| dc.description.abstract |
Yerba Mate (Ilex paraguariensis), a tea known for its high antioxidant content, was supplemented to 24 of 48 Holstein calves to assess its effect on the calves' performance. Calves were weighed and blood samples were taken each week. Serum was assayed for metabolic parameters (total protein, albumin, urea, non-esterified fatty acids, triglycerides and β-hydroxybutyric acid) and markers of oxidative status [advanced oxidation protein products, 8-isoprostane and total antioxidant capacity (TAC) concentration]. Supplemented calves had higher triglyceride levels (P < 0.05) suggesting that Yerba Mate induced fat mobilisation and usage. A significant effect of the interaction time of sampling × diet (P < 0.05) was noted for plasma TAC concentration with the Yerba mate calves presenting significantly lower levels of TAC on the last week of the trial. Yerba Mate supplemented calves had significantly lower levels of total protein (P < 0.05) and albumin (P < 0.05) compared with the non-supplemented calves. The net result was reduced liveweight in Yerba Mate supplemented calves (P < 0.001) and thus the hypothesis that Yerba Mate supplementation would increase dairy calves' growth rates was rejected. This study demonstrated that supplementation of Yerba Mate to dairy calves had significant effects on their metabolic and oxidative status, which resulted in lower liveweight at the end of the trial. |
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