Influence of supplementation of growing diets enriched with rumen-protected methionine and lysine on feedlot performance and characteristics of digestion in Holstein steer calves

Applied Animal Science 35:318–324 https://doi.org/10.15232/aas.2019-01843 © 2019 American Registry of Professional Animal Scientists. All rights reserved.

NUTRITION: Original Research

Influence of supplementation of growing diets enriched with rumen-protected methionine and lysine on feedlot performance and characteristics of digestion in Holstein steer calves M. F. Montaño,1 J. O. Chirino,1 B. C. Latack,2 J. Salinas-Chavira,3 and R. A. Zinn,2* PAS 1 Department of Nutrition and Biotechnology of Ruminants, Instituto de Investigaciones en Ciencias Veterinarias, Universidad Autónoma de Baja California, Mexicali, Baja California, México 21386; 2Department of Animal Science, University of California, Holtville 92250; and 3Department of Animal Nutrition, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma de Tamaulipas, Cd. Victoria, Tamaulipas, México 87000

ABSTRACT Objectives: The objective of this research was to evaluate the influence of rumen-protected methionine and lysine on growth performance of calf-fed Holstein steers during the initial 84-d feedlot phase and relate responses to measures of AA supply to the small intestine. Material and Methods: Seventy-two Holstein steer calves (128 ± 9 kg) were blocked by weight and assigned to 12 pens (6 steers per pen). Steers were fed a diet based on steam-flaked corn formulated to provide 105% of theoretical MP requirements plus 0, 0.4, and 0.8% Smartamine ML (Adisseo, Alpharetta, GA; 55% l-lysine-HCl and 15% dl-methionine coated with a pH-sensitive polymer). Six Holstein steers (143 ± 13 kg) with cannulas in rumen and proximal duodenum were used in a crossover design to evaluate characteristics of digestion and AA supply to the intestine of the basal diet plus 0 versus 0.8% Smartamine ML. Results and Discussion: Methionine and lysine supplementation did not affect DMI (P = 0.27) but enhanced ADG, gain efficiency (linear effect, P = 0.03), and estimated dietary NE (linear effect, P = 0.04). Amino acid supplementation increased (P < 0.01) intestinal supply of methionine and lysine and postruminal (2.4%, P = 0.03) and total-tract (3.2%, P < 0.01) N digestion. Metabolizable methionine and lysine supplies for the growth performance trial were associated (R2 ≥ 0.88) with the efficiency of ME for maintenance and gain. Implications and Applications: Supplementation with rumen-protected methionine and lysine may enhance gain efficiency and dietary energetics of growing Holstein calves during the early growing phase. The magnitude of The authors declare no conflict of interest. *Corresponding author: razinn@​ucdavis​.edu

the response is likely dependent on the otherwise general adequacy of nonspecific MP. Key words: Holstein, feedlot, amino acid supplementation, performance, digestion

INTRODUCTION In feedlots located in the southwestern United States and northern Mexico, Holstein calves are typically fed growing and finishing diets based on steam-flaked corn formulated to contain 12 to 13% CP, using urea as a primary source of supplemental N (Zinn et al., 2007; Vasconcelos and Galyean, 2007). Theoretically, these diets satisfy average metabolizable AA requirements for overall growing finishing period (300 to 350 d on feed; NRC, 2000) but do not meet requirements during the early stages of growth (first 112–140 d; Zinn and Shen, 1998). Deficiencies in EAA during the initial growing phase negatively influence ADG and gain efficiency, causing economic losses. Estimates of AA requirements based on nitrogen retention and growth performance reveal that methionine and lysine are first limiting (Hussein and Berger, 1995; Wessels et al., 1997; Zinn et al., 2007). With few exceptions (i.e., fishmeal), native protein supplements commonly fed to feedlot cattle (i.e., oilseed meals, distillers grains) are not adequate sources of metabolizable methionine and lysine (NRC, 2000). Hence, their supplementation, even at very high inclusion rates, is not sufficient to overcome theoretical deficiencies. Very little research has been reported that evaluates ruminally protected AA supplementation in practical feedlot diets that are expected to be otherwise adequate in MP. Torrentera et al. (2017) observed that initial 56-d growth performance and efficiency of energy utilization were enhanced when Holstein steers were calf fed diets supplemented with rumenprotected methionine and lysine. However, the magnitude

