Effect of different protein sources on lamb growth and carcass characteristics

Five pelleted diets, based on barley, a roughage and five different protein sources (soybean meal solv. extd. (SBM), sunflower meal solv. extd. (SUN), sweet white lupin seeds (L), SBM/SUN, SBM/L) were investigated in a growing trial on 30 male Apennine lambs. Feeding consumption was not significantly affected by the diets however, lambs receiving the diet containing lupin, as main protein source, trended towards better feed conversion rates. Diets did not significantly affect final live weight, average daily gain, feed conversion rate and protein efficiency ratio (PER); also these parameters appeared slightly better in the lambs receiving the diet containing lupin, as main protein source. There were no significant differences in slaughtering animal performances among the diets. Results obtained indicate that sweet white lupine and sunflower meal can replace soybean meal as protein supplement.