HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Thompson, N. R. Articles by Ralston, N. P. Search for Related Content PubMed Articles by Thompson, N. R. Articles by Ralston, N. P.

Genetic and Environmental Factors in the Development of the American Red Danish Cattle^{1, 2,}

Dairy Department, Michigan State University, East Lansing

ABSTRACT

Genetic and environmental factors in the development of the American Red Danish cattle were investigated. The intrasire regression of production on inbreeding was –23.1 lb. milk and –0.3 lb. butterfat for each additional 1% of inbreeding. Two lethal defects, paralyzed hind quarters and ankylosis, appeared in the second cross to Red Danish sires. Calf mortality and cow sterility apparently increased with successive crosses.

Heritability of butterfat production was estimated as 0.39 ± 0.11, repeatability as 0.43. Average adjusted butterfat production in the foundation, first-cross, second-cross, and third-cross generations was 351, 379, 377, and 389 lb., respectively. Butterfat yield did not vary significantly with month of calving but increased 2.0 lb. (P < 0.01) for each additional month of previous calving interval and increased 1.0 lb. (P < 0.01) for each additional day of lactation period. An upward environmental trend of 6.5 lb. butterfat per cow per year (P < 0.01) also was found.

¹ Published with the approval of the Director of the Michigan Agricultural Experiment Station as Journal Article No. 1973.

² The data are from theses submitted by L. J. Cranek, Sr., and N. R. Thompson in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Michigan State University, 1952 and 1955, respectively.

³ Present address: Department of Dairy Science, Virginia Polytechnic Institute, Blacksburg.

⁴ Present address: Route 1, Box 4, Garwood, Texas.