibility for RB or BH with or without which illustrates a positive associative effect of supplementation. Forage NDF digestibility of CS fiber-based coproduct supplementation on BH with supplementation increased compared with hay digestibility in this study. Highfill et al. (1987) CS alone, which may reduce physical fill in the reported that high-fiber supplements such as soy - rumen over time and can allow greater voluntary hulls and corn gluten feed may be less susceptible feed intake (Dado and Allen, 1995). to negative feed interactions by lessening inhib- itory effects on starch digestion and/or avoid- Diet Costs ing potential shifts in native ruminal microflora. Table  3 shows the diet costs for annual RB Galloway et al. (1993) suggested that supplementa- baleage, CS, and BH hay. Baleage was shown to tion of growing cattle consuming moderate-qual- be more expensive on a per head basis than hay, ity tropical grass hay with a low-to-moderate level at $1.37/d vs. $0.95/d. Silage was intermediate at of DE (20 kcal/kg of BW) from corn or soybean $1.02/d. This diet cost was similar a baleage system hulls may increase digestible OM intake with- from Hersom et al. (2007). The authors reported a out adverse effects on fiber digestibility. Forage diet cost for baleage of $1.26/d in a split BH hay/ IVDMD decreased with the addition of supple- baleage system. In drylot feeding systems, such as ment in BH- and CS-based diets and had a more the one used in the present study, feed costs rep- negative impact on fiber digestibility in these resent a large proportion of the cost of gain per diets. Forage IVDMD values in this study were Figure 1. Forage diet in vitro digestion dynamics over a 48-h incubation period. RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 bermudagrass hay harvested on a 4-wk frequency from May to June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. *Means differ P < 0.02. Table  4. IVDMD and NDF digestibility (%  DM basis) of conserved forage diets with or without supplementation Item* % RB CS BH RB + 50:50 CS + CC:CSM BH + 50:50 SE P-value IVDMD 70.4b 67.8c 52.6d 65.6c 58.4d 80.5a 3.5 0.0158 NDFD 49.9c 55.6b 44.6d 45.9cd 61.8a 44.9d 2.4 0.0001 *Values based on average after 48 h of digestion. RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 bermu- dagrass hay harvested on a 4-wk frequency from May to June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. a,b,c,d Within a row, means without common superscripts differ P < 0.10. Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 278 Forte et al. characteristics of whole-crop small grains harvested head. Producers should evaluate forage and sup- at milk and dough stages. J. Anim. Sci. 69:1766–1774. plementation costs using a partial budget approach doi:10.2527/1991.6941766x in order to develop cost-effective feeding strategies Coffey, K. P., W.  K. Coblentz, T. G. Montgomery, during the backgrounding phase. J. D. Shockey, K. J. Bryant, P. B. Francis, C. F. Rosenkrans, Jr, and S. A.  Gunter. 2002. Growth perfor- mance of stocker calves backgrounded on sod-seeded SUMMARY AND CONCLUSIONS winter annuals or hay and grain. J. Anim. Sci. 80:926–932. doi:10.2527/2002.804926x Results of this study suggest that diets contain- Dado, R. G., and M. S. Allen. 1995. Intake limitations, feed- ing RB-based diets can support gains in growing ing behavior, and rumen function of cows challenged with beef calves similar to those of BH or CS, although rumen fill from dietary fiber or inert bulk. J. Dairy Sci. 78:118–133. doi:10.3168/jds.S0022-0302(95)76622-X observed DMI was lower for CS than baleage or Galloway, D. L., Sr, A. L. Goetsch, L. A. Forster, Jr, A. R. Patil, hay systems. Conserved forages fed in this study W. Sun, and Z. B. Johnson. 1993. Feed intake and digest- were moderate in quality. Forage stage of matu- ibility by cattle consuming bermudagrass or orchard- rity at harvest is a key factor influencing forage grass hay supplemented with soybean hulls and (or) corn. nutritional value, intake, supplementation type, J. Anim. Sci. 71:3087–3095. doi:10.2527/1993.71113087x Gordon, C. H., J. C. Derbyshire, E. A. Kane, D. T. Black, and and level in this system. If forage nutritive value J. R. McCalmont. 1960. Consumption and feeding values alone meets the target daily growth requirements of silages as affected by dry matter content. J. Dairy Sci. of weaned calves, additional supplementation may 43:866 (Abstr.). not be needed. However, if forage nutritive value is Hancock, D. 2010. Reducing losses and getting high qual- deficient, as was the case in this study, calves may ity forage. In: J. White and D. Duncan, editors. benefit from supplementation. Choice of supple - Georgia Cattleman. Macon (GA): Georgia Cattlemen’s Association. ment type (fiber vs. starch-based) and level may Hawkins, D. R., H.  E. Henderson, and D. B.  Purser. 1970. influence forage digestion dynamics. Fiber-based Effect of dry matter levels of alfalfa silage on intake and supplementation approaches had a positive associa- metabolism in the ruminant. J. Anim. Sci. 31:617–625. tive effect on dry hay but not high-moisture forage doi:10.2527/jas1970.313617x diets. Forage digestion kinetics and protein fraction Hersom, M., D.  Driver, B.  Faircloth, and J.  Wasdin. 