Effects of Weaning Modes on the Intestinal pH, Activity of Digestive Enzymes, and Intestinal Morphology of Piglets

Simple Summary Previous research has discovered that various weaning and mixing modes reduce weaning stress in piglets. However, there are not as many existing reports on whether relieving weaning stress with different weaning and mixing modes can promote the intestinal health of piglets. The results of this study showed that two weaning modes, 2% (v/v) glutaraldehyde spray, and weaning after mixing, can increase the daily weight gain of piglets, lower their intestinal pH, boost the activity of their digestive enzymes, and improve intestinal morphology, compared with conventional weaning modes. These discoveries indicate that these two weaning modes can reduce weaning stress to a certain extent. The present study investigated the effects of weaning modes on the intestinal pH, digestive enzyme activities, and intestinal morphology of piglets. A total of 27 litters of "Duroc boars x Landrace x Large White" piglets were selected and randomly divided into three groups. Those groups were the conventional weaning group (C), the odorant spray group (S), and the weaning-after-mixing group (M), with three repeats in each group and three litters in each repeat. The experiment began seven days before weaning, and ended seven days after weaning. The piglets were euthanized on the eighth day after weaning, and the jejunum and ileum tissues and contents were sampled. The pH and enzyme activities of the intestinal contents were determined, and the intestinal morphologies were revealed using H&E staining. It was concluded that a 2% glutaraldehyde spray on the body surfaces of piglets after weaning could increase average weight after nursery, lower intestinal pH, increase the activities of digestive enzymes, improve intestinal morphology, and relieve weaning stress. It was also found that weaning after mixing could increase the average weight after nursery, lower intestinal pH, improve intestinal morphology, and reduce weaning stress.