Salmonella Enteritidis infection, corticosterone levels, performance and egg quality in laying hens submitted to different methods of molting.

In commercial layer poultry farming, molt induction is an important tool used by egg producers to prolong the production cycle of laying hens. Conventional molt induction programs involve total feed withdrawal, which raises questions about animal welfare and increased infection susceptibility. The high incidence of paratyphoid salmonellosis infections in commercial poultry farming is still an important health challenge because in addition to affecting the birds, such infections also cause public health problems. In this context, experiments were performed with laying hens at 79 wk of age to compare the conventional forced molting method (fasting) with an alternative method (free wheat bran supply) and determine their effect on the persistence of vaccine antibodies against Newcastle disease, the control and reduction of experimentally inoculated Salmonella Enteritidis, and the performance and egg quality of hens. A reduction (P < 0.05) of Salmonella Enteritidis in the crop and lower production of corticosterone were observed in the birds that received wheat bran compared with those subjected to total fasting. Moreover, a better performance (P < 0.05) with regard to egg production, egg mass, and feed conversion/kg and dozen eggs was observed in the hens that received the alternative treatment compared to the conventional forced molting method. Thus, the use of wheat bran for forced molting was found to be feasible and met the welfare needs of the hens.

Evaluation of the Relationship Between the Breeders Age, Breed and the Incubator Types on Quality and Animal Welfare in the Hatchery

About 33.3% of chicken life is conditioned by the result of embryonic development. Therefore, understanding and improving the early phase of the broilers life is critical to guarantee their well-being. Thus, the objective of this research was to evaluate the relationship between the breeders age, breed and the incubator types on quality and animal welfare in the hatchery. The experimental design was completely randomized in a 2 x 2 x 3 factorial arrangement (incubator, breed and age), with 12 treatments and 6 replicates each. The eggs derived of Cobb 500 and Rosss breeders at the beginning of the laying period, middle age and at the end of the laying period. It is concluded that the size of the eggs is related to the breeders age and breed, which influences directly the number of bled eggs. In addition, well-being in the hatchery can be affected by decreased hatching and contamination that is higher in older breeders. Cobb eggs also need more attention because they are larger, therefore, they have a higher risk of breakage and they are more sensitive to the low concentration of CO2 at the hatcher.(AU)

Evaluation of the Relationship Between the Breeders Age, Breed and the Incubator Types on Quality and Animal Welfare in the Hatchery

About 33.3% of chicken life is conditioned by the result of embryonic development. Therefore, understanding and improving the early phase of the broilers life is critical to guarantee their well-being. Thus, the objective of this research was to evaluate the relationship between the breeders age, breed and the incubator types on quality and animal welfare in the hatchery. The experimental design was completely randomized in a 2 x 2 x 3 factorial arrangement (incubator, breed and age), with 12 treatments and 6 replicates each. The eggs derived of Cobb 500 and Rosss breeders at the beginning of the laying period, middle age and at the end of the laying period. It is concluded that the size of the eggs is related to the breeders age and breed, which influences directly the number of bled eggs. In addition, well-being in the hatchery can be affected by decreased hatching and contamination that is higher in older breeders. Cobb eggs also need more attention because they are larger, therefore, they have a higher risk of breakage and they are more sensitive to the low concentration of CO2 at the hatcher.

Evaluation of incubation yield, vaccine response, and performance of broilers submitted to in-ovo vaccination at different embryonic ages

The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p < 0.05) when eggs were vaccinated before 18 days of incubation. Greater Marek's disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.(AU)

Evaluation of incubation yield, vaccine response, and performance of broilers submitted to in-ovo vaccination at different embryonic ages

The aim of this study was to evaluate the effects of in-ovo vaccination on different incubation days of broiler embryos derived from young and old breeders on incubation indexes, vaccine response, and broiler performance. A number of 20,160 fertile eggs was distributed according to a completely randomized design in a 4 x 2 factorial arrangement (in-ovo vaccination on 16, 17, 18, or 19 days of incubation, and breeders of 31 or 52 weeks of age), totaling eight treatments with 15 replicates of 168 eggs each. Vaccination procedures and vaccines (strains and doses) were those routinely applied in commercial hatcheries. After hatch, 960 male chicks were housed and distributed according to the same experimental design previously applied in the hatchery. There were hatching losses (p < 0.05) when eggs were vaccinated before 18 days of incubation. Greater Marek's disease antibody titers were obtained when the in-ovo vaccination was performed on day 19 of incubation, regardless breeder age. Embryonic age at vaccination did not compromise broiler performance in the field, and the flexibility of embryonic age for in-ovo vaccination can reduces incubation costs.