Genetics and Heritability By: Collette Cason
History • The bovine species surprisingly holds a rare relationship with humans. • In some cultures cattle raising were an indication of power and strength. • They did not know much about the history of genetics in cattle, and still do not know much.
Present Day • For the last 10 years across the world they have switched from Profit Index (know) to Profitable Lifetime Index (know). • Cloning, and the most common way of cloning is SCNT, which stands for somatic cell nuclear transfer. It basically increases the production level with the desirable traits that the breeder or breeders have bought or picked.
Techniques • Cross breeding certain cattle enough to get one dominate feature such as Holstein are used for there significant milk production. • In 1990, started using DNA and molecular cloning for creating genome linkage maps. With these maps scientist could identify chromosomal locations of (OTI) (know!!). • From the past 10 years they have become more modified in molecular genetics. Like they can alternate precise genotypes in thousands.
Techniques Continued • The Gould Ranch of Fort Morgan, Colorado ultrasounds all of their bulls and heifers. They use this technique to see what superior carcass features have developed in the cattle over the years and to see what they need to do differently the next time they breed. • Other options are embryo transfer and AI work. This allows you to pick a bull from where ever and not worry about traveling and still get exactly what you want for a low price and quick shipment.
Diseases • Spinal Muscular Atrophy – This disease is usually found in brown European cattle breeds. Its fast acting, and causes horrible weak legs. • Spinal Dysmielination - affects mainly brown cattle breeders, affects the rear end in weakness. • Bovine progressive Degenerative Myeloencephalopathy (“Weaver Syndrome”). The disease cripples the hind legs, and then soon makes cattle not able to walk.
Diseases Continued • Spastic Paresis – This disease is caused by the “hyperextension of the rear limbs or straight hock. (Makes it painful and difficult to walk, they act stiff) • Spastic Syndrome – caused from sire bulls in Artificial insemination , affects all breeds, intermittent bilateral spasms of the skeletal muscles of the pelvis girdle. • Craniofacial defects such as: Deformed cleft lip and/or cleft plate.
Diseases Continued • Chondrodysplasia and Congenital Paunch Calf Syndrome - Chondrodysplasia is poor bone development, most commonly from Italy as “Bulldog calf” (Flat head, short nose, sloping forehead, and short and stump limbs. Affects calves. • Complex Vertebral Malformation- Most worried disease to Holstein breeder. The spinal system is basically grown all out of place. The spine has grown incorrect and out of place, causing other limbs to not grow correct either.
What to Expect Weaver Syndrome Spastic Paresis Spastic Syndrome Cleft Lip
Chondrodysplasia and Congenital Paunch Calf Syndrome. Complex Vertebral Malformation
Bibliography • ftp://ftpaipl.arsusda.gov/pub/curtvt/hapmap/bovhapmap-V37.pdf • http://www.animalbehavioronline.com/qtl.html • http://www2.vet.unibo.it/staff/Gentile/Lavori%20scientifici/Slovenian%20veterinary%20Research.pdf • http://www.cattletoday.com/archive/2008/April/CT1529.shtml • http://www.thecattlesite.com/articles/2917/using-pli-to-breed-for-profit
Bibliography Continued • http://img.tfd.com/vet/thumbs/gr53.jpg