Effects of dietary supplementation of selenium-enriched probiotics on productive performance and intestinal microflora of weanling piglets raised under high ambient temperature

Abstract Text: Probiotics have been suggested as one of the most desirable alternatives to feed antibiotics for swine. The objective of this study is to evaluate the efficacy of a selenium-enriched probiotics (SeP) preparation on productive performance and intestinal microflora of piglets raised under high ambient temperature. Forty-eight crossbred weanling piglets (28 days old) randomly allotted into 12 pens (4 piglets/pen) and 4 dietary treatments (3 pens/treatment) were fed ad libitum for 42 days a basal diet (control; Con), or the basal diet supplemented with probiotics (Pro), sodium selenite (ISe), or the SeP preparation. The basal diet contained 0.16 mg/kg-diet of total intrinsic Se, and the ISe and SeP preparations elevated the total Se level to 0.46 mg/kg-diet. The Pro and SeP preparations contained equivalent amounts of Lactobacillus acidophilus and Saccharomyces cerevisiae (approximately 10¹¹ and 10⁹ CFU/mL, respectively). Blood and fecal samples were collected on days 0, 14, 28 and 42 post-initiation of the feeding trial. The SeP group had higher final BW (p < 0.05), greater ADG (p < 0.05), lower FCR (p < 0.01), and lower diarrhea incidence (p < 0.01) than the Pro, ISe or Con group. Blood Se concentration and GSH-Px activity were both higher (p < 0.01) in the SeP group than in the Pro, ISe or Con group. On days 28 and 42, the serum concentrations of T3 were higher (p < 0.01) and T4 lower (p < 0.01) in the SeP group than in the ISe, Pro or Con group. On day 28, the serum T3 in the ISe group was higher (p < 0.01) than in the Pro or Con group, and on days 28 and 42 the serum T4 were lower (p < 0.01) in the ISeP group than in the Pro or Con group. Also on days 28 and 42, the fecal counts of Lactobacillus bacteria was higher (p < 0.01) while Escherichia coli lower (p < 0.01) in the SeP or Pro group than in the ISe or Con group. The results of RFLP showed that the fecal microbial flora in the SeP group changed the most (numerically) as compared to the Pro or ISe group. In conclusion, the overall results of this study indicate that this SeP preparation may serve as a better alternative to antibiotics than pure probiotics for using as a growth promoter for piglets.

Keywords: probiotics, selenium, pig, productive performance, fecal microflora, glutathione peroxidase, thyroid hormone