All experimental protocols were approved by the Biosafety and Animal Care and Use Committees at Sichuan Agriculture University. Thirty-two boars with an average body weight of 15.0 ± 1.4 kg were randomly assigned to 4 groups: 3 treatment groups (T1, T2 and T3) fed with different ratios of dietary sunflower oil and fish oil, and a control group (C). Diets were formulated based on NRC recommendations (2012) [19] for breeding boars according to body weight. The fatty acid compositions of the oils and the basal diet (C, without oil supplementation) are presented in Table 1, and the fatty acid compositions of all diets are presented in Table 2. The onset of puberty (sperm production) occurs at 120–180 days in conventional boars. During the present study, boars were fed ad-lib from 1 to 18 weeks, and subsequently fed restricted diets. Boars were housed individually at an ambient temperature between 18 and 22 °C, and had free access to water.