Footpad lesions in broilers in the final stage of breeding: influence of the thermal environment and bed

The quality, characteristics of broiler litter and incidence of foot lesions in broilers can be influenced and directly related to the thermal environment provided to birds, which is represented by air temperature and humidity. There are few researches that seek to define the interactions and effects of the environment on the physical and chemical characteristics of broiler litter and the incidence of lesions in foot pad of the birds. Thus, the objective of this study was to verify the influence of litter quality and thermal environment on the incidence of foot pads lesions of broilers. The experiment was carried out in five climatic chambers, of the Federal University of Vigosa, in Vigosa, Minas Gerais, Brazil. Five treatments were tested, including comfort recommended by Cassuce (CTC) (2013), stress by moderate heat (ECL), moderate heat (ECM), strong heat (ECA) and severe heat (ECS), with temperatures equal to 25, 28, 31, 34 and 37 degrees C, respectively. It were used 105 broilers in the final stage of growth, with density of 14 birds.m-2 housed in cages in the climatic chambers. To assess the litter quality, analyses of moisture and total nitrogen Kjedahl analyzes were carried out weekly, in samples form three cages per chamber. The evaluation of the quality of the foot pad was made with basis on scores associated to the different types of lesions observed in five birds per treatment. The scores were classified as: 0 = no lesion; 1 = no external injury; 2 = external injury. It was possible to conclude that litter quality had influence on the incidence of birds foot pad lesions, being a higher number of lesions observed in the treatments that presented high moisture concentration. The total Kjedahl nitrogen and the environment did not present significant influences in the incidence of lesions in the foot pads of birds.