2007. Utilization of round bale silage as a compliment to hay characterization may provide useful information production. Gainesville (FL): 2007 University of Florida for selecting and adjusting feeding regimens in dry- Beef Report. p. 25–28. lot preconditioning programs in the Southeastern Highfill, B. D., D. L. Boggs, H. E. Amos, and J. G. Crickman. United States. Beef producers considering the use 1987. Effects of high fiber energy supplements on fermen - of annual RB baleage should compare the costs of tation characteristics and in vivo and in situ digestibili- their current production system to additional con- ties of low quality fescue hay. J. Anim. Sci. 65:224–234. doi:10.2527/jas1987.651224x siderations needed to make and feed high-quality Lourenco, J. M., M. A.  Froetschel, J. R.  Segers, J. J.  Tucker, high-moisture forages to determine the viability of and R. L. Stewart, Jr. 2017. Utilization of canola and sun- its use as an alternative feeding system during the o fl wer meals as replacements for soybean meal in a corn backgrounding phase. silage-based stocker system. Transl. Anim. Sci. 4:592–598. doi:10.2527/tas2017.0068 Mandebvu, P., J. W.  West, R. N.  Gates, and G. M.  Hill. 1998. LITERATURE CITED Effect of hay maturity, forage source, or neutral detergent AOAC. 1990. Official methods of analysis. 15th ed. Arlington fiber content on digestion of diets containing Tifton 85 ber - (VA): Association of Official Analytical Chemists. mudagrass and corn silage. Anim. Feed Sci. Technol. 73:281– Avent, R. K., C. E.  Ward, and D.L.  Lalman. 2004. Market 290. doi:10.1016/S0377-8401(98)00152-7 evaluation of preconditioning feeder calves. J. Agr. Appl. Martin, N., D. Mertens, and M.B. Hall. 2008. Fiber digestibil- Econ. 36:173–183. doi:10.1017/S1074070800021933 ity and starch content of corn silage. In: G. Shewmaker Bal, M. A. 2006. Effects of hybrid type, stage of maturity, and and R. Thaemert, editors. Proceedings of the Idaho fermentation length on whole plant corn silage quality. Alfalfa and Forage Conference; Burley, ID; February 26 Turk. J. Vet. Anim. Sci. 30:331–336. to 27, 2008. Moscow (ID): University of Idaho. Beck, P. A., M. Anders, B. Watkins, S. A. Gunter, D. Hubbell, Martin, R. M., R. S. Walker, M. T. Kearney, and C. C. and M. S.  Gadberry. 2013. 2011 and 2012 early careers Williams. 2015. Effects of feeding baleage to beef calves achievement awards: improving the production, envir- on performance, rumen function, and metabolic response onmental, and economic efficiency of the stocker cattle during the fall backgrounding period. Prof. Anim. Sci. industry in the Southeastern United States. J. Anim. Sci. 31:324–332. doi:10.15232/pas.2015-01402 91:2456–2466. doi:10.2527/jas.2012-5873 McCormick, M. E., J. F.  Beatty, and J. M.  Gillespie. 2002. Bergen, W. G. 1972. Rumen osmolality as a factor in feed intake Ryegrass bale silage research and management practices. control of sheep. J. Anim. Sci. 34:1054–1060. doi:10.2527/ LSU AgCenter Res. Sum. #144. jas1972.3461054x McCormick, M. E., G. J.  Cuomo, and D. C.  Blouin. 1998. Bergen, W. G., T. M. Byrem, and A. L. Grant. 1991. Ensiling Annual ryegrass stored as balage, haylage, or hay Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 279 for lactating dairy cows. J. Prod. Agric. 11:293–300. Columbia (MO): University of Missouri Extension. doi:10.2134/jpa1998.0293 Studstill, M. W. 2014. Improving management techniques in Mitchell, C.C., and G.  Huluka. 2017. The basis of soil test- southeastern beef production [MS Thesis]. Athens (GA): ing in Alabama. Auburn University Agronomy and University of Georgia. Soils Departmental Series No. 324A. [accessed May 1, USDA Agricultural Marketing Service. 2018. Hay Reports. 2018]. http://www.aces.edu/anr/soillab/forms/documents/ [accessed March 28, 2018]. https://www.ams.usda.gov/ ay-324A.pdf. market-news/hay-reports. NRC. 2016. Nutrient requirements of beef cattle. 8th rev. ed. Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods Washington (DC): The National Academies Press. for dietary fiber, neutral detergent fiber, and nonstarch pol - Peterson, E. B., D. R.  Strohbehn, G. W.  Ladd, and ysaccharides in relation to animal nutrition. J. Dairy Sci. R. L.  Willham. 1989. Effects of preconditioning of beef 74:3583–3597. doi:10.3168/jds.S0022-0302(91)78551-2 calves before and after entering the feedlot. J. Anim. Sci. Young, A. W., and R. G.  Kauffman. 1978. Evaluation of 67:1678–1686. doi:10.2527/jas1989.6771678 beef from steers fed grain, corn silage or haylage-corn Steevens, B., R.  Belyea, and R.  Crawford. 1993. Using a silage diets. J. Anim. Sci. 46:41–47. doi:10.2527/ microwave oven to determine moisture in forages. G3151. jas1978.46141x Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Translational Animal Science Oxford University Press

Conserved forage-based systems for backgrounding weaned beef calves

Translational Animal Science , Volume 2 (3) – Sep 1, 2018
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Abstract

