Single Nucleotide Polymorphisms of Growth Hormone and Insulin‐Like Growth Factor‐1 Genes and Their Association With Growth Traits of Goats: A Systematic Review

Abstract

Insulin-like growth factor-1 (IGF-1) and growth hormone (GH) genes are vital for animal growth. This study aimed to review the single nucleotide polymorphisms (SNPs) of IGF-1 and GH genes and their associations with growth traits of goats. This study is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Databases (Google Scholar, PubMed, ScienceDirect and Web of Science) were evaluated. Eight SNPs of the IGF-1 gene were found in the selected studies, whereas nine SNPs of GH gene were discovered. One article found two SNPs (1617 G>A and 5752 G>C) that were similar to the ones of two other articles, each for the GH gene, and these articles found that body weight (BW) was not associated with the SNPs. All the other articles discovered different SNPs from each other for both genes. Four of the articles found an association between GH genotypes and BW. One article discovered a relationship between GH genotypes and withers height and chest width (CW) and three articles found an association between GH genotypes and heart girth (HG). Four articles discovered an association between IGF-1 genotypes and BW and one article discovered it with CW. This study concluded that the IGF-1 gene might be used as a potential molecular marker for the genetic improvement of BW and CW in goat breeding, whereas the GH gene can be used for the genetic improvement of BW, withers height, HG, body length and CW in goat breeding.