Effect of feeding system on growth and carcass characteristics of Improved Jezersko-Solčava lambs

Abstract

The objective of this study was to evaluate the effect of feeding system on growth and carcass characteristics of Improved Jezersko-Solčava (JSR) weaned lambs. Thirty-five lambs (25.48 kg) housed in group pens were divided into four groups and offered different diets which consisted of hay and second harvest in the ratio of 40:60 and a supplement of 650 g concentrate (Diet 1), hay and second harvest in the ratio of 40:60 (Diet 2), hay and 650 g of concentrate (Diet 3), and just hay (Diet 4) for 50 days. Daily intake was calculated by weighting the offered amount and leftovers of concentrate and forage. Daily intake per lamb contained 15.56 MJ, 14.38 MJ, 16.57 MJ, and 12.23 MJ ME for the Diet 1, 2, 3, and 4, respectively. Lambs were slaughtered at 30.77 kg of live weight. Lambs fed Diet 1 reached the highest DG (165.5 g/day), followed by Diet 3 (146.89 g/day), Diet 2 (123.55 g/day) and Diet 4 (75.51 g/day). HCW and CCW were higher in Diet 1 and 3, compared to Diet 2 and 4. Lambs fed Diet 3 had the highest DP (45.35%), followed by Diet 1, 2, and 4 with 44.33, 41.10 and 39.51%, respectively. The lowest kidney-pelvic fat was observed in lambs fed Diet 4 (5.64) and the highest in Diet 3 (7.66). These results demonstrate that fattening of weaned JSR lambs fed by forage-concentrate diets produced heavier carcasses than those only fed by forage, without significant effects on carcass fatness or carcass conformation.