The voluntary intake and utilization of roughage–concentrate diets by sheep. 2. Barley and soya bean meal supplementation of hay diets

Abstract

SUMMARYThree levels of soya bean meal (0%, 25% and 50% of the intake of hay dry matter) combined with three levels of pelleted barley (0%, 50% and 100% of the intake of hay dry matter) in a factorial arrangement of treatments were offered to Welsh Mountain ewe lambs receiving hay ad libitum for 14 weeks.When barley was not given, soya bean meal added at 25% of the hay intake increased hay voluntary intake from 287 g/day to 412 g/day but hay intake was depressed to 339 g/day by a further increase in the level of soya bean meal. When barley was given, soya bean meal did not affect hay intake. With one exception, an increase in barley reduced hay intake, with the result that there were no differences between treatments in the digestible energy intakes of lambs receiving barley at each level of soya bean meal. In general, it was found that an increase in the concentrate allowance (barley + soya bean) reduced hay intake, whereas an increase in the crude protein content of the concentrate increased hay intake. The relationship between live-weight change, metabolizable energy intake and live weight was examined by regression analysis. Although live weight and voluntary intake were unrelated at the start of the experiment, a positive relationship emerged as the experiment progressed.