Abstract:

【Objective】 The present study was performed to investigate the effect of castration on the growth performance,carcass quality traits and muscle fatty acid composition of male pigs. 【Method】 Eighteen pairs of male pigs were selected from six litters according to a matched-pairs design. Each pair was composed of two male full siblings with similar body weight, and one of the pigs from each pair was randomly selected to be castrated at 35 days old. The pigs were weighed at 5, 12, 21 and 30 weeks old and blood samples were collected for subsequent determination of hormones. Nine pairs of pigs were randomly selected to be slaughtered at 21 weeks of age, the other pairs were slaughtered at 30 weeks of age, and the carcass traits were determined then. 【Result】 Boars had significant higher serum testosterone concentrations compared with barrows at 12, 21 and 30 weeks of age (P＜0.01). The barrows grew faster than the boars before 21 weeks, but the barrows had a high significant growth difference at 30 weeks. The barrows had a significant higher average back fat thickness, leaf fat percentage and fat percentage, but lower average skin thickness and lean meat percentage than boars at both 21 and 30 weeks (P＜0.01), significant higher carcass weight,foot weight and loin eye area were found in boars than barrows at 30 weeks (P＜0.05). Compared to boars, higher intramuscular fat content (IMF) was found in barrows at 21 weeks. The content of several saturated fatty acids and total monounsaturated fatty acid (MUFA) were significantly higher (P＜0.01), and total polyunsaturated fatty acid (PUFA)was significantly lower in the longissimus dorsi muscle of barrows than in boars. Serum testosterone concentrations was significantly negatively correlated with C16:0, C18:1and MUFA, but positively correlated with C18:0 and PUFA. 【Conclusion】 The growth performance and carcass quality traits of male pigs were significantly influenced by castration.

Key words: castration')">castration, growth, carcass traits, fatty acid composition