GENETIC AND GENOMIC FACTORS INFLUENCING GESTATIONAL LENGTH IN BEEF CATTLE
Date
2022-09-19
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
Type
Thesis
Degree Level
Masters
Abstract
Gestation length in beef cattle is typically measured as the length of time in days from breeding to calving and is a trait under moderate genetic influence. Currently, the research surrounding gestation length variation is primarily conducted in dairy breeds because of increased use of artificial insemination (AI) in dairy operations compared with the beef industry. Identifying genetic regions and variants associated with the trait would allow for greater understanding of the variability in gestation length. This study aimed to evaluate the selection success of breeding bulls with predicted short or long gestation lengths on their offspring’s gestation lengths, birth weights and weaning weights and calving ease, and to investigate the genetic basis of gestation length. Five Hereford bulls were bred to 153 first-calf heifers using AI, and the calf records were used to determine influence of sire on economically important traits. A genetic analysis of the sires was completed to determine if there were specific variants in the coding exon sequences of six candidate genes (SIGLEC5, SIGLEC14, CTU1, FOXD2, EXOC4, ZNF613) that could be associated with gestation length. Kompetitive Allele Specific PCR (KASP) was used to genotype dams, sires, and their offspring for the c.617T>G, p.H143Q mutation identified through sequence analysis. Significant (P<0.05) effects of sire, dam breed, and calf sex were observed on measured traits. The genotype of the sire for c.617T>G also had a significant effect on gestation length, with TT sired calves gestating for 5.5 days shorter on average than GG sired calves. This study provides evidence of a potential genetic marker that could be used for gestation length prediction in Canadian beef cattle operations.
Description
Keywords
gestation length, beef cattle, genetics, reproduction, animal breeding, production
Citation
Degree
Master of Science (M.Sc.)
Department
Animal and Poultry Science
Program
Animal Science