title: The influences of ambient temperature and crude protein levels on performance and serum biochemical parameters in broilers.
abstract: This study was undertaken to investigate the effects of ambient temperature, crude protein levels and their interaction on performance and serum biochemical parameters of broiler chickens. A total of 216 Arbor Acre broiler chickens (108 males and 108 females) were used in a 2 × 3 factorial arrangement and randomly reared at two temperatures (normal temperature: 23 °C; daily cyclic high temperature: 28-32 °C) and fed on three diets with different crude protein levels (153.3, 183.3 or 213.3 g/kg, with constant essential amino acids) from 28 to 42 days of age. Daily cyclic high ambient temperature decreased final body weight, average daily weight gain, average daily feed intake and serum total protein contents (p < 0.001, p < 0.001, p < 0.001, p = 0.008 respectively), but increased feed/gain, mortality, respiratory rate, rectal temperature, serum uric acid contents and serum creatine kinase activity (p = 0.008, p = 0.003, p < 0.0001, p < 0.0001, p < 0.0001, p = 0.003 respectively), irrespective of crude protein levels. At the ambient temperature, reducing crude protein levels resulted in an increase in feed/gain (p < 0.001), but a decrease in serum total protein and uric acid contents. Only serum creatine kinase activity in broiler chickens was interacted by daily cyclic high ambient temperature and dietary crude protein levels (p = 0.003). These results indicated that daily cyclic high ambient temperature had a great effect on performance and serum biochemical parameters in broiler chickens, whereas dietary crude protein levels affected them partially.
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, China.
authors.forename: Q W
authors.initials: QW
authors.lastname: Liu
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: J H
authors.initials: JH
authors.lastname: Feng
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Chao
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, China.
authors.forename: L M
authors.initials: LM
authors.lastname: Wei
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, China.
authors.forename: F
authors.initials: F
authors.lastname: Wang
authors.affiliation: Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Haikou, China.
authors.forename: R P
authors.initials: RP
authors.lastname: Sun
authors.affiliation: Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: M H
authors.initials: MH
authors.lastname: Zhang
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001831:Body Temperature; D002645:Chickens / Q000097:blood / Q000254:growth & development*; D004032:Diet / Q000662:veterinary; D004044:Dietary Proteins / Q000378:metabolism*; D005260:Female; D006799:Housing, Animal; D008297:Male; D012119:Respiration; D013696:Temperature
chemical_list: D004044:Dietary Proteins
keywords: biochemical parameters; broiler; crude protein level; daily cyclic high temperature; performance