The performance of pregnant ewes and their progeny when offered grass silage, maize silage or a maize silage/ensiled super pressed pulp mixture during late pregnancy

Abstract

Twenty four mature twin-bearing ewes in late pregnancy were used to compare the effects of feeding grass silage (GS), maize silage (MS) or a maize silage/ensiled super pressed pulp mixture (MS/ESPP), 60:40 on a DM basis, on voluntary feed intake, ewe weight and body score changes, lamb birth weight, colostrum yield and quality, and lamb growth rate to weaning. Each of the diets was supplemented with a barley/soya-bean concentrate (BS) containing 208 g crude protein kg −1 DM. The trial commenced on day 98 of pregnancy from whence the ewes were individually fed and their diet supplemented with BS at the rate of 213.5 g DM ewe −1 day −1 from days 98 to 125 of pregnancy and at 427 g DM day −1 from days 126 of pregnancy until parturition. The ewes were milked at 1, 10, and 18 h post lambing. Silage DM intakes (kg day −1) were higher on the MS/ESPP diet ( P < 0.05) than on the GS or MS silage-based diets. From days 98 to 142 of pregnancy, mean ewe weight gains (kg) of 9.11, 11.37 and 13.12 (sem = 1.009) ( P < 0.01), and body condition losses of 0.14, 0.34 and 0.02 (sem = 0.105) ( P < 0.05) were recorded for GS, MS and MS/ESPP, respectively. Ewe body weight losses between day 98 and 24 h post lambing (kg) were 2.50, 2.44 and 1.44 (sem = 1.152) and litter birth weights (kg) of 9.84, 9.36 and 10.62 (sem = 0.434) ( P < 0.05) were recorded for GS, MS and MS/ESPP, respectively. Colostrum yield (g) at 1 h of 605 ± 92.0, 526 ± 78.5 and 711 ± 74.8 and total colostrum yield (g) at 18 h of 1927 ± 163.3, 1690 ± 139.4, 2208 ± 132.7 ( P < 0.05) were recorded for GS, MS and MS/ESPP, respectively. Overall, there were only minor differences in performance between grass and maize silages but when 40% of the maize silage was replaced with ESPP, both DM and total DM intakes were increased relative to the MS treatment; the ewes gained more weight and lost least body condition, total colostrum yield was higher, and the lambs had a higher growth rate up to weaning.