† ‡,2 || $ Erin M. Forte, Mary Kimberly Mullenix, Jennifer J. Tucker, Joshua B. Elmore, and Werner G. Bergen † ‡ University of Georgia Extension, Oglethorpe, GA 31068; Department of Animal Sciences, Auburn University, || Auburn, AL 36849; Department of Animal and Dairy Science, University of Georgia, Tifton, GA 31793; and Alabama Cooperative Extension System, Auburn, AL 36849 ABSTRACT: A 45-d backgrounding study was the animals did not differ (P = 0.50 and P = 0.99, conducted to compare animal performance, for- respectively) across treatments. Calf ADG for RB, age nutritive value, digestion dynamics, and diet BH, and CS diets were 0.61, 0.72, and 0.72  kg/d, costs of conserved forage systems for weaned beef respectively, and did not differ across treatments calves. One hundred and eight weaned Angus × (P  =  0.57). Based on these results, these forage Simmental beef calves (initial BW 279 ± 34 kg) were options supported a similar level of gain when used randomly assigned to one of three diets (n = 3 pens/ for backgrounding beef calves. Forage in vitro DM treatment): 1) free-choice annual ryegrass (RB; cv. digestibility differed 48  h after digestion, and BH ‘Marshall’) baleage and 4 kg of a 50/50 mixture of + 50:50 had greater 48-h digestibility than when pelleted soybean hulls and corn gluten feed, 2) free- unsupplemented, which may be related to comple- choice Tifton 85 bermudagrass (BH) and 3 kg of a mentary forage-supplement interactions. In diets 50/50 mixture of pelleted soybean hulls and corn containing RB and CS, digestibility was greater gluten feed, or 3)  free-choice corn silage (CS; cv. with no supplementation at the 48-h time point. Pioneer P1662YHR) and 2  kg of a 85% cracked These data support the observation that supple- corn and 15% cottonseed meal mixture. Diets were mentation type and level influence conserved for - formulated to achieve a target gain of 0.9  kg/d age diet digestibility compared with forage alone. based on the NRC (2000) requirement for a 270 kg The cost of feeding a baleage-based diet in this growing calf. Animal performance (initial BW, final system was higher ($1.37/d) than CS or BH diets BW, and ADG) was measured on days 0 and 45 ($1.02 and $0.95/d, respectively). Results suggest of the study. Forage nutritive value and an in vitro that RB baleage-based diets may support a simi- digestion trial were conducted to evaluate supple- lar level of gain to BH or CS diets in growing beef mentation effects on forage diet digestion dynam- calves, but supplement type, level, and ration costs ics. Data were analyzed using PROC Mixed in SAS should be evaluated when determining cost-effec- 9.4 as a completely randomized design. Pen was the tive backgrounding options in the Southeastern experimental unit. Mean initial and final BW of United States. Key words: annual ryegrass, baleage, bermudagrass, corn silage, coproduct feeds © The Author(s) 2018. Published by Oxford University Press on behalf of the American Society of Animal Science. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com Transl. Anim. Sci. 2018.2:272–279 doi: 10.1093/tas/txy063 Corresponding author: mullemk@auburn.edu This publication was supported by the Alabama Received April 2, 2018. Agricultural Experiment Station and the Alabama Accepted May 20, 2018. Cattlemen’s Association State Beef Checkoff Program. Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 273 INTRODUCTION beef calves and 2) evaluate nutritive value charac- teristics and in vitro digestion dynamics of these There are over 9.8-million head of cattle and systems. calves in the Southeastern United States, with calves being primarily sold at weaning. Depending MATERIALS AND METHODS on cattle market cycles, backgrounding calves for a 45- to 60-d period post weaning may be a profitable alternative. Backgrounding provides an opportu- Animal and Feed Management nity for calf identification, castration and dehorn - A 45-d backgrounding trial was conducted at ing, administration of vaccinations, and training the E.V. Smith Research Center in Shorter, Alabama the animal to eat from feed bunks and drink from from September 15 to October 30, 2015. All proce- a clean water source (Peterson et al., 1989). Avent dures were previously reviewed and approved by the et  al. (2004) suggested that producers might con- Auburn University Institutional Animal Care and sider keeping weaned calves on-farm for a mini- Use Committee (PRN 2015–2710). One hundred mum of 45 d post weaning to take advantage of and eight Angus × Simmental calves were weaned greater seasonal feeder calf prices later in the sea- on September 2, 2015, placed in feeding pens, and son. Midsummer- and fall-weaning programs in given ad libitum access to bermudagrass (BH) hay the Southeastern often coincide with periods of and water. Calves were sorted by sex, weight (initial low-quality forage available for grazing or the fall BW 283  ±  16  kg), age, and randomly assigned to forage production gap in the region. Producers one of three diet treatments on September 8 for a commonly wean and background calves in a drylot 7-d diet acclimation period (n = 9 pens). Nine feed- feeding setting or place calves onto dormant pas- ing pens were used for the study with three pens per tures and feed hay with a supplement and mineral treatment. Twelve calves were allocated per pen (six mix. In either method, conserved forages are the heifers and steers, respectively) to allow for 0.45 m primary forage source in these diets. However, fre- of bunk space per calf. Individual pen space was quent rainfall and high humidity may limit the abil- 2 2 286 m with a 72 m covered loafing area and inline ity for a 3- to 5-d window to adequately cure hay in feed bunks 6.7 m in length. Treatments consisted of the Southeast, which may decrease forage quality three conserved forage diets (% DM basis): 1) Free- due to prolonged harvest frequency between cut- choice annual RB (cv. ‘Marshall’) baleage and 4 kg tings. Alternative harvest methods such as silage of a 50/50 mixture of pelleted soybean hulls and or baleage production require less drying time, corn gluten feed, 2) Free-choice Tifton 85 BH and which may allow for earlier harvests when quality 3  kg of a 50/50 mixture of