Departamento de Producción Animal, Universidad Politécnica de Madrid, 28040 Madrid, Spain.
J Anim Sci. 2011 Nov;89(11):3481-9. doi: 10.2527/jas.2010-3357. Epub 2011 Jun 16.
In total, 360 pigs slaughtered at 125 kg of BW and destined for the dry-cured industry were used to study the influence of sex and castration [immunocastrated males (IMC), surgically castrated males (CM), and intact females (IF)] in 2 terminal Large White sire lines [Top York (TY) and Tempo (TE)] on growth performance and carcass and meat quality. The female line was Large White × Landrace. The IMC pigs were immunized against gonadotropin-releasing factor (GnRF) with Improvac at 78 (experimental d 16) and 126 (experimental d 64, 48 d before slaughter) d of age. Each of the 6 treatments was replicated 6 times (10 pigs/pen). Through the day of the first Improvac injection (62 to 78 d of age), IMC and IF grew at a slower rate (P < 0.001) than CM with no differences (P = 0.95) in feed intake. The CM had greater G:F than IF, with IMC being intermediate (P < 0.01). From 78 to 126 d of age (between Improvac injections), the IMC pigs ate less feed (P < 0.001) and grew at a slower rate than CM, with IF being intermediate. The IMC pigs were more feed efficient than IF, and both were more efficient than CM (P < 0.001). However, from 126 to 174 d of age (from the second Improvac injection to slaughter), IMC pigs grew at a faster rate (P < 0.001) and were more efficient (P < 0.001) than IF and CM. Overall, IMC and CM pigs grew at a faster rate (P < 0.01) than IF, and IMC were more efficient than the other sexes (P < 0.001), but had reduced (P < 0.001) carcass yield compared with CM and IF. The IMC and IF pigs also had less (P < 0.001) backfat depth than CM. Intact females had greater (P < 0.01) loin yield but less intramuscular fat than IMC and CM and greater (P < 0.05) fresh and trimmed ham yields than CM, with IMC being intermediate. Crossbreds from TE sires grew at a faster rate (P < 0.001) than crossbreds from TY sires, but no differences (P = 0.23 and 0.14, respectively) were found for feed intake or efficiency. Crossbreds from TY produced greater (P < 0.05) fresh and trimmed ham yield, but less (P < 0.01) loin yield and intramuscular fat content than crossbreds from TE. In conclusion, IMC pigs are more efficient, but have less carcass yield than CM and IF. The intramuscular fat content is least for IF and similar for IMC and CM. Crossbreds from TE sires were larger and had greater intramuscular fat content, but slightly less trimmed ham yield compared with crossbreds from TY sires. Immunocastrated pigs can replace CM for the production of heavy pigs destined for the dry-cured industry. Because of increased carcass weight, crossbreds from TE sires may have an advantage over crossbreds from TY sires.
总共使用了 360 头体重为 125 公斤的育肥猪，用于研究干腌工业中性别和去势[免疫去势公猪（IMC）、手术去势公猪（CM）和未去势母猪（IF）]对 2 个终端长白公猪系[Top York（TY）和 Tempo（TE）]的生长性能和胴体及肉质的影响。母本系为长白猪×兰德瑞斯猪。IMC 猪在 78（试验 d 16）和 126（试验 d 64，屠宰前 48 天）日龄时用 Improvac 免疫促性腺激素释放因子（GnRF）。每个处理重复 6 次（每栏 10 头猪）。在首次注射 Improvac（62-78 日龄）之日起，IMC 和 IF 的生长速度（P < 0.001）比 CM 慢，而采食量无差异（P = 0.95）。CM 的饲料效率比 IF 高，IMC 则处于中间水平（P < 0.01）。从 78 日龄到 126 日龄（两次 Improvac 注射之间），IMC 猪的采食量减少（P < 0.001），生长速度比 CM 慢，IF 则处于中间水平。IMC 猪比 IF 猪的饲料效率更高，比 CM 猪的饲料效率更高（P < 0.001）。然而，从 126 日龄到 174 日龄（从第二次注射 Improvac 到屠宰），IMC 猪的生长速度（P < 0.001）和饲料效率（P < 0.001）比 IF 和 CM 更快。总体而言，IMC 和 CM 猪的生长速度（P < 0.01）比 IF 更快，IMC 的饲料效率（P < 0.001）比其他性别更高，但与 CM 和 IF 相比，胴体产量降低（P < 0.001）。IMC 和 IF 猪的背膘厚度也比 CM 猪低（P < 0.001）。未去势母猪的腰肉产量较高（P < 0.01），但肌肉内脂肪含量比 IMC 和 CM 少，与 CM 相比，新鲜和修整火腿产量较高（P < 0.05），而 IMC 则处于中间水平。TE 公猪的杂种猪生长速度（P < 0.001）比 TY 公猪的杂种猪快，但采食量或效率无差异（分别为 P = 0.23 和 0.14）。TY 公猪的杂种猪的新鲜和修整火腿产量较高（P < 0.05），但腰肉产量和肌肉内脂肪含量较低（P < 0.01）比 TE 公猪的杂种猪。总之，IMC 猪的饲料效率更高，但胴体产量比 CM 和 IF 低。IF 的肌肉内脂肪含量最低，与 CM 相似。TE 公猪的杂种猪比 TY 公猪的杂种猪体型更大，肌肉内脂肪含量更高，但修整火腿产量略低。免疫去势猪可以代替 CM 用于生产用于干腌工业的重型猪。由于胴体重量增加，TE 公猪的杂种猪可能比 TY 公猪的杂种猪具有优势。
