A protein allowance for lactating beef cows
Zahra, S.A.; Topps, J.H.; Miller, T.B.
Proceedings of the Nutrition Society 35(2): 106a-107a
1976
ISSN/ISBN: 0029-6651 PMID: 972861 Document Number: 101178
2 groups of 4 Hereford X Friesian cows in their 1st lactation were given from the 29th day of lactation (kg/day) 8 hay, 1 barley, 1.5 dried sugar beet pulp and 1 soya bean meal (97 MJ metabolizable energy (ME) and 840 g digestible protein/day) or 8 hay, 2 barley and 1.5 dried sugar beet pulp (97 MJ ME and 500 g digestible protein/day). No differences were seen between treatments in milk yield and calf growth but the cows receiving the higher amount of protein gained a considerable amount of wt. (+301 vs. -12 g/day with low protein diet), yielded more milk protein (34 vs. 31 g/kg, P < 0.05) and excreted appreciably more N and urea in their urine (74.4 and 125 g/day respectively vs. 27.2 and 48 g/day with the low protein diet, P < 0.01).