Production of epidermal growth factor expressing Lactococcus Lactis and its potential for enhancing early-weaned piglet growth

仔猪断奶后立即出现消化功能紊乱及相应的生长速度减慢是育成猪管理中的主要问题之一。仔猪在此期间经历压力，主要是由于食物成分的变化，导致粘膜受损，减少营养物质的消化和吸收。因此，可供肠道病原菌使用的底物更多，仔猪更容易感染和腹泻。开发一种日粮来刺激早期断奶仔猪的肠道发育，可能有助于优化它们在这个关键阶段的表现。已知表皮生长因子(EGF)可刺激肠道的发育，将其添加到配方中可促进仔猪从轮状病毒感染中恢复肠道。我们推测，使用食品级乳球菌将EGF局部输送到胃肠道可能有利于改善早期断奶仔猪的生产性能。我们将使用基因工程的方法来产生分泌表皮生长因子的乳球菌，并测试在饲料中加入这些EGF运送细菌是否会促进仔猪的肠道发育，从而促进早期断奶仔猪的性能。这是首次采用体内方法，以食品级细菌(乳球菌)为生物反应器，运送对家畜有益的重组因子的研究。因此，该项目的成功完成将产生更多高质量的出版物，并为改善动物生产提供新的机会。

Disturbed digestive function and the associated reductions in growth rates during the period immediately after weaning is one of the major problems in nursery pig management. Piglets experience stress during this period, largely due to changes in food composition, leading to a damaged mucosa and to reduce nutrient digestion and absorption.  As a result, more substrate it available for enteric pathogenic bacteria and piglets become more susceptible to infection and diarrhea. Developing a diet to stimulate intestinal development of early weaned pigs may help to optimize their performance in this critical stage. Epidermal growth factor (EGF) is known to stimulate the development of intestine and its supplementation into formulas was shown to facilitate the recovery of intestines in piglets from rotavirus infection. We hypothesized that locally deliver EGF to the GI tract using food-grade Lactococcus Lactis may be beneficial for improving early-weaned piglet performance. We will use a genetic engineering approach to generate Lactococcus Lactis that secrets epidermal growth factor and test if including these EGF delivering bacteria into feed enhances piglet intestinal development, and thus, early-weaned piglet performance. This is the first study using the in vivo approach to deliver recombinant factors that are beneficial to the livestock animals using food grade bacteria (Lactococcus Lactis) as bioreactor. Successful completion of the project should therefore generate  high quality publications and provide novel opportunities for improving animal production.