Montaño et al.: Rumen-protected methionine and lysine for feedlot Holstein calves

of responses to supplementation, although statistically appreciable, was not sufficient to meet theoretical requirements for methionine, lysine, arginine, threonine, and histidine. In their trial, the basal diet based on steam-flaked corn contained urea as the sole source of supplemental N and, consequently, did not meet theoretical (NRC, 2000) MP requirements for this early growing phase. The objective of the present study was to further evaluate the influence of rumen-protected methionine and lysine supplementation levels on early growth performance of calf-fed Holstein steers fed a conventional diet based on steamflaked corn and supplemented (distillers dried grains plus solubles) to exceed theoretical MP requirements.

MATERIALS AND METHODS Animal care and handling techniques were approved by the University of California Animal Care and Use Committee.

Trial 1. Feedlot Growth Performance and Plasma AA Concentration Seventy-two Holstein steer calves (128 ± 9 kg, approximately 105 d of age) were used to evaluate the influence of supplemental rumen-protected methionine and lysine on growth performance and dietary energetics during the initial 84-d feedlot growing phase. Calves were obtained from a commercial calf ranch (CalfTech, Tulare, CA). Upon arrival at the University of California Desert Research and Extension Center (Holtville, CA), steer calves were vaccinated against infectious bovine rhinotracheitis, bovine viral diarrhea (type 1 and 2), parainfluenza-3, bovine respiratory syncytial virus (Cattle Master Gold FP 5 L5, Pfizer Animal Health, New York, NY), and clostridia (Ultrabac 8, Pfizer Animal Health) and were treated against internal and external parasites (Dectomax, Pfizer Animal Health) and injected with 1,500 IU of vitamin E (as d-α-tocopherol) 500,000 IU of vitamin A (as retinyl-palmitate), 50,000 IU of vitamin D3 (Vital E-AD, Stuart Products, Bedford, TX), and 300 mg of tulathromycin (Draxxin, Pfizer Animal Health). Steers calves were blocked by initial shrunk (off-truck) weight into 4 groups and randomly assigned within weight groupings to 12 pens (6 steers per pen). Pens were 43 m2 with 22 m2 of overhead shade, automatic waterers, and 2.4-m fenceline feed bunks. Steers were allowed ad libitum access to feed and water. Fresh feed was provided twice daily at 0600 and 1400 h, offering approximately 40% of daily consumption in the morning feeding and the remainder in the afternoon feeding. Compositions of experimental diets are shown in Table 1. The basal diet used distillers dried grain plus solubles and urea as sources of supplemental N. The basal diet was formulated to meet (105%) theoretical MP requirements (NRC, 2000) based on previously observed growth performance responses of calf-fed Holstein steers at similar initial weight managed under similar conditions

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(ADG and DMI of 1.55 kg and 5.4 kg/d, respectively; Zinn et al., 2007). Dietary treatments consisted of the basal diet plus 0, 0.4, and 0.8% Smartamine ML (55% l-lysine-HCl and 15% dl-methionine coated with a pH-sensitive polymer, Adisseo, Alpharetta, GA). Energy gain (EG, Mcal/d) was calculated by the equation EG = 0.0557BW0.75 × ADG1.097, where EG is the daily deposited energy (NRC, 1984). Maintenance energy (EM, Mcal/d) was calculated by the equation EM = 0.084BW0.75 (Garrett, 1971). From the derived estimates of energy required for maintenance and gain, the NEm and NEg values of the diet were obtained using the quadratic formula x = (−b − √b2 − 4ac)/2a, where x = diet NEm, Mcal/kg; a = −0.877DMI; b = 0.877EM + 0.41DMI + EG; c = −0.41EM, and NEg = 0.877NEm − 0.41 (Zinn and Shen, 1998). Data for growth performance variables were analyzed in a randomized complete block design, considering initial shrunk weight groupings for blocks, and pen as experimental unit (Statistix 10, Analytical Software, Tallahassee, FL), according to the following statistical model: Yij = μ + Bi + Tj + εij, where μ is the common experimental effect, Bi represents initial weight block effect, Tj represents dietary treatment effect, and εij represents the residual error. In determination of ADG, interim and final weights were reduced 4% to account for digestive tract fill.

