Abstract:
8A THE EFFECTS OF SUPPLEMENTS OF PROTEIN CONCENTRATES ON THE MILK PRODUCTION OF COWS GRAZING HIGH QUALITY PASTURES G.L. ROGERS,* and P.J. MOATE* Yields of milk and milk protein from cows fed freshly cut white clover-perennial ryegrass herbage were increased by abomasal infusions of sodium oaseinate (Rogers et al. 1979) or supplements of formaldehyde-treated casein (Rogers et al. 1980).- This suggests that the amount and/or quali'ty -e of protein entering the duodenum was limiting milk synthesis despite the high protein content of the herbage. high lupin or a DM). ment In this study, Friesian-Jersey crossbred cows in mid lactationgrazed quality,pasture (18 MJ and 33 g N/kg DM). Supplements given werewhole grain (48 g N/kg DM), or a mixture of crushed heated lupins and oats; mixture of soyabean'meal (SBM) and sunflower seed meal (SSM) (72,g N/kg In each.of these three experiments control cows were given no suppleor an isocaloric amount of crushed oats (14 g N/kg DM). , and milk protein,but obtained with oats. quality and/orquantity from the supplements The protein sypplements increased yields of milk the response was not significantly different from that The results (Table 1) suggest that differences in the of protein absorbed from the small intestine resulting of,protein or oats was small. TABLE 1 . Effect of protein and energy supplements on milk yield and, . composition ROGE RS, G.L., BRYANT , A.M. and MC LEAY , L.M. (1979). N.Z. Jl Agric. Res. 22: 533. RSIG.L., PORTER , R.H.D., CLA .RKE, T. and STEWART J.A. (1980); Aust .RbGE J. Agric, Res. 31: 1147. * Dairy Research Institute, Ellinbank, Via Warragul, Vic. 3820.
