ABSTRACT Brazil is one of the world’s largest broiler meat exporters. Broiler meat is one of the most consumed meats worldwide. The most significant challenge for strategic business management when optimizing the financial returnis knowing exactly where to invest. The same happens in the broiler production chain. The present research aimed to investigate which were the most central actors in the broiler supply chain and the dynamics of the chain. The current study was done based on the poultry chain business relations, from 2000 to 2015, of the leading actors of the Brazilian broiler production chain. The centrality indicator was established through social network analysis (SNA) approach, to determine their positions in the chain as a whole. The most used indicators within network analysis are those designed to identify the extent to which one actor occupies a more central position than another. The Gephi® software was applied to calculate the structural attributes and indicators of the network. Results were estimated using the RapidMiner® software. A model was presented that shows one infrastructure indicator as an explanatory variable. The findings indicate that the centrality indicator was weakly influenced when compared to the other variables, such as market demand, wide variations on the scenario, and mergers or acquisitions.

Brazilian poultry production is prospering, and negative-pressure broiler houses are increasingly used to improve environmental control. One important issue is the color of the side curtains used in such houses due to the influence of colors on broiler behavior. This study aimed at evaluating the influence of different curtain color on the welfare of 7-day-old broilers, considering luminosity and other environmental parameters. Chicks were housed in three different negative-pressure broiler houses either with black (T1), blue (T2), or yellow (T3) side curtains. House environment (luminosity, dry-bulb temperature, air relative humidity, air velocity, and gas emissions) and the behavior of chicks on day 7 after housing were evaluated in three consecutive flocks in the morning and in the afternoon. Data were submitted to multivariate analysis, Kruskal-Wallis' test, and Pearson's correlation test. Luminosity and ITU were influenced by curtain color, and some of the evaluated behaviors were associated with luminosity or other environmental parameter.

In tropical poultry-producing countries, poultry houses usually have little environmental control. This study investigated the effect of dietary vitamin D on the incidence of leg abnormalities of a fast-growing broiler strain reared under harsh conditions. In this study, 300 one-day-old male broilers were distributed in two treatments with three replicates of 50 birds each. One group was fed a placebo and the other group was fed 25-hydroxycholecalciferol (25-OH-D3) in a soluble form. The environmental variables were weekly recorded during until birds were 49 days old. Birds were weekly gait scored, and their walking speed and vertical force while walking were assessed. Post-mortem examination was performed and skeletal lesions were assessed. Control birds presented more leg problems than those that ingested 25-OH-D3. These results suggest that dietary vitamin D is effective in decreasing the severity of lameness by reducing tibial dyschondroplasia and other leg abnormalities.

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.

There are many situations that involve health risks to the Brazilian rural worker, and animal production is just one of them. Inhalation of organic dust, which has many microorganisms, leads in general to respiratory allergic reactions in some individuals, "asthma-like syndrome", and mucous membrane inflammation syndrome, that is a complex of nasal, eye, and throat complaints. Furthermore, workers might have farmer's hypersensitivity pneumonia, that is a respiratory health risk along the years. The objective of this study was to evaluate the potential pulmonary health risks in poultry production workers in the region of Curitiba, PR, Brazil. Interviews using a pre-elaborated questionnaire with 40 questions were made with 37 broiler production workers, which were submitted to a pulmonary function test. Results of restrictive function with lower FEV1 (the maximum respiratory potential, the forced expiratory volume in the first second of exhalation) and FVC (forced vital capacity) represented 24.32% of the total of workers, and severe obstruction represented 2.70%. Other symptoms were found in 67.57% of the workers as well. The results showed that those who work more than 4 years and within more than one poultry house, exceeding 5 hours per day of work, presented higher pulmonary health risks. It is concluded that the activities within broiler houses may induce allergic respiratory reaction in workers. The use of IPE (individual protection equipment) besides special attention to the air quality inside the housing may be advised in a preventive way.