- 1BIOMIN America Inc., San Antonio, TX, USA
- 2BIOMIN Holding GmbH, Getzersdorf, Austria
- 3Department of Animal Nutrition, West Bengal University of Animal and Fishery Sciences, Kolkata, India
The recent trend toward reduction of antibiotic growth promoters
(AGP) in North American poultry diets has put tremendous pressure on the
industry to look for viable alternatives. In this context, phytogenic
feed additives (PFA) are researched to improve gut health and thereby
performance. An experiment was conducted with the objective to evaluate
the effects of PFA as an alternative to AGP on small intestinal
histomorphology, cecal microbiota composition, nutrient digestibility,
and growth performance in broiler chickens. A total of 432-day-old
Vencobb 400 broiler chicks were randomly assigned to one of three
dietary groups, each consisting of 12 replicate pens (
n = 12
chicks/pen). The chicks were fed a corn–soybean meal-based control
(CON), CON + 500 mg/kg of AGP (bacitracin methylene disalicylate
containing 450 mg active BMD/g), or CON + 150 mg/kg of proprietary blend
of PFA (Digestarom
® Poultry) until 39 days of age when
samples were collected. Birds fed either AGP or PFA had increased villus
height in all three segments of the small intestine in comparison to
the birds fed CON (
P ≤ 0.05). Furthermore, the PFA-fed birds had
significantly increased villus height and lower crypt depth compared to
AGP fed birds (
P ≤ 0.05). Birds fed either additive also had
increased total tract digestibility of dry matter, crude protein, and
ether extract (
P ≤ 0.05). The strong effect of the PFA on villus
height in the jejunum may suggest augmented nutrient absorption in
PFA-fed birds. Although both additives reduced total cecal counts of
anaerobic bacteria and
Clostridium spp., PFA alone reduced the total coliform count while increasing the
Lactobacillus spp. count (
P
≤ 0.05). These results suggest the establishment of beneficial
microbial colonies in PFA-fed birds. Overall, both PFA and AGP increased
body weight gain while lowering the feed conversion ratio (
P ≤ 0.05). Hence data from this experiment demonstrate the efficacy of PFA as a substitute to AGP in poultry diets.
Ganapathi Raj Murugesan