Skip to main content Accessibility help
×
Home

Leucine and protein metabolism in the lactating dairy cow mammary gland: responses to supplemental dietary crude protein intake

  • Brian J. Bequette (a1), John A. Metcalf (a2), Diane Wray-Cahen (a2), F. R. Colette Backwell (a1), John D. Sutton (a3), Michael A. Lomax (a2), John C. Macrae (a1) and Gerald E. Lobley (a1)...

Summary

Mammary gland protein metabolism, determined by an arteriovenous difference technique, was monitored in four Holstein-Friesian dairy cows in response to supplemental dietary protein (provided as rumen-protected soyabean meal) during late lactation (weeks 24–30). Each cow was offered two isoenergetic diets composed of grass silage (170 g crude protein/kg dry matter) plus either a low (108 g/kg) or medium (151 g/kg) crude protein concentrate in a single crossover design involving two 21 d periods. On day 21, arteriovenous measurements across the mammary gland were made during a 13 h continuous i.v. infusion of [1-13C]leucine and with frequent (2 hourly) milk sampling during the final 6 h. Although total milk yield was slightly increased (+1 kg/d) by protein supplementation, milk protein yield was not significantly affected. Whole body protein flux (protein synthesis plus oxidation) was not significantly affected by supplementation. Total mammary gland protein synthesis (milk plus non-milk protein) was also not affected by supplementation but on both diets gland synthesis was always greater (by 20–59%) than milk protein output. The fractional oxidation rate of leucine by the mammary gland was significantly increased by protein supplementation (0·047 v. 0·136). Although the enrichment of leucine in secreted milk protein continued to increase, the final value (at 13 h) was 0·94 of the arterial plasma free leucine plateau value (not significantly different), suggesting almost exclusive use of plasma free leucine for milk protein synthesis. Based on current feeding schemes for dairy cattle, a fixed proportion (0·65–0·75) of the additional protein intake (+490 g/d) should have been partitioned into milk protein. Instead, leucine oxidation by the mammary gland was increased. Whether oxidation of other amino acids was also enhanced is unknown but if amino acid oxidation and the ‘additional’ non-milk protein synthesis occurring in the gland are not crucial to milk synthesis, then by reducing such activities improvements in the efficiency of converting absorbed amino acid into milk protein can be achieved.

