Extracts of laminarin improve growth rate and small intestinal morphology in new born chicks, but does not influence Campylobacter colonisation

Abstract Text:

Promoting growth performance, while limiting the proliferation of bacteria such as Campylobacter jejuni, is a key goal of the broiler industry. Therefore, the objective of this study was to evaluate the effects of supplementing the post-hatch diet with laminarin and fucoidan extracts on growth performance, small intestinal morphology and Campylobacter (C.) jejuni colonisation following an experimental challenge in 13 day old chicks. The experiment consisted of three diets: 1) basal diet, 2) basal diet + 200ppm Laminarin (LAM) and 3) basal diet + 200 ppm LAM and 160 ppm Fucoidan (LAM/FUC). Day old Ross chicks (n=135), were housed in groups of three, with 15 replicates per treatment group. On day three, all chicks were orally gavaged with 0.1ml 10⁶ colony forming units of C. jejuni. Following humane sacrifice on day 13, caecal digesta samples were collected for enumeration of C. jejuni and Lactobacillus. Ileal tissue was also collected post-slaughter in order to examine small intestinal morphology. Chicks offered  diets containing seaweed extracts LAM or LAM/FUC had  increased live weights (311 g, s.e. 4.14 and 302 g, s.e. 3.99, respectively, P < 0.05) compared to the basal diet (290 g, s.e 3.99) at the end of the experimental period (day 13). The mean total intake for the chicks fed the LAM and LAM/FUC extracts at the end of the experiment (day 13) were 373g/d (s.e. 3.89), 411g/d (s.e. 4.03) and 411 g/d (s.e 3.89) respectively, with chicks fed the basal diet having lower feed intake compared to both the LAM and LAM/FUC fed chicks (P<0.05). Dietary inclusion of LAM/FUC combination increased the feed conversion ratio (FCR) (1.63 g/g vs 1.69 g/g; s.e ± 0.02) compared to the basal diet (P < 0.05). Chicks offered the LAM diet had increased ileal villus height compared to chicks offered the basal diet (307µm vs. 231µm s.e ± 17.24, P<0.05). There was no effect of LAM or LAM/FUC extracts on the proliferation of C. jejuni or on Lactobacilli numbers in the caecum. In conclusion, supplementation with LAM or LAM/FUC in the post hatch period improved growth performance and positively modified small intestinal architecture, but did not impact the extent of C. jejuni proliferation. 

Keywords: broiler chicks, Campylobacter jejuni, performance, histology, Seaweed