FATORES QUE INFLUENCIAM A INCIDÊNCIA DE MIOPATIAS PEITORAIS EM FRANGOS DE CORTE

Abstract

This study aimed to evaluate the importance of productive, environmental, and myopathy-related variables in the overall variability of broiler production systems, as well as to analyze the relationships between these sets of variables and the effects of the month of the year, sex, genetic lineage, and rearing system on the occurrence of muscle myopathies, specifically Deep Pectoral Myopathy (DPM) and emerging myopathies, Wooden Breast (WB) and Spaghetti Meat (SM). The research was conducted at a federally inspected slaughterhouse located in the Southwest region of Goiás, between September and December 2024, totaling the analysis of 6,182 loads, corresponding to approximately 27.8 million birds with an average weight between 2.5 and 3.84 kg, an average age of 36 to 42 days, and up to 12 birds per cage. The variables studied included gender, lineage, density (kg/m²), rearing system, distance from the farm to the slaughterhouse, and weather conditions. The data were subjected to Principal Component Analysis (PCA) and Tukey's test. The results indicated that the variability of the broiler production system was predominantly explained by environmental variables, followed by factors associated with the incidence of muscle myopathies and, to a lesser extent, by productive and operational characteristics. The principal component analysis showed that the first components concentrated most of the total variance, highlighting the influence of climatic variables such as temperature, humidity, wind, and precipitation, in addition to MPP, WB, and SM myopathies. Complementarily, Tukey's test revealed significant differences in losses due to myopathies as a function of the month of the year, genetic lineage, and rearing system, with higher values observed in December, in the ROSS (A) lineage and in the Dark House system, while sex exerted a secondary influence. These results demonstrate the combined action of environmental, productive, and management factors in the occurrence of muscle myopathies in broilers.