The effects of supplemental copper on rumen fermentation parameters and carcass composition of Lori-Bakhtiary male lambs

This experiment was conducted to determine the effect of supplemental Cu on rumen parameters and carcass composition of male lambs. Twenty four 3–4 month old male Lori-Bakhtiary lambs were used in this experiment. The lambs were housed in individual pens and assigned randomly to one of three treatments. Treatments were as follows: 1) without supplement (control), 2) lambs received 5 mg Cu/kg DM, and 3) lambs received 10 mg Cu/kg DM. Additives were fed before AM feeding. Feed offered and refusals were recorded daily prior to the morning feeding. Body weight was measured every two week of experiment. Also rumen fluid was sampled to evaluate the parameters. At the end of fattening period, lambs were slaughtered and carcass characteristics were measured. Results showed that addition 10 mg Cu/kg DM to feed lambs was reduced significantly feed efficiency and average daily gain (p<0.05). Additives Cu had no significant effect on DMI and final body weight (p>0.05). Also, body weight, and dressing percentage were not affected by supplementations (p>0.05). Lambs received 10 mg Cu/kg DM had lower back fat versus others (p=0.04). Levels of copper added did not affect on profile of fatty acids. Supplement Cu had no effect on rumen fluid ammonia nitrogen, but with the addition of high levels of Cu was tend to reduced in the rumen fluid pH (p=0.07). Also, VFA concentration in rumen fluid samples was not affected by the add-Cu (p>0.05). The strong inverse relationship numerical was between the Cu level and total VFA in rumen fluid. Based on the results of this experiment supplement Cu sulfate in rang of 5 to the 10 mg Cu/kg DM could affect rumen microorganism’s activities and fat production of the lambs.