Buffered formic acid and a monoglyceride blend coordinately alleviate subclinical necrotic enteritis impact in broiler chickens

Abstract

<p>The objective of this study was to evaluate the effect of 2 different doses of a partially buffered formic acid product (Amasil NA; 61% formic acid, 20.5% sodium formate), and a monoglyceride blend of short- and medium-chain fatty acids (BalanGut LS P) on necrotic enteritis (<b>NE</b>) infected broilers in terms of performance, intestinal microbial population and shortchain fatty acids concentrations in the gastrointestinal tract. A total of 528-day-old as hatched Ross 308 broilers were allocated to 48 pens with 11 birds in each pen. Six dietary treatments applied in the study were: T1) nonsupplemented diet (Control); T2) antibiotic supplemented diets; T3) and T4) high (Starter: 0.5%; Grower and Finisher: 0.5%) and low (Starter: 0.3%; Grower and Finisher: 0.2%) dose of Amasil NA; and groups T5) and T6) high (Starter: 0.3%; Grower and Finisher: 0.2%) and low dose (Starter: 0.3%; Grower: 0.15%; Finisher: 0.075%) of (BalanGut LS P). All birds in this study were fed starter (d 0-10), grower (d 11−24) and finisher (d 25−35) diets and challenged with NE. To induce subclinical NE, oral administrations of <i>Eimeria</i> oocysts (d 9) followed by inoculation of <i>Clostridium perfringens</i> strains (d 14 and 15) were applied. Results showed that birds fed the high dose of Amasil NA, had a higher feed conversion ratio (<b>FCR</b>, <i>P</i> < 0.05) compared to the nonsupplemented group during the starter period. Antibiotic supplementation reduced FCR during the grower (<i>P</i> < 0.001), finisher (<i>P</i> < 0.05) and overall (<i>P</i> < 0.001) periods of the experiment. Both levels of BalanGut LS P and low levels of Amasil NA enhanced overall FCR (<i>P</i> < 0.05) compared to the birds in the nonsupplemented group. Compared to the nonsupplemented group, high levels of Amasil NA and low levels of BalanGut LS P improved FCR in the finisher stage (<i>P</i> < 0.05). On d 16, cecum digesta of birds fed with antibiotic supplemented diets showed a significantly lower number of <i>C. perfringens</i> (<i>P</i> < 0.001) compared to the nonsupplemented and high level of BalanGut LS P group. <i>Bacillus</i> (<i>P</i> < 0.01) and <i>Ruminococcus</i> numbers were significantly lower in the birds fed with high level of Amasil NA (<i>P</i> < 0.05) compared to the antibiotic supplemented diets. High doses of Amasil NA, showed the highest propionate concentration in the cecum (<i>P</i> < 0.001). The study suggests that supplementation of BalanGut LS P and Amasil NA at different feeding phases may achieve optimal performance improvement in broilers under NE challenge.</p>