Immediate and longer term response of dairy cows to level of nutrition in early lactation

A.M. Bryant, T.E. Trigg

Ruakura Animal Research Station, Hamilton

Proceedings of the New Zealand Society of Animal Production. 1979, 39: 139-147

The first of two grazing trials of 26 weeks and involved five groups of 12 cows that, on average, had calved 30 days earlier. A control group was well fed throughout. Other groups were offered restricted grazing during weeks 1 to 3, 1 to 6, 7 to 9 or 7 to 12 so as to reduce daily DM intake by about 20%.

The second trial involved three sets of twins in the first year and six in the second. One member of each set was well fed throughout, whereas the other was offered restricted grazing during weeks 1 to 6 of lactation so that DM intake was reduced by 48%. Measurements were for 24 weeks and included estimation of energy balances.

In both trials the yield of milk and constituents was reduced during underfeeding, but total effects following underfeeding were small and generally not significant.

Alterations in energy partitioning measured during weeks 8 to 18 in the second trial represented an advantage to the well-fed control equivalent to 7.9 MJ ME/day. Although this was small, it could account for 72% of the differences in milk production observed during that time.

Keywords: NZSAPAB;

Last Updated 12-09-1998