Research Article

Comparative Efficacy of an Organic Acid Blend and Bacitracin Methylene Disalicylate as Growth Promoters in Broiler Chickens: Effects on Performance, Gut Histology, and Small Intestinal Milieu

Table 4

Effect of feeding organic acid blend (OA) and bacitracin methylene disalicylate (BMD) at different dose levels on pH of different segments of the gastrointestinal tract, microbial counts in the digesta contents of the small intestine and length of the villi in different segments of the small intestine.

Dietary treatmentsPooled SEContrast P value
MeasurementsControl (Basal diet)OABBMDDose effectBetween treatments
1 g/kg diet2 g/kg diet0.5 g/kg diet1.0 g/kg dietOABMD

pH in different segments of the gastrointestinal tract

Microbial counts of the digesta in different segments of the small intestine (log10 CFU/g digesta)
Escherichia coli 3.783.383.
Other coliforms2.722.62.632.650.630.422NSNSNS
Lactobacillus spp.2.436.**QNS *

Height of villi (μm) in different segments of small intestine
Duodenum1513152416671197123825.74 *L**LQ***
Jejunum99610491063984128716.37 *Q***LQ *
Ileum7997528226977477.46 *LQ***LQ *

Birds were harvested on d 35,  sLignificant linear effect, sQignificant quadratic effect, *at P<.05, **at P<.01, *at $P<.001, P<.1.
Tests for Salmonella and Clostridium were negative and hence the results are not shown.