Interactions of Sires With Feeding and Management Factors in Illinois Holstein Cows

The objectives of this research were to estimate components of phenotypic variation in milk yield due to the interactions between sires and several feeding and management factors and to examine the implications of the estimated interactions in sire evaluation for milk yield. Data on feeding and management practices in Illinois Holstein herds on official DHI and DHIR testing programs were obtained by questionnaires. Milk yield data were first lactation records, begun in 1973, of purebred or grade Holstein heifers. Part records were extended to 305-day records and then adjusted for age and month of calving. The feeding and management practices were source of roughage for milking herd during summer, amount of grain fed to heifers between 12 and 18 months of age, amount of grain fed to heifers during two months before calving, and ideal weight for breeding heifers. Variance components were estimated by Methods 1 and 3 of Henderson.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Dairy Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Mohemmad, Waheed Abdul

• Biology, Genetics

Language dc:language

eng

Identifier

(UMI)AAI8026561

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/68556