Kantas D, Papatsiros V, Tassis P, Tzika E, Pearce M C, Wilson S
Department of Animal Production, Technological and Educational Institute of Larissa, 41110 Larissa, Greece.
J Anim Sci. 2014 May;92(5):2251-8. doi: 10.2527/jas.2013-6924. Epub 2014 Mar 18.
The aim of this study was to evaluate safety (in terms of detecting possible adverse clinical effects attributable to vaccination), efficacy, and effects on growth performance of a gonadotropin releasing factor analog-diphtheria toxoid conjugate (commercially distributed as Improvac; Zoetis, Zaventem, Belgium) in male pigs raised in a commercial Greek farm. A total of 1,230 male pigs was enrolled in 16 weekly batches and allocated to 3 groups: barrows (castrated on the next day after birth [study Day 0]), pigs vaccinated with the above-mentioned product, and intact boars. Vaccinated pigs were injected subcutaneously with 2 mL of the anti-gonadotropin releasing factor (GnRF) vaccine at 9 to 11 wk of age (60-78 d) and 15 to 17 wk of age (102-120 d) and slaughtered at 22 to 25 wk of age (152-176 d). No clinical abnormalities or adverse events attributable to vaccination occurred. Mean BW of vaccinated pigs was 6% greater compared with barrows at slaughter (P < 0.0001). The vaccinated pigs had greater ADG than barrows from castration to slaughter (8%). In detail, a lower ADG from first to second vaccination (-12%; P < 0.0001) and a 27% greater ADG from second vaccination to slaughter (P < 0.0001) were observed. The ADG of vaccinated pigs and intact boars was not significantly different throughout the study, except from first to second vaccination (boars greater; P = 0.0059) and second vaccination to slaughter (vaccinates greater; P = 0.0390). Feed conversion ratio of barrows was 11 and 8% greater compared with vaccinated pigs (P = 0.0005) and boars (P = 0.0062) from first to second vaccination but was 23 to 26% lower compared with vaccinated pigs (P < 0.0001) and intact boars (P < 0.0001) from first vaccination to slaughter and 7 to 9.5% lower from the second vaccination to slaughter (P = 0.0029 and P = 0.0003 for vaccinates and intact boars, respectively). At slaughter, the belly fat androstenone concentration of all vaccinated pigs and 64% of intact boars was below 200 ng/g. Belly fat skatole concentration was below 20 ng/g in samples from all groups. In conclusion, vaccination against GnRF using the GnRF analog-diphtheria toxoid conjugate tested did not induce adverse clinical effects, proved effective, and compared with physical castration, resulted in greater BW at slaughter and improved ADG and feed conversion ratio from first vaccination to slaughter.
本研究旨在评估一种促性腺激素释放因子类似物 - 白喉类毒素结合物（商品名为Improvac；比利时杨森制药公司，扎芬特姆）在希腊一家商业农场饲养的雄性猪中的安全性（检测归因于疫苗接种的可能不良临床效应）、有效性及其对生长性能的影响。总共1230头雄性猪被纳入16个每周一批次，并分为3组：去势公猪（出生后第二天[研究第0天]去势）、接种上述产品的猪和未去势公猪。接种疫苗的猪在9至11周龄（60 - 78天）和15至17周龄（102 - 120天）时皮下注射2 mL抗促性腺激素释放因子（GnRF）疫苗，并在22至25周龄（152 - 176天）时屠宰。未发生归因于疫苗接种的临床异常或不良事件。屠宰时，接种疫苗的猪的平均体重比去势公猪高6%（P < 0.0001）。从去势到屠宰，接种疫苗的猪的平均日增重比去势公猪高8%。详细而言，观察到从第一次到第二次接种疫苗期间平均日增重较低（-12%；P < 0.0001），而从第二次接种疫苗到屠宰期间平均日增重高27%（P < 0.0001）。在整个研究过程中，接种疫苗的猪和未去势公猪的平均日增重没有显著差异，除了从第一次到第二次接种疫苗期间（未去势公猪较高；P = 0.0059）和从第二次接种疫苗到屠宰期间（接种疫苗的猪较高；P = 0.0390）。从第一次到第二次接种疫苗期间，去势公猪的饲料转化率分别比接种疫苗的猪高11%和比未去势公猪高8%（P = 0.0005），但从第一次接种疫苗到屠宰期间，去势公猪的饲料转化率比接种疫苗的猪低23%至26%（P < 0.0001），比未去势公猪低23%至26%（P < 0.0001），从第二次接种疫苗到屠宰期间，去势公猪的饲料转化率比接种疫苗的猪低7%至9.5%（接种疫苗的猪和未去势公猪分别为P = 0.0029和P = 0.0003）。屠宰时，所有接种疫苗的猪和64%的未去势公猪的腹部脂肪雄烯酮浓度低于200 ng/g。所有组样本的腹部脂肪粪臭素浓度均低于20 ng/g。总之，使用所测试的GnRF类似物 - 白喉类毒素结合物进行GnRF疫苗接种未诱导不良临床效应，证明有效，并且与物理去势相比，屠宰时体重更大，从第一次接种疫苗到屠宰期间平均日增重和饲料转化率得到改善。
