title: Effects of outdoor access on growth performance, carcass composition, and meat characteristics of broiler chickens.
abstract: The present study was conducted to investigate the effects of outdoor access on the growth performance and meat quality of broiler chickens. Thirty-five-day-old female broilers were divided into 3 groups with 6 replicates of 124 birds each: (1) birds reared indoors (control group); (2) birds reared with outdoor access since 36 d of age (35-d group); and (3) birds reared with outdoor access since 71 d of age (70-d group). The results showed that outdoor access had no effect on growth performance, carcass yield, meat yield, muscle protein content, muscle fiber characteristics, or water-holding capacity (P > 0.05). Chickens from the outdoor access groups had a better appearance and degree of evenness. Birds in the outdoor access groups had a significantly lower lung percentage than birds in the control group (P < 0.05), whereas the kidney percentage of the 35-d group was significantly lower than that of the control group (P < 0.05). The meat of chickens in the 35-d group had higher L* values than that of the control group (P < 0.05). Compared with rearing indoors, outdoor access significantly increased the shear force of the breast muscle in both the 35 d and 70-d group (P < 0.05) and decreased the fat content of the thigh muscle in the case of 35-d group (P < 0.05). Birds in the 35-d group also had lower fat content in their thigh muscles than did the birds in the 70-d group (P < 0.05). The thigh muscles of the birds in the 35-d group showed lower levels of MUFA and higher levels of PUFA than those of the control group and 70-d group (P < 0.05). In conclusion, outdoor access had no effect on growth performance and yield traits but could improve the meat quality; birds reared with outdoor access from 36 d of age had better appearance and meat quality than those with outdoor access from 71 d of age.
authors.affiliation: Department of Animal Science, South China Agricultural University/Guangdong Provincial Key Laboratory of Agro-Animal Genomics and Molecular Breeding/Key Laboratory of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou, 510642, China.
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: W
authors.initials: W
authors.lastname: Jiang
authors.forename: H Z
authors.initials: HZ
authors.lastname: Tan
authors.forename: G F
authors.initials: GF
authors.lastname: Xu
authors.forename: X B
authors.initials: XB
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Wei
authors.forename: X Q
authors.initials: XQ
authors.lastname: Wang
mesh_terms: D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D002645:Chickens / Q000254:growth & development / Q000502:physiology*; D002681:China; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005260:Female; D006799:Housing, Animal; D008460:Meat / Q000592:standards*; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D011897:Random Allocation
chemical_list: D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D009124:Muscle Proteins