Effects of copper bearing montmorillonite on the growth performance, intestinal microflora and morphology of weanling pigs

A total of 128 weaning pigs (Duroc x Landrace x Yorkshire) at an average initial body weight of 7.5 +/- 0.6 kg were used to investigate the effects of copper bearing montmorillonite (Cu-MMT) on the growth performance, intestinal microflora, bacterial enzyme activities, and intestinal morphology. The pigs were allocated to four dietary treatments in a randomized complete block design (four replicates of eight pigs per replicate) for 45 days. The dietary treatments were: (1) basal diet, (2) basal diet + 1.5 g/kg MMT, (3) basal diet + 36 mg/kg copper as CuSO4 equivalent to the copper in the Cu-MMT treatment group or (4) basal diet + 1.5 g/kg Cu-MMT. The results showed that supplementation with Cu-MMT improved (P < 0.05) growth performance, reduced (P < 0.05) the total viable counts of intestinal Clostridium and Escherichia coli, depressed (P < 0.05) the activities of intestinal beta-glucosidase and beta-glucuronidas, and increased (P < 0.05) villus height and the villus height to crypt depth ratio at the small intestinal mucosa as compared with control. Supplementation with MMT also increased (P < 0.05) villus height and the villus height to crypt depth ratio at the jejunum as compared with control. However, supplementation with MMT or CuSO4 had no (P > 0.05) effect on growth performance, intestinal microflora and bacterial enzymes as compared with control. Supplementation with CuSO4 had no (P > 0.05) effect on the small intestinal morphology as compared with control. Supplementation with Cu-MMT increased daily gain, decreased viable counts of Clostridium and E. coli and activity of beta-glucuronidase in colonic contents (P < 0.05) as compared with MMT or CuSO4, and increased (P < 0.05) villus height and the villus height to crypt depth ratio at the small intestinal mucosa as compared with CuSO4. The results indicated that Cu-MMT is more effective than MMT or CuSO4 in enhancing the growth, intestinal microflora and morphology of weanling pigs. (C) 2004 Elsevier B.V. All rights reserved.