The objective of this study was to evaluate the addition of IGF-I to pig insemination doses stored at 158C, in conjunction with the addition of different amounts of vitamin E (a-tocopherol). Semen samples (n 5 12) from four boars were treated by the addition of different concentrations of vitamin E, ranging up to 400 mg/ml. Immediately after processing and after the doses had been stored at 158C for 24 or 72 h, samples were warmed at 378C and 30 ng/ml of IGF-I was added. The assessments were made after 10 and 120 min of IGF-I addition. There was a minor effect of the vitamin E added before cooling and IGF-I added after storage on sperm quality. The addition of 400 mg/ml of vitamin E to diluted semen reduced ( P , 0.01) the malondialdehyde (MDA) production in boar semen stored at 158C for 72 h, regardless of the addition of IGF-I as additive during a 120 min incubation period at 378C. In these conditions, IGF-I also reduced ( P , 0.05) the MDA production in semen samples without addition of vitamin E. IGF-I in the presence of vitamin E reduced ( P 5 0.03) the glucose intake in freshly diluted boar semen samples before cooling. It was concluded that the addition of 400 mg/ml of vitamin E reduces the MDA production in boar semen stored at 158C for 72 h, regardless of the presence of IGF-I additive. The addition of IGF-I in doses stored for 72 h with vitamin E ensures higher sperm motility after 120 min of incubation at 378C.

No abstract