Effects of genetic selection for fast growth on the development of wooden breast myopathy in broilers
Creators: name: Emambu, M.
name: Haron, A.
name: Lokshtanov, D.
name: Shinder, D.
name: Druyan, S.
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Medicine
subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Physiology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Computational Biology

description: This study investigated the physiological and molecular mechanisms leading to wooden breast (WB) by comparing growth parameters, oxygen consumption rate, thyroid hormone and gene expression patterns in fast- versus slow-growing broiler lines (Cobb500 and L1986, respectively).WB was observed in Cobb500 broilers only and was first diagnosed on d 21 post-hatch. Compared to the slow-growing L1986, Cobb500 showed a significantly higher growth rate, relative breast weight, breast thickness, meat pH and water-retention capacity (drip loss). Correspondingly, there was significantly lower relative heart weight, relative right ventricular weight, triiodothyronine and thyroxine concentrations and oxygen consumption rate.Compared to No-WB Cobb500, the WB-affected samples exhibited higher relative breast weight, breast thickness and drip loss and lower plasma total thyroxine (T4) concentrations.Selection for fast growth was associated with differential expression of genes involved in hypoxia (<i>PLOD2</i>), energy metabolism (<i>FABP3, FABP4, CD36, and LPL</i>), endoplasmic reticulum stress, muscle regeneration (<i>CSRP3</i>) and fibre-type switching (<i>ANKRD1</i>). WB-affected samples exhibited an upregulation of <i>CSRP3, PLOD2</i> and <i>ANKRD1</i>, while <i>CD36</i> was downregulated. Taken together, selection for fast growth and muscle gain is not matched by adequate cardiac and metabolic support systems. This study investigated the physiological and molecular mechanisms leading to wooden breast (WB) by comparing growth parameters, oxygen consumption rate, thyroid hormone and gene expression patterns in fast- versus slow-growing broiler lines (Cobb500 and L1986, respectively). WB was observed in Cobb500 broilers only and was first diagnosed on d 21 post-hatch. Compared to the slow-growing L1986, Cobb500 showed a significantly higher growth rate, relative breast weight, breast thickness, meat pH and water-retention capacity (drip loss). Correspondingly, there was significantly lower relative heart weight, relative right ventricular weight, triiodothyronine and thyroxine concentrations and oxygen consumption rate. Compared to No-WB Cobb500, the WB-affected samples exhibited higher relative breast weight, breast thickness and drip loss and lower plasma total thyroxine (T4) concentrations. Selection for fast growth was associated with differential expression of genes involved in hypoxia (<i>PLOD2</i>), energy metabolism (<i>FABP3, FABP4, CD36, and LPL</i>), endoplasmic reticulum stress, muscle regeneration (<i>CSRP3</i>) and fibre-type switching (<i>ANKRD1</i>). WB-affected samples exhibited an upregulation of <i>CSRP3, PLOD2</i> and <i>ANKRD1</i>, while <i>CD36</i> was downregulated. Taken together, selection for fast growth and muscle gain is not matched by adequate cardiac and metabolic support systems.