The effects of grazing intensity on herbage consumption and animal production. I. Short-term effects in strip-grazed dairy cows

Abstract

1. The object of the experiment was to determine the effects of varying the quantities of herbage available to cows on their diet and milk production. 2. Four groups of five Ayrshire cows were strip grazed for three periods of 3-4 weeks on areas calculated from sample cuts to supply (A) 25, (B) 35, (C) 45 or (D) 55 lb. dry matter per cow per day. These periods were interspersed between four standard periods of 2-3 weeks, in which all the cows were strip grazed on 50-60 lb. dry matter per head per day. 3. Measurements of milk production and of herbage consumption, by the chromic oxide-faecal nitrogen technique, were made for the last 12 or 16 days of experimental and last 8 days of standard periods. The observations made in the standard periods were used as covariates in the analyses of those made in the experimental periods.