Performance and intestinal health of weanling pigs fed with dietary nucleotides

Abstract

Previous studies reported benefits to growth performance, intestinal histology and reduced diarrhea for pigs supplemented with nucleotide additive as a replacement to antimicrobial growth promoters. The purpose of this study was to evaluate the effects of nucleotide levels on performance, occurrence of diarrhea, relative weight of organs, intestinal histology, and intestinal microbiota of weanling pigs. One hundred and sixty 21-d weaned pigs (6.43 ± 0.71 kg BW) were used in a randomized complete block design experiment with five treatments, eight replications per treatment and four animals per pen (experimental unit). The treatments were basal diet with 120 ppm of chloro-hydroxyquinoline (antimicrobial), and basal diet with 0 (control), 100, 150, or 200 ppm of nucleotides. The average daily gain (ADG), average daily feed intake (ADFI), gain to feed ratio (G:F), and occurrence of diarrhea were calculated from day 1 to 14, day 14 to 34, and day 1 to 34 of the experiment. A day after the end of the experiment, one animal from each pen was slaughtered to evaluate the relative weight of organs, intestinal histology, and intestinal microbiota. From day 1-14 and day 14-34 of the experiment, performance was not affected by the treatments. For the total experimental period (day 1-34), increasing the dietary concentrations of nucleotides linearly improved the final body weight and average daily gain. Salmonella spp. was detected only in the control treatment, without affecting the other microorganisms. Pigs fed with antibiotic had a lower occurrence of diarrhea from day 1-14 compared to pigs fed with nucleotide treatments. Although increasing the occurrence of diarrhea in the first 14 days, dietary nucleotides added up to 200 ppm, improve the final body weight and average daily gain at 34 days post weaning. Nucleotides and antimicrobial not shown beneficial effects on organ weights, and intestinal histology of nursery pig, however, are able to decrease the population of Salmonella spp. at small intestine.