title: The effect of dietary methionine levels on fattening performance and selected blood and tissue parameters of turkeys.
abstract: A total of 490 eight-week-old female Hybrid Converter turkeys (body weight 4.11 ± 0.03 kg) were divided into 5 groups with 7 replicates of 14 birds each. For 8 weeks, basal diets were supplemented with methionine (Met) at following levels (weeks 9-12/weeks 13-16 of age): Group 1 - 0.34/0.29%, Group 2 - 0.39/0.34%, Groups 3 and 4 - 0.45/0.38% and 0.51/0.41%, respectively, Group 5 - 0.58/0.47%. Only in the first feeding phase the body weight gain (BWG) was affected by Met levels with the significantly highest BWG in Group 3. No treatment effects were found for feed conversion ratio, carcass yield, carcass composition and meat colour. The blood superoxide dismutase activity was significantly highest in Groups 2 and 3. The concentrations of reduced glutathione in the liver were linearly increased (p = 0.018), whereas the ratio of reduced glutathione to oxidised glutathione was highest in Group 3 (quadratic contrast, p = 0.004). It can be concluded that turkeys from Group 3 (Met levels age depending 15% and 10% above recommendations by NRC) were characterised by a well-balanced physiological response. Attention should be paid to the immune response of birds to higher dietary Met levels: plasma IgA concentrations decreased, whereas IL-6 and TNF-α levels increased in turkeys fed diets with the highest Met content.
authors.affiliation: a Department of Poultry Science, Faculty of Animal Bioengineering , University of Warmia and Mazury in Olsztyn , Olsztyn , Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Jankowski
authors.affiliation: a Department of Poultry Science, Faculty of Animal Bioengineering , University of Warmia and Mazury in Olsztyn , Olsztyn , Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Kubińska
authors.affiliation: b Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences , Olsztyn , Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Juśkiewicz
authors.affiliation: c Department of Biochemistry and Toxicology, Faculty of Biology and Animal Breeding , University of Life Sciences , Lublin , Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Czech
authors.affiliation: b Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences , Olsztyn , Poland.
authors.forename: Zenon
authors.initials: Z
authors.lastname: Zduńczyk
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition / Q000187:drug effects; D004032:Diet / Q000662:veterinary*; D004305:Dose-Response Relationship, Drug; D005260:Female; D008715:Methionine / Q000008:administration & dosage / Q000494:pharmacology*; D018482:Muscle, Skeletal / Q000254:growth & development; D014422:Turkeys / Q000097:blood / Q000254:growth & development*; D015430:Weight Gain / Q000187:drug effects*
chemical_list: D008715:Methionine
keywords: Antioxidant properties; carcass quality; fattening performance; immune response; methionine; turkeys