Trial 2. Characteristics of Digestion Six Holstein steers (143 ± 13 kg) with cannulas in rumen and proximal duodenum (Zinn and Plascencia, 1993) were used in a crossover design to evaluate characteristics of digestion of the basal diet and treatment effects on AA supply to the intestine. Treatments consisted of the same basal diet as in trial 1 (Table 1) supplemented with 0 versus 0.8% (DM basis) Smartamine ML. Chromic oxide (0.3%) was also included as an indigestible marker to estimate duodenal flow and fecal excretion of DM. Chromic oxide was premixed with minor ingredients (urea, limestone, and trace mineral salt) before incorporation into complete mixed diets. Smartamine ML was top dressed on feed at time of feeding. Steers were housed (indoor facility) in individual pens (4 m2) with a concrete floor covered with neoprene carpet, automatic waterers, and individual feed bunks. Experimental diets were fed daily in equal portions at 0800 and 2000 h. Dry matter intake was restricted to 2.8 kg/d (2.1% live weight). Experimental periods consisted of 10 d for diet adjustment and 4 d for sample collection. During collection, duodenal and fecal samples were collected twice daily as follows: d 1, 1030 and 1630; d 2, 0900 and 1500; d 3, 0730 and 1500; and d 4, 0600 and 1200. Individual samples consisted of approximately 700 mL of duodenal chyme and 200 g (wet basis) of fecal material. Samples for each steer within each collection period were composited for analysis. Upon completion of the experiment, ruminal fluid was obtained via the ruminal cannula from all steers and composited

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for isolation of ruminal bacteria via differential centrifugation (Bergen et al., 1968). Feed, duodenal fluid, and fecal samples were subjected to the following analysis: DM (oven drying at 105°C until no further weight loss, method 930.15, AOAC International, 2000), ash (method 942.05, AOAC International, 2000), Kjeldahl N (method 984.13, AOAC International, 2000), and chromic oxide (Hill and Anderson, 1958). Duodenal samples were analyzed for ammonia N (method 941.04, AOAC International, 2000), AA (method 982.30 E, AOAC International, 2006), and purines (Zinn and Owens, 1986). Duodenal flow and fecal excretion of DM were calculated based on marker ratio, using chromic oxide. Feed and duodenal samples were analyzed for microbial OM and microbial N leaving the abomasum using purines as a microbial marker (Zinn and Owens, 1986). Organic matter fermented in the rumen was considered equal to OM intake minus the difference between the amount of total OM reaching the duodenum and microbial OM reaching the duodenum. Feed N escape

to the small intestine was considered equal to total N leaving the abomasum minus ammonia-N, microbial N, and endogenous N (0.195 × BW0.75; Ørskov et al., 1986). The study was analyzed as a 2 × 2 crossover design experiment (Statistix 10, Analytical Software) according to the following statistical model: Yijk = μ + Si + Pj + Tk + Eijk , where Yijk is the response variable, μ is the common experimental effect, Si is the steer effect, Pj is the period effect, Tk is the treatment effect, and Eijk is the residual error.

RESULTS AND DISCUSSION Treatment effects on growth performance and dietary NE are shown in Table 2. Methionine and lysine supplementation did not affect DMI (P = 0.27) but enhanced ADG, gain efficiency (linear effect, P = 0.03), and estimated dietary NE (linear effect, P = 0.04). Improved ADG, gain efficiency, and dietary NE are the consistent

Table 1. Composition of experimental diets (DM basis) Smartamine ML, % Item1 Ingredient composition, % DM   Sudangrass hay  Tallow   Molasses, cane   Distillers grain   Steam-flaked corn  Urea   Trace-mineral salt  Limestone   Dicalcium phosphate   Magnesium oxide   Smartamine ML   Rumensin 90 Nutrient composition, DM basis (NRC, 1996)  NEm, Mcal/kg  NEg, Mcal/kg   CP, %   Rumen DIP,2 %   Rumen UIP,2 %   Ether extract, %   Ash, %   Nonstructural carbohydrates, %   NDF, %   Calcium, %   Phosphorus, %   Potassium, %   Magnesium, %   Sulfur, %

