عنوان
پدید آورنده
موضوع
رده
کتابخانه
محل استقرار
TLpq2465463283
انگلیسی
The Role of Poultry Parasites in Gut Health and Production
[Thesis]
Chadwick, Elle Victoria
Beckstead, Robert
North Carolina State University
2020
123
Ph.D.
North Carolina State University
2020
Protozoal infections are becoming more prevalent in the commercial poultry industry with the removal of antibiotics and certain preventative and therapeutic drugs, leading the industry to need a better understanding of these protozoa and their effects on the gut health. Eimeria species of coccidia infect all commercial poultry and can cause coccidiosis while Histomonas meleagridis usually infects longer living poultry and progresses to blackhead disease. Both protozoa cause intestinal damage, resulting in profit losses and animal welfare concerns. In the poultry industry, progression on protozoal disease management and research is dependent on the economic influence of the bird type. The objectives of this dissertation were to identify areas of research needed in relation to protozoal management in commercial poultry production, dependent on bird-type and protozoan, as well as identify potential protozoa outbreak preventative strategies. With broilers, significant economic losses on this highly profitable bird-type has been due to coccidiosis while blackhead disease is rarely observed. Multiple coccidia vaccines are available while the industry is currently testing feed additive gut health modulators to aid the broiler if infection occurs. The use of sodium bisulfate, a natural feed additive, was tested in the diet when broilers were challenged with an increased dosage of a multi-species coccidia vaccine. The sodium bisulfate treatment resulted in infected broilers with greater body weight, improved villi structure and less gut leakage compared to the infected control treatment with sodium bisulfate having no observed effects on the parasite. The use of sodium bisulfate feed additive should be tested in the field to determine its gut health efficacy in coccidia- challenged broilers outside of a research setting. With longer-living chickens, coccidia vaccines are regularly applied during rearing while infection with H. meleagridis during egg production causes animal welfare concerns due to the inflamed cecal tissue. This inflammatory response has a secondary effect of a decrease in performance leading to economic losses. H. meleagridis vaccines are currently being examined, but it is not known when to vaccinate the birds to allow for immunity without significant production loss. The conducted broiler breeder trial indicated that H. meleagridis infection that led to blackhead disease prior to pullets reaching sexual maturity has limited effects on egg production and quality. This study infers that early introduction of H. meleagridis to a chicken laying flock does not lead to production or economic losses and the rearing period should be considered for vaccination purposes. Turkeys suffering from coccidiosis may have limited to no disease signs, but intestinal health can suffer leading to secondary infections. On the contrary, blackhead disease in turkeys causes high mortality. The sequential infections with Eimeria species then H. meleagridis exacerbate disease signs in chickens but this has yet to be studied in turkeys. The turkey case report suggests that poor poult quality and improper cocci cycling leads to increased susceptibility to blackhead disease with high mortality and production losses. Controlled, experimental studies still need to be conducted for further explanation of the protozoan interaction. Potential ailments for coccidiosis in turkeys should be examined to decrease secondary infections, like blackhead disease. The data presented herein emphasizes the significance of the health, maturity, and microbe balance of the poultry gut in relation to the entry and establishment of protozoal parasites in poultry production.
Animal sciences
Beckstead, Robert
Chadwick, Elle Victoria
مطالعه متن کتاب p
[Thesis]
276903
a
Y
