Effect of Dietary Lactose on Cecal Morphology, pH, Organic Acids, and Salmonella enteritidis Organ Invasion in Leghorn Chicks

Abstract

The effect of 14 or 19 days of 10% dietary lactose administration on Salmonella enteritidis (SE) colonization and histological, morphometric, and organic acid changes of the ceca were investigated. At Day 13 or 18, chicks were challenged with 10(8) cfu of SE. Chicks were killed and cultured 24 h later. A reduction in the total number of positive SE organ invasions was observed following 14 days (P < .001) or 19 days (P < .005) of treatment in chicks fed with lactose. Histological examination revealed a marked reduction in lamina propria thickness of ceca, as well as subjective epithelial cell proliferation from chicks following either 14 or 19 days of lactose administration. Using morphometric analysis, a reduction in the mean lamina propria thickness in chickens fed with lactose during 14 or 19 days was observed as compared with controls (P < .05). Yet, an increase (P < .05) in the mean epithelial cell length in both lactose-treated groups was observed as compared with controls. Lactose decreased luminal pH (P < .05) and increased the concentration of acetic, propionic, butyric, and lactic acid (P < .05). These data indicate that lactose-induced resistance to SE organ invasion is associated not only with an increase in organic acid concentration but also with measurable morphological changes of the cecal mucosa.

A note on the effects of selected prebiotics on the performance and ileal microbiota of broiler chickens

“…In the present study, the pH of caecal digesta was lower in birds provided diets with inulin and lactose. Also Corrier et al (1991), who provided 2.5% lactose in drinking water, and Tellez et al (1993), who administrated 10% of lactose in feed, reported a lowered pH in the caecal contents of broilers.…”

Subpopulation Characteristics of Egg-Contaminating Salmonella enterica serovar Enteritidis as Defined by the Lipopolysaccharide O Chain

“…There is some molecular evidence that the cecum supports the growth and colonization of subpopulations of Salmonella that vary in LPS O-chain composition, whereas the intestine favors smooth strains (33). Gut physiology can be manipulated, and many types of biological controls and diets have been designed with the idea of excluding pathogenic salmonellae from the gut (6,24,26,27,30,42,50). Refinement of these approaches to suppress the emergence of subpopulations of S. enterica serovar Enteritidis that have tropism for the reproductive tract of the hen might further reduce the number of contaminated eggs that reach the market.…”

The effects of dietary whey protein concentrate level on performance, selected intestinal tract and blood parameters, and thiobarbituric acid reactive substances in the liver and breast meat of broiler chickens

“…The results of some studies have shown the ability of chicken gut anaerobic microbiota to convert lactose to short-chain organic acids, especially lactate and propionate (Rehman et al, 2009). A lower pH of the digesta resulting from lactose fermentation may have a positive impact on intestinal histomorphology and/or on the colonization of beneficial microflora in the gastrointestinal tract when administered at both very high (10%) or moderate (2.8%) levels (Tellez et al, 1993;Samli et al, 2007). Conflicting data exist, however, about the effects of dietary lactose on chicken growth performance.…”