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Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa
Dissertation (MSc (Agric))--University of Pretoria, 2018.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2019
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| _version_ | 1867613691254407168 |
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| access_status_str | Open Access |
| author2 | Webb, E.C. (Edward Cottington) |
| author_browse | Webb, E.C. (Edward Cottington) |
| author_facet | Webb, E.C. (Edward Cottington) |
| collection | Thesis |
| dc_rights_str_mv | © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc (Agric))--University of Pretoria, 2018. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/70559 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:40:10.037Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2019 |
| publishDateRange | 2019 |
| publishDateSort | 2019 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/70559 Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa Webb, E.C. (Edward Cottington) elan3db@gmail.com De Bruyn, Elandri UCTD Milk urea nitrogen Nutrient management Food production Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-03 Natural and agricultural sciences theses SDG-12 Dissertation (MSc (Agric))--University of Pretoria, 2018. This study was based on measurements taken from the milk recording scheme of the Agricultural research Council (ARC). In this study the effects of milk urea nitrogen (MUN) on reproduction parameters of dairy cows in South Africa was investigated. The Analysis of Variance (ANOVA) procedure confirmed that MUN has a significant influence on reproduction performance in South African dairy cows. The correlation between MUN and intercalving period (ICP) demonstrated that cows are taking longer to fall pregnant as MUN increases. Other more complex reproduction parameters were also calculated as well as their correlations with MUN. The first is reproduction performance (RP) which was negatively correlated with MUN. The second parameter was reproductive index (RI) which was also negatively correlated with MUN. This means that overall reproduction in dairy cows decline as MUN concentrations are increased. The breeds used in this study were Holstein and Jersey dairy cows. Analysis of variance results confirmed breed differences for the effects of MUN on reproduction parameters. It was found that reproductive success declines with increasing MUN concentrations in Jersey cows regardless the season. Analyses of the interaction between breed and season, indicate that the most important interaction was between Jersey cows in summer. This implies a different urea threshold for Jersey cows between seasons, as well as between Jersey cows and Holstein cows. bs2026 Animal and Wildlife Sciences MSc (Agric) Unrestricted SDG-02: Zero hunger SDG-03: Good health and well-being SDG-12: Responsible consumption and production 2019-07-08T09:46:51Z 2019-07-08T09:46:51Z 2019/04/17 2018 Dissertation De Bruyn, E 2018, Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa, MSc (Agric) Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/70559> A2019 http://hdl.handle.net/2263/70559 en © 2019 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Milk urea nitrogen Nutrient management Food production Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-03 Natural and agricultural sciences theses SDG-12 Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title | Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title_full | Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title_fullStr | Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title_full_unstemmed | Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title_short | Effects of milk urea nitrogen on reproduction parameters of dairy cows in South Africa |
| title_sort | effects of milk urea nitrogen on reproduction parameters of dairy cows in south africa |
| topic | UCTD Milk urea nitrogen Nutrient management Food production Natural and agricultural sciences theses SDG-02 Natural and agricultural sciences theses SDG-03 Natural and agricultural sciences theses SDG-12 |
| url | http://hdl.handle.net/2263/70559 |