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Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators
Thesis (MScAgric)--Stellenbosch University, 2025.
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| Language: | English |
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867614094848163840 |
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| access_status_str | Open Access |
| author | Rice, Joshua Arthur |
| author2 | Lambrechts, Helet |
| author_browse | Lambrechts, Helet Rice, Joshua Arthur |
| author_facet | Lambrechts, Helet Rice, Joshua Arthur |
| author_sort | Rice, Joshua Arthur |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Thesis (MScAgric)--Stellenbosch University, 2025. |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132267 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:46:35.101Z |
| 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:10019.1/132267 Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators Rice, Joshua Arthur Lambrechts, Helet Van Zyl, Johan Hendrik Combrink Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Science. Heifer calves -- Growth Calves -- Performance records Calves -- Feeding and feeds -- Nutritional aspects. Animal nutrition -- Measurement Ruminants -- Feeding and feeds -- Monitoring Dairy cattle -- South Africa -- Management UCTD Thesis (MScAgric)--Stellenbosch University, 2025. Rice, J. A. 2025. Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/dbd0a787-0385-4b4d-b5e2-3b37d595398c ENGLISH ABSTRACT: South African dairy producers have to manage high input costs and low-income margins in an effort to stay profitable. Dairy producers thus have been necessitated to increase herd size and increase the intensification of production to offset the higher input costs. One of the drawbacks of this identification, is that Intensified dairy production systems are characterized by a short reproductive lifespan of Holstein cows (± 2.3 lactations), which increase the demand for replacement heifers. It is known that an earlier weaning age and heavier weaning weight, affect the lactation performance of heifers positively. Therefore, this study investigated the potential of milk replacer (MR) volume fed (i.e. 4L/day, 6L/day and 9L/day) and calf starter (CS) feed crude protein level (i.e. 210 g/kg DM and 260 g/kg DM) on forestomach- and gastrointestinal tract (GIT) function, growth performance and calf wellbeing in 48 Holstein heifer calves during the pre-weaning period. The initiation of GIT function was studied using diagnostic imaging of the abomasum for the first four hours after the ingestion of colostrum. An interaction between clot size and passive immunity transfer was observed, with increasing clot size as a percentage of abomasum size, being associated with more effective immunoglobulin (Ig) G transfer. The white blood cell profile, and more particularly neutrophil to lymphocyte ratio, and BHBA levels, were used as physiological indicators of calf wellbeing. Based on the findings from this study, dairy heifer calves can successfully ingest and digest up to 9L of MR fed per day, without placing pressure on the digestive capacity of the GIT. Allometric growth parameters and other growth-related parameters such as average daily gain and feed conversion ratio were recorded as indicators of calf performance. Calf performance and growth parameters were influenced by the MR volume fed and CS crude protein level, however, no interaction was observed. Similarly, no interaction was observed between MR volume fed and CS feed crude protein level when monitoring the initiation of rumen development and -function. Calf starter feed intake was affected by MR volume fed, with a decrease in pre-weaning CS feed intake observed with an increase in the MR volume fed. Calf starter crude protein levels were also found to have an influence on calf starter intake, with higher crude protein levels being linked to an increase in CS feed intake. Rumen wall thickness was monitored using diagnostic imaging and a positive relationship between cumulative rumen wall growth and cumulative calf starter feed intake, was found. No differences in rumen wall thickness or growth rate were observed between different MR volumes fed or CS feed crude protein level. Milk feeding volumes and calf starter feed crude protein content both independently affected calf performance and forestomach initiation and development. AFRIKAANSE OPSOMMING: Suid-Afrikaanse suiwelprodusente moet hulle produksiesisteme teen hoë insetkoste en lae-inkomste marges bestuur in 'n poging om winsgewend