Yao-Dong  Li, Yan-Nan  Ma, Peng-Jia  He, Michael A.  Brown, Zhao-Min  Lei, Jing  Zhu, Hai-Rong  Zhang, Jun  Li, Jian-Ping  Wu, 
    Effects of Growth Hormone (GH) and Growth Hormone Receptor (<I>GHR</I>) 
  Gene Polymorphisms on Milk Production Traits in Holstein and Holstein x Chinese Yellow Cattle Crosses,
    Journal of Animal and Veterinary Advances,
    Volume 12,Issue 14,
    2013,
    Pages 1210-1216,
    ISSN 1680-5593,
    javaa.2013.1210.1216,
    (https://makhillpublications.co/view-article.php?doi=javaa.2013.1210.1216)
    Abstract: The 3 years of data from 464 purebred Holstein and Holstein 
  cross (unimproved Holstein-Chinese Yellow cattle crosses, improved Holstein-Chinese 
  Yellow cattle crosses) cattle were used to evaluate effects of polymorphisms 
  in both GH and GHR on milk yield and quality. Traits evaluated included 305 
  days milk, milk fat, milk protein and lactose yield and 305 days milk fat, milk 
  protein and milk lactose percentage. Three genotypes and two genotypes were 
  found within the <I>GH</I> and <I>GHR</I> genes, respectively. Based on mixed 
  model least squares analyses (SAS<SUP>&reg;</SUP>, 
  Raleigh, NC, USA) there was evidence of genotypic difference for GH in 305 days 
  milk yield for improved Holstein-Chinese Yellow cattle and purebred Holstein 
  (p&lt;0.10) but only a weak trend for genotypic differences across breed groups 
  (p&lt;0.15). Genotypic differences for GH in milk fat, protein and lactose yield 
  were not evident in unimproved Holstein-Chinese Yellow cattle or purebred Holstein 
  cattle (p&gt;0.10) but there were trends for genotypic differences in milk fat, 
  protein and lactose yield in improved Holstein-Chinese Yellow cattle (p&lt;0.10). 
  There was little evidence of genotypic differences for GHR in any trait (p&gt;0.20). 
  Results from this research suggest polymorphisms in GH can affect milk yield 
  and quality but such effects may be dependent on percentage Holstein in the 
  cow.
    Keywords: Cattle;Holstein cattle;Chinese Yellow;GH gene;GHR gene;polymorphism;milk production