Effect of feeding systems on live-weight, reproductive performance, milk yield and composition, and the growth of lambs in native

To produce lambs of the Ojalada breed, included within the Protected Geographical Indication “Lechazo de Castilla y Leon”, three feeding systems were compared (40 ewes/treatment): a) IND + CH + C, ewes kept indoors and fed chopped straw plus concentrate, prepared on location and distributed mechanically (total mixed ration; TMR); b) IND + W+C, ewes kept indoors and fed whole straw in the form of large bales, plus concentrate (TMR); and c) GR + C, free-range grazing plus concentrate (control group). Live-weight, reproductive endpoints, milk production and composition (10 sheep from single lambing/treatment), and growth of lambs up to 35 days were assessed. Live-weight of ewes from the IND + CH + C group were similar to those in the GR + C group (p> 0.05). Treatments did not differ for fertility or prolificacy, except for fecundity in the IND + W + C group compared to values for the IND + CH + C and GR + C groups. The quantity of milk produced through 35 days did not differ (~1,300 mL d–1), with peak production in all three groups in the third week of lactation (~1,500 mL d–1). Milk chemical composition generally did not differ among treatments; only ewes in the IND + CH + C group presented greater protein content in the third week of lactation. Although treatments did not differ in live-weight at birth to 35 days, IND + CH + C lambs differed in average daily gains, reaching 9 kg of live-weight (minimum weight for slaughter) at ages younger than the other groups whether from simple or double lambing. We can conclude that this type of production, keeping sheep closed and fed a TMR, is possible