pelleted soybean hulls is greater and weather conditions are not favorable and corn gluten feed, and 3) Free-choice corn silage for curing. McCormick et  al. (2002) reported that (CS; cv. Pioneer P1662YHR) and 2  kg of a 85% annual ryegrass (RB; Lolium multiflorum ) is one cracked corn and 15% cottonseed meal mixture. of the most successful forage species for making Supplemental feeds were selected to reflect readily baleage in the Southeastern region because of its available feed sources in the Southeast and used to high forage quality, which provides a good environ- develop backgrounding diet systems that are reflec - ment for fermentation when baled between 40% and tive of local industry practice. Diets were formu- 60% moisture. To date, there have been few studies −1 −1 lated to achieve a target gain of 0.9 kg hd d based evaluating the animal performance, forage nutritive on the NRC (2016) requirement for a 270-kg grow- value dynamics, and diet costs of conserved for- ing calf with an expected DMI of 2.5% of BW per age-based diet systems for backgrounding calves in day. Supplemental feed level was determined based the Southeastern United States. This is especially on expected animal nutrient requirements and for- important as forages conserved through ensiling age quality analysis for each treatment. Diets were have been previously shown to result in reduced formulated to be isocaloric, and composition is DMI compared with forage conserved by nonensil- listed in Table 1. Forage was fed in bunk line feed- ing processes (Gordon et al., 1960; Hawkins et al., ers, and 30% excess was added to expected DMI 1970; Bergen, 1972), which may influence feed man - requirements to ensure cattle had ad libitum access agement recommendations during the background- to the forage component of individual diets. Feed ing phase for beef cattle operations. The objectives supplements for each treatment were top-dressed of this study were to 1) provide a system-level com- on forage in the bunk daily. Calves were placed in parison of animal performance and ration costs of pens on day -5 to allow for acclimation to the diet. conserved forage-based diets for backgrounding Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 274 Forte et al. Table 1. Chemical composition of conserved forages and coproduct supplements fed during a 45-d back- grounding trial for weaned beef calves Item RB* CS BH 50/50 SH: CGF 85/15 CC:CSM SE Moisture, % as-fed 59.3 72.0 14.8 9.5 13.1 — Nutrient analysis CP 10.0a 6.9c 9.9b 16.2 13.2 0.35 NDF 56.5b 38.0c 67.0a 51.2 19.4 2.78 ADF 34.9a 19.9b 35.0a 27.9 10.0 2.27 *RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 ber- mudagrass hay harvested on a 4-wk frequency from May through June 2015; 50/50 SH:CGF = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; 85/15 CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. Values reported on a % DM basis. a,b,c Within a row, means without common superscripts differ (P <0.10). Feed was weighed in and out of bunks on a daily study. BH hayfields were fertilized in late April 2015 basis throughout the duration of the feeding trial. with 112-kg N/ha and P and K according to Auburn Estimated forage intake per pen is reported in the University Soil Testing Laboratory recommenda- RESULTS AND DISCUSSION. Cattle had access tions. An additional 112-kg N/ha was applied fol- to water and mineral (Wind and Rain All Season 7 lowing harvest in July. For each forage treatment, Complete, Purina, Shoreview, MN) ad libitum for five core samples were collected from each forage all treatments during the evaluation. Animal BW type weekly throughout the 45-d backgrounding was measured on days -7, 0, 21, and 45 during the period. Samples were composited by forage type backgrounding trial to evaluate BW gain and ADG. and week and transported to the Auburn University Animals were weighed in the morning before being Ruminant Nutrition laboratory for storage prior to fed. Initial BW, final BW, and ADG are reported in nutritive value analysis. Baleage and silage samples Table 3. were freeze-dried using a VirTis Genesis 35L freeze dryer (SP Scientific, Gardiner, NY). Dried samples of all forages were ground to pass a 1-mm screen Forage Management and Laboratory Analysis using a Wiley Mill (Thomas Scientific, Swedesboro, Annual RB was planted on a 6-ha field into pre - NJ) before nutritive value analysis. During the pared seedbed on October 30, 2015. At planting, feeding evaluation, hand-grab samples of baleage, 33-kg N/ha, and P and K were applied according to silage, and hay were taken each day at the morn- recommendations from the Auburn University Soil ing feeding. Samples from each forage type within Testing Laboratory (Mitchell and Huluka, 2017). week were composited and used for laboratory An additional 56-kg N/ha was applied to the area analyses. Forage samples from each week were ana- in late January 2015. Annual RB was harvested as lyzed for concentrations of NDF and ADF accord- baleage in the boot-to-early dough stage on April ing to the procedure described by Van Soest et al. 22, 2015 and allowed to wilt for 24 h to achieve a (1991) using an ANKOM 2000 Automated Fiber moisture level of 40% to 60% prior to baling and Analyzer (ANKOM Technology, Macedon, NY). wrapping. Moisture range of baleage prior to bal- Forage concentration of CP was analyzed accord- ing was determined using a microwave test (Steevens ing to the Kjeldahl procedure (AOAC, 1990) using et al., 1993). Baleage was wrapped using