FEED INPUT AND MILK OUTPUT OF DAIRY COWS FED FIVE LEVELS OF GRAIN
- 1 December 1975
- journal article
- Published by Canadian Science Publishing in Canadian Journal of Animal Science
- Vol. 55 (4) , 565-570
- https://doi.org/10.4141/cjas75-070
Abstract
Forty Holstein–Friesian cows were fed concentrate at one of five levels (0.15, 0.20, 0.25, 0.30, or 0.35 kg concentrate/kg milk produced) and alfalfa hay to appetite. In a 280-day lactation period with twice-a-day milking, average milk production was 19.9 kg/day and increased 0.150 kg/0.01-kg increase of concentrate per kilogram of milk produced (P < 0.05). The rate of change in milk production, feed intake, and milk constituents was not affected by the breed–class–average (BCA) index of the cows over the BCA range studied. For each 0.01-kg increase in concentrate per kilogram of milk produced, daily increase in production of solids-not-fat was 0.0138 kg and of protein was 0.0052 kg (P < 0.05). Total energy secreted in milk increased, but not significantly, as the level of concentrate feeding increased. However, the proportion of energy consumed that was secreted in the milk declined from 26.8 to 23.5% (P < 0.10) as the level of concentrate feeding was increased.Keywords
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