Copyright

References

Hide All
Agricultural and Food Research Council 1992 Nutritive requirements of ruminant animals: protein. Nutrition Abstracts and Reviews B 62 787835
Agricultural Research Council 1980 Nutrient Requirements of Ruminant Livestock: Technical Review, 2nd edn.Farnham Royal: Commonwealth Agricultural Bureaux
Altman, P. L. & Dittmer, D. S. (Eds) 1968 Metabolism. Bethesda, MD: Federation of American Societies of Experimental Biology
Backwell, F. R. C., Bequette, B. J., Metcalf, J. A., Wray-Cahen, D., France, J., Crompton, L., Beever, D. E., Lobley, G. E. & MacRae, J. C. 1994 a Peptide utilization by the mammary gland of lactating dairy goats. Animal Production 58 433A (Abstr.)
Backwell, F. R. C., Bequette, B. J., Wilson, D., Calder, A. G., Metcalf, J. A., Wray-Cahen, D., Macrae, J. C., Beever, D. E. & Lobley, G. E. 1994 b Utilization of dipeptides by the caprine mammary gland for milk protein synthesis. American Journal of Physiology 267 R1R6
Baracos, V. E., Brun-Bellut, J. & Marie, M. 1991 Tissue protein synthesis in lactating and dry goats. British Journal of Nutrition 66 451465
Bequette, B. J., Backwell, F. R. C., Dhanoa, M. S., Walker, A., Calder, A. G., Wray-Cahen, D., Metcalf, J. A., Sutton, J. D., Beever, D. E., Lobley, G. E. & MacRae, J. C. 1994 a Kinetics of blood free and milk-casein amino acid labelling in the dairy goat at two stages of lactation. British Journal of Nutrition 72 211220
Bequette, B. J., Metcalf, J. A., Wray-Cahen, D., Backwell, F. R. C., Sutton, J. D., Lomax, M. A., Lobley, G. E. & MacRae, J. C. 1994 b Effect of dietary crude protein level on protein metabolism in the mammary gland of the dairy cow. Animal Production 58 433A (Abstr.)
Bickerstaffe, R., Annison, E. F. & Linzell, J. L. 1974 The metabolism of glucose, acetate, lipids and amino acids in lactating dairy cows. Journal of Agricultural Science 82 7185
Boirie, J., Fauquant, J., Rulquin, H., Maubois, J. -L. & Beaufrere, B. 1995 Production of large amounts of [13C]leucine-enriched milk proteins by lactating cows. Journal of Nutrition 125 9298
Calder, A. G. & Smith, A. 1988 Stable isotope ratio analysis of leucine and ketoisocaproic acid in blood plasma by gas chromatography/mass spectrometry. Use of tertiary butyldimethylsilyl derivatives. Rapid Communications in Mass Spectrometry 2 1416
Champredon, C., Debras, E., Mirand, P. P. & Arnal, M. 1990 Methionine flux and tissue protein synthesis in lactating and dry goats. Journal of Nutrition 120 10061015
Choung, J. J. & Chamberlain, D. G. 1992 Protein nutrition of dairy cows receiving grass silage diets. Effects on silage intake and milk production of postruminal supplements of casein or soya-protein isolate and the effects of intravenous infusions of a mixture of methionine, phenylalanine and tryptophan. Journal of the Science of Food and Agriculture 58 307314
Choung, J. -J. & Chamberlain, D. G. 1993 The effects of abomasal infusions of casein or soya-bean-protein isolate on the milk production of dairy cows in mid-lactation. British Journal of Nutrition 69 103115
Clark, J. H. 1975 Lactational responses to postruminal administration of proteins and amino acids. Journal of Dairy Science 58 11781197
Davis, S. R., Collier, R. J., McNamara, J. P., Head, H. H. & Sussman, W. 1988 Effects of thyroxine and growth hormone treatment of dairy cows on milk yield, cardiac output and mammary blood flow. Journal of Animal Science 66 7079
Davis, S. R. & Mepham, T. B. 1976 Metabolism of l-[U-14C]valine, l-[U-14C]leucine, l-[U-14C]histidine and l-[U-14C]phenylalanine by the isolated perfused lactating guinea-pig mammary gland. Biochemical Journal 156 553560
Elwyn, D. H., Launder, W. J., Parekh, H. C. & Wise, E. M. 1972 Roles of plasma and erythrocytes in inter-organ transport of amino acids in dogs. American Journal of Physiology 222 13331342
France, J., Bequette, B. J., Lobley, G. E., Metcalf, J. A., Wray-Cahen, D., Dhanoa, M. S., Backwell, F. R. C., Hanigan, M. D., MacRae, J. C. & Beever, D. E. 1995 An isotope dilution model for partitioning leucine uptake by the bovine mammary gland. Journal of Theoretical Biology 172 369377
Guinard, J. & Rulquin, H. 1994 Effect of graded levels of duodenal infusions of casein on mammary uptake in lactating cows. 2. Individual amino acids. Journal of Dairy Science 77 33043315
Hanigan, M. D., Calvert, C. C., De Peters, E. J., Reis, B. L. & Baldwin, R. L. 1991 Whole blood and plasma amino acid uptakes by lactating bovine mammary glands. Journal of Dairy Science 74 24842490
Harris, P. M., Skene, P. A., Buchan, V., Milne, E., Calder, A. G., Anderson, S. E., Connell, A. & Lobley, G. E. 1992 Effect of food intake on hind-limb and whole body protein metabolism in young growing sheep: chronic studies based on arteriovenous techniques. British Journal of Nutrition 68 389407
Lobley, G. E., Milne, V., Lovie, J. M., Reeds, P. J. & Pennie, K. 1980 Whole body and tissue protein synthesis in cattle. British Journal of Nutrition 43 491502
MacRae, J. C., Buttery, P. J. & Beever, D. E. 1988 Nutrient interactions in the dairy cow. In Nutrition and Lactation in the Dairy Cow, pp. 5575 (Ed. Garnsworthy, P. C.). London: Butterworths
Metcalf, J. A., Wray-Cahen, D., Chettle, E. E., Sutton, J. D., Beever, D. E., Crompton, L. A., MacRae, J. C., Bequette, B. J. & Backwell, F. R. C. 1996 The effect of dietary crude protein as protected soyabean meal on mammary metabolism in the lactating dairy cow. Journal of Dairy Science. In press
Ministry of Agriculture, Fisheries and Food 1986 Feed Composition. Marlow: Chalcombe Publications
National Research Council 1989 Nutrient Requirements of Dairy Cattle, 7th edn.Washington, DC: National Academy Press
Oddy, V. H., Lindsay, D. B. & Fleet, I. R. 1988 Protein synthesis and degradation in the mammary gland of lactating goats. Journal of Dairy Research 55 143154
Pocius, P. A., Clark, J. H. & Baumrucker, C.. 1981 Glutathione in bovine blood: possible source of amino acids for milk protein synthesis. Journal of Dairy Science 64 15511554
Razooki-Hasan, H., White, D. A. & Mayer, R. J. 1982 Extensive destruction of newly synthesized casein in mammary explants in organ culture. Biochemical Journal 202 133138
Read, W. W., Read, M. A., Rennie, M. J., Griggs, R. C. & Halliday, D. 1984 Preparation of CO2 from blood and protein-bound amino acid carboxyl groups for quantification and 13C-isotope measurements. Biomedical Mass Spectrometry 11 348352
Roets, E., Verbeke, R., Massart-Leën, A. M. & Peeters, G. 1974 Metabolism of [14C]citrulline in the perfused sheep and goat udder. Biochemical Journal 144 435446
Van Der Iest, R. & Hillerton, J. E. 1989 Short-term effects of frequent milking of dairy cows. Journal of Dairy Research 56 587592
Wohlt, J. E., Clark, J. H., Derrig, R. G. & Davis, C. L. 1977 Valine, leucine, and isoleucine metabolism by lactating bovine mammary tissue. Journal of Dairy Science 60 18751882

Related content

Powered by UNSILO

Leucine and protein metabolism in the lactating dairy cow mammary gland: responses to supplemental dietary crude protein intake

  • Brian J. Bequette (a1), John A. Metcalf (a2), Diane Wray-Cahen (a2), F. R. Colette Backwell (a1), John D. Sutton (a3), Michael A. Lomax (a2), John C. Macrae (a1) and Gerald E. Lobley (a1)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.