Efeito da fonte de óleo e dos níveis de suplementação de vitamina E na ração sobre o congelamento de sêmen de suínos

Abstract

The objective of this work was to evaluate the effects of addition of oil and of levels of supplementation of E vitamin on the boar sperm cryopreservation. It was used 24 Dalboar 85 boars, at 12 to 18 months, distributed in a complete random design, in a 2 × 3 factorial arrangement, with two source of oil (soybean and salmon) and three levels of E vitamin (150, 300 and 450 mg/kg). Semen was collected weekly (1 collection/male), diluted in centrifuge media (1:1) and kept at 25ºC for 2 hours. After centrifugation (800 g, 10 minutes), the pellet was suspended in freezing medium for the final concentration of 1 × 109 sperm/mL. The semen was packaged into 0.5 mL straws and placed inside a test tube (17ºC, 35 minutes). After this period, the straws were removed from the tube and kept for 25 minutes more, submitted to nitrogen vapor for 20 minutes and then dip into liquid nitrogen. After thawing, the semen of animals fed the ration added with soybean oil reduced motility, vigor, percentage of live sperm and HOST. The average motility of the semen after dilution and during cryopreservation process was 85 and 84% for the animals fed salmon and soybean oil, respectively. However, after thawing, the motility of the sperms of animals fed ration with salmon and soybean oil was reduced to 30 and 24%, respectively. Semen of animals treated with soybean oil presented lower percentage of live sperm and normal morphology when compared to the ones treated with salmon oil. Supplementation of salmon oil in diet for swines reduces the negative traits observed in thawed semen of boars.