Effect of grazing background and flushing supplementation on reproductive performance in Sarda ewes

Abstract

Different grazing backgrounds and type of flushing were compared; treatments were three availability levels of herbage (Italian ryegrass grazed continuously by lactating ewes and kept close to 30, 60 and 90 mm sward height) and three flushing diets: control, unsupplemented, 250 g day −1 whole corn grain and 270 g day −1 soybean meal. Both concentrates were offered from 2 weeks before to 3 weeks after ram introduction. Herbage allowance during flushing was 1804 g dry matter (DM) day −. Ovulation rate (OR) was higher in ewes coming from the 90 mm grazing than from 30 mm (1.60 vs. 1.18 ova per ewe ovulating, P < 0.08) and 60 mm (1.27 ova per ewe ovulating, not significant); soybean meal-fed ewes ovulated more than whole corn grain counterparts (1.67 vs. 1.11 ova per ewe ovulating, P < 0.02) and control ewes (1.25 ova per ewe ovulating, P < 0.08). The OR increase from soybean meal compared with whole corn was associated with higher intake of herbage, energy and crude protein as well as higher plasma insulin level before ram introduction.