title: Evaluation of White Striping prevalence and predisposing factors in broilers at slaughter.
abstract: White striping ( WS: ) is an alteration of breast and thigh muscles of broiler chickens characterized by the presence of white striations parallel to the direction of muscle fibers. This study was performed to evaluate the prevalence and the predisposing factors to WS in commercial broilers of different weight reared in northern Italy. Fifty seven broiler flocks, including animals of medium- and heavy-weight, were grossly evaluated at slaughter for the presence of WS. For each flock, breeding data (mean BW at slaughter, ADG, sex, color of skin and fat, genetic line, age, antibiotic treatment, and prevalence of deep pectoral myopathy) were collected and statistically analyzed to assess their correlation with WS. Histology of breast fillets affected by different grades of WS was performed to evaluate potential differences between medium- and heavy-weight broilers. The overall prevalence of WS in medium- and heavy-weight broilers (mean BW 2.59 ± 0.13 kg and 3.64 ± 0.34 kg, respectively) was 70.2 ± 7.9% and 82.51 ± 8.5%, respectively, while the percentage of severe WS was 13.3 ± 7.1% and 25.7 ± 12.8%, respectively. A strong correlation was found between presence of WS, BW at slaughter, and ADG (Pearson correlation = 0.69, P < 0.01; Pearson correlation = 0.67, P < 0.01). WS also closely correlated with the prevalence of deep pectoral myopathy (Spearman's Rho slaughterhouse 1 = 0.74, Spearman's Rho slaughterhouse 2 = 0.51, P < 0.01). No correlation was found between genetics or sanitary status of the flock and WS. Histology confirmed that breasts with WS lesions were affected by a polyphasic degenerative and necrotizing myopathy, and that the lesions, as expected, were more severe in heavy-weight broilers. In conclusion, WS is a major concern in commercial meat poultry reared in Italy, affecting more severely heavier broilers, and it is mainly related to the BW and ADG of animals.
authors.affiliation: MSD Animal Health s.r.l., Via F.lli Cervi snc, Centro Direzionale Milano Due - Palazzo Canova, 20090, Segrate (MI), Italy elisa.russo1982@gmail.com.
authors.forename: Elisa
authors.initials: E
authors.lastname: Russo
authors.affiliation: Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università 16, 35020, Legnaro, Padova, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Drigo
authors.affiliation: MSD Animal Health s.r.l., Via F.lli Cervi snc, Centro Direzionale Milano Due - Palazzo Canova, 20090, Segrate (MI), Italy.
authors.forename: Corrado
authors.initials: C
authors.lastname: Longoni
authors.affiliation: MSD Animal Health s.r.l., Via F.lli Cervi snc, Centro Direzionale Milano Due - Palazzo Canova, 20090, Segrate (MI), Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pezzotti
authors.affiliation: Avicola Alimentare Monteverde s.r.l., via San Donato 31, Rovato (BS), Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Fasoli
authors.affiliation: Mouse & Animal Pathology Laboratory, Fondazione Filarete, Viale Ortles 22/4, 20139, Milano.
authors.forename: Camilla
authors.initials: C
authors.lastname: Recordati
mesh_terms: D000003:Abattoirs; D000818:Animals; D001835:Body Weight; D002645:Chickens / Q000033:anatomy & histology; D008297:Male; D008460:Meat / Q000592:standards*; D018482:Muscle, Skeletal / Q000473:pathology*
keywords: breast fillet; broiler chicken; daily gain; deep pectoral myopathy; white striping