Means to improve the robustness of newly weaned pigs exposed to mycotoxin-contaminated feeds **

真菌毒素，包括脱氧雪腐镰刀菌烯醇(DON)，是真菌感染的次级代谢产物，经常发生在谷物和玉米中。猪是最容易感染DON的牲畜物种，暴露的症状包括饲料摄入量和生长减少，这意味着加拿大猪肉行业在只有轻微DON污染的情况下损失了6000万美元的利润。加拿大生物系统公司(CBS)正在开发一种新型饲料添加剂(NUTRA-MIX)，可用于减轻DON对猪的负面影响。据推测，含有吸收剂、酵母多糖和维生素的饲料添加剂(即营养混合物)将通过刺激肠道发育和提高免疫系统的健壮性来缓解暴露于DON的断奶仔猪的生长性能下降。本研究旨在通过对育成期间暴露于非污染玉米的断奶仔猪肠道健康发育和免疫系统功能指标的研究，评价营养混合剂对仔猪生长性能的影响，并了解其作用机制。断奶后，256头猪被随机分配到32个猪圈，每组8头，分配到苗圃饲粮中，饲喂受真菌毒素污染的日粮(DON每公斤全价3 mg)或未污染的玉米，并按2×2因子安排添加或不添加纽特拉混合饲料。将确定生长性能、对大肠杆菌感染的适应能力以及对肠道健康和发育的评估。体液和细胞介导的免疫反应将在接种疫苗后进行测量。如果我们的假设得到支持，毫无疑问，CBS将立即将这些结果转化为有利于加拿大养猪业的改进产品，特别是在生产商寻找抗生素的替代品以促进生长并改善他们的猪的健康和福祉的时候。从项目结果中扩大业务也将确保CBS的增长，为公司增加收入，并确保其员工的工作保障。

Mycotoxins, including deoxynivalenol (DON), are secondary metabolites of fungal infections that frequently occur in cereal grains and corn. Pigs are the most susceptible livestock species to DON and symptoms of exposure include reduced feed intake and growth, which represents a $60 million loss of profits for the Canadian pork industry with only modest DON contamination. Canadian Bio-Systems Inc. (CBS) is developing a novel feed additive (NUTRA-MIX) that can be used to mitigate negative impact of DON for swine. It is hypothesized that a feed supplement containing absorbents, yeast polysaccharides, and vitamins (i.e. NUTRA-MIX) will mitigate the reduction in growth performance for weanling pigs exposed to DON by stimulating gut development and improving immune system robustness. The objectives are to evaluate the effect of NUTRA-MIX on growth performance and understand its mode of action through indices of gut health and development and immune system function of weanling pigs exposed to DON-contaminated corn during the nursery period. After weaning, 256 pigs will be randomly allocated to 32 pens of 8 pigs and assigned to nursery diets made with mycotoxin-contaminated (3 mg DON/kg complete diet) or uncontaminated corn and with or without NUTRA-MIX supplementation in a 2X2 factorial arrangement. Growth performance, resilience to an E. coli infection, and evaluation of gut health and development will be determined. Humoral and cell-mediated immune responses will be measured in response to vaccination. If our hypothesis is supported, there is no doubt that CBS will immediately translate these results into improved products that will benefit the Canadian swine industry, particularly as producers look for alternatives to antibiotics for growth promoting benefits and to improve the health and wellbeing of their pigs. Expanded business from the results of the project will also ensure the growth of CBS, increase revenue for the company, and ensure job security for its employees.