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The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs
Thesis (MScAgric)--Stellenbosch University, 2025.
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614012496150529 |
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| access_status_str | Open Access |
| author | Van Schalkwyk, Elzette |
| author2 | Lambrechts, Helet |
| author_browse | Lambrechts, Helet Van Schalkwyk, Elzette |
| author_facet | Lambrechts, Helet Van Schalkwyk, Elzette |
| author_sort | Van Schalkwyk, Elzette |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132338 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:45:16.097Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132338 The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs Van Schalkwyk, Elzette Lambrechts, Helet Van Zyl, Johan Hendrik Combrink Strydom, Phillip Evert Ganswindt, Andre Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Science. Lambs -- Growth -- Nutritional aspects Lambs -- Development Lamb (Meat) -- Quality -- Data processing Feedlots Proteins in animal nutrition Sheep -- Feeding and feeds -- Evaluation Sheep -- Productivity Lambs -- Health Animal culture -- Data processing Stocking density Animal wellbeing -- Data processing UCTD Thesis (MScAgric)--Stellenbosch University, 2025. van Schalkwyk, E. 2025. The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/b179d613-1b31-4e5a-a3a5-baada889b48d ENGLISH ABSTRACT: Consumer concerns surrounding animal welfare and ethical production, especially in intensive production systems such as feedlots, increased over the last couple of years, with a critical attitude about ethical food production. Intensification of production systems are however unavoidable as global protein demand is increasing due to the rapid population growth. The absence of clear guidelines regarding individual space allowance in indoor feedlot systems that will allow for expression of normal behaviour and thus ensure animal wellbeing, necessitated this study that investigated the influence of three different stocking densities on the growth, wellbeing, and meat quality of two different sheep breeds. A total of 30 Dorper- and 30 Dohne Merino (DM) castrated ram lambs, respectively, were randomly allocated to three different stocking densities of 0.5m2, 0.75m2, or 1m2 per sheep, at 10 animals per treatment group. Animals received a commercial feedlot diet during both the two-week adaptation period, as well as a six-week feedlot period. Feed-and water intake, and weekly live weight were recorded during both periods. To qualify and quantify the wellbeing of the rams, the temperament of all animals was assessed at the start of the study, after the adaptation period, and again at the end of the feedlot period. Behavioural observations were conducted for a total of 21 hours every week, and weekly faecal glucocorticoid metabolite concentration and differential white blood cell count, respectively, were determined as physiological wellbeing parameters. All animals were slaughtered at the end of the feedlot period, and the left loin muscle was used to determine meat quality parameters, shelf-life parameters, and meat proximate chemical composition. Individual feed and water intake could not be measured, but based on observational data, the Dorper sheep consumed less water than the Dohne Merino sheep. Feed intake was similar between the two breeds, with a corresponding similar live weight reported for the entire trial period. The DM rams housed at the medium stocking density had an average heavier live weight, when compared the DM rams housed at the low stocking density. Stocking density did not negatively influence the rams’ ability to express normal activity- and subsistence behaviour during the feedlot period. Sheep temperament, differential white blood cell count, and faecal glucocorticoid metabolite concentration were similar for all stocking density groups. Dorper rams were more reactive and experienced a higher degree of adaptation stress when introduced to the feedlot system. The redness value of the meat samples was the only parameter influenced, with samples obtained from the low stocking density groups that had the highest redness values on Day 0 of the shelf-life study. Differences between the Dorper and DM breeds were observed and even though contradicting and surprising at times, all reported values fell within the normal ranges for consumers. This study highlighted the multi-faceted nature of animal behaviour, animal wellbeing, and product quality, as affected by stocking density and breed. Based on the findings of this study, it can be advised that sheep can be maintained in indoor feedlot systems at stocking densities of up to 0.5m2 per animal, without raising concerns for animal wellbeing. AFRIKAANSE OPSOMMING: Verbruikers se kommer rakende dierewelsyn en etiese