RESUMO
Physical, chemical and organoleptic characteristics of 20 ram lambs representing four fat-tailed genotypes Awassi, Red Karaman, Tushin and AwassixTushin were compared. After slaughter, carcasses were chilled at 5 degrees C for 24h, graded and evaluated. Then, the carcasses were dissected into wholesale cuts and longissimus dorsi (LD) and semimembranosus (SM) muscles were excised. The muscles were subjected to moisture, protein, fat and ash analyses and they were cooked to evaluate palatability. Cold carcass weight of RK and AxT lambs were heavier (P<0.01) than those of A and T lambs. AxT crossbreds had higher (P<0.05) cold dressing percentage and larger LD area than T lambs. However, the influence of genotype on the proportion of boneless retail cuts and marbling were not significant. Most of the proportions of wholesale cuts except for sirloin and flank were not affected by the genotype. The sensory panel found the meat from all genotypes acceptable (tenderness, juiciness, flavor and acceptability). Chemical composition of meat from the different genotype was not significantly different. The study reveals generally insignificant differences in chemical, physical and organoleptic properties between fat-tailed lambs with different genetic backgrounds.
RESUMO
Growth performance of 168 Awassi (A), Morkaraman (M), Tushin (T) purebred lambs and their crosses AxM, MxT, AxM and TxM reared under semi-intensive management in Turkey were evaluated. The lambs grazed on pasture for 84 days and were provided with a concentrate diet (1.5-2.0% of their live weight). Birth weight and average daily weight gain during the pre-grazing period for M, A, T, MxT, AxM and TxM crossbred lambs were 2.91, 3.61, 3.70, 4.30, 2.63, and 3.79kg and 186, 129, 160, 160, 163, and 168g, respectively. Corresponding estimates were 20, 15, 15, 17, 20 and 19kg for initial fattening weight; 168, 169, 160, 176, 174 and 184g for average daily weight gain on fattening, and 34, 30, 28, 32, 35, and 34kg for final fattening weight, respectively. The amounts of concentrate consumed per kg weight gain in addition to grazing on pasture for purebred and crossbred lambs were 1.89, 1.86, and 1.97 and, 1.78, 1.82, and 1.71kg, respectively. The genotype of lamb and type of birth significantly affected the birth weight. Besides the genotype and the type of birth, age of dam and sex had a significant influence on the average daily weight gain during the pre-grazing period. Average daily weight gain during the fattening period was significantly affected by sex.