ABSTRACT Locomotion problems in broiler chickens can cause economic losses of up to 40% of the total revenues due to carcass condemnation and downgrading at processing. Leg disorders, such as femoral lesions, tibial dyschondroplasia, and spondylolisthesis, substantially impact the welfare of chickens as these disorders can prevent birds from reaching the feeders and drinkers, thus reducing feed and water intake. The most important issues related to broiler welfare reported in the last two decades are their growing sensitivity to metabolic and locomotion problems due to the fast growth rates and inactivity. Traditional methods for the determination of gait score include the manual scoring of animal behavior in the broiler house. Recorded video images can also be used for manual scoring of chicken gait score. However, scoring of some animal-based information by human experts and manual methods remain difficult, time consuming and expensive when implemented at farm level. In an effort to objectively detect leg disorders, this study aimed at validating the photogrammetry technique as a non-invasive method for identifying locomotion problems in broilers. Photogrammetry allows determining the geometric properties of broilers from digital photos that are processed and analyzed using a computer software. Results obtained using photogrammetry were tested for their correlation with those obtained by accepted methodologies, including gait score and macroscopic examination of femoral degeneration and tibial dyschondroplasia. The photogrammetry results agreed with the results of the afore mentioned accepted methods.

Abstract This study evaluated the performance, carcass yield and quality, and physiological stress indicators of broilers of three genetic strains reared at three housing densities for 29 days. A total of 828 day-old male chicks, with average initial weight of 40.0± 2.0g were used. Three genetic strains (Cobb 500, Ross 808, and Ross 508, with 276 birds each) and three housing densities (17, 19, and 21 broilers/m²) were tested. A completely randomized experimental design in a 3 x 3 factorial arrangement, with four replicates of 23 birds each, was applied. The following responses were evaluated: performance parameters (average weekly body weight, average daily gain, feed intake, feed conversion ratio), physiological stress indicators (blood glucose levels, blood cell counts), and carcass yield and quality (dermatosis, bruising, dermatitis, and femoral degeneration scores). Average weekly body weight (BW) and daily weight gain (DWG) were not influenced by rearing density (p≥0.05), but Cobb 500 broilers were the heaviest during the analyzed period. In the second week, Ross 508 birds showed better feed conversion ratio (FCR) when housed at the density of 17 broilers/m² (p≤0.001), whereas the best FCR of Ross 808 and Cobb 500 broilers was obtained at 21 broilers/m² (p≤0.001). Carcass yield was not influenced by the treatments (p≥0.05). Physiological stress indicators were not affected by the treatments, and remained within normal ranges (p≥0.05). Dermatosis scores (scratches) increased (p≤0.05) when housing density increased from 17 to 19 broilers /m².

ABSTRACT Rearing environmental conditions are important for turkey production, because this bird is particularly sensitive to heat stress. This study aimed at measuring the wattle temperature response of turkeys of three different ages (61, 96, and 131 days old) exposed to different combinations of dry bulb temperature, relative humidity, and wind speed ranges, as an indication of their physiological responses. The experiment was conducted with 42 male birds housed in a controlled environment chamber and exposed to different combinations of two air speed (WS) ranges (WS1 = 0.3-0.6 ms-1, considered low, and WS2 = 1.2-1.6 ms-1, considered high), dry bulb temperature (DBT) between 22 and 34 °C, and relative humidity (RH) between 40 to 90 %. The statistical analysis showed that WS, DBT, and RH significantly influenced wattle temperature of 61-d-old turkeys, while only WS and DBT influenced this response when turkeys were 96 days old. Furthermore, DBT was highly correlated with both low and high WS. In 131-day-old turkeys, WT response was virtually the same at both wind speed ranges when high DBT was applied. Turkey wattle temperature was influenced by wind speed, and was dependent on both environmental dry bulb temperature and relative humidity, as well as bird age.