title: Association of genetic polymorphism in GH gene with milk production traits in Beijing Holstein cows.
abstract: Associations were analysed between polymorphisms of the growth hormone gene (GH-MspI) (localized in intron 3) and milk production traits of Beijing Holstein cows (a total of 543 cows). Polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method was used for identification of various genotypes. Frequencies of genotypes were 0.77, 0.21 and 0.02 for A/A, A/B and B/B, respectively. The frequency of the GH A allele is 0.875. The results of the least squares means show that in all three lactations, the GH A/A cows yielded more milk (P less than 0.01 for lactation I and P less than 0.05 for lactations II and III), whereas A/B cows showed higher milk fat content than A/A individuals (P less than 0.05 for lactations I and II, and P less than 0.01 for lactation III). The A/A cows yielded more fat than A/B individuals (P less than 0.01 only in lactation I). The A/A cows yielded more milk protein than A/B individuals (P less than 0.01 for lactations I, II, and III). The A/A cows produced milk of higher protein content than of A/B individuals (P less than 0.05 only in lactation II).
authors.affiliation: College of Life Science, Liaocheng University, Liaocheng, Shandong 252059, People's Republic of China. glzhou@lctu.edu.cn
authors.forename: Guo Li
authors.initials: GL
authors.lastname: Zhou
authors.forename: Hai Guo
authors.initials: HG
authors.lastname: Liu
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.forename: Shan Li
authors.initials: SL
authors.lastname: Guo
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhu
authors.forename: Yu Hou
authors.initials: YH
authors.lastname: Wu
mesh_terms: D000818:Animals; D002417:Cattle / Q000235:genetics* / Q000502:physiology; D019003:Deoxyribonuclease HpaII / Q000378:metabolism; D004041:Dietary Fats / Q000032:analysis; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D013006:Growth Hormone / Q000235:genetics*; D007774:Lactation / Q000235:genetics*; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D008894:Milk Proteins / Q000032:analysis; D016133:Polymerase Chain Reaction / Q000662:veterinary; D011110:Polymorphism, Genetic / Q000502:physiology*; D012150:Polymorphism, Restriction Fragment Length
chemical_list: D004041:Dietary Fats; D008894:Milk Proteins; D013006:Growth Hormone; D019003:Deoxyribonuclease HpaII