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The development of standard lactation curves for the South African Jersey population
Dissertation (MSc (Animal Breeding and Genetics))--University of Pretoria, 2016.
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| Format: | Thesis |
| Language: | English |
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2026
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| _version_ | 1867613724045475840 |
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| access_status_str | Open Access |
| author2 | Van Marle-Köster, Este |
| author_browse | Van Marle-Köster, Este |
| author_facet | Van Marle-Köster, Este |
| collection | Thesis |
| description | Dissertation (MSc (Animal Breeding and Genetics))--University of Pretoria, 2016. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/110164 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:40:41.342Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2026 |
| publishDateRange | 2026 |
| publishDateSort | 2026 |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/110164 The development of standard lactation curves for the South African Jersey population Van Marle-Köster, Este wernerbrand@outlook.com Mostert, B.E. Brand, Werner Lactation Jersey Milk solids Curves Milk Dissertation (MSc (Animal Breeding and Genetics))--University of Pretoria, 2016. Standard lactation curves are used to predict milk, butterfat and protein lactation yields for lactations in progress and are generally derived with lactation curve functions that describe the shape of the curve and the direction of production. Several lactation curve equations have been proposed since 1923 (Brody et al., 1923) to accurately simulate the natural lactation yield curve shape of dairy animals. In this study available models were investigated for the prediction of lactation yield from test-day records. Test-day records of Jersey cows participating in the South African Dairy Animal Improvement Scheme were downloaded from the Livestock Operational and Genetic Information Exchange (Logix) database of the South African Stud Book and Animal Improvement Association. A total of 4 218 547 records consisting of 610 102 lactations from 228 728 cows from 1 039 herds for all lactations for the period 2002-2013 were used for this study. It was found that the Wilmink (1987) curve was most suitable for predicting milk yields, with a kvalue of 0.065 and 0.1 for first and later parities, respectively. The Ali & Schaeffer (1987) equation was most suitable for predicting milk solid lactation yields. A total of 23 age classes were created. Age of calving had the largest effect on yields, followed by herd and season of calving effects. Cows calving between 70-76 months of age (5+ parities) produced the most milk. Cows calving during late autumn had the highest lactation yields. The Best Linear Unbiased Estimates (BLUES) for these estimates were used to create a total of 2 760 standard lactation curves (SLACS) for each trait and were derived successfully during this study. These SLACS will be used by the South African Stud Book and Animal Improvement Association to estimate lactation yields for records in progress and short lactations of Jersey cows participating in the Logix Milk Recording Scheme. These curves are used dynamically to estimate lactation yield early in lactation. This will benefit farmers as they can make management decisions early in the lactation of a cow, especially with regards to nutrition. The accuracy of estimated breeding values for production traits of young sires will be increased where limited progeny information is available. Animal and Wildlife Sciences MSc (Animal Breeding and Genetics) 2026-05-15T17:26:31Z 2026-05-15T17:26:31Z 16/02/03 2016 Dissertation http://hdl.handle.net/2263/110164 en application/pdf |
| spellingShingle | Lactation Jersey Milk solids Curves Milk The development of standard lactation curves for the South African Jersey population |
| title | The development of standard lactation curves for the South African Jersey population |
| title_full | The development of standard lactation curves for the South African Jersey population |
| title_fullStr | The development of standard lactation curves for the South African Jersey population |
| title_full_unstemmed | The development of standard lactation curves for the South African Jersey population |
| title_short | The development of standard lactation curves for the South African Jersey population |
| title_sort | development of standard lactation curves for the south african jersey population |
| topic | Lactation Jersey Milk solids Curves Milk |
| url | http://hdl.handle.net/2263/110164 |