Fattening performance, slaughter, carcass, meat quality and some genes expressions at different slaughter weights of Lalahan (Kivircik x Akkaraman G1) genotype lambs

This research was carried out to examine the fattening performance, slaughter, carcass, some meat quality characteristics, and expression levels of some genes that affect fatty acid composition in Lalahan genotype lambs slaughtered at three different slaughter weights. Thirty-six male lambs of Lalahan genotype, which constitute the animal material of the study, were randomly divided into three groups and fed intensively. Six lambs from each group were slaughtered at the average SW of 35(Gr35), 40(Gr40), and 45(Gr45) kg. The means were calculated 241.50±17.90, 243.33±29.68, and 235.45±26.15g for DWG, and 3.590, 3.958 and 4.392 for FCR in the groups, respectively. The means in the groups were obtained 45.26±0.57, 44.66±1.15, and 46.11±0.85% for chilled dressing; 61.82±0.60, 61.04±0.47, and 57.53±0.74% (P<0.001) for lean, 13.57±0.24, 14.05±0.17, and 19.46±0.68% (P<0.001) for fat, 18.52±0.68, 18.58±0.42, and 17.99±0.34% for bone content in whole carcass; 31.57±0.71, 30.04±0.58, and 28.41±0.27% (P<0.01) for leg, 13.39±0.23, 12.63±0.46, and 14.72±0.56 (P<0.05) for back, 8.41±0.13, 7.88±0.26, and 7.19±0.12 (P<0.001) for loin percentages, respectively. The means of the groups in 24h of the post-mortem were determined 5.38±0.04, 5.50±0.03, and 5.45±0.02 (P<0.05) for pH, 40.55±0.57, 40.60±0.79, and 41.17±0.23, 16.73±0.24, 17.04±0.40, and 18.47±0.37 (P<0.01), 8.98±0.78, 8.80±0.73, and 8.67±0.40 for L* a* b*, 11.53±0.45, 12.50±0.43, and 12.93±0.54% for WHC, 27.72±1.14, 28.55±0.74, and 26.48±1.05% for CL, respectively. The averages in the groups were calculated 0.16±0.03, 0.18±0.04, and 0.15±0.04 for ΣPUFA/ΣSFA, 1.01±0.03, 1.10±0.04, and 1.03±0.08 for ΣUFA/ΣSFA, 9.86, 10.87, and 9.33 for ω6/ω3, 0.65, 0.57 and 0.59 for AI, 1.13, 1.04 and 1.17 for TI, respectively. The averages obtained from the fats of liver, MLD, and tail were determined as 0.36±0.01, 0.07±0.005, and 0.06±0.004 for ΣPUFA/ΣSFA, 1.11±0.03, 0.95±0.03, and 1.08±0.08 for ΣUFA/ΣSFA, 13.24, 9.27 and 7.52 for ω6/ω3, 0.55, 0.69 and 0.58 for AI, 1.01, 1.21 and 1.12 for TI, respectively. Except FASN gene (P<0.05), expression differences of SREBP-1c and PPARγ genes in liver and MLD tissues were insignificant among Gr35, Gr40 and Gr45, while the all differences of the 3 genes in gluteal adipose tissue were insignificant. As a result, it was determined that the Lalahan sheep genotype, originating from the Kıvırcık breed, was similar or better than the Kıvırcık breed in terms of fattening performance, slaughter, carcass and meat quality. Furthermore, it has been concluded that Lalahan sheep genotype has the potential to produce quality meat in the conditions of the Central Anatolian Region, and 40 kg could be recommended as the appropriate slaughter weight for the genotype. Keywords: Carcass, Gene Expression, Lamb Fattening, Meat Quality, Sheep, Slaughter