Bull Traits Measured Early in Life as Indicators of Herd Fertility
نویسندگان
چکیده
This study investigated the genetic relationships of blood hormones, scrotal size, body weight, condition score and flight time measured on young bulls to 12 months of age with key reproductive traits in Brahman and Tropical Composite breeds (n=4079). Heritability of the traits ranged from 0.17 to 0.72 indicating potential for genetic change in both populations. Genetic correlations with presence of sperm in the ejaculate at 12 months of age, percent normal sperm at 2 years old, and heifer age at puberty were moderate, in some cases up to 0.61, indicating a potential to improve the efficiency of selection of breeding replacements.
منابع مشابه
Determining Reproductive Fertility in Herd Bulls
ity of a beef operation is the percentage of the calf crop weaned, which, in turn, is determined mainly by the number of cows bred during the breeding season. The herd bull influences overall herd fertility more than any other single animal. Because the bull also supplies half of the genetics to all of the calves he sires, bull selection can be the most powerful method of genetic improvement in...
متن کاملThe Reproductive and Nutritional Management of Beef Bulls
pregnancy rate is one of the most important factors determining profit or loss. Considerable emphasis and focus is placed on the nutritional and reproductive management of the cow herd; but, unfortunately, in most operations little emphasis is placed on the bull. However, each bull is expected to impregnate from 15 40 females during the breeding season in a typical cow-calf operation and, thus,...
متن کاملMolecular Markers for Fertility in Farm Animals
A genetic marker is a gene or DNA sequence with known localization on a chromosome. It can be de-scribed as a variation that can be measured or detected by a suitable method, and can be used subsequently to detect the presence of a specific genotype. Such variations occurring at chromosomal or DNA level can serve as genetic markers. The progress in development of molecular markers suggests thei...
متن کاملManagement Factors Influencing Fertility in Synchronized and Natural Breeding Programs
Artificial insemination provides a method to inseminate a large number of females to a single sire that has been selected and proven to be an industry leader for economically relevant traits. Thus, genetic change in a herd can occur quickly through the use of artificial insemination. With natural service, herd bulls are also selected for economically relevant traits but are limited on the numbe...
متن کاملSpermatozoa Molecules in Relation to Bulls Fertility
Bull fertility may be defined as the process by which spermatozoa fertilize and activate the ovum and then support embryonic development. Bull fertility is a complex trait having relatively low heritability and plays a vital role for efficient production and reproduction of bovine. Various mechanisms involved in regulating bull fertility associated phenotype and reliable biomarkers are poorly d...
متن کامل