Plane of nutrition effects in late pregnancy and during lactation on beef cows and their calves to weaning

摘要

Abstract A study of the effects of relatively high and very low planes of nutrition in late pregnancy, together with high and low levels of feeding from calving to weaning, on the performance of hill-country beef cows and their calves, is described. On 22 June 1965 140 three- to eight-year-old pregnant Aberdeen Angus cows were allocated to four balanced groups. Thereafter, one group was fed on a high plane of nutrition before and after calving (H-H); one group was fed on a high plane before calving, then a low plane between calving and weaning (H-L); a third group was fed on a low plane before calving, then a higher plane (L-H); and a fourth group was fed at a low level both before and after calving (L-L). High (H-H, H-L) and low (L-H, L-L) pre-calving groups were maintained on their respective treatments for, on average, 90 and 87 days respectively before calving. High plane pre-calving cows (H-H, H-L) gained 58 lb in liveweight, and low plane (L-H, L-L) pre-calving groups lost 80 lb between their initia...