The aim of the study is to present a review about the "Wooden Breast Syndrome" (WBS) syndrome, which is a muscle disorder that has become increasingly important in recent years, and the etiology of the abnormalities caused by this myopathy, and its histological, macroscopic, and microscopic features. Besides, the effects on the visual, sensory, functional, mechanical quality and processing properties of the breast meat of broilers and their negative effects on the poultry industry were also discussed. Since this myopathy gives a hard structure to the pectolaris major muscle, it is called "Wooden Breast" in public. It is assumed that the leading direct and indirect causes of WB syndrome in broilers are pectoral muscle hypertrophy (volume increase in muscle cells), rapid growth rate, and high breast meat yield. Also, age, gender, diet, feed restriction, oxidative stress, genetics, etc. factors are also thought to be effective. However, the etiology of WB syndrome is still unclear in many aspects. As a result of the macroscopic examination of the wooden breast meat, a striking stiffness, swelling, viscous exudate (inflammatory fluid), petechial (purple-red bleeding spots) fluid, and a pale appearance in the pectoral major muscles are observed, and the lesions that occur can be detected by palpation. Due to these visual and sensory defects in breast meat, the consumability of meat decreases and this leads to significant economic losses for the poultry industry.

The present study is designed to attract attention to macroscobic and microscobic findings, causes and economic losses of wooden breast which is a significant muscle problem leading to visual and sensory differences in poultry breast meat quality. Wooden Breast is a crucial problem in poultry industry. It has started to seriously affect poultry production in European and other countries, and especially in United States of America. Woody breast formation is a situation characterized with completely hardened breast fillet or with swelling easily understood when touched. Surface of the fillet contains exudate with petechial bleeding or non-bleeding viscous gelatine. Woody structure called “wooden” can occur not only in breast meat but also in legs. Growth rate, gender, energy level of the feed, amino acid level, and selenium supplement are the factors affecting wooden breast-woody breast meat formation. Shaded colour, surface leak and abnormally hard tissue are seen in macroscopic image of woody breast. In microscopic findings, muscle fibers are less and round. Lesions don’t contain pathogenic micro-organisms, they are aseptic. Colour of the meat of woody breast is brighter and whiter, and (L* value) This muscle problem affects muscles visually and sensorial; but it doesn’t have a negative effect on human health. The more white lines and woody structure in breast meat, the less they are accepted among European consumers.