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Description:
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Antibiotic resistance as a result of continuous use has been a thorny issue in pig production . Focus has been directed therefore to use of probiotic supplementation as alternative . Probiotic supplementation has been suggested to benefit the host animal by stimulating appetite , improving intestinal microbial population balance , digestion and improvement of growth performance . Furthermore studies have also suggested a role for probiotics in stimulating the immune system .
The objective of this study was to determine the effects of dietary supplementation of Lactobacillus -based probiotics on growth and gut health of newly weaned pigs . Twenty nursery pigs weaned at 21 -d of age (6 .68 ± 0 .27 kg BW ) were allotted to 2 treatment groups representing : (1 ) CON (probiotic -free ; corn -soy diet ) and (2 ) PB (test group fed a diet containing 0 .2 % lactobacillus based probiotics ) . Pigs were housed individually in metabolism crates and fed the diets for 15 -d . At d -15 , all pigs were euthanized to collect gut tissues and digesta . There were no differences (P > 0 .05 ) in body weight , ADG , ADFI and FE between the treatments during 15 -d period . The numbers of E . coli , Bifidobacteria , Lactobacillus spp . , and total anaerobics in colon digesta were altered , although not statistically significant (P > 0 .05 ) . Major VFAs were acetate , propionate , isobutyrate , butyrate , isovalerate , and valerate . Acetate accounted for more than 60 % of the total VFAs in both treatments while isobutyrate accounted for less that 0 .5 % of the total VFAs in both treatments . There was no difference (P > 0 .05 ) observed in amount of VFAs in both treatments . There was also no difference (P > 0 .05 ) in the apparent ileal digestibility of amino acids in the diets . Villi height was greater (P < 0 .05 ) in the treatment group as compared to control group .
A separate study was conducted to investigate the effects dietary supplementation with Lactobacillus -based probiotics elicits on the immune status of the nursery pig . Differential blood counts were determined on whole blood samples collected on d 13 of the study period . Total RNA was isolated from mesenteric lymph nodes . Gene expression was determined using a 12 ,000+ pig specific custom microarray , results of which were validated with quantitative PCR . For differential blood counts , there were no differences (P > 0 .05 ) in lymphocyte , neutrophil and monocyte , WBC count , RBC count , hematocrit , and hemoglobin among treatment groups . Microarray results identified significant difference in the expression of 80 genes that were altered by lactobacillus -based probiotics supplementation . Of these genes , nine were comparatively induced ( > 2 .0 fold ) and the rest were comparatively repressed ( > 2 .0 fold ) . Functional analyses of these genes identified 25 distinctly enriched functional categories . One of the primary functional categories identified showed significant repression of catalytic activity genes , which represented the majority of repressed transcripts (24 .4 % ) . Analyses indicated that lactobacillus based probiotics supplementation altered genes responsible for carbohydrate transport activity , cellular physiology process , defense to pathogens and immune response . In addition , genes related to proteolysis including PRSS2 and CTRB and genes involved in lipid metabolism including LIPC and PLA2G1B were also altered by lactobacillus based probiotic supplementation .
Collectively , dietary supplementation of Lactobacillus -based probiotics at 0 .2 % may have beneficial effects by positively interacting with the intestinal mucosa and the microflora if the length of feeding was increased . The results from these studies indicate that dietary supplementation of Lactobacillus -based probiotics to nursery pig diets may be considered as a nutritional strategy for enhancing intestinal health and possibly positive immune response . Nonetheless , further studies are required to confirm and to elucidate the responsible mechanisms . In addition , the extent to which altered gene expression may affect the animal’s response to actual immune challenge conditions should be determined . |