P. MARINOVA, T. POPOVA, V. BANSKALIEVA, E. RAICHEVA, M. IGNATOVA and V. VASILEVA
Institute of Animal Science, BG-2232 Kostinbrod, Bulgaria
MARINOVA, P., T. POPOVA, V. BANSKALIEVA, E. RAICHEVA, M. IGNATOVA and V. VASILEVA, 2007. Effect of fish oil supplemented diet on the performance, carcass composition and quality in lambs. Bulg. J. Agric. Sci., 13: 729-737
Two groups of 7 animals (age 75 days ) each of local Zapadnostaroplaninska sheep breed were fed for 28 days controlled iso-nitrogenous diets, containing either no added fat (control) or fish oil (experimental) added at 2.5 % of wet weight of concentrate.
Dietary fish oil supplementation did not induce significant changes in the feed intake and average daily gain of the animals. Carcasses from both groups were light <13 kg according to (S) EUROP system and classified in category (B). The carcasses from the fish oil supplemented animals had lighter colour and increased thickness (by 33.16%) of the back fat over m.Longissimus dorsi at the 11th rib. Half carcass weight and the weights of separate carcass cuts tended to be lower in the lambs fed fish oil. The percentage distribution and the weight of the meat, bones and fats in the half carcass did not differ significantly among the groups. The subcutaneous fat deposition differed among the separate cuts in response to fish oil supplementation. Its content was significantly reduced in the loin of the animals from the experimental group (P<0.05).
Fish oil increased the intramuscular fat content in the half carcass of the lambs by 16 % and stimulated its deposition in the separate cuts, significantly in the shoulder (P<0.05).
The deposition and distribution of body fat observed in this study suggest that the polyunsaturated fatty acids from the fish oil could be a repartitioning factor for carcass fats in lambs and could have a favorable effect on the carcass fatness and quality.