0  

12.00 2.50 4.00 25.00 53.21 0.75 0.40 1.90 0.16 0.06 0.00 0.0165   2.17 1.51 15.70 58.70 41.30 7.56 6.53 49.10 24.20 0.90 0.45 0.86 0.28 0.20

0.4  

12.00 2.50 4.00 25.00 52.81 0.75 0.40 1.90 0.16 0.06 0.40 0.0165   2.16 1.50 16.10 57.30 42.70 7.56 6.53 49.10 24.20 0.90 0.45 0.86 0.28 0.20

0.8  

12.00 2.50 4.00 25.00 52.41 0.75 0.40 1.90 0.16 0.06 0.80 0.0165   2.15 1.49 16.50 55.90 44.10 7.56 6.53 49.10 24.20 0.90 0.45 0.86 0.28 0.20

Smartamine ML, Adisseo (Alpharetta, GA); Rumensin 90 (Elanco Animal Health, Indianapolis, IN). 2 DIP = degradable intake protein; UIP = undegradable intake protein. 1

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Table 2. Treatment effects on growth performance and dietary energetics of feedlot steers (trial 1) Smartamine ML,1 % Item

0

Days on treatment Pen replicates, no. Weight, kg  Initial  Final ADG, kg DMI, g/d ADG/DMI Dietary NE, Mcal/kg  Maintenance  Gain Observed/expected dietary NE  Maintenance  Gain 1

P-value

0.4

84 4

  127 248 1.44 5.54 0.260   1.93 1.28   0.889 0.859

0.8

84 4   129 257 1.52 5.58 0.273   2.01 1.36   0.932 0.913

SEM

84 4

     

  128 258 1.56 5.52 0.282   2.06 1.40   0.957 0.945

Linear      

1 3 0.03 0.08 0.005   0.04 0.03   0.016 0.020

0.65 0.04 0.03 0.89 0.03   0.04 0.04   0.02 0.02

Adisseo (Alpharetta, GA).

Table 3. Treatment effects on characteristics of ruminal and total-tract digestion (trial 2) Smartamine ML,1 % Item Intake, g/d  DM  OM  N Leaving abomasum, g/d  OM  N   Nonammonia N   Microbial N   Feed N Ruminal digestion, %  OM   Feed N MN efficiency2 N efficiency3 Postruminal digestion, %  OM  N Fecal excretion, g/d  DM  OM  N Total-tract digestion, %  DM  OM  N

0  

2,826 2,631 68.9   1,330 71.4 68.5 35.8 24.6   63.1 64.3 21.7 0.995   56.2 73.4   678 584 18.9   76.0 77.8 72.6

0.8  

2,848 2,653 72.4   1,347 73.2 70.3 35.4 26.8   62.6 63.0 21.5 0.971   56.7 75.2   675 586 18.2   76.3 77.9 74.9

Adisseo (Alpharetta, GA). Duodenal microbial N (MN; g/kg of OM fermented in the rumen). 3 Duodenal nonammonia N (g/g of N intake). 1 2

SEM          

26.0 1.6 1.7 0.51 2.0   0.01 0.03 0.48 0.026   0.003 0.005   13.2 13.4 0.33   0.46 0.01 0.004

P-value          

0.59 0.37 0.43 0.51 0.39   0.66 0.72 0.75 0.48   0.26 0.03   0.88 0.91 0.12   0.63 0.85 0.01

Quadratic      

0.18 0.31 0.54 0.67 0.82   0.66 0.66   0.66 0.66

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growth performance responses to improved metabolizable AA nutrition (Zinn et al., 2007). During this early feedlot growing phase, metabolizable methionine and lysine are expected to be co-limiting AA in calves fed a diet based on steam-flaked corn. Based on the NRC (2000, level 1), the metabolizable methionine and lysine requirements of a steer during this initial 84-d growing phase with an average weight of 193 kg and an ADG of 1.56 kg are 12.5 and 40.1 g/d, respectively. These estimates correspond closely to requirements of 12.3 and 39.5 g/d, respectively, using empirically derived equations of Zinn and Shen (1998). Based on observed DMI (5.52 kg/d), the corresponding estimated MP supply (NRC, 2000) exceeded requirements by 8% (675 vs. 627 g/d, respectively). Nevertheless, the corresponding expected metabolizable methionine and lysine supplies (NRC, 2000, level 1) for steers fed the basal diet were 9.7 and 31.0 g/d, respectively. Thus, although the basal diet exceeded expected MP supply, estimated supply of metabolizable methionine and lysine were markedly deficient (78 and

