Dietary supplementation with ovine serum immunoglobulin attenuates acute effects on growth, organ weights, gut morphology and intestinal mucin production in the growing rat challenged with Salmonella enteritidis

The aim was to determine the effect of orally administered ovine serum immunoglobulin (Ig) on growth performance, organ weight, gut morphology and mucin production in the Salmonella enteritidis--gavaged growing rat. Four groups consisted of non-gavaged rats fed a casein-based control basal diet (BD) and three groups of rats gavaged with 1×10(7) CFU S. enteritidis and fed a casein-based diet, a diet containing freeze-dried ovine Ig (FDOI) or a casein-based diet containing inactivated ovine Ig (IOI). The rats were randomly allocated to one of the four groups (n=15/group) and received their respective diets for an 18-day experimental study. Gavaging took place on day 15. Average daily gain and body gain : feed ratio (post-gavage, 3 days) were significantly (P<0.05) higher for the Salmonella-challenged rats fed the FDOI diet compared to those fed the BD and IOI diets. At the end of the study, the small intestine and colon were significantly (P<0.05) heavier for the gavaged rats fed the FDOI diet compared to the gavaged rats fed either the BD or IOI diet. Moreover, the relative weights of the caecum, liver and spleen of the gavaged rats fed the BD or IOI diet were significantly (P<0.05) heavier compared to the gavaged rats fed the FDOI diet. Generally, the gavaged rats fed the FDOI diet had significantly (P<0.05) higher goblet cell counts and luminal mucin protein contents than the gavaged rats fed either the BD or IOI diet and had a more functional gut morphology. Overall, the FDOI fraction prevented the acute effects of S. enteritidis.