Increase in profits corresponding to a one unit increase in Estimated Breeding Value (EBV) for 3 production traits and for 21 type traits were estimated from 31,123 merged "Official" first lactation records, type records and Estimated Breeding Value (EBVs) records of Canadian Holstein cows using multivariate REML and a mixed model accounting for herd and year of calving effects. The same regression model was used to estimate the same profit increases corresponding to a one unit change in EBVs from 336 merged "Non-Official" first lactation records, type records and EBV records of Canadian Holstein Cows to investigate whether purebred breeders are selecting their animals according to type and production performances while commercial producers are selecting animals that maximize their milk profits. Finally, the usefulness of DHAS cow records for increasing milk profits was investigated by comparing the average profit level of cows with "Official" milk records and their time of registration under the DHAS scheme. / Size had the largest negative impact on profits, with estimates ranging from $-$41.70 $ pm$ 6.60 to $-$26.62 $ pm$ 5.91. Chest width and fore attachment had the largest positive impact on profits, with estimates ranging from 4.30 $ pm$ 5.94 to 16.82 $ pm$ 6.00 and from 4.71 $ pm$ 3.52 to 14.57 $ pm$ 3.97 respectively. Grade cows were found to have on average lower EBVs for most type and production traits than purebred cows. However, grade and purebred cows generated similar milk profits. Finally, the efficiency of using information provided by DHAS to increase profits did not increase with the number of years of participation with DHAS.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.27498 |
| Date | January 1997 |
| Creators | Bouchard, Alexandra Karine. |
| Contributors | Baker, L. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Agricultural Economics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001619086, proquestno: MQ37096, Theses scanned by UMI/ProQuest. |
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