title: Effect of genotype, gender and feed restriction on growth, meat quality and the occurrence of white striping and wooden breast in broiler chickens.
abstract: Due to their importance for the control of meat quality in broiler chickens, the present study aimed at identifying the factors associated with the occurrence of myopathies and characterizing the meat properties when affected by myopathies. To this aim, a total of 768 broiler chickens were reared until slaughter (46 d) to evaluate the effect of genotype, gender, and feeding regime (ad libitum vs. restricted rate, 80% from 13 to 21 d of age) on performance and meat quality. Standard broilers were heavier (3,270 vs. 3,139 g; P<0.001) and showed lower feed conversion (1.56 vs. 1.61; P<0.001) than the high-yield broilers. Males showed higher final live weight (3,492 vs. 2,845 g) and lower feed conversion (1.54 vs. 1.63) than females (P<0.001). Feed restriction decreased final live weight (3,194 vs. 3,142 g; P<0.01) and feed conversion (1.60 vs. 1.57; P<0.01) compared to ad libitum feeding. At gross examination, feed restriction tended to increase white-striped breasts (69.5 vs. 79.5%; P<0.10), whereas females showed less wooden breasts than males (8.0 vs. 16.3%; P<0.05). White-striped fillets had higher pHu (5.87 vs. 5.83), and lower a* (-0.81 vs. -0.59) and b* color indexes (13.7 vs. 14.5) (P<0.05), whereas wooden breast fillets exhibited higher cooking losses (25.6 vs. 22.1%) and AK-shear force (4.23 vs. 2.84 kg/g) compared with normal fillets (P<0.001). At histological examination, 3.1% of pectoralis major were normal, 26.6% mildly degenerated, 45.3% moderately degenerated, and 25.0% severely degenerated. In conclusion, genotype had a moderate effect on growth without modifying myopathy occurrence. In contrast, gender and feed restriction affected performance, meat quality, and breast abnormalities.
authors.affiliation: Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy angela.trocino@unipd.it.
authors.forename: A
authors.initials: A
authors.lastname: Trocino
authors.affiliation: Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Piccirillo
authors.affiliation: Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Birolo
authors.affiliation: Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Radaelli
authors.affiliation: Department of Comparative Biomedicine and Food Science (BCA), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Bertotto
authors.affiliation: Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Filiou
authors.affiliation: Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, I-47521Cesena, Forlì Cesena, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Petracci
authors.affiliation: Department of Agronomy Food Natural Resources Animal and Environment (DAFNAE), University of Padova, Viale dell'Università 16, I-35020 Legnaro, Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Xiccato
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002645:Chickens / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D005260:Female; D005838:Genotype; D008297:Male; D008460:Meat / Q000032:analysis*; D010369:Pectoralis Muscles / Q000254:growth & development / Q000378:metabolism; D011897:Random Allocation; D012737:Sex Factors
keywords: growth; histology; meat quality; myopathies