Department of Physiology and Biochemistry of Animal Nutrition, Estación Experimental del Zaidín, CSIC, Camino del Jueves s/n, 18100 Armilla, Granada, Spain.
Department of Physiology and Biochemistry of Animal Nutrition, Estación Experimental del Zaidín, CSIC, Camino del Jueves s/n, 18100 Armilla, Granada, Spain.
Animal. 2021 Apr;15(4):100187. doi: 10.1016/j.animal.2021.100187. Epub 2021 Feb 23.
Immunocastration (IC, vaccination against gonadotropin releasing hormone (GnRH)) is one alternative to surgical castration (SC) for preventing sexual development and boar taint in male pigs. A temporal increase in performance has been described for IC pigs before the second vaccination against GnRH. The objective of this work was to assess the effects of IC on Iberian male and female pigs (fed diets of increasing CP content) on performance, nitrogen retention (NR) and digestibility, and carcass traits. Fifty-four pure Iberian pigs individually housed were allocated to a 3 × 3 factorial arrangement with three sex groups (IC males, IC females and SC males), three diets (153, 137 and 119 g CP/kg DM; 14 MJ metabolisable energy/kg DM) and six pigs per treatment combination. Pigs were vaccinated at 18 weeks of age (40 kg BW) and seven weeks later (70-80 kg BW) and fed at 0.9 × ad libitum on BW basis. Two digestibility and nitrogen balance assays were performed before and after the second vaccination, respectively. Pigs were slaughtered at 105 kg BW. Before the second vaccination, Iberian IC males showed higher growth rate (g/day), feed efficiency, NR (g/day) and efficiency of NR than the other groups (P < 0.001). The NR and efficiency of NR was 40% greater in IC v. SC males (P < 0.001). After the second vaccination, no differences in performance between sex groups were detected (P > 0.05). Growth rate and feed efficiency were higher in IC males than in the other groups for the whole experimental period (from the first vaccination to slaughter; P < 0.001). After the second vaccination, differences among sex groups in NR and the efficiency of NR disappeared (P > 0.05). NR efficiency was 0.177 on average. No significant effects of dietary CP were detected on performance. The NR was greater in pigs fed the 153 CP diet (17 to 37%; P > 0.05). Lean components of carcass (sirloin, loin and butt lean) were greater in IC males than in the other groups (0.001 < P < 0.05). There were no significant sex group×dietary CP interactions. Iberian IC males grew at higher rate, deposited more protein, and more efficiently, than Iberian SC males before the second vaccination against GnRH. Iberian IC females showed similar growth performance to SC males and intermediate protein deposition efficiency between IC and SC males. Despite the higher growth performance, protein deposition rate, and efficiency of protein deposition of IC males v. SC males, no significant differences in amino acid requirements were detected between them.
免疫去势（IC，针对促性腺激素释放激素（GnRH）的疫苗接种）是防止雄性猪的性发育和公猪异味的一种替代手术去势（SC）的方法。已经描述了在第二次针对 GnRH 的疫苗接种之前，IC 猪的性能会暂时提高。本研究的目的是评估 IC 对伊比利亚公猪和母猪（饲喂 CP 含量逐渐增加的日粮）的性能、氮保留（NR）和消化率以及胴体性状的影响。54 头单独饲养的纯伊比利亚猪被分配到一个 3×3 因子安排，三个性别组（IC 公猪、IC 母猪和 SC 公猪）、三种日粮（153、137 和 119g CP/kg DM；14MJ 可代谢能/kg DM）和每个处理组合的六头猪。猪在 18 周龄（40kg BW）时接种疫苗，七周后（70-80kg BW），按 BW 基础的 0.9×自由采食。在第二次疫苗接种前后分别进行了两次消化率和氮平衡测定。猪在 105kg BW 时屠宰。在第二次疫苗接种之前，伊比利亚 IC 公猪的生长速度（g/天）、饲料效率、NR（g/天）和 NR 效率均高于其他组（P<0.001）。与 SC 公猪相比，IC 公猪的 NR 和 NR 效率高 40%（P<0.001）。第二次疫苗接种后，各组之间的性能没有差异（P>0.05）。在整个实验期间（从第一次疫苗接种到屠宰），IC 公猪的生长速度和饲料效率均高于其他组（P<0.001）。第二次疫苗接种后，各组之间 NR 和 NR 效率的差异消失（P>0.05）。NR 效率平均为 0.177。日粮 CP 对性能没有显著影响。饲喂 153 CP 日粮的猪 NR 较高（17-37%；P>0.05）。IC 公猪的胴体瘦肉成分（里脊、腰肉和臀部瘦肉）大于其他组（0.001<P<0.05）。性别组×日粮 CP 之间没有显著的互作。在第二次针对 GnRH 的疫苗接种之前，伊比利亚 IC 公猪的生长速度、沉积的蛋白质量和效率均高于伊比利亚 SC 公猪。伊比利亚 IC 母猪的生长性能与 SC 公猪相似，介于 IC 公猪和 SC 公猪之间。尽管 IC 公猪的生长性能、蛋白质沉积率和蛋白质沉积效率均高于 SC 公猪，但它们的氨基酸需求没有显著差异。