an in-line a FOSS Kjeltec 8200 (FOSS, Eden Prairie, MN). wrapper with six layers of polyethylene plastic with Forage CP was then determined as N × 6.25. a 50% overlap and stored until the time of feeding. Corn was planted on April 1, 2015 and harvested In Vitro DM Digestibility Trial as silage and chopped in the milk stage on July 13, 2015 and stored in polyethylene silo storage bags An in vitro fermentation trial was conducted prior to feeding. CS fertility rates were 200-kg N/ha with each forage type and diet used in the feeding at planting, and P and K applied according to rec- study using 75  mL flasks as described in a proto - ommendations from the Auburn University Soil col by Lourenco et al., 2017. Treatments for the in Testing Laboratory (Mitchell and Huluka, 2017). vitro study included RB, BH, or CS with or without Tifton 85 BH was harvested as hay on a 28-d inter- supplemental feed. Initial sample weight per incu- val for the study from May to July 2015 and stored bation flask was 0.75  g (forage plus supplement). in a pole barn until the start of the backgrounding The amount of each diet added to the incubation Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 275 jars was estimated based on a 272 kg growing steer Nalgene bottles and placed in a freezer (−20 °C) to consuming 2.5% of their BW per day in DM with stop fermentation. Bottles were allowed to thaw at a target ADG of 0.9 kg/d. Supplemental feed type room temperature 3 d later, and diet residues were and amount were representatives of level provided filtered through a Buchner funnel using Whatman to calves in the 45-d feeding trial. Treatments were filter paper (Grade 40)  and a vacuum pump. Diet organized in a 3 × 2 factorial design as three forage residues were placed in a 50 °C forced-air oven to types with or without supplement and are described dry for 48  h. Digestibility at each time point was in Table 2. Diets were subjected to in vitro digestion calculated as the difference between initial sample for seven time points: 0, 3, 6, 12, 18, 24, and 48 h to weight and residual weight. A  NDF analysis was evaluate in vitro DM and NDF digestibility. conducted on sample residue to remove microbial Rumen contents were collected at the Auburn debris and determine in vitro DM digestibility and University College of Veterinary Medicine from a NDF digestibility. cannulated Holstein cow that was offered access to BH hay ad libitum and supplemental feed limit fed Diet Cost Analysis twice a day. This feed consisted of a 15% CP supple- Forage DM cost per ton and daily ration ment consisting of soy hull pellets, corn gluten feed, costs per calf were calculated for each treatment. and whole cottonseed, plus 8 oz of Meagalac (Arm Data from the Alabama Weekly Hay Report and and Hammer Nutrition, Princeton, NJ). Rumen Alabama Weekly Feedstuff Report (USDA AMS, contents were transported to the Auburn University 2018) for the time of the study for each forage and Ruminant Nutrition laboratory in prewarmed supplement were used to determine a ration cost for thermos containers where it was strained through each diet (Table 3) per head per day. cheesecloth to remove particulates. Digestion flasks (75 mL, glass Erlenmeyer flasks) were prepared for the study with 0.75 g of each diet, 16.5 mL of rumen Statistical Analysis fluid, and 33  mL of phosphate-carbonate buffer Data from the feeding trial were evaluated using (pH 6.8; McDougall’s buffer). Each mixture was the PROC MIXED procedure of SAS 9.4. The flushed with CO and sealed with a rubber stopper experiment was a completely randomized design before being placed in a 39 °C water bath incubator with pen as the experimental unit during the 45-d (ThermoFisher Scientific, Waltham, MA) for 48 h. backgrounding study. Diet was considered a fixed Stoppers were retrofitted with a three-way value and effect. The PDIFF option of LSMEANS was used 50  mL syringe and needle to remove gas pressure to separate treatment means, and because of the throughout the study. Each treatment was run in low number of animals, differences were declared duplicate over the respective time points during the when P < 0.10 for all analyses. A first-order autore - 48-h observation period (n  =  84 flasks). Digestion gressive covariance structure was used, and calf sex flasks were removed at the respective time point, was included as a covariate. Regression analysis and contents of the flask were transferred to plastic was performed with in vitro digestibility data to evaluate changes in fermentation metrics over the Table  2. In vitro digestibility trial forage diet incubation times up to 48 h. composition* Treatment Forage (g) Supplemental feed (g) RB 0.75 — Table  3. Animal performance, cost of forage DM CS 0.75 — per metric ton, and daily ration costs for growing BH 0.75 — beef calves from conserved forage diets during a RB + 50:50 0.51 0.24 45-d preconditioning trial CS + CC:CSM 0.63 0.12 BH + 50:50 0.52 0.23 Item RB* CS BH SE Initial BW, kg 287 282 282 8.2 *Diets are based on a 250-kg steer consuming 2.5% BW in DM. Final BW, kg 314 315 314 5.9 Supplemental feed inclusion is estimated based on amount offered to ADG, kg/d 0.61 0.72 0.73 0.12 animals in the 45-d backgrounding trial. Forage DM cost per metric ton 137 160 123 — RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS  =  corn silage harvested in the milk stage; BH  =  Tifton 85 Diet costs ($/head/day) 1.37 1.02 0.95 — bermudagrass hay harvested on a 4-wk frequency from May through June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten *RB  =  annual ryegrass baleage harvested in the boot stage, feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% CS = corn silage harvested in the milk stage, BH = Tifton 85 bermu- mixture of cottonseed meal, respectively. dagrass hay harvested on a 4-wk frequency from May to June 2015. Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 276 Forte et al. RESULTS AND DISCUSSION lower than those reported in other recent evalua- tions, which supports the observation that annual RB in this study was in the dough rather than boot Animal Performance stage of maturity at harvest. Coffey et  al. (2002) performed a 3-yr study providing ad libitum access There were no differences (P  =  0.33) in initial to BH supplemented with grain sorghum for grow- BW, final BW, or ADG of beef calves fed annual ing stocker calves. The authors reported an ADG RB-, CS-, or BH-based rations during the 45-d of 0.71 kg/d across the 3 yr. These data are similar backgrounding trial (Table  3). Gain per day was to those observed in the present study when moder- between 0.61 and 0.73  kg/d for calves consuming ate-quality BH was fed. Based on published trials, the diets evaluated. Estimated forage intake per animal performance from RB may vary, but values pen was 193, 231, and 94  kg/d on an as-fed basis similar to or greater than those of traditional CS- for RB-, CS-, or BH-based rations, respectively, or hay-based diets are commonly observed. across the 45-d feeding period. As a percentage of calf BW during the trial, estimated DMI was 2.5 for RB, 1.8% for CS, and 2.2% for BH, illustrat- Forage Nutritive Value and In Vitro Digestibility ing that intake was equal to or below the formu- Table  1 shows the nutritive value of each of lated intake of 2.5% of BW per day. This level of the forages used in the preconditioning diets in this intake is sufficient to support ADG of 0.7 kg/d for study. Differences were observed in CP, NDF, ADF, growing calves, but diet nutrient density at the lev- and TDN% among forage types (P < 0.10). Forage els of consumption reported was not sufficient to concentration of CP for RB and BH was greater support the target of 0.9 kg/d. As the silage system than CS. This observation fits with expected values had a lower reported DMI, this must be taken into for CS, which commonly range from 6.8% to 9.3% account when making comparative assessments CP (Bal, 2006; Martin et al., 2008). Fiber constitu- between these backgrounding systems. In fer- ents were greater for BH and RB than CS. BH hay mented feeds, the actual availability of feed protein/ and CS quality in this study was similar to those nitrogen to the rumen microbiota is often reduced reported in the literature with a comparable harvest (Bergen et al., 1991). Because of this, a lower DM frequency. Mandebvu et al. (1998) evaluated forage digestibility in ensiled feedstuffs may occur if no nutritive value characteristics of Tifton 85 BH hay protein supplementation is practiced, which has a harvested at 3.5  wk and 7  wk in comparison with depressing effect on observed DMI. Although cot- CS. The authors reported CP values of 15.5% DM tonseed meal was provided as a protein supplement at 3.5  wk and 9.0% DM at 7  wk, although fiber as part of CS-based diets, at the level of intake constituents were greater in their study than those observed, a combination of low protein intake and observed for the 4-wk harvest frequency used in availability may have reduced animal gains in this this trial. Forage CP of CS in their trial was 9.3% system relative to other reported trials. In a 121 DM, which is greater than what was observed in d trial, Young and Kauffman (1978) observed an the present study at 6.9% DM. Lower CP values in ADG for growing calves fed a CS-based diet of the present study may be attributed to differences 1.09 kg/d consuming 2.4% of BW per day in DM. in N fertilization and harvest times between the two When comparing early boot stage cereal rye (Secale studies. McCormick et al. (1998) harvested annual cereale) and RB baleage to late-bloom stage rye RB for baleage in the boot stage and observed and RB baleage, BH baleage, and BH hay, Martin greater CP and digestibility values than were seen et  al. (2015) experienced ADGs lower than those in this study, which is likely attributed to differences observed in the present study at 0.46 kg/d for 60 d in stage of maturity at harvest. Beef producers for growing beef calves when supplemented with a often target daily gains of 0.7 to 0.9 kg in precon- self-limiting molasses-based liquid protein supple- ditioning and stocker systems (Beck et  al., 2013). ment. The authors reported a mean CP of 12.8% The nutritive value of forage reported in this trial and TDN of 64.5% (DM basis) for boot stage rye highlights the need for additional supplementation and RB. However, Hancock (2010) found that beef to be provided if gain is to be achieved for growing replacement heifers fed RB (16.3% CP and 65.9% beef calves, which is illustrated by the level of ani- TDN, respectively) had a greater ADG (0.88 kg/d) mal performance observed in the present study. than those fed BH or RB hay (16.1% and 14.7% In vitro DM digestibility of forage diets CP; 62.9% and 62.4% TDN, respectively). The increased in a quadratic manner with increasing values observed for RB in the present study were Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 277 time of digestion (Figure  1). There were no dif- consistent with