Ozlem Cangar

Quantification of the Spatial Distribution of Surface Temperatures of Broilers

Thermal comfort is of great importance in chickens to preserve body temperature homeostasis during the growth period and during environmental thermal challenges. Because surface temperatures contribute much to thermal comfort, this research is aimed at studying spatial distribution of surface temperatures of broiler chickens. For this purpose, temperatures of 26 different parts on the chicken body surface were measured using thermography during the growth period of 6 wk. It was observed that there were significant differences in spatial distribution of broiler surface temperatures. The greatest temperatures were measured at the positions with little or no feathering (i.e., cheek, skull, and inner thigh). The least temperatures were observed on the places with thickest feather cover (i.e., wing and breast). The surface temperatures decreased as a function of age from approximately 36 to 28 degrees C. The spatial temperature range on the surface of the bird varied from 6 degrees C in wk 1 to 15 degrees C on wk 6. Temperature differences between the surface of the chicken and its surroundings were also studied, and it was found that in the range of 1 to 6 wk the age of the bird had significant effects on temperature difference (P < 0.0001). The temperature difference between the surface of the chicken and environment was at a maximum on wk 4 during the growth period of 6 wk.

A Relational Study of Gait Score (As a Measure for Lameness) With Breast Muscle Yield in Broiler Chickens

A fast genetic change, developments in the feed and the management of the broiler chicken during the last 50 years led to an improved efficiency of broiler meat production. However due to the fast growth rates and inactivity of the chickens there is also a growing rate in occurrence in metabolic and locomotion problems One of the reasons of locomotion or gait problems may be due to the fact that the skeleton structure cannot support the 3 dimensional distribution of body weight of the animal, especially the genetically increased mass of the breast muscle. Therefore this study focuses on the relation of gait score as a measure of lameness with breast muscle weight of individual chickens. For these reason 124 39 days old broiler chickens were slaughtered and their breast muscle were dissected and weighed. The chickens prior to slaughtering were also manually scored by experts for their gait scores. They were also weighed and sexed. Afterwards a statistical relation is sought between the percentages of breast muscle weight (or breast muscle yield) and the gait scores of the animals. It was observed that sex and gait score had a significant effect on the absolute breast muscle weight (p < 0.001 in both cases). On the other hand no evidence was found on the effects of sex and gait score on the breast muscle yield (p = 0.77 and p = 0.42).

Spatial distribution of surface temperatures and heat loss in broilers chickens.

For effective climate control, more efficient energy use, and better design of broiler houses, it is crucial to study the animal’s surface temperatures to understand heat transfer from the bird to the environment. Therefore, in this research, spatial distributions of surface temperatures of broiler chickens were studied through the bird growth period of 6 weeks. Temperatures of 26 different parts on the body surface were measured by using thermography. It was observed that there were significant differences in spatial distribution of broiler surface temperatures. The highest temperatures (39-41°C) were measured at the positions with little or no feathering (e.g.: cheek, skull and inner thigh). The lowest temperatures (26-37°C), on the other hand, were observed on the places with thickest feather cover (e.g.: wing and breast). The surface temperatures increased in function of age and varied 3-4 °C during week 1 to 7-13 °C until week 6. Temperature differences between the surface of the chicken and its surroundings were also studied as a driving force in convective heat loss of the animal. It was found with an age from 1 to 6 weeks the age and the body parts had significant effects on the heat flux (p<0.0001). Heat loss from the surface of the chicken to the environment increased up to 4th week showing a maximum on the 4th week, and then decreased during the remainder of the growth period.