The productivity of dairy cows fed irrigated subterranean clover herbage [Trifolium subterraneum]
1992
Stockdale, C.R. (Victorian Dept. of Agriculture, Kyabram (Australia). Kyabram Research Inst.)
A number of experiments were undertaken to establish the productivity of lactating dairy cows when offered green, immature subterranean clover herbage and to study its utilization by these cows. The research included indoor feeding and grazing experiments and intensive metabolism studies. Levels of daily intake varied from 8 to 22 kg DM per cow and in early lactation, milk yields as high as 28 kg per day were sustained. Marginal returns to extra feeding, up to 15 kg DM per day in early lactation, averaged 1.4 kg milk for each additional kg of DM eaten above 8 kg DM per day. In late lactation, the return to additional feeding was 1.0 kg milk per kg of extra DM consumed over a similar range. Beyond 15 kg DM per day, the return increasingly diminished. One grazing experiment (in winter) did produce an unusual result: the cows offered most pasture did not perform as well as those offered an intermediate amount. It was considered that this was due to a characteristic of subterranean clover whereby the leaves are considerably less digestible than the rest of the plant; this resulted in selection of a lower quality diet by the supposedly best fed cows.
Показать больше [+] Меньше [-]