Effects of Different Weaning Weight on Growth Performance, Serum Biochemical Indices and Intestinal Health of Piglets

A 3-week feeding experiment was conducted to explore the effects of different weaning weights on growth performance, apparent nutrient digestibility, serum biochemical indices, and intestinal health of piglets weaned at 21 days of age. Forty healthy (Landrace × Yorkshire) binary crossbred pigs with the same birth age and weaned at Day 21 were assigned to two treatments including L (5.0-5.5 kg) and H (6.5-7.0 kg), each with five replicates and four piglets per replicate. The two groups were fed the same diet. Data revealed that the average daily gain of high-weight piglets after weaning at 21 days was significantly higher than that of low-weight weaned piglets (p < 0.05); The crude fat (EE) and crude protein (CP) of H-piglets was significantly higher than that of l-piglets; There was no significant difference in the contents of total protein (TP), alkaline phosphatase (ALP), glutamic pyruvic transaminase (ALT), cholesterol (CHO), glucose (GLU), immunoglobulin M (IgM), triglyceride (TG), albumin (ALB), glutamic oxaloacetic transaminase (AST) and UREA between H-piglets and l-piglets after weaning at 21 days (p > 0.05). There was no significant difference in the villus height (VH), crypt depth (CD) and VH:CD ratio (VRC), and no significant difference in the relative abundance of intestinal flora at phyla and genus level (p > 0.05). In summary, the growth performance of piglets after weaning at 21 days is related to their weaning weight.