Abstract:
THE VALUE OF VARIOUS VEGETABLE PROTEIN CONCENTRATES COWS GRAZING PASTURE C. LEMERLE and T. TRIGG FOR LACTATING M. ETHERIDGE, The supplementation of grazing cows with concentrates is recieving considerable attention in Victoria. In general, cereal . grains form the large proportion of concentrates fed to cattle. These are high in energy and low in protein which predisposes them to the problems of subtitution and milk fat depression (Trigg et al. 1983). Increasing the level of protein in the supplement may have a stimulatory effect on milk yield and milk fat production (Trigg et al. 1982). They found that increasing levels of protein infusion to the abomasum resulted in an increase in partition of nutrients towards milk rather than body tissue. Vegetable proteins differ in their rumen degradability and little is known of the relative efficacy of these to produce milk when offered to cows at pasture. This experiment was designed to investigate the effects of four protein supplements on milk production. Twenty Friesian/Jersey cows (5 per group) in early lactation strip grazed good quality irrigated autumn pasture and were offered either linseed meal (LSM), soybean meal (SBM), sunflower twice per day after . meal (SFM), or cotton seed nuts (CSN), milking at a rate of 1 kg of crude protein per day. The experiment was preeceded by a nylon bag digestibility trial designed to indicate the order of rumen degradability and rate of disappearance of the supplements tested. Results are shown in the table. TRIGG, T.E., STOCKDALE, C.R., CALLAGHAN, ANN and CURRIE, R. (1983) 'Recent advances in Animal Nutrition in Australia 1983' P 61. (University of New England Publishing Unit: Armidale) TRIGG, T.E., PARR, C.R., DAY, A.M. and PARSONS, B.W. (1982) '9th Energy Symposium, Norway'. Vol. 29, P42, eds A. Ekern and F. Sundstol. (European Association for Animal Production). Kyabram Research Institute, R.M.B. 3010, Kyabram, Vic, 3620