77% of estimated requirement, respectively). All other EAA were supplied in excess of estimated requirements with the apparent exception of histidine (supplying 74%). Greenwood and Titgemeyer (2000) observed that in Holstein steers limit fed a soybean hull–based diet, the elimination of histidine from an abomasal AA infusate cocktail depressed N retention. Nevertheless, cattle histidine requirements have not been directly assessed. At issue is the variability in observed histidine content of bovine empty body tissue (Ainslie et al., 1993). In establishing histidine requirements, the NRC (2000) assigns an average whole empty body tissue histidine content of 2.5%. In contrast, Ainslie et al. (1993; from which the NRC approach was derived) observed in their studies an average empty body tissue histidine content of 2.07%. Applying this latter value, expected metabolizable histidine supply would exceed requirements (supplying 105%). Consistent with prior studies (Zinn et al., 2007; Montaño et al., 2016) increasing metabolizable methionine and lysine supply did not affect DMI. This result may reflect

Table 4. Expected versus observed supply of indispensable AA to the small intestine of Holstein steers (trial 2) Smartamine ML,1 % Item Methionine   NRC (2000) level 1   Leaving abomasum Lysine   NRC (2000) level 1   Leaving abomasum Histidine   NRC (2000) level 1   Leaving abomasum Phenylalanine   NRC (2000) level 1   Leaving abomasum Threonine   NRC (2000) level 1   Leaving abomasum Leucine   NRC (2000) level 1   Leaving abomasum Isoleucine   NRC (2000) level 1   Leaving abomasum Valine   NRC (2000) level 1   Leaving abomasum Arginine   NRC (2000) level 1   Leaving abomasum 1

Adisseo (Alpharetta, GA).

0  

6.2 6.4   19.8 22.0   7.4 8.4   17.4 18.7   17.0 17.8   32.6 38.5   16.3 17.5   20.6 20.7   15.7 16.5

0.8  

7.1 7.4   22.9 25.6   7.4 8.5   17.5 19.0   17.0 18.1   32.6 39.4   16.4 17.7   20.6 21.0   15.8 16.5

SEM  

  0.1     0.4     0.1     0.3     0.3     0.6     0.3     0.3     0.3

P-value  

  <0.01     <0.01     0.38     0.43     0.39     0.32     0.41     0.48     0.76

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some attempt to consume not only sufficient energy but also sufficient amounts of EAA to sustain their genetic potential for growth, consistent with the low ratio of observed versus expected dietary NEm and NEg for the basal diet. Zinn et al. (2007) observed that with a conventional growing–finishing diet based on steam-flaked corn (urea as sole source of supplemental N), supplementation of the diet with fishmeal to provide estimated metabolizable AA requirements increased the ratio of observed versus expected dietary NE for calf-fed Holstein steers during the initial 112-d growing period from 0.87 to 0.97. In the present 84-d study, metabolizable AA supplementation increased the ratio of observed versus expected dietary NE from 0.87 to 0.95 (linear effect, P = 0.02). Supplementation with fishmeal in the prior study (Zinn et al., 2007) provided metabolizable histidine in excess of theoretical requirements (NRC, 2000). The similarities in growth performance responses between the prior study (Zinn et al., 2007) where metabolizable histidine supply exceeded theoretical requirements and the present study where metabolizable histidine supply was deficient indicate that histidine requirements are likely overestimated. As stated previously, this is likely due to an overestimation of histidine content of empty body tissue protein. Treatment effects on characteristics of ruminal and total-tract digestion are shown in Table 3. As expected, supplemental AA did not affect (P > 0.20) ruminal and total-tract OM digestion (averaging 63 and 78%, respectively) and ruminal microbial efficiency (averaging 22 g of microbial N/kg of OM fermented). Ruminal degradation of feed N averaged 64%, which is in agreement (108%) with that expected based on diet formulation (59%; NRC, 2000). In contrast, flow of microbial N to the small intestine was less (11%) than expected based on the NRC (2000, level 1). There were no treatment effects (P > 0.20) on flow of dietary and microbial N to the small intestine. Supply of nonammonia N to the small intestine average 69 g/d, in agreement with that expected (69 g/d; NRC, 2000), corresponding to a MP supply of 129 g/kg of DMI. Consistent with Torrentera et al. (2017), supplementation with 0.8% Smartamine increased postruminal (2.4%, P = 0.03) and total-tract (3.2%, P < 0.01) apparent N digestion. Increased postruminal N is expected in that virtually all rumen-protected methionine and lysine entering the small intestine is metabolizable (Robert and Williams, 1997). Treatment effects on observed and expected (NRC, 2000) EAA flow to the small intestine are shown in Table 4. Smartamine ML supplementation increased (P < 0.01) duodenal flow of methionine and lysine, corresponding to ruminal escape values of 33 and 34%, respectively. With respect to the basal diet, observed intestinal AA supply was in good agreement (108%) with that expected, lending general support to NRC (2000) standards. Similar consistencies between observed and expected (NRC, 2000) in-

