Resumo:
The general objective of this thesis was to evaluate the influence of flaxseed on the performance of Boer goats. The objective of Experiment 1 was to determine the voluntary intake of nutrients and the production, quality and stage of embryonic development in Boer goats fed diet supplemented with levels of flaxseed. Experiment 2 was to determine the nutrient intake, body weight and blood biochemistry of Alpine goats fed diet contains levels of flaxseed. In Experiment 1, 24 female Boer goats were randomly assigned to one of four groups with 0, 4, 8 or 12% of flaxseed inclued in the diet. Results from Experiment 1 showed that there was no effect of diets (P>0.05) on dry matter intake. However, there was an linear increment (P<0.001) for the intake of fat and linear declined on the consumption of non-fiber carbohydrates (P<0.05). Morever, there were dieatry effects (P<0.05) on the total number of collected embryos, viable embryos and degenerate embryos as well as for the morphological quality of viable embryos and for the developmental stages of embryos.
This study indicates that the inclusion of 4 or 8% of flaxseed in diets of Boer goats diet increases the number of viable embryos with incidence of lower degenerated embryos. In the experiment 2, a total of 21 Alpine goats were randomly assigned to one of the four dietary groups with 0, 5, 10 or 15% of brown flaxseed inclued in the diet. The dry matter intake decreased linearly (P<0.001) and the difference in declined was 53.49% between control and the group that had 15% of flaxseed included in the diet. However, there was no dietary effect (P>0.05) on the daily weight gain. The consumption of non-fiber carbohydrates was reduced linearly (P<0.001). The plasma concentration of lipid profile showed an increasing linear behavior (P<0.05). It is apparent that inclusion of flaxseed upto 15% in the diet of Alpine goats could meet the energy demand through increase consumption of fat, regardless of decreased dry matter intake without having an effect on average daiy gain.