Impact of Supplementary Microbial Additives Producing Antimicrobial Substances and Digestive Enzymes on Growth Performance, Blood Metabolites, and Fecal Microflora of Weaning Pigs

Abstract

Simple Summary The aim of the present study was to confirm that microbial additives producing antimicrobial substances and digestive enzymes increased the health of weaning pigs by improving blood metabolites and fecal microflora. Pediococcus acidilatic BBG-L1 and Lactobacillus plantarum SK3121 produced antimicrobial activity, while Bacillus subtilis SK877, B. subtilis BBG-B20, and Saccharomyces cerevisiae BBG-Y6 produced digestive-enzyme activity. The mixtures of these microbes were used as microbial additives and applied into weaning pigs for 21 d with different levels following 0, 0.5, 1.0, and 1.5% of the diet as fed. In the present study, dietary microbial additives had no effects on growth performance of weaning pigs, except for the feed efficiency. However, dietary microbial additives could improve the health status of weaning pigs. This could be seen in increasing immune response, glucose, and insulin in the blood, as well as reducing Salmonella and Escherichia coli in the fecal samples of the pigs. Furthermore, the supplementary microbial additive at 1.0% presented the highest improvement in blood metabolites. Therefore, the present study concluded that dietary microbial additives presented antifungal and digestive-enzyme activities that improved the health status of weaning pigs, and a supplementary level of 1.0% was recommended to improve feed efficiency, blood metabolites, and fecal microflora effectively. The present study investigated the effects of microbial additives producing antimicrobial and digestive-enzyme activities on the growth performance, blood metabolites, and fecal microflora of weaning pigs from 21 to 42 d of age. A total of 144 weaning pigs (1:1 ratio of gilt and boar; 21 d of age; 7.40 +/- 0.53 kg of average body weight) were randomly distributed into four supplementary levels of microbial additive (0 vs. 0.5 vs. 1.0 vs. 1.5% of fresh weight) with three pens of replication, consisting of 12 weaning pigs per pen. All weaning pigs were maintained with the same basal diet for 21 d. Blood and feces were subsampled at day 21. Feed efficiency tended to increase linearly (p = 0.069) with an increasing supplementation level. Insulin, insulin-like growth factor 1, and blood glucose presented a quadratic effect (p < 0.05) with an increasing supplementation level, and these blood metabolites were highest at the 1% supplementation level. Immunoglobulin G in blood increased linearly by (p < 0.05) increasing the supplementation level. Salmonella and Escherichia coli in feces were decreased linearly by (p < 0.05) increasing the supplementation level. In conclusion, supplementation of microbial additive at 1.0% improved the feed efficiency, blood metabolites, and fecal microflora of weaning pigs.