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Effects of protein concentration in the diet on milk yield, change in body composition and the efficiency of utilization of body tissue for milk production in ewes

  • R. T. Cowan (a1), J. J. Robinson (a1), I. McHattie (a1) and K. Pennie (a1)


Twenty-five mature Finnish Landrace × Dorset Horn ewes, each suckling two lambs, were used to measure the effects of dietary concentration of crude protein on food intake, milk yield and changes in body composition during the first 6 weeks of lactation. Diets were complete mixes of milled hay and concentrates, and the amounts of barley and fish meal were altered to give crude protein concentrations of 116 and 143g/kg dry matter. Ten ewes were slaughtered at 5 to 7 days of lactation and the remaining ewes were slaughtered at 40 to 43 days of lactation.

The higher concentration of crude protein in the diet did not alter food intake or digestion. Milk yield was not altered in the first 3 weeks of lactation but was increased in weeks 4 and 5 (P<0·05). Production of milk protein was increased by a higher protein concentration in the diet (P<0·01) and this effect was evident from the 2nd week of lactation. Weight of chemically determined fat in the body decreased from 179 to 13-0kg from 6 to 42 days of lactation (P<0·001) for ewes on diets of both concentrations of crude protein.

It was concluded that the higher level of protein intake during early lactation increased yields of milk and milk protein. The data suggest that the energy lost from the body was used more efficiently by ewes given the diet of high, rather than low, protein content.



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Blaxter, K. L., Graham, N. McC. and Wainman, F. W. 1959. Environmental temperature, energy metabolism and heat regulation in sheep. III. The metabolism and thermal exchanges of sheep with fleeces. J. agric. Sci., Camb. 52: 4149.
Cowan, R. T., Robinson, J. J., Greenhalgh, J. F. D. and McHattie, I. 1979. Body composition changes in lactating ewes estimated by serial slaughter and deuterium dilution. Anim. Prod. 29: 8190.
Cowan, R. T., Robinson, J. J., McDonald, I. and Smart, R. 1980a. Effects of body fatness at lambing and diet in lactation on body tissue loss, feed intake and milk yield of ewes in early lactation. J. agric. Sci., Camb. 95: 497514.
Cowan, R. T., Robinson, J. J., McHattie, I. and Fraser, C. 1980b. The prediction of body composition in live ewes in early lactation from live weight and estimates of gut contents and total body water. J. agric. Sci., Camb. 95: 515522.
Gonzalez, J. S., Robinson, J. J., McHattie, I. and Mehrez, A. Z. 1979. The use of lactating ewes in evaluating protein sources for ruminants. Proc. Nutr. Soc. 38: 145A (Abstr.).
Gordon, F. J. 1977. The effect of protein content on the response of lactating cows to level of concentrate feeding. Anim. Prod. 25: 181191.
Gordon, F. J. and Forbes, T. J. 1970. The associative effect of level of energy and protein intake in the dairy cow. J. Dairy Res. 37: 481491.
Hogue, D. E. 1967. Protein requirements of lactating ewes. Proc. Cornell Nutr. Conf. Feed Mfrs, pp. 118122.
Huber, J. T. and Thomas, J. W. 1971. Urea-treated corn silage in low protein rations for lactating cows. J. Dairy Sci. 54: 224230.
Journet, M. and Remond, B. 1981. Response of dairy cows to protein level in early lactation. Livest. Prod. Sci. 8: 2135.
Oldham, J. D., Broster, W. H., Napper, D. J. and Siviter, J. W. 1979. The effect of a low-protein ration on milk yield and plasma metabolites in Friesian heifers during early lactation. Br. J. Nutr. 42: 149162.
Ørskov, E. R., Grubb, D. A. and Kay, R. N. B. 1977. Effect of postruminal glucose or protein supplementation on milk yield and composition in Friesian cows in early lactation and negative energy balance. Br. J. Nutr. 38: 397405.
Papas, A. 1977. Protein requirements of lactating Chios ewes. J. Anim. Sci. 44: 672679.
Robinson, J. J., Fraser, C., Gill, J. C. and McHattie, I. 1974. The effect of dietary crude protein concentration and time of weaning on milk production and body-weight change in the ewe. Anim. Prod. 19: 331339.
Robinson, J. J., McHattie, I., Calderon Cortes, J. F. and Thompson, J. L. 1979. Further studies on the response of lactating ewes to dietary protein. Anim. Prod. 29: 257269.
Roffler, R. E., Satter, L. D., Hardie, A. R. and Tyler, W. J. 1978. Influence of dietary protein concentration on milk production by dairy cattle during early lactation. J. Dairy Sci. 61: 14221428.
Sparrow, R. C., Hemken, R. W., Jacobson, D. R., Button, F. S. and Enlow, C. M. 1973. Three protein percents on nitrogen balance, body weight change, milk production and composition of lactating cows during early lactation. J. Dairy Sci. 56: 664 (Abstr.).
Sykes, A. R. and Field, A. C. 1972. Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe. III. Some observations on the use of biochemical parameters in controlling energy undernutrition during pregnancy and on the efficiency of utilization of energy and protein for foetal growth. J. agric. Sci., Camb. 78: 127133.

Effects of protein concentration in the diet on milk yield, change in body composition and the efficiency of utilization of body tissue for milk production in ewes

  • R. T. Cowan (a1), J. J. Robinson (a1), I. McHattie (a1) and K. Pennie (a1)


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