Feed particle size and processing form affects intestinal mucin secretion and adherence of Salmonella to the ileum of pigs

August 1, 2005 — Adam Moeser (ed. Scott Hurd)
  [ES]

An experiment was conducted to investigate the effects of feed particle size and processing on morphological characteristics of the intestine and the adhesion of Salmonella enteric serovar Typhimurium DT12 to the ileum of pigs. Ninety six pigs (approximately ~33 kg BW) were assigned to one of 4 experimental diets. Experimental diets were based with barley, wheat, and soybean meal and differed only with regard to particle size (fine vs. coarse) and feed processing form (non-pelleted vs. pelleted). The experimental diets were: fine non-pelleted (F-NP), coarse non-pelleted (C-NP), fine pelleted (FP), and coarse pelleted (CP). Water and diets were fed to pigs on an ad libitum basis for 28 days after which a representative number of pigs (n=6 pigs/diet treatment) were euthanized and segments of the small and large intestine were harvested for morphological and histological analyses and in vitro Salmonella adhesion assays.

Results: Experimental diets had no effect of weight gain or feed intake,however feed:gain was significantly improved in pigs fed pelleted feed (P<0.05). There was a statistically significant interaction between form of feed and particle size with pigs fed the C-NP diets having longer villi compared with pigs fed CP diets. Increased crypt depths were observed in the colon of pigs fed coarse feed compared with finely ground feed (P<0.05). Intestinal mucin staining (neutral, acidic and sulfomucins)was greater in pigs fed pelleted feed compared with non-pelleted feed when measured in the distal small intestine (P = 0.01). There were no differences between experimental diets with regards to lectin binding characteristics in the distal small intestine or cecum. Using an in vitro pig intestine organ culture model, ileum from pigs fed non-pelleted feed had less adherence of Salmonella compared to ileal tissues from pigs fed pelleted feed.

Overall, results from this study suggest that pigs fed pelleted diets had increased mucin secretion in the villi of the distal small intestine compared with non-pelleted feed. The increased mucin secretion in pelleted diets may enhance the adherence of Salmonella to the ileum.

Reference:

Hedemann MS, Mikkelsen LL, Naughton PJ, and Jensen BB. Effect of feed particle size and feed processing on morphological characteristics in the small and large intestine of pigs and on adhesion of Salmonella enterica serovar Typhimurium DT12 in the ileum in vitro. J. Anim. Sci. 83: 1554-1562, 2005.