Effect of three feeding systems on fattening performance of Lori-Bakhtiari male lambs.

The study was conducted to examine the effects of physical form of ration on fattening performance of Lori-Bakhtiari male lambs. Thirty six healthy male lambs with 41.2 3.27 Kg body weight were randomly assigned to one of three experimental diets (n=12): traditional ration (as control treatment), total mixed ration (as mixed treatment) and total mixed ration in form of block (block treatment). Lambs were randomly distributed into 3 dietary treatments with 3 replicates and 4 lambs in each replication based on completely randomized design. Total experimental period was 90 days. Diets in mixed and block treatments were similar in feed ingredients and composition, metabolizable energy (2.39 MCal/Kg DM) and crude protein (13.9 %). Metabolizable energy and crude protein in control treatment was 2.36 MCal/Kg DM and 13.3% respectively. The rations were fed ad-labitum to lambs three times daily. During a 3 month experiment, dry matter intake (DMI), lamb live weight and weight gain were recorded and feed conversion ratio was calculated. Results showed that, final live weight and average daily gain were significantly (p 0.01) affected by physical form of diet. The lambs fed block ration had higher average daily gain (219 gram/day) than lambs fed mixed ration (193 gram/day) and traditional ration (170 gram/day). Average feed intake in control, mixed and block treatments were 1523, 1644 and 1714 gram/d/head respectively and difference between control and other treatments was statistically significant (p 0.05). Feed conversion ratio at the end of fattening period was not significantly different between all treatments but in block treatment was better than others (8.99, 8.50 and 7.84 in control, mixed ration and block treatments respectively). Profit per lamb was lower in control treatment than other groups. It was concluded that, if providing block of ingredients was possible at same area, using block in fattening period of male Lori-Bakhtiari lambs may increased fattening performance. Key words: Lori-Bakhtiari sheep, Diet physical form, Feedlot, Performance