those reported in the literature ferences among treatments in IVDMD until the under similar growing conditions (McCormick 48  h after digestion (Table  4; P  =  0.02), which et  al., 1998; Martin et  al., 2008). Overall, forage was attributed to greater variation (mean CV IVDMD reflects moderate-to-high quality forage of 12% across time points) at these time points. used in this study. There were no differences in Supplementation of BH increased IVDMD, NDF digestibility for RB or BH with or without which illustrates a positive associative effect of supplementation. Forage NDF digestibility of CS fiber-based coproduct supplementation on BH with supplementation increased compared with hay digestibility in this study. Highfill et al. (1987) CS alone, which may reduce physical fill in the reported that high-fiber supplements such as soy - rumen over time and can allow greater voluntary hulls and corn gluten feed may be less susceptible feed intake (Dado and Allen, 1995). to negative feed interactions by lessening inhib- itory effects on starch digestion and/or avoid- Diet Costs ing potential shifts in native ruminal microflora. Table  3 shows the diet costs for annual RB Galloway et al. (1993) suggested that supplementa- baleage, CS, and BH hay. Baleage was shown to tion of growing cattle consuming moderate-qual- be more expensive on a per head basis than hay, ity tropical grass hay with a low-to-moderate level at $1.37/d vs. $0.95/d. Silage was intermediate at of DE (20 kcal/kg of BW) from corn or soybean $1.02/d. This diet cost was similar a baleage system hulls may increase digestible OM intake with- from Hersom et al. (2007). The authors reported a out adverse effects on fiber digestibility. Forage diet cost for baleage of $1.26/d in a split BH hay/ IVDMD decreased with the addition of supple- baleage system. In drylot feeding systems, such as ment in BH- and CS-based diets and had a more the one used in the present study, feed costs rep- negative impact on fiber digestibility in these resent a large proportion of the cost of gain per diets. Forage IVDMD values in this study were Figure 1. Forage diet in vitro digestion dynamics over a 48-h incubation period. RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 bermudagrass hay harvested on a 4-wk frequency from May to June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. *Means differ P < 0.02. Table  4. IVDMD and NDF digestibility (%  DM basis) of conserved forage diets with or without supplementation Item* % RB CS BH RB + 50:50 CS + CC:CSM BH + 50:50 SE P-value IVDMD 70.4b 67.8c 52.6d 65.6c 58.4d 80.5a 3.5 0.0158 NDFD 49.9c 55.6b 44.6d 45.9cd 61.8a 44.9d 2.4 0.0001 *Values based on average after 48 h of digestion. RB = annual ryegrass baleage harvested in the boot-to-early dough stage; CS = corn silage harvested in the milk stage; BH = Tifton 85 bermu- dagrass hay harvested on a 4-wk frequency from May to June 2015; 50:50 = 50% mixture of soybean hulls and 50% corn gluten feed, respectively; CC:CSM = 85% mixture of cracked corn and 15% mixture of cottonseed meal, respectively. a,b,c,d Within a row, means without common superscripts differ P < 0.10. Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 278 Forte et al. characteristics of whole-crop small grains harvested head. Producers should evaluate forage and sup- at milk and dough stages. J. Anim. Sci. 69:1766–1774. plementation costs using a partial budget approach doi:10.2527/1991.6941766x in order to develop cost-effective feeding strategies Coffey, K. P., W.  K. Coblentz, T. G. Montgomery, during the backgrounding phase. J. D. Shockey, K. J. Bryant, P. B. Francis, C. F. Rosenkrans, Jr, and S. A.  Gunter. 2002. Growth perfor- mance of stocker calves backgrounded on sod-seeded SUMMARY AND CONCLUSIONS winter annuals or hay and grain. J. Anim. Sci. 80:926–932. doi:10.2527/2002.804926x Results of this study suggest that diets contain- Dado, R. G., and M. S. Allen. 1995. Intake limitations, feed- ing RB-based diets can support gains in growing ing behavior, and rumen function of cows challenged with beef calves similar to those of BH or CS, although rumen fill from dietary fiber or inert bulk. J. Dairy Sci. 78:118–133. doi:10.3168/jds.S0022-0302(95)76622-X observed DMI was lower for CS than baleage or Galloway, D. L., Sr, A. L. Goetsch, L. A. Forster, Jr, A. R. Patil, hay systems. Conserved forages fed in this study W. Sun, and Z. B. Johnson. 1993. Feed intake and digest- were moderate in quality. Forage stage of matu- ibility by cattle consuming bermudagrass or orchard- rity at harvest is a key factor influencing forage grass hay supplemented with soybean hulls and (or) corn. nutritional value, intake, supplementation type, J. Anim. Sci. 71:3087–3095. doi:10.2527/1993.71113087x Gordon, C. H., J. C. Derbyshire, E. A. Kane, D. T. Black, and and level in this system. If forage nutritive value J. R. McCalmont. 1960. Consumption and feeding values alone meets the target daily growth requirements of silages as affected by dry matter content. J. Dairy Sci. of weaned calves, additional supplementation may 43:866 (Abstr.). not be needed. However, if forage nutritive value is Hancock, D. 2010. Reducing losses and getting high qual- deficient, as was the case in this study, calves may ity forage. In: J. White and D. Duncan, editors. benefit from supplementation. Choice of supple - Georgia Cattleman. Macon (GA): Georgia Cattlemen’s Association. ment type (fiber vs. starch-based) and level may Hawkins, D. R., H.  E. Henderson, and D. B.  