A note on the growth and food consumption of crossbred lambs of five sire breeds

Abstract

ABSTRACTLambs, 8 weeks of age, the offspring of sires of the Scottish Blackface, East Friesland, Finnish Landrace, Suffolk and Texel breeds mated to Scottish Blackface females as a common maternal breed were fed ad libitum on a concentrate containing barley and fish meal for 14 weeks. Live weight and food intake were measured at intervals of 2 weeks.Live-weight gain varied between sire breeds, Suffolk crosses having the greatest growth rate and the Blackface lambs the least, but there were no significant differences in their food conversion ratios. Food intakes were compared with those predicted by two methods. When the only criteria for prediction were live weight and the metabolizability of the diet the prediction was poor, whereas very accurate agreement was found when the criteria for prediction included consideration of the changes in energy efficiency with food intake and with maturity.