Weight gain and faecal nitrogen excretion in grazing British and Zebu crossbred steers

Abstract

The excretion of faecal nitrogen by 16 grazing steers, eight Hereford x Shorthorn and eight Zebu crossbreds, was determined at intervals over a period of 11 months. It was found that the non-dialysable faecal nitrogen fraction was the one most strongly correlated with gain. Statistically this fraction accounted for 68% of the variation in average gain of the two breed groups between measurement intervals, and for 75% of the variation in weight gain between individual steers during the summer gain period. The data gave no indication of inherent breed differences in intake, as judged by non-dialysable nitrogen excretion.