The effect of dietary protein level on performance characteristics of coccidiosis vaccinated and nonvaccinated broilers following mixed-species Eimeria challenge

Abstract

A series of experiments were conducted to investigate the effect of starter diet protein levels on the performance of broilers vaccinated with a commercially available live oocyst coccidiosis vaccine before subsequent challenge with a mixed-species Eimeria challenge. Data indicated that an increasing protein concentration in the starter diet improved broiler performance during coccidiosis vaccination. Prechallenge performance data indicated that vaccination could decrease BW and increase feed conversion ratio. The time period most important for the observed effects appeared to be between 13 and 17 d of age. This reduction in performance parameters of vaccinated broilers compared with nonvaccinated broilers was eliminated by the conclusion of the experiments (27 d) in the diet groups with higher protein. Vaccination was effective at generating protective immunity against Eimeria challenge, as evidenced by increased (P < 0.05) BW gain, improved feed conversion, reduced postchallenge mortality, and reduced lesion development in vaccinated broilers compared with nonvaccinated broilers. These observations support numerous other reports that confirm live oocyst vaccination can be used effectively as a preventive against avian coccidiosis in commercially reared broilers. More important, these findings suggest that reduced protein concentration of starter diets can lead to significant losses in broiler performance when using a vaccination program to prevent coccidiosis.

The influence of indigestible protein on broiler digestive tract morphology and caecal protein fermentation metabolites

“…The mortality results were opposite to current literature theories related to IDP effects on health. However, changes in the digestive tract morphology due to vaccination (Lee et al, ) or the production of some protein fermentation metabolites (Barnes et al, ; Igarashi et al, ) could have promoted higher systemic infection when the birds were fed the LIP diet. The battery cage experiment provided an environment free of coccidiosis infection and was used to confirm the digestibility of the diets, while in the floor experiment days 14 and 28 collections represented periods of active response and recovery to coccidiosis vaccination respectively.…”

Longitudinal Characterization of Coccidiosis Control Methods on Live Performance and Nutrient Utilization in Broilers

“…However, mild infections that occur during the process of vaccinal oocyst cycling, which involves the initial infection, oocyst shedding and sporulation, and reinfection, may compromise broiler growth through reduced feed intake or feed efficiency, and the relatively short lifespan of broilers may be insufficient for compensatory gain (4,5). Impaired feed efficiency during vaccine cycling is presumably due in part to nutrient malabsorption associated with intestinal damage and inflammation associated with the sub-clinical, vaccine-induced infection (5)(6)(7).…”

Gastric digestion of protein through pancreozyme action optimizes intestinal forms for absorption, mucin formation and villus integrity

“…The nature of such correction is prone to error by variation in amounts of mucosal sloughing as well as failed autolysis of digestive enzymes. Furthermore, these endogenous losses also vary with intestinal location used for collection, nature of the N-free feed, age of bird, and lumen microbial load (Butts et al, 1991;Adedokun et al, 2007a,b;Kamisoyama et al, 2010;Lee et al, 2011). Amino acids most consistently observed with endogenous loss indicate that mucin was a dominant contributor.…”