Wooden breast – a novel myopathy recognized in broiler chickens

Abstract

Abnormally hard breast fillet consistency began to emerge in commercial broiler chickens around 2010. Due to the remarkable muscle hardness, the condition acquired the vernacular name ‘wooden breast myopathy’. This myopathy starts to develop after two weeks of age at the earliest and typically proceeds into chronic myodegeneration in three to four weeks of age. The lesion begins focally and typically develops into a diffuse lesion that involves the entire major pectoral muscle. The restricted location of wooden breast lesion in the m. pectoralis major distinguishes it from several other myodegenerative diseases that widely affect the skeletal muscle system and often the cardiac and smooth muscle systems too. Although industry-wide incidence rates are difficult to assess, it has been estimated that approximately 5-10% of commercially produced breast fillets exhibit severe WB. Even at low incidence rates, the costs to industry are substantial, as breast fillets with the wooden breast condition are often downgraded and sold at a discount, used for further processing, or in extreme cases, discarded. Because the etiology of wooden breast is still unclear, in the future, study of the early lesions, pathogenesis and the possible reduction of animal welfare are likely to gain more attention.

Broiler genetics influences proteome profiles of normal and woody breast muscle

“…Woody breast ( WB ) starts developing in broilers at as early as 2 wk of age. A chronic myodegradation may appear at 3 to 4 wk of age ( Baltic et al., 2019 ). According to Sihvo et al.…”

“…Various factors affect the development of WB, including the broiler's genotype, gender, egg incubation condition, diet, and feeding allocation ( Tijare et al., 2016 ; Bowker and Zhuang, 2017 ; Meloche et al., 2018 ; Zhang et al., 2020a ; Oviedo-Rondón et al., 2020 ). One factor that has been consistently associated with the incidence of WB is heavier body weight and thicker fillets ( Trocino et al., 2015 ; Baltic et al., 2019 ).…”

“…(2016) suggested that the proportion and mobility of the extra-myofibrillar water fraction within the muscle increases in the WB condition, which decreases the ability of the muscle to retain water. Even though this quality issue does not impose a food safety risk, its unappealing appearance and impaired nutritional quality (higher in fat and collagen, poor water-holding capacity and texture) have a negative economic impact on poultry companies ( Soglia et al., 2016 ; Bowker and Zhuang, 2017 ; Baltic et al., 2019 ) because WB is downgraded or even discarded in more severe cases.…”

Wooden breast and white striping: comparative occurrence in three poultry companies

“…However, lesions in poultry meat have led to economic losses within the industry, especially due to WS and WB (Huang & Ahn 2018, Zanetti et al 2018. Once WS and WB impair the appearance and functional quality of breast meat (Huang & Ahn 2018), affected breast fillets are often downgraded and sold at a discount, used for further processing, or even discarded (Baltic et al 2019). The notable discolorations on the skin-side surfaces of severe WB fillets after cooking and the white striations on the ventral surfaces of raw WS fillets negatively impacts the purchasing decisions of consumers (Huang & Ahn 2018).…”

Innovative Characterization Based on Stress Relaxation and Creep to Reveal the Tenderizing Effect of Ultrasound on Wooden Breast

“…Histology observation showed the main characteristics of WB as necrosis and fibrosis, connective tissue infiltration, lipid infiltration, fiber diameter increase, fiber degeneration and regeneration, and inflammatory cell infiltration [ 12 , 15 , 16 ]. Analysis of meat quality found that shear force and compression force in WB are significantly higher than those in the normal breast (NB) [ 14 , 17 ], thus causing low consumer acceptance and economic loss. Xing [ 18 ] surveyed the incidence of WB in China, and the proportion was approximately 61.9%.…”