Degree Type

Dissertation

Date of Award

1985

Degree Name

Doctor of Philosophy

Department

Animal Science

Abstract

Data from the Thai-Danish Dairy Farm in Thailand were used. Ten breeds and their crosses were grouped into breed groups from Europe, India and Local breeds. The optimum proportion of crossbreeding for dairy cattle between European x tropical breeds for reproduction and production efficiencies appeared to be between 37% and 62% European breeding. Halfbred European x tropical breeds were probably the most suitable for reproductive fitness. Additive effects of European breed groups were mostly larger than the additive effects of India and Local breed groups and also larger than the magnitude of general heterosis.;Additive effects of India breed groups were generally greater than the additive effects of Local breed groups. Additive effects of Indian breed groups were not consistently larger than the magnitude of general heterosis. General heterosis was important for all reproduction and production traits for all three parities.

DOI

https://doi.org/10.31274/rtd-180813-13358

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Sompop Kassumma

Language

en

Proquest ID

AAI8524670

File Format

application/pdf

File Size

182 pages

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