Protein energy concentrates for milk production.

Abstract

Animal Production in Australia Vol. 15 PROTEIN AND ENERGY CONCENTRATES FOR MILK PRODUCTION. ALLISON HODGE* and G. L. ROGERS* Ryegrass/white clover pasture is generally assumed to provide adequate protein for milk production by grazing cows. Recent studies have shown that milk production was increased by post-ruminal supplements of casein (Rogers et al., 1980). We have compared commercially available energy or protein concentrates as supplements for grazing cows in early and mid-lactation. In early lactation 4 groups of IO cows were offered pasture ad libitum (DMD : 78%; N : 2.3%; M E : 11.2 MJ/kg) with nil supplement or with isocaloric amounts of crushed oats (4.4 kg; DMD : 74%; N : 1.9%; ME : 12.1 MJ/kg) or with whole soya bean and maize meal (4 kg; 60% WSB/40% MM; DMD : 84%; N : 4.1%; ME : 14 MJ/kg). In mid-lactation cows were offered pasture (DMD : 72%, N : 2.1%, ME : 11 MJ/kg) and silage (DMD, 65%; N, 1.8%; ME, 9.4), restricted to provide 70% of energy requirements, with supplements of either crushed oats (4.4 kg), WSB/m (4 kg), or a mixed cottonseed and soya bean meal (4 kg; 80% CSM/20% SBM; DMD : 63%; N : 5.8%; ME : 9.3 MJ/kg). Table 1. Effects of supplements on milk production. EARLY LACTATION MID LACTATION In both experiments protein supplements increased production of milk and milk protein compared with crushed oats. Fat yield was not increased by the WSB/MM supplement due to a marked reduction in milk fat concentration; this was not the case with CSM/SBM. Milk production by cows when restricted or fed to improved by protein concentrates. In further work the from protein and cereal concentrates has been found to intakes of cows supplemented with cereals, rather than se (Rogers et al., 1983). In practice, the usefulness is limited by their high cost relative to cereals. appetite on pasture was difference in responses be due to lower pasture an effect of protein per of protein concentrates (1980). ROGERS, G.L., PORTER, R.H.D., CLARKE, T and STEWART, J.A. Agric. Res. 31 : 1147 - 1152. == Aust. J. ROGERS, G.L., ROBINSON, I.B. and MOATE, P. (1983). Recent Advances in Animal Nutrition, Univ. of New England. (In Press). * Department of Agriculture, Dairy Research Institute, Ellinbank, Vic 3820.