Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/24/2004
Publication Date: 7/27/2004
Citation: Wells, J., Yen, J., Miller, D.N. 2004. Effect of dry skim milk on fecal bacterial populations and salmonella shedding in growing-finishing swine[abstract]. Journal of Animal Science 82(Suppl. 1):174-175.
Technical Abstract: Dry skim milk (DSM) contains approximately 55% lactose and lactose has been suggested to have prebiotic effects in the mammalian digestive system. Barrows were fed growing, growing-finishing, and finishing diets from age 10-14 wk, 14-18 wk and 18-22 wk, respectively. For each feeding phase, diets were formulated to contain 0 or 10% DSM (balanced with ME and apparent ileal digestible AA). Animals were weighed every two wk. DSM did not alter animal gain, feed intake, or feed conversion (P>0.05). Fecal samples were collected from 40 animals (20 with DSM and 20 without DSM) at wk 10 (d 0 on diets), 14, 18, and 22, and were analyzed for Lactobacillus sp. (LAB), Enterobacteraceae (EB), coliforms (CF), generic Escherichia coli (EC), and Salmonella sp. At week 10, fecal bacterial counts (log10 CFU/g feces) were 9.55, 7.26, 7.01, and 6.93 for LAB, EB, CF, and EC populations, respectively. The EB, CF, and EC populations decreased through wk 14 and 18 (P<0.05), but were still higher with the DSM diet (P<0.05). The LAB population decreased over time in the absence of DSM in the diet, whereas DSM sustained higher LAB counts (P<0.05). At wk 22, populations of EB, CF, and EC were higher (P<0.05) than wk 18 for the diet without DSM, but no change was observed with DSM. As a result, no differences between the diets were observed at week 22. Salmonella were detected in 70% of the animals at wk 10 and 14, but only 20% at wk 18 and 22. DSM did not affect Salmonella shedding, but pooled analysis indicated that fewer recurring incidences of Salmonella shedding occurred in animals with higher LAB bacteria. Nonetheless, weight gain for individual animals was not affected by Salmonella shedding in this study. It is concluded that 10% DSM affects fecal bacterial populations, but not Salmonella shedding in growing-finishing pigs.