[en] The three-step technique was used to determine the requirements of total amino acids (TAA)
and the first-limiting amino acid (AA) in growing double- muscled Belgian Blue bulls (BBb). In Exp. 1, three double-muscled BBb weighing initially 306 ± 28 kg received a basal diet consisting of 30% meadow hay and 70% concentrate that was poor in digestible protein but had adequate NE because of continuous infusion of dextrose into the duodenum. The intestinal apparent digestibility of essential AA (EAA) was defined according to their duodenal and ileal flows. It averaged 72% but varied between 60% for Met and 79% for Arg. In Exp. 2, five double-muscled BBb (334 ± 22 kg) received the same diet supplemented with duodenal infusions of dextrose and four doses of Na-caseinate (28, 56, 84, and 112% of intestinal digestible dietary AA) in a 4 × 4 Latin square design with one additional animal. Nitrogen retention for the basal diet alone and the four increasing supplements of Na-caseinate reached 49, 61, 70, 80, and 86 g/d, respectively. Nitrogen utilization improved from 34.3% without Na-caseinate supplementation to a maximum of 40.6%, with the third dose supplying 788 g/d of apparently digestible AA. Based on patterns of plasma concentrations, Met, Phe, and Arg were probably the limiting AA when animals optimized N utilization. In Exp. 3, six double-muscled BBb (315 ± 25 kg) fed the basal diet received duodenal infusions of dextrose and AA, equivalent to the third dose in Exp. 2, except for digestible Met (9.3, 14.4, 18.4, 22.4, 26.4, and 30.4 g/d) in a 6 × 6 Latin square design. The Met requirement was close to 26.4 g/d on the basis of N retention.
AOAC. 1984. Official Methods of Analysis (14th Ed.). Association of Official Analytical Chemists, Airlington, VA.
Bergen, W. G. 1979. Free amino acids in blood of ruminants - physiological and nutritional regulation. J. Anim. Sci. 49:1577-1589.
Bogaerts, D. F., L. O. Fiems, J. M. Vanacker, B. G. Cottyn, and C. V. Boucqué. 1995. Effect of protein and energy level on nitrogen balance and muscle protein turnover of finishing Belgian White-Blue double-muscled bulls. In: Proc. 7th Int. Symp. on Protein Metabolism and Nutrition, Vale de Santarém, Portugal. p 62.
Campbell, C. G., E. C. Titgemeyer, and G. St-Jean. 1997. Sulfur amino acid utilization by growing steers. J. Anim. Sci. 75:230-238.
Cecava, M. J., and J. E. Parker. 1993. Intestinal supply of amino acids in steers fed ruminally degradable and undegradable crude protein sources alone and in combination. J. Anim. Sci. 71:1596-1605.
Cohen, S. A., and D. J. Strydom. 1988. Amino acid analysis utilizing phenylisothiocyanate derivatives. Anal. Biochem. 174:1-16.
Coomer, J. C., H. E. Amos, M. A. Froetschel, K. K. Ragland, and C. C. Williams. 1993. Effects of supplemental protein source on ruminal fermentation, protein degradation, and amino acid absorption in steers and on growth and feed efficiency in steers and heifers. J. Anim. Sci 71:3078-3086.
Dagnelie, P. 1986. Théories et méthodes statistiques. Vol 2. Presses agronomiques de Gembloux, Belgium.
Dehareng, D., and B. B. Ndibualonji. 1994a. Naissance et destinée de l'ammoniaque ruminale: revue. 1. Naissance dans le rumen et destinée dans le tube digestif. Ann. Med. Vet. 138:387-398.
Dehareng, D., and B. B. Ndibualonji. 1994b. Naissance et destinée de l'ammoniaque ruminale: revue. 2. Absorption et destinée ultérieure. Empoisonnement à l'ammoniaque. Ann. Med. Vet. 138:401-415.
Fenderson, C. L., and W. G. Bergen. 1975. An assessment of essential amino acid requirements of growing steers. J. Anim. Sci. 41:1759-1766.
François, E., N. Thill, and A. Théwis. 1978. Méthode rapide de dosage de l'oxyde de chrome dans les aliments, les fèces et les contenus digestifs par titrage après oxydation nitroperchlorique. Ann. Zootech. 27:355-361.
Gabel, M., S. Poppe, and B. Pieper. 1988. Amino acids deposition in dependence on energy level of the diet in fattening bulls (SMR). Wiss. Z. Univ. Rostock Math-Naturwiss. Reihe 37:115.
Gengler, N., C. Seutin, F. Boonen, and L. D. Van Vleck. 1995. Estimation of genetic parameters for growth, feed consumption, and conformation traits for double-muscled Belgian Blue bulls performance-tested in Belgium. J. Anim. Sci. 73:3269-3273.
Henry, Y. 1993. Affinement du concept de la protéine idéale pour le porc en croissance. INRA Prod. Anim. 6(3):199-212.
Hogan, J. P., R. H. Weston, and J. R. Lindsay. 1968. Influence of protein digestion on plasma amino acid levels in sheep. Aust. J. Biol. Sci. 21:1263-1275.
