Effect of breeder age and slaughter weight on meat quality traits of broiler breast and leg meats [Einfluss des alters der elterntiere und des schlachtgewichts auf qualitätseigenschaften von broiler-brust- und -schenkelfleisch]

The objective of the present study was to evaluate the effect of breeder age (28-wk vs. 48-wk of age breeders) on meat quality traits of breast and leg meats of broilers slaughtered at 1800, 2100 and 2400 g weights. The pH24, colour, thawing and cooking loss, texture, initial protein solubility and myofibril dimensions were measured. Slaughter weight affected pH24, lightness, thawing and cooking loss and protein solubilities of broiler breast and leg meat.Tenderness of leg meat decreased with slaughter weight. Breast meat from 48-wk breeders lost more water during thawing. A significant breeder age by slaughter weight interaction showed that the increases in initial myofibrillar protein solubility of breast meat and both initial myofibrillar and sarcoplasmic protein solubilities of leg meat with slaughter weight were higher in broilers from 28-wk breeders than those from 48-wk breeders There was negative correlation between breast meat pH24 and L*, b*, and thawing loss whereas leg meat pH24 was positively correlated with a*, negatively correlated with b*, texture, thawing and cooking loss. A negative correlation was found between cooking loss and myofibrillar protein solubilities of breast meat.The results suggested that breeder age may affect thawing loss of breast meat and total initial protein solubility of both breast and leg meats. Higher myofibrillar protein solubility found for breast and leg meat of broilers from 28-wk breeders may indicate better functional qualities. © Verlag Eugen Ulmer, Stuttgart

Muscle structure and gene expression in pectoralis major muscle in response to deep pectoral myopathy induction in fast-and slow-growing commercial broilers

PubMed: 293553882-s2.0-850422317161. The objective of this study was to determine muscle structure and gene expression in pectoralis major (p. major) muscle of broilers in response to deep pectoral myopathy (DPM) induction. 2. A total of 160 chickens from slow-and fast-growing broilers were raised under same conditions. Half of the broilers from each strain were encouraged to wing flap when they reached 2800 g body weight. Pectoralis minor (p. minor) muscle of the broilers was inspected for the occurrence of DPM and p. major samples were collected from broilers with or without DPM. The muscle fibre area and number, capillary number and the signalling pathways of vascular development (vascular endothelial growth factor A, VEGFA) and muscle contraction regulation (actin alpha 1, ACTA1; myosin light chain kinase 2, MYLK2 and ATPase Ca+2 transporting gene 1, ATP2A1) were studied in p. major muscle. 3. DPM induction increased fibre area of p. major muscle with a greater rate in the slow-growing strain compared with fast-growing line. Although the capillary number was higher in slow-growing compared with fast-growing broilers, in the case of DPM induction, the number of capillaries was similar between strains. 4. Expression of VEGFA, MYLK2 and ATP2A1 was greater in slow-than in fast-growing broilers. DPM induction increased expression of ACTA1, VEGFA and ATP2A1 in p. major muscle of broilers from both strains; however, MYLK2 expression was downregulated. 5. Changes in capillary density and expression of VEGFA found in the p. major muscle of broilers with DPM suggest increased blood flow to increase oxygen availability. The upregulation of ATP2A1 by DPM induction could be attributable to alterations in calcium ion transportation from the cytoplasm into the sarcoplasmic reticulum. 6. The results are evidence of changes in muscle structure and gene expression pathways in p. major muscle of broilers with DPM. © 2018 British Poultry Science Ltd.Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK: 115O434This work was supported by The Scientific and Technological Research Council of Turkey [115O434]