去势对公猪生长性能和胴体品质的影响

Effects of castration on growth performance and carcass qualities in the boar

试验选用40头新生仔公猪,由5头健康母猪哺乳,每头母猪哺乳去势和完整仔公猪各4头。保育期开始分别饲养,记录全程的采食量和各阶段体重;分别于20、38、85、135和185日龄采集每头猪的粪便和血液样品,用于测定粪臭素和吲哚的含量;并分析血清中雄烯二酮、睾酮(T)、三碘甲腺原氨酸(T3)和生长激素(GH)水平;育肥末屠宰并分析胴体品质。结果显示,去势对猪的日增重无显著影响(P>0.05)。完整公猪平均背膘厚和肌内脂肪含量低于去势公猪(P<0.05);完整公猪脂肪中粪臭素和吲哚水平、血清中雄烯二酮水平高于去势公猪(P<0.05)。185日龄时,完整公猪血清中生长激素水平明显高于去势公猪(P<0.05)。各个日龄完整公猪血清中睾酮水平均极显著高于去势公猪(P<0.01)。结论:去势并不显著影响公猪的生长速率,但显著增加了背膘厚和肌内脂肪含量;完整公猪脂肪和血清中粪臭素和吲哚水平,血清中雄烯二酮水平均显著高于去势公猪。

Fourty newborn boars were selected and nursed by 5 healthy lactating sows （each 4 castrated and 4 entire boars by one sow）. These castrated and entire boars were raised separately since the nursing period, the feed intake and the body weight for each pig throughout all periods were recorded. At the age of 20, 38, 85, 135 and 185 days, feces and blood samples were collected from each pig to detect the skatole and indole levels, as well as the serum concentrations of androstenone, testosterone （T）, triiodothyronine （T3） and growth hormone （GH）. Pigs were slaughtered at the end of finishing period to evaluate carcass qualities. Results showed that castration had no significant influence on average daily gain （ P〉0. 05 ）. The backfat thickness and intramuscular fat content of the entire pigs were lower than those of the castrated pigs （ P〈0. 05 ）. Fat skatole and indole levels, and androstenone status in sera of the pigs were higher than those of the castrated pigs （P〈0. 05）. At the age of 185 day, the growth hormone in sera of the pigs was higher than the castrated pigs （P〈0.05）. Serum testos- terone levels of the pigs at all time were significantly higher than the castrated pigs （ P〈0. 05 ）. In conclusion, castration had no effect on the growth rate of the pigs, but increased the backfat thickness and intramuscular fat significantly. The entire boars had higher skatole and indole levels in the fat and serum, and testosterone level in sera than the castrated pigs.