Abstract:
There is a necessity for the implementation
of in-feed probiotics in the poultry production
industry, following strict regulations around the use
of antibiotic growth promoters (AGP). Bacillus spp.
are becoming an attractive alternative because of their
functionality and stability. This study aims to evaluate
the effect of a novel multi-strain Bacillus based probiotic
on growth performance and gut health in male
Ross 308 broiler chickens challenged with Clostridium
perfringens Type A. Broilers on a 4 phase feeding
program were fed diets containing either a standard
metabolizable energy (ME) (100%) or a reduced ME
(98%) level. The test probiotic was compared to an
un-supplemented negative control and a commercial
benchmark product as positive control over a 35 D
feeding trial, using a 2 × 3 factorial experimental design.
Chicks were inoculated with a once-off dose of
C. perfringens on day 14. Growth performance was
measured weekly to calculate body weight (BW), feed
intake (FI) and feed conversion ratio (FCR). Villi histomorphology,
gut lesions, and liver weight were assessed
at day 35. Broilers fed the reduced ME diet with the test
probiotic achieved higher final BWs (P = 0.037) and
FCR (P = 0.014) than the negative control. Broilers
fed the standard ME diet with the test probiotic
showed improved (P = 0.001) FCR than the negative
control from day 21 onwards. Increased duodenal
villi height (P = 0.012) and villi height to
crypt depth ratio in the duodenum (P < 0.0001)
and jejunum (P = 0.0004) were observed in broilers
fed the reduced ME diet containing the test probiotic.
Additionally, the test probiotic resulted in significantly
reduced relative liver weights in both ME
groups. Consequently, the results suggest that the
novel multi-strain Bacillus based probiotic enhanced
broiler performance and improved gut health and is
thus attractive as an alternative to AGP’s in broiler
production.
