Effects of nutritional experience in early and adult life on the performance and dietary habits of sheep

Abstract

In a series of four experiments, comparisons were made of the grazing preferences, food intake, live weight and wool production of sheep having experience of several contrasting nutritional environments. The environments ranged from semi-arid plant communities and sown pastures to hay fed in pens. The sheep were compared on sown pastures at Canberra, A.C.T., and at Bakers Hill, Western Australia. What appeared to be only small differences in experience resulted in marked differences in grazing preferences, which persisted for more than a year, despite attempts to remove them. Experience in different environments was also reflected in food intake. The differences in organic matter intake per kilogramme live weight were generally not as distinctive as differences in preferences. Seasonal patterns of live weight were significantly different in all experiments for sheep with different experience, and smaller differences were observed in wool production. An effect of previous nutritional experience of ewes on lamb birth weight and growth rates was evident. In general, sheep moved from pastoral areas to sown pastures took longer to adapt than did sheep moved from one type of sown pasture to another or from sown pastures to pastoral areas. Adult sheep took longer to adjust to a new environment than did lambs. Only in one experiment did there appear to be persistent effects of previous experience on production. Show more