Hornick, J. L., C. Van Eenaeme, A. Clinquart, M. Diez, and L. Istasse. 1998. Different periods of feed restriction before compensatory growth in Belgian Blue bulls: I. Animal performance, nitrogen balance, meat characteristics, and fat composition. J. Anim. Sci. 76:249-259.
Hovell, F. D. DeB., E. R. Ørskov, D. A. Grubb, and N. A. MacLeod. 1983. Basal urinary nitrogen excretion and growth response to supplemental protein by lambs close to energy equilibrium. Br. J. Nutr. 50:173-187.
Koeln, L. L., T. G. Schlagheck, and K. E. Webb. 1993. Amino acid flux across the gastrointestinal tract and liver of calves. J. Dairy Sci. 76:2275-2285.
Lobley, G. E. 1986. The physiological bases of nutrient responses; growth and fattening. Proc. Nutr. Soc. 45:203-214.
Michaux, C., A. Stasse, R. Sonnet, P. Leroy, and R. Hanset. 1983. La composition de la carcasse de taureaux culards Blanc-Bleu Belge. Ann. Med. Vet. 127:349-375.
Minet, V., C. Van Eenaeme, P. Raskin, I. Dufrasne, A. Clinquart, J. L. Hornick, M. Diez., P. Mayombo, P. Baldwin, J. M. Bienfait, and L. Istasse. 1996. Stratégies d'engraissement du taurillon Blanc Bleu Belge culard - Performances, qualité des carcasses et de la viande, approche métabolique et bilan économique. Ministère des Classes Moyennes et de l'Agriculture, Administration Recherche et Développement, Brussels, Belgium.
Ørskov, E. R. 1991. Progress and new frontiers in knowledge of protein nutrition in ruminants. In: 6th Int. Symp. on Protein and Nutrition. EAAP Publ. No. 59. pp 80-87. Herning, Denmark.
Ørskov, E. R., and N. A. MacLeod. 1982. The determination of the minimal nitrogen excretion in steers and dairy cows and its physiological and practical implications. Br. J. Nutr. 47:625-635.
Ragland-Gray, K. K., H. E. Amos, M. A. McCann, C. C. Williams, J. L. Sartin, C. R. Barb, and F. M. Kautz. 1997. Nitrogen metabolism and hormonal responses of steers fed wheat silage and infused amino acids or casein. J. Anim. Sci. 75:3038-3045.
Richardson, C. R., and E. E. Hatfield. 1978. The limiting amino acids in growing cattle. J. Anim. Sci. 46:740-745.
Robinson, T. F., D. H. Beerman, T. M. Byrem, D. G. Fox, and D. E. Ross. 1995. Effects of abomasal casein infusion on nitrogen and amino acid absorption and utilization in growing steers. In: 7th Int. Symp. on Protein Metabolism and Nutrition. EAAP Publ. No. 81. pp 153-156. Vale de Santarém, Portugal.
SAS. 1985. SAS User's Guide: Statistics (Version 5 Ed.). SAS Inst. Inc., Cary, NC.
Satter, L. D., and L. L. Slyter. 1974. Effect of ammonia concentration on rumen microbial protein production in vitro. Br. J. Nutr. 32:199-208.
Seal, C. J., and D. S. Parker. 1991. Isolation and characterization of circulating low molecular weight peptides in steer, sheep and rat portal and peripheral blood. Comp. Biochem. Physiol. 99B:679-685.
Shain, D. H., R. A. Stock, T. J. Klopfenstein, and D. W. Herold. 1998. Effect of degradable intake protein level on finishing cattle performance and ruminal metabolism. J. Anim. Sci. 76:242-248.
Storm, E., and E. R. Ørskov. 1984. The nutritive value of rumen micro-organisms in ruminants. 4. The limiting amino acids of microbial protein in growing sheep determined by a new approach. Br. J. Nutr. 52:613-620.
Tamminga, S., W. N. Van Straalen, A.P.J. Subnel, R.G.M. Meijer, A. Steg, C.J.G. Wener, and M. C. Block. 1994. The Dutch protein evaluation system: The DVE/OEB system. Livest. Prod. Sci. 40:139-155.
Titgemeyer, E. C., and N. R. Merchen. 1990a. Sulfur-containing amino acid requirement of rapidly growing steers. J. Anim. Sci. 68:2075-2083.
Titgemeyer, E. C., and N. R. Merchen. 1990b. The effect of abomasal methionine supplementation on nitrogen retention of growing steers postruminally infused with casein or nonsulfur-containing amino acids. J. Anim. Sci. 68:750-757.
Van Es, A.J.H., and Y. Van der Honing. 1977. Het nieuwe energetische voederwaarderingssysteem voor herkauwers: Wijze van afleiding en uiteindelijk voorstel. Report IVVO. 92:1-48.
Veenhuizen, J. J., A. D. Mc Gilliard, and J. W. Young. 1984. Apparatus for total collection of urine from steers. J. Dairy Sci. 67:1865-1867.
Wessels, R. H., and E. C. Titgemeyer. 1997. Protein requirement of growing steers limit-fed corn-based diets. J. Anim. Sci. 75:3278-3286.
Williams, A. P. 1994. Amino acid requirement of the veal calf and beef steer. In: J.P.F. D'Mello (Ed.) Amino Acids in Farm Animal Nutrition, pp 329-349. CAB International, Wallingford, U.K.
