Productive, Qualitative, and Physiological Aspects of Layer Hens Fed with Propolis

ABSTRACT Laying hens reared under tropical conditions are usually under heat stress. Propolis is known for its pharmaceutical properties, such as increasing cell tolerance to hyperthermia, because of its antioxidants effects. This study aimed at evaluating the influence of different dietary propolis inclusion levels on the performance, egg quality, and bird surface temperature of layers. In this experiment 120 55-wk-old Isa Brown(r) layers were distributed according to a completely randomized experimental design into four treatments (0, 1, 2 and 3% dietary propolis inclusion levels), with three replicates of ten birds each. Performance and egg quality parameters, and birds' surface temperature were evaluated. Egg production, egg mass, feed intake, and feed conversion ratio were influenced by the treatments. Bird surface temperature was not affected by propolis dietary inclusion. The egg yolk color changed with the treatment (p<0.05) when brightness and red and yellow concentration were considered. Evaluators noted a slight difference among treatments during the sensory analysis. The use of propolis in the hens' diet did not improve performance and worsened the eggs' quality

Black bone syndrome in chiken meat

Black bone syndrome (BBS) affects poultry industry, and it is caused by the darkening of the tissue adjacent to the bone due to leak age of bone marrow contents during cooking. The objective of this experiment was to estimate BBS incidence in chicken thighs. A completely randomized experimental design, with two treatments (refrigerated or frozen) of 50 replicates each, was applied. The influence of BBS on meat quality was assessed according to bone lightness (*L), and meat appearance and sensorial characteristics. Lightness was measured using a colorimeter (Minolta® 410R) positioned on the proximal epiphyseal growth plate. Meat quality was evaluated after roasting by assigning scores for appearance (acceptable = no darkening, intermediate = little darkened, and unacceptable = severe darkening). Twelve refrigerated and 12 frozen thighs were used for sensorial analysis (adjacent muscle appearance, odor, tenderness, and flavor), assessed using a hedonic scale (1 = bad to 10 = very good) by trained panelists. Lightness was submitted to ANOVA and Tukey's test (p37.5=normal). The incidence of BBS was 35%,with a 16%increase thighs were frozen. Meat taste was not influenced by the treatments. Meat appearance, flavor, and tenderness were not affected by freezing or refrigeration, only by BBS degree. It was concluded that freezing increases the incidence of BBS and chicken thighs with bones presenting lower luminosity have worse meat quality

Influence of genetic strain and season on back scratch lesions in broilers

This study aimed at evaluating the influence of genetic strain, sex, and season on the incidence of back scratches during the rearing period. Male and female broilers of two genetic strains reared during the hot or cold season were evaluated. This meta-analysis included 894 samplings in 351 broiler houses of contracted farms located in the state of Mato Grosso do Sul, Brazil, in 2010. Broilers of all ages (1 to 43 days) were sampled, capturing 2% of the birds in the house at each sampling. Each flock was evaluated twice, in 21-day intervals. Broilers were reared as single-sex flocks; there were no straight-run flocks. Scratch lesions were classified as present or absent. Strain A broilers presented lower scratch rates (p < 0.05) than strain B birds. During the starter period (1 a 21 days), males presented higher scratch rates (p < 0.05) than females, and the incidence of these lesions was lower during the hot season compared with the cold season. It was concluded that different management practices can be adopted to minimize back scratches in broilers of different sexes and strains during hot and cold seasons, such as reducing weight control frequency and the period of chick containment in brooder circles

Equilibrium Condition during Locomotion and Gait in Broiler Chickens

ABSTRACT The experiment was carried out with the objective of evaluating a methodology to estimate the angulation and equilibrium condition, relating them to gait score and the main diseases of the locomotion system in males and females of commercial broiler strains. A completely randomized experimental design in a factorial arrangement (2x2) was applied, consisting of two sexes and two genetic strains, with five replicates of 53 chickens each. The following characteristics related to broiler locomotion were studied: gait score (GS); incidence of Valgus (VAL) and Varus (VAR) deformities and of pododermatitis (POD); body angle relative the ground (ANG); equilibrium condition (EC); body weight (BW) and breast weight (BrW); and incidence of femoral degeneration (FD), tibial dyschondroplasia (TD) and spondylolisthesis (SPO). GS, and VAL and VAR were assessed inside a broiler house. Birds were then photographed to estimate ANG and EC. Birds were sacrificed at 42 days of age and analyzed for FD, TD, and SPO. Breast percentage was not influenced by sex or strain. Males showed better ANG than females, regardless of strain. Overall, the strains studied showed prostrated EC. The correlation between GS and the evaluated traits was low. There was a moderate to high association between EC and ANG both in males and females. GS showed low correlation with locomotion problems, and therefore, it is a poor indicator of skeletal diseases. On the other hand, the moderate to high correlations of ANG and EC with locomotion problems make them better indicators of bone diseases than gait score, which is possibly more related to EC and body posture than to bone pathologies