Effects of a Lactobacillus salivarius mixture on performance, intestinal health and serum lipids of broiler chickens

Abstract

The ban or severe restriction on the use of antibiotics in poultry feeds to promote growth has led to considerable interest to find alternative approaches. Probiotics have been considered as such alternatives. In the present study, the effects of a Lactobacillus mixture composed from three previously isolated Lactobacillus salivarius strains (CI1, CI2 and CI3) from chicken intestines on performance, intestinal health status and serum lipids of broiler chickens has been evaluated. Supplementation of the mixture at a concentration of 0.5 or 1 g kg-1 of diet to broilers for 42 days improved body weight, body weight gain and FCR, reduced total cholesterol, LDL-cholesterol and triglycerides, increased populations of beneficial bacteria such as lactobacilli and bifidobacteria, decreased harmful bacteria such as E. coli and total aerobes, reduced harmful cecal bacterial enzymes such as β-glucosidase and β-glucuronidase, and improved intestinal histomorphology of broilers. Because of its remarkable efficacy on broiler chickens, the L. salivarius mixture could be considered as a good potential probiotic for chickens, and its benefits should be further evaluated on a commercial scale.

Fig 1. Effects of dietary supplementations of a mixture of three L. salivarius strains (LC) on populations of cecal lactobacilli, bifidobacteria, total aerobes and E. coli of broiler chickens at 21 and 42 d of age enumerated using the conventional spread plate method and expressed as log₁₀ CFU g^-1.

Columns represent means of six birds in each treatment group (one chicken per replicate cage) ± SD. Within each period, columns with different letters differ significantly (P < 0.05). Control, basal diet; 0.05% LC, basal diet + 0.5 g kg^-1 LC; 0.1% LC, basal diet + 1 g kg^-1 LC.

Fig 2. Effects of dietary supplementations of a mixture of L. salivarius strains (LC) on populations of cecal lactobacilli, bifidobacteria and E. coli of broiler chickens at 21 and 42 d of age quantified using real-time PCR and expressed as log₁₀ copy number g^-1.

Columns represent means of six birds in each treatment group (one chicken per replicate cage) ± SD. Within each period, columns with different letters differ significantly (P < 0.05). Control, basal diet; 0.05% LC, basal diet + 0.5 g kg^-1 LC; 0.1% LC, basal diet + 1 g kg^-1 LC.

Fig 3. A representative photomicrograph showing intestinal villi and crypts of a broiler (fed diet supplemented with 1 g kg^-1 of a mixture of L. salivarius CI1, CI2 and CI3) at 42 d of age.

Villus height was measured from the top of the villus to the villus-crypt junction (long bar). Crypt depth was measured as the distance between the basement membrane and the mouth of crypt (short bar).