Controlled breeding of dairy heifers

Observations over a five year period

Authors

  • Ken E. Leslie Department of Clinical Studies, University of Guelph Guelph, Ontario, N1G 2W1 Canada
  • John S. Walton Department of Animal and Poultry Science, University of Guelph Guelph, Ontario, N1G 2W1 Canada
  • Ken G. Bateman Department of Clinical Studies, University of Guelph Guelph, Ontario, N1G 2W1 Canada
  • Roger K. Shantz Elora Dairy Research Center, University of Guelph, Guelph, Ontario, N1G 2W1, Canada

DOI:

https://doi.org/10.21423/bovine-vol0no21p146-149

Keywords:

artificial insemination, reproductive management, conception rates, reproduction, cows

Abstract

Over a five year period from 1979 to 1983, 191 Holstein-Friesian heifers were artificially inseminated at present times following estrus synchronization with two injections of prostaglandin analogue 11 days apart. The heifers were not selected prior to synchronization and no heat detection methods were used. Overall conception rates for the five year period were 59.8% on timed inseminations; however, the pregnancy rates ranged from 50% in Years 3 and 5 to 76.2% in Year 4. The average interval from first to last calving for groups of heifers which conceived to synchronized insemination was 19 days. There was no significant difference in conception rates between heifers that were greater than 16 months of age and those less than 16 months old.

Cover image of the 21st Volume of the Bovine Practitioner: a photo of the Louisville skyline at sunset, the lights of the skyscrapers reflecting in the river. The sky is blue and purple and for a just moment the city seems still.

Downloads

Published

1986-11-01

Issue

No. 21 (1986 November)

Section

Articles

How to Cite

Controlled breeding of dairy heifers: Observations over a five year period. (1986). The Bovine Practitioner, 21, 146-149. https://doi.org/10.21423/bovine-vol0no21p146-149

Most read articles by the same author(s)