Table 5. Estimated supply (g/d) versus requirements (g/d; NRC, 2000, level 1) of metabolizable AA1 Smartamine ML,2 % Period 1–84 d

0

0.4

0.8

Requirement (NRC, 2000)

Methionine Lysine Arginine Threonine Leucine Isoleucine Valine Histidine Phenylalanine

10.3 34.5 25.9 27.9 60.5 27.4 32.5 13.2 29.3

11.2 38.9 26.1 28.1 61.0 27.6 32.7 13.3 29.5

12.2 42.6 25.8 27.8 60.3 27.3 32.3 13.1 29.2

12.6 39.5 20.4 24.1 41.3 17.3 24.7 15.4 21.6

Diets were formulated to meet average MP requirements. Supply of metabolizable AA were based on intestinal AA supply per kilogram of DMI observed in trial 2 adjusted for corresponding DMI observed in trial 1, assuming intestinal AA digestion of 80% (NRC, 2000). Metabolizable AA requirements were estimated based on observed average live weight and weight gain for cattle on respective treatments (Table 2; NRC, 2000). 2 Adisseo (Alpharetta, GA). 1

testinal AA supplies for steers fed growing–finishing diets based on steam-flaked corn has been reported previously (Zinn et al., 2007; Torrentera et al., 2017). Metabolizable AA supply along with the theoretical requirement (NRC, 2000) based on average growth rate of steers in trial 1 are shown in Table 5. Metabolizable AA supplies were estimated based on trial 2 extrapolating to DMI observed in trial 1 (Zinn and Owens, 1993). Accordingly, methionine was the first limiting AA. Consistent with previous studies involving calf-fed Holstein steers (Zinn et al., 2007; Torrentera et al., 2017), changes in estimated metabolizable methionine supplies in trial 1 were closely associated (R2 ≥ 0.88) with the efficiency of utilization of metabolizable energy for maintenance and gain (observed vs. expected dietary NE).

APPLICATIONS Dietary supplementation to meet metabolizable methionine and lysine requirements will enhance ADG, gain efficiency, and efficiency of energy utilization of calf-fed Holstein steers during the early growing phase. Metabolizable methionine and lysine deficiencies of conventional diets based on steam-flaked corn and supplemented with distillers dried grains to meet expected MP requirements can be satisfied through addition of rumen-protected methionine and lysine. The observed MP and AA supplies to the small intestine were in good agreement with those expected, supportive of the NRC (2000).

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ACKNOWLEDGMENTS

NRC. 1996. Nutrient Requirement of Beef Cattle. 7th ed. Natl. Acad. Sci., Washington, DC.

This project was supported through the University of California Agricultural Experiment Station with Hatch funding from the USDA National Institute of Food and Agriculture (CA-D-ASC-6578-H). Appreciation is expressed to CONACYT, Mexico, for sabbatical support of M. F. Montaño.

NRC. 2000. Nutrient Requirements of Beef Cattle. 7th ed. Natl. Acad. Press, Washington, DC.

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