Vetanco SA, Villa Martelli B1603, Province of Buenos Aires, Argentina.
Vetanco USA, Saint Paul, MN 55114, USA.
Poult Sci. 2021 Sep;100(9):101329. doi: 10.1016/j.psj.2021.101329. Epub 2021 Jun 11.
This study evaluated growth performance and cross-protection against Eimeria spp. using a subunit coccidia vaccine in 2 independent challenge experiments. In both trials, chickens were challenged with E. acervulina, E. maxima, and E. tenella oocysts. In Exp 1, 1000-day-old chickens were allocated in one of 2 treatments 1) Control group; 2) Biotech Vac Cox group. The vaccine was orally gavaged on d 2 and 16 of life and coccidia challenge was on d 21. Performance parameters were evaluated on d 21, 35, and 42. On d 34, coccidia lesions were scored. Oocysts per gram of feces (OPG) were evaluated on d 28, 35, and 42. In Exp 2, 900-day-old chickens were assigned in one of 2 treatments 1) Control group; 2) Biotech Vac Cox group. The vaccine was orally gavaged on d 2 and 16 of life and coccidia challenge was on d 21. Performance parameters were evaluated on d 21, 27, 35, and 42, and lesion scores and OPG at d 27. In Exp 1, chickens vaccinated had significantly lower feed intake (FI) at d 21 and feed conversion ratio (FCR) at d 35 compared to control chickens (P < 0.05). Vaccinated chickens showed a significant reduction (P ≤ 0.05) in OPG for E. maxima to nondetectable levels and for all coccidian species at d 42 compared to control chickens. In Exp 2, the chickens vaccinated showed a significant increase in BW, BW gain (BWG) and reduction in FCR on d 27, 35, and 42 (P ≤ 0.05). Vaccinated chickens had significantly lower (P ≤ 0.05) lesion scores for all 3 Eimeria species. Moreover, vaccinated chickens had a reduction in total OPG of 35.50% (P = 0.0739). Studies to evaluate the serological and mucosal immune response are currently being evaluated. This inactivated, orally delivered subunit vaccine offers significant cross-protection to Eimeria spp. and eliminates the needs to treat broilers with live oocysts, enhanced ease of use, and greater biosecurity to producers.
本研究通过两次独立的攻毒试验，评估了使用亚单位球虫疫苗对鸡生长性能和对艾美耳球虫属的交叉保护作用。在这两项试验中，鸡均受到柔嫩艾美耳球虫、毒害艾美耳球虫和堆形艾美耳球虫卵囊的攻毒。在试验 1 中，1000 日龄鸡被分为 2 种处理之一：1）对照组；2）Biotech Vac Cox 组。疫苗在 1 日龄和 16 日龄时经口灌服，21 日龄进行球虫攻毒。在 21、35 和 42 日龄时评估性能参数。在 34 日龄时，对球虫病变进行评分。在 28、35 和 42 日龄时评估每克粪便中的卵囊数（OPG）。在试验 2 中，900 日龄鸡被分为 2 种处理之一：1）对照组；2）Biotech Vac Cox 组。疫苗在 1 日龄和 16 日龄时经口灌服，21 日龄进行球虫攻毒。在 21、27、35 和 42 日龄时评估性能参数，并在 27 日龄时评估病变评分和 OPG。在试验 1 中，与对照组鸡相比，接种疫苗的鸡在 21 日龄时的采食量（FI）和 35 日龄时的饲料转化率（FCR）显著降低（P＜0.05）。接种疫苗的鸡在 42 日龄时对最大艾美耳球虫的 OPG 显著减少（P≤0.05）至无法检测水平，对所有艾美耳球虫属物种的 OPG 也显著减少（P≤0.05）。在试验 2 中，接种疫苗的鸡在 27、35 和 42 日龄时体重（BW）、体重增加（BWG）和 FCR 显著增加（P≤0.05）。与对照组鸡相比，接种疫苗的鸡的所有 3 种艾美耳球虫的病变评分显著降低（P≤0.05）。此外，接种疫苗的鸡的总 OPG 减少了 35.50%（P=0.0739）。目前正在评估血清学和黏膜免疫反应的研究。这种经口给予的、灭活的亚单位疫苗对艾美耳球虫属提供了显著的交叉保护作用，并且消除了对肉鸡用活卵囊进行治疗的需要，提高了易用性，增加了生产者的生物安全性。
