de la Rosa C, Hogue D E, Thonney M L
Department of Animal Science, Cornell University, Ithaca, NY 14853-4801, USA.
J Anim Sci. 1997 Sep;75(9):2328-34. doi: 10.2527/1997.7592328x.
The objective of this experiment was to compare vaccination schedules for ewes and their lambs to raise antibody concentrations to epsilon-toxin of Clostridium perfringens, the causative agent of enterotoxemia. Half of 200 Finnsheep x Dorset ewes were vaccinated with C. perfringens type D toxoid vaccine 3 wk before lambing. Serum samples were obtained from 20 ewes that were to be vaccinated and 20 ewes that would remain unvaccinated before treatment and at wk 2, 1, and 0 before the start of lambing. Antibody concentrations in sera of unvaccinated ewes remained at 2 IU/mL, but they peaked in vaccinated ewes at 15 IU/mL by wk 1 before lambing. Lambs from each of the first 13 and the first 14 sets of triplets from vaccinated and unvaccinated ewes, respectively, received one of three vaccination treatments: no vaccine (control), vaccination on d 1 and 21 of age, or vaccination on d 21 and 42 of age. Antibody concentrations declined in sera of vaccinated ewes from 8.5 IU/mL immediately after lambing to 3 IU/mL 12 wk later. Vaccination of lambs did not increase sera antibody concentration. However, prepartum vaccination of ewes significantly increased lamb antibody concentrations (19 IU/mL) compared with lambs reared by unvaccinated ewes (2 IU/mL). Vaccination of ewes resulted in lambs with higher antibody concentrations until wk 10 postpartum. Concentrations declined to .6 IU/mL in all lambs at 12 wk. Because concentrations of .2 IU/mL may be protective, these results indicate that vaccination of ewes before lambing imparts passive protection in lambs to 12 wk of age, whereas vaccination of young lambs provides no added protection.
本实验的目的是比较母羊及其羔羊的疫苗接种方案，以提高针对产气荚膜梭菌ε毒素（肠毒血症的病原体）的抗体浓度。200只芬兰羊×多塞特母羊中有一半在产羔前3周接种D型产气荚膜梭菌类毒素疫苗。在处理前以及产羔开始前第2周、第1周和第0周，从20只待接种疫苗的母羊和20只不接种疫苗的母羊中采集血清样本。未接种疫苗的母羊血清中的抗体浓度保持在2 IU/mL，但接种疫苗的母羊血清中的抗体浓度在产羔前第1周达到峰值，为15 IU/mL。分别来自接种疫苗和未接种疫苗母羊的前13组和前14组三胞胎羔羊接受了三种疫苗接种处理之一：不接种疫苗（对照）、在1日龄和21日龄时接种疫苗、或在21日龄和42日龄时接种疫苗。接种疫苗的母羊血清中的抗体浓度在产羔后立即从8.5 IU/mL降至12周后的3 IU/mL。羔羊接种疫苗并未提高血清抗体浓度。然而，与由未接种疫苗的母羊饲养的羔羊（2 IU/mL）相比，母羊产前接种疫苗显著提高了羔羊的抗体浓度（19 IU/mL）。母羊接种疫苗使羔羊在产后第10周前具有更高的抗体浓度。所有羔羊在12周时抗体浓度降至0.6 IU/mL。由于0.2 IU/mL的浓度可能具有保护作用，这些结果表明，母羊在产羔前接种疫苗可使羔羊在12周龄前获得被动保护，而幼龄羔羊接种疫苗则不会提供额外保护。
