RESUMO
The aims of the current study were to assess the inclusion levels of grape byproduct replacing jiggs hay in lambs diets and to evaluate signs of copper poisoning. Thirty-four Texel and Corriedale crossbred female lambs were used in a randomized block experimental design. The treatments comprised four levels of grape byproduct (0; 100; 200 and 300â¯g/kg DM) in replacement of jiggs hay. The diets were adjusted to the same ZnCu ratio (6:1) of the basal diet. Grape byproduct consumption at up to 30%, led to similar weight gain in the different treatments (Pâ¯=â¯.92), which was suitable for growing lambs. Grape byproduct in the diet had linear effect on GGT (Pâ¯<â¯.001) and AST (Pâ¯<â¯.0001) enzymes as well as on total bilirubin (Pâ¯=â¯.05). In addition, the highest grape byproduct addition showed the highest consumption of hay (Pâ¯<â¯.01). Hay replacement by grape byproduct at up to 300â¯g/kg in the DM was satisfactory to weight gain and did not negatively affect feed intake and weight gain of growing lambs. Maintaining zinc:copper ratio in sheep diets is not effective in preventing liver damage caused by increased dietary copper concentrations over a period of 70â¯days.