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Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line
Dissertation (MSc(Agric))--University of Pretoria, 2010.
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University of Pretoria
2013
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| _version_ | 1867613627347894272 |
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| access_status_str | Open Access |
| author2 | Jansen van Rensburg, Christine |
| author_browse | Jansen van Rensburg, Christine |
| author_facet | Jansen van Rensburg, Christine |
| collection | Thesis |
| dc_rights_str_mv | © 2010, 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, 2010. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/27678 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:39:09.096Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| 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:2263/27678 Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line Jansen van Rensburg, Christine Casey, N.H. (Norman Henry) willem.steyn@topigs.com Steyn, Willem Johannes Finisher pigs Diets Ad libitum UCTD Dissertation (MSc(Agric))--University of Pretoria, 2010. The current modern commercial pig is an animal that has evolved through deliberate breeding programs, controlled environmental influences and nutrition to yield a highly efficient feed converter and fertile animal. The objective of this study was to measure the growth performances and carcass characteristics of entire male grower – finisher pigs which were subjected to different seasonal variations, nutrient dense diets, feeding regimes and group situations under South African circumstances. Period 1 was conducted in the winter from 6 June 2008 to 13 August 2008 and Period 2 in the summer from 3 October 2008 to 10 December 2008. The sire lines that were selected for the experiment had the same genetic breeding values (Topigs Selection Index value), of which two sire lines were the same in both Period 1 and Period 2 and one of two different sires lines was used either in Period 1 or Period 2. The animals were fed two different rations, a high (FH) and a low ration (FL), with the low ration’s specifications being 95 % of the high ration. The animals were randomly allocated three different feed regimes throughout the trial; restricted single feeding (RSF), ad libitum single feeding (ASF) and ad libitum group feeding (AGF). In the winter animals had a greater growth response compared to the summer, with end weight and average daily gain being significant (P<0.05) higher. A significant (P<0.05) improvement in average daily gain, feed efficiency and protein deposition rate were observed when animals were fed a higher energy and protein content in their diet, especially during summer. A significant (P<0.05) improved feed conversion was observed for restricted animals, but end weight, average daily gain and average protein deposition rates were significant (P<0.05) lower compared to ad libitum group and individually fed animals. In conclusion; the impact of decreasing the nutrient density of the diet for growing pigs through incremental changes in diet composition had a variable impact on overall growth performance and carcass quality. Feeding the high energy and protein ration improved growth performance during summer, but also in the initial stages of growth when feed intake capacity was limited. The objective when formulating diets should be to provide the essential amino acids and energy in amounts needed to support maximal and efficient growth. Using growth models estimated optimal feed intake curves will not deliver optimal results. Only when measuring and calculating the actual feed intake and protein deposition rates optimal performance levels will be reached. Measurements of feed intake and growth performance data derived from pigs penned individually should be adjusted before they can be applied to commercial situations or research conditions in which pigs are penned in groups. Animal and Wildlife Sciences unrestricted 2013-09-07T12:00:37Z 2011-09-08 2013-09-07T12:00:37Z 2011-04-14 2010-08-08 2011-09-01 Dissertation Steyn, WJ 2010, Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line, MSc(Agric) dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/27678 > E11/411/gm http://hdl.handle.net/2263/27678 http://upetd.up.ac.za/thesis/available/etd-09012011-144756/ © 2010, 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 | Finisher pigs Diets Ad libitum UCTD Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title | Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title_full | Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title_fullStr | Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title_full_unstemmed | Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title_short | Effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| title_sort | effects of ad libitum and restricted diets in different feeding regimes on growth and carcass attributes of boars of a selected genetic line |
| topic | Finisher pigs Diets Ad libitum UCTD |
| url | http://hdl.handle.net/2263/27678 http://upetd.up.ac.za/thesis/available/etd-09012011-144756/ |