Effects of natural and heat modified palygorskite supplementation on the laying performance, egg quality, intestinal morphology, digestive enzyme activity and pancreatic enzyme mRNA expression of laying hens

This study was conducted to investigate the effects of natural and heat modified palygorskite supplementation on the laying performance, egg quality, intestinal morphology, digestive enzyme activity and pancreatic enzyme mRNA expression of laying hens. Two hundred and seventy Hy-Line Brown laying hens (30 wk old) were randomly allocated to 3 groups consisted of 6 replicates of 15 hens, receiving the following diets for 8 wk, respectively: 1) basal diet (control group); 2) basal diet plus 2% natural palygorskite; 3) basal diet plus 2% heat modified palygorskite. Compared with the control group, palygorskite supplementation exerted no undesirable effects on laying performance and egg quality. Natural palygorskite inclusion significantly enhanced villus height in duodenum, protease activity in jejunal digesta and amylase activity in pancreas, however, this beneficial effect was not observed in modified palygorskite group, even though these parameters in which also maintained numerically higher levels. In addition, palygorskite supplementation, in either natural or modified form, increased the mRNA abundance of pancreatic amylase. The results indicated that dietary palygorskite supplementation, especially the natural palygorskite, could improve the digestive function and intestinal morphology, which may contribute to the simultaneously similar laying performance and egg quality.