produksie, veral in intensiewe produksiestelsels soos voerkrale, het oor die afgelope paar jaar toegeneem, met ’n kritiese houding teenoor etiese voedselproduksie. Die intensifisering van produksiestelsels is egter onafwendbaar aangesien wêreldwye proteïenbehoeftes toeneem soos die bevolking groei. Die afwesigheid van duidelike riglyne rakende individuele spasietoekenning in binnenshuise voerkraalstelsels, wat die uitdrukking van normale gedrag moontlik maak en sodoende dierewelsyn verseker, het hierdie studie uiters noodsaaklik gemaak. Die studie het die invloed van drie verskillende veedigthede op die groei, welsyn en vleiskwaliteit van twee verskillende skaaprasse ondersoek. ’n Totaal van 30 Dorper- en 30 Dohne Merino (DM) gekastreerde ram-lammers is lukraak aan drie verskillende veedigthede van 0.5m², 0.75m², of 1m² per skaap toegewys, met 10 diere per behandelingsgroep. Diere het ’n kommersiële voerkraalrantsoen ontvang tydens beide die twee-week aanpassingsperiode, sowel as die ses-week voerkraalperiode. Voer- en waterinname, asook weeklikse lewende massa, is gedurende beide periodes aangeteken. Om die ramme se welsyn te kwalifiseer en te kwantifiseer, is die temperament van al die diere aan die begin van die studie, na die aanpassingsperiode, en weer aan die einde van die voerkraalperiode geëvalueer. Gedragswaarnemings is vir ’n totaal van 21 uur per week uitgevoer, en weeklikse fekale glukokortikoïed-metabolietkonsentrasie en differensiële witbloedsel- tellings is bepaal as fisiologiese welsynsparameters. Alle diere is aan die einde van die voerkraalperiode geslag, en die linker lendespier is gebruik om vleiskwaliteitsparameters, raklewe-parameters en die proksimale chemiese samestelling van die vleis te bepaal. Individuele voer- en waterinname kon nie gemeet word nie, maar waarneming toon dat die Dorper-skape minder water gedrink het as die Dohne Merino-skape. Voerinname was soortgelyk tussen die twee rasse, lewende massas was dieselfde tussen die twee rasse tydens die voerkraalperiode. Die DM-ramme wat by die medium veedigtheid gehuisves is, het gemiddeld ’n swaarder lewende massa gehad in vergelyking met die DM-ramme wat by die lae veedigtheid gehuisves is. Veedigtheid het nie ’n negatiewe invloed gehad op die ramme se vermoë om normale gedrag tydens die voerkraalperiode uit te druk nie. Temperament, differensiële witbloedsel-tellings en fekale glukokortikoïed- metabolietkonsentrasies was soortgelyk vir al die veedigtheidsgroepe. Dorper-ramme was meer reaktief en het ’n hoër mate van stres ervaar toe hulle aan die voerkraalstelsel blootgestel is. Die rooiheidswaarde van die vleismonsters was die enigste parameter wat beïnvloed is, met monsters van diere van die lae veedigtheidsgroepe wat die hoogste waardes op Dag 0 van die raklewe studie getoon het. Verskille tussen die Dorper- en DM-rasse is waargeneem, en hoewel dit soms teenstrydig en verrassend was, het alle aangetekende waardes binne die normale verbruikerstandaarde geval. Hierdie studie beklemtoon die komplekse aard van dieregedrag, dierewelsyn en produkgehalte soos beïnvloed deur veedigtheid en ras. Op grond van die bevindinge van hierdie studie kan dit aanbeveel word dat skape in binnenshuise voerkraalstelsels teen digthede van tot 0.5m² per dier gehou kan word, sonder om kommer oor dierewelsyn te laat ontstaan. Masters 2025-06-04T08:58:03Z 2025-06-04T08:58:03Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132338 en Stellenbosch University xv, 7 pages unnumbered, 149 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Lambs -- Growth -- Nutritional aspects Lambs -- Development Lamb (Meat) -- Quality -- Data processing Feedlots Proteins in animal nutrition Sheep -- Feeding and feeds -- Evaluation Sheep -- Productivity Lambs -- Health Animal culture -- Data processing Stocking density Animal wellbeing -- Data processing UCTD Van Schalkwyk, Elzette The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title | The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title_full | The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title_fullStr | The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title_full_unstemmed | The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title_short | The influence of stocking density on the growth, wellbeing, and meat quality of intensively reared lambs |
| title_sort | influence of stocking density on the growth wellbeing and meat quality of intensively reared lambs |
| topic | Lambs -- Growth -- Nutritional aspects Lambs -- Development Lamb (Meat) -- Quality -- Data processing Feedlots Proteins in animal nutrition Sheep -- Feeding and feeds -- Evaluation Sheep -- Productivity Lambs -- Health Animal culture -- Data processing Stocking density Animal wellbeing -- Data processing UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132338 |
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