Purser. 1970. influence forage digestion dynamics. Fiber-based Effect of dry matter levels of alfalfa silage on intake and supplementation approaches had a positive associa- metabolism in the ruminant. J. Anim. Sci. 31:617–625. tive effect on dry hay but not high-moisture forage doi:10.2527/jas1970.313617x diets. Forage digestion kinetics and protein fraction Hersom, M., D.  Driver, B.  Faircloth, and J.  Wasdin. 2007. Utilization of round bale silage as a compliment to hay characterization may provide useful information production. Gainesville (FL): 2007 University of Florida for selecting and adjusting feeding regimens in dry- Beef Report. p. 25–28. lot preconditioning programs in the Southeastern Highfill, B. D., D. L. Boggs, H. E. Amos, and J. G. Crickman. United States. Beef producers considering the use 1987. Effects of high fiber energy supplements on fermen - of annual RB baleage should compare the costs of tation characteristics and in vivo and in situ digestibili- their current production system to additional con- ties of low quality fescue hay. J. Anim. Sci. 65:224–234. doi:10.2527/jas1987.651224x siderations needed to make and feed high-quality Lourenco, J. M., M. A.  Froetschel, J. R.  Segers, J. J.  Tucker, high-moisture forages to determine the viability of and R. L. Stewart, Jr. 2017. Utilization of canola and sun- its use as an alternative feeding system during the o fl wer meals as replacements for soybean meal in a corn backgrounding phase. silage-based stocker system. Transl. Anim. Sci. 4:592–598. doi:10.2527/tas2017.0068 Mandebvu, P., J. W.  West, R. N.  Gates, and G. M.  Hill. 1998. LITERATURE CITED Effect of hay maturity, forage source, or neutral detergent AOAC. 1990. Official methods of analysis. 15th ed. Arlington fiber content on digestion of diets containing Tifton 85 ber - (VA): Association of Official Analytical Chemists. mudagrass and corn silage. Anim. Feed Sci. Technol. 73:281– Avent, R. K., C. E.  Ward, and D.L.  Lalman. 2004. Market 290. doi:10.1016/S0377-8401(98)00152-7 evaluation of preconditioning feeder calves. J. Agr. Appl. Martin, N., D. Mertens, and M.B. Hall. 2008. Fiber digestibil- Econ. 36:173–183. doi:10.1017/S1074070800021933 ity and starch content of corn silage. In: G. Shewmaker Bal, M. A. 2006. Effects of hybrid type, stage of maturity, and and R. Thaemert, editors. Proceedings of the Idaho fermentation length on whole plant corn silage quality. Alfalfa and Forage Conference; Burley, ID; February 26 Turk. J. Vet. Anim. Sci. 30:331–336. to 27, 2008. Moscow (ID): University of Idaho. Beck, P. A., M. Anders, B. Watkins, S. A. Gunter, D. Hubbell, Martin, R. M., R. S. Walker, M. T. Kearney, and C. C. and M. S.  Gadberry. 2013. 2011 and 2012 early careers Williams. 2015. Effects of feeding baleage to beef calves achievement awards: improving the production, envir- on performance, rumen function, and metabolic response onmental, and economic efficiency of the stocker cattle during the fall backgrounding period. Prof. Anim. Sci. industry in the Southeastern United States. J. Anim. Sci. 31:324–332. doi:10.15232/pas.2015-01402 91:2456–2466. doi:10.2527/jas.2012-5873 McCormick, M. E., J. F.  Beatty, and J. M.  Gillespie. 2002. Bergen, W. G. 1972. Rumen osmolality as a factor in feed intake Ryegrass bale silage research and management practices. control of sheep. J. Anim. Sci. 34:1054–1060. doi:10.2527/ LSU AgCenter Res. Sum. #144. jas1972.3461054x McCormick, M. E., G. J.  Cuomo, and D. C.  Blouin. 1998. Bergen, W. G., T. M. Byrem, and A. L. Grant. 1991. Ensiling Annual ryegrass stored as balage, haylage, or hay Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018 Backgrounding weaned beef calves with conserved forages 279 for lactating dairy cows. J. Prod. Agric. 11:293–300. Columbia (MO): University of Missouri Extension. doi:10.2134/jpa1998.0293 Studstill, M. W. 2014. Improving management techniques in Mitchell, C.C., and G.  Huluka. 2017. The basis of soil test- southeastern beef production [MS Thesis]. Athens (GA): ing in Alabama. Auburn University Agronomy and University of Georgia. Soils Departmental Series No. 324A. [accessed May 1, USDA Agricultural Marketing Service. 2018. Hay Reports. 2018]. http://www.aces.edu/anr/soillab/forms/documents/ [accessed March 28, 2018]. https://www.ams.usda.gov/ ay-324A.pdf. market-news/hay-reports. NRC. 2016. Nutrient requirements of beef cattle. 8th rev. ed. Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods Washington (DC): The National Academies Press. for dietary fiber, neutral detergent fiber, and nonstarch pol - Peterson, E. B., D. R.  Strohbehn, G. W.  Ladd, and ysaccharides in relation to animal nutrition. J. Dairy Sci. R. L.  Willham. 1989. Effects of preconditioning of beef 74:3583–3597. doi:10.3168/jds.S0022-0302(91)78551-2 calves before and after entering the feedlot. J. Anim. Sci. Young, A. W., and R. G.  Kauffman. 1978. Evaluation of 67:1678–1686. doi:10.2527/jas1989.6771678 beef from steers fed grain, corn silage or haylage-corn Steevens, B., R.  Belyea, and R.  Crawford. 1993. Using a silage diets. J. Anim. Sci. 46:41–47. doi:10.2527/ microwave oven to determine moisture in forages. G3151. jas1978.46141x Translate basic science to industry innovation Downloaded from https://academic.oup.com/tas/article-abstract/2/3/272/5006259 by Ed 'DeepDyve' Gillespie user on 31 July 2018

Journal

Translational Animal Science – Oxford University Press

Published: Sep 1, 2018

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