Perfil metabólico, qualidade e congelabilidade seminal de reprodutores caprinos suplementados com semente de linhaça (Linum usitatissimum) na dieta

Abstract

The study aimed to evaluate the effect and the best level of inclusion of flaxseed (Linum usitatissimum) in the diet of reproductive goats, through the metabolic profile, physical and morphological quality of fresh semen and seminal freezability. 16 males Saanen were used distributed into four experimental groups received the following levels of flaxseed in diet: 0%, 4%, 8% and 12%, for a period of 70 days. The animals were submitted to fortnightly collections of blood from beginning to end of the experiment to determine the metabolic profile. The seminal collections started 25 days after the beginning of the diets, were carried out by the technique of artificial vagina, using a female mannequin, twice a week. After collecting, it was proceeded the physical and morphological seminal evaluation. The lots considered suitable, according to the Brazilian College of Animal Reproduction - CBRA (HENRY and NEVES, 1998), were cryopreserved using the citrate-yolk medium. The lots were evaluated after thawing for physical aspects and subjected to additional tests. It was used a completely randomized design with four replicates per treatment. The data were analyzed by ANOVA and evaluated by regression analysis, adopting a 5% level of significance. No significant difference was found for total cholesterol, LDL and urea (P>0.05). There was a linear decrease behavior in plasma glucose concentration (P<0.05). It was observed cubic behavior for concentration of plasma riglycerides, HDL and VLDL presenting a maximum level of 8.96, 9.50 and 8.95% of flaxseed in the diet, respectively (P<0.05). There was no difference (P>0.05) for the seminal aspect and sperm turbulence. It was observed positive quadratic behavior for variables: ejaculate volume, sperm concentration and sperm vigor (P<0.05). It was observed cubic behavior for progressive sperm motility presenting a maximum optimal of 9.92% of flaxseed (P<0.05). It was observed quadratic negative behavior for major defects, minor defects and total (P<0.05). There was no difference (P>0.05) for post-thaw progressive motility and five minutes in thermotolerance test (TTR), post-thaw sperm vigor, at five and 60 minutes in the TTR and loss of vigor (P>0.05). There was quadratic positive behavior for motility in TTR at 60, 120 and 180 minutes post-thaw sperm vigor at 120 and 180 minutes post-thaw (P<0.05). It was observed negative quadratic behavior for loss of motility and hyposmotic test (P<0.05). There was cubic behavior for acrosomal integrity test presenting an optimum maximum level of 3.25% of flaxseed in the diet (P<0.05). The addition of up to 12% of flaxseed in the diet of reproductive goats was effective in improving production, quality and freezing semen. However, the addition of up to 4% of flaxseed in the diet of male goat can be utilized without impairing the health of the animals.