Effect of weaning system on lamb growth, mammary gland development and ewe milk production in dairy sheep managed in an outdoor pasture-based commercial farming system

Abstract

The objective was to merge science and practice to determine the feasibility of a mixed suckling and milking system compared with a traditional exclusive suckling management system on the production performance of dairy sheep and their progeny in an outdoor pasture-based farming system at commercial scale. At 14 d postpartum, twin- and triplet-bearing mixed-age East Friesian ewes were randomly allocated to either a mixed system of once-a-day milking,suckling and early weaning (MS, n=61) or control with exclusive suckling and later weaning (Ctrl, n=57) using a randomised block design. MS lambs had lower live weight at weaning (14.6 vs. 16.7 kg; P<0.001) but 3-5weeks post-weaning average daily gain and mammary gland mass was similar between groups. Ewe lamb mammary mass was positively associated with post-weaning but not pre-weaning live weight gain (P<0.01). Weaning system influenced the percentage of protein, total solids and fat (MS > Ctrl) while milk yield, somatic cell count and lactose levels were not different. This study highlighted that the MS comparedwith Ctrl system had no negative effects on dam or progeny performance.