Growth performance, feeding behaviour, serum biochemical and meat quality traits of Karayaka lambs fed pastures consisting of different relative forage quality

This study aimed to evaluate how pastures with four relative forage quality (RFQ) indices, 89 (89RFQ), 105 (105RFQ), 121 (121RFQ) and 147 (147RFQ), affect the growth, feeding behaviour, serum biochemistry and meat quality of Karayaka male lambs. Thirty-six lambs (90 days old, 22.8 ± 0.14 kg body weight) were assigned to graze on one of the pastures, established with different forage compositions to achieve the target RFQ indices, with three replicates for 60 days. The 121RFQ lambs had higher body weight and gain than the 105RFQ lambs ( p <  0.05). The 121RFQ lambs had the highest, the 89RFQ and 105RFQ lambs had intermediate and the 147RFQ lambs had the least DMI ( p <  0.05). The 121RFQ and 89RFQ lambs had a better feed conversion ratio than the 105RFQ lambs ( p <  0.05). The 121RFQ and 89RFQ lambs had a better feed conversion ratio compared to 105RFQ ( p <  0.05). Water intake was higher in the 105RFQ lambs than in the 121RFQ and 147RFQ lambs ( p <  0.05). The grazing history influenced the feeding behaviour, with lambs generally preferring forages from pastures they had previously grazed. The Longissimus dorsi muscle b* value was higher in the 121RFQ lambs than in the 147RFQ lambs ( p <  0.05). The 89RFQ and 105RFQ lambs had higher meat fat and also serum triglyceride contents compared to the 121RFQ and 147RFQ lambs, respectively ( p <  0.05). The 121RFQ pasture could enhance the growth performance without compromising carcass yield and meat quality traits, except for muscle b* value and fat content. Furthermore, prior grazing experience influences subsequent forage selection in lambs.