Productive performance and carcass characteristics of lori-bakhtiari finishing lambs supplemented with sodium bicarbonate or magnesium oxide

Effect of sodium bicarbonate (SB) and magnesium oxide (MgO) in high concentrate fed Lori-Bakhtiari lambs was studied on productive performance and carcass characteristics. Eighteen weaned (90 days old) Lori-Bakhtiari male lambs divided into three equal groups were fed basal diet. Each group received a basal diet for 75 days with one of the following three treatments: (1) no additives (NA); (2) 0.05% magnesium oxide and (3) 0.2% sodium bicarbonate. Lambs were individually confined to 1.5 m2 metabolic cages. Cold and hot carcass weight (kg) and hot dressing (%) were higher in group receiving MgO than the SB group (p 0.05) in visceral fat contents (kidney, rumen mesenteric) in lambs of control and treated groups. Body weight (kg) and average daily gain (ADG) was higher in group receiving MgO than the SB group (p<0.05). No effect of MgO or SB in the diet was observed on weight of liver, lungs, blood and lie. Heart weight was greater (p<0.05) for lambs consumed diets supplemented with MgO. The results showed that the use of 0.05% magnesium oxide in the diet can increase dry matter intake, weight gain and improvement is weight and percent carcass than the control group and sodium bicarbonate.   Key words: Hot dressing, skin, lungs, lamb, carcass.