Growth Performance and Carcass Traits of Zel Breed Lambs Fed Different Ratios of Forage and Concentrate

The research aimed to determine the most effective ratio of forage to concentrate on feed intake, body weight, and carcass traits of male Zel fattening lambs. The current study was performed using 20 lambs of 16-week-old for 90 days in a completely randomized design with four treatments and five replications. Experimental treatments were included different ratios of forage to concentrate (80:20, 70:30, 60:40, and 50:50). Traits were measured during the fattening period. The collected data were analyzed by LSmeans and regression procedure in SAS software. Effect of different ratios of forage to concentrate was significant on the feed intake, body weight traits (P 0.01), slaughter weight (P 0.05), weight gain during rearing (P 0.05), daily weight gain (P 0.05), feed intake (P 0.01), feed conversion ratio (P 0.01), the weight of digestive system contents (P 0.05), hot and cold carcass weight (P 0.05), carcass percentage (P 0.05) and back fat thickness (P 0.05). The linear change in the mentioned traits was due to the increase of the concentrate to forage ratio (P 0.01). As the percentage of concentrate in the ration increases, feed intake was increased. The concentrate is palatable and contains more energy and nutrients than forage. Therefore, lambs that consumed more concentrate had higher body and slaughter weight. Based on the results for optimal performance in fattening lambs, a ration with ratio of forage to concentrate equal (50:50) is recommended.