Banca de DEFESA: IARA CRISTINA MARINS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : IARA CRISTINA MARINS
DATE: 26/07/2021
TIME: 13:30
LOCAL: Webconferência via Google Meet - meet.google.com/afk-ovux-cox
TITLE:

Influence of chicken density on the effective temperature of griller broiler on carcass condemnation.

KEY WORDS:

Ambience, broiler, dermatosis, thermography.

PAGES: 45
BIG AREA: Ciências Agrárias
AREA: Medicina Veterinária
SUMMARY:

Losses in slaughterhouses by condemned birds represent a high loss for agribusiness and the search for solutions to reduce these losses is a necessity of the agricultural sector. Therefore, the aim of this study was to evaluate different housing densities in Griller broiler lots on the performance results, the temperature on the back of the chicken and the percentage of carcasses condemnations for dermatosis. Evaluations were carried out in four houses with a Dark House rearing system, with two housing densities, 17 and 19 chicken per square meter, two houses for each density, evaluated by three consecutive batches, totaling two treatments (housing density) with six replications (houses x lots), and all lots were subjected to the same ambient conditions. Lots composed of only females of the Cobb or Ross lineage were housed, and the lots were accompanied by housing to slaughter, with emphasis on 7, 14, 21, 23 and 25 days of age. Through thermal imaging, the effective temperature was evaluated, measured on the back of the chickens. Temperature readings were taken at three points within the houses, each point corresponding to a box, with measurements taken from three randomly chosen chickens at each point. The thermal image capture was performed four times a day at the ages mentioned above, at 04:00, 08:00, 14:00 and 20:00 hours. Daily weight gain, feed conversion, mortality, and percentage of dermatosis and arthritis were also evaluated as well as carcass condemnation after slaughter under the criteria of the Federal Inspection Service. The data were tested for normality of distribution and homogeneity of the residues using the Shapiro Wilk and Levene tests and submitted to Person correlation analysis (PROC CORR) and analyzed using the MIXED procedure. There was interaction between age and time on the back temperature of griller broilers (P<0.05). The chicken had higher temperatures on the back at 7 days, regardless of the time evaluated. At ages 21 and 23 days they had higher back temperature when compared to other ages from the first week, in the afternoon at 14:00 and 20:00 hours. In all stages of rearing the chickens had higher temperatures at 14:00 and 20:00 hours compared to the times of 4:00 and 8:00 hours, so the chickens had greater difficulty in losing heat in the 21 to 23 days, in afternoon and evening. There was a high correlation between partial carcass condemnation and dermatosis (r=0.8469). There was an effect of housing density on the back temperature (P<0.05). The average temperature of the back was higher with 17 chicks per square meter. There was no effect of housing density on performance, dermatosis, arthritis and partial carcass condemnation (P>0.05). Therefore, the higher housing density of griller broilers did not increase the effective temperature, and did not influence performance, dermatosis, arthritis and partial carcass condemnations. Special attention is needed to ages 21 and 23 and times 14:00 and 20:00 where higher values of back temperature occurred and there may be an opportunity for gain.

BANKING MEMBERS:
Presidente - 1085177 - VANESSA PERIPOLLI
Externo ao Programa - 1849719 - JUAHIL MARTINS DE OLIVEIRA JUNIOR
Externo à Instituição - MARCEL MANENTE BOIAGO - EDESC