Urea in poultry nutrition - Review -

Growth promotion and antibiotic induced metabolic shifts in the chicken gut microbiome

Antimicrobial growth promoters (AGP) have played a decisive role in animal agriculture for over half a century. Despite mounting concerns about antimicrobial resistance and demand for antibiotic alternatives, a thorough understanding of how these compounds drive performance is missing. Here we investigate the functional footprint of microbial communities in the cecum of chickens fed four distinct AGP. We find relatively few taxa, metabolic or antimicrobial resistance genes similarly altered across treatments, with those changes often driven by the abundances of core microbiome members. Constraints-based modeling of 25 core bacterial genera associated increased performance with fewer metabolite demands for microbial growth, pointing to altered nitrogen utilization as a potential mechanism of narasin, the AGP with the largest performance increase in our study. Untargeted metabolomics of narasin treated birds aligned with model predictions, suggesting that the core cecum microbiome might be targeted for enhanced performance via its contribution to host-microbiota metabolic crosstalk.

This study compares the functional profiles of the cecal microbiome among chickens fed four different antimicrobial growth promoters. Chickens receiving narasin exhibited the largest performance increase via apparent nitrogen recycling by the core cecal microbiome.

Intestinal microbial ecology and hematological parameters of broiler fed cassava waste pulp fermented with Acremonium charticola

Aim:

The aim of this study was to evaluate the effect of feeding Acremonium charticola-fermented cassava pulp (AC-FCP) on the intestinal microbial ecology and hematological indices of broiler chickens.

Materials and Methods:

A total of 240 male Lohman day-old-chicks were randomly allotted to one of the four experimental diets including control diet, control diet + antimicrobials (neomycin; 300 mg/kg diet), diet containing AC-FCP (16 g/100 g diet) or diet containing AC-FCP + antimicrobials. At day 28, the birds from each pen were blood sampled, sacrificed and immediately the internal organs were removed and weighed. Digesta were obtained from the ileum and cecum.

Results:

Birds fed AC-FCP had lower (p<0.05) coliform bacteria count in the ileal digesta than birds fed control diet or control diet + antimicrobials. Butiric acid was higher (p<0.05) in the cecal content of birds fed AC-FCP than in other birds. Propionic acid was also higher in AC-FCP fed birds than in other birds although statistically not significant. The percentages of lymphocytes and heterophils were higher (p<0.05) and tended (p=0.07) to be lower, respectively, in broilers fed control diet than in other birds. The birds provided control diet had lower (p<0.05) heterophils to lymphocytes ratio compared to those receiving AC-FCP or AC-FCP + antimicrobials. Serum total protein and globulin were higher (p<0.01) in birds fed control diet or control diet + antimicrobials compared to AC-FCP or AC-FCP + antimicrobials fed birds. Serum albumin was lower (p<0.01) in AC-FCP birds than that in other birds. There was a tendency (p=0.09) that birds fed AC-FCP diet had lower total serum cholesterol than other birds.

Conclusion:

Feeding AC-FCP has potential to improve the intestinal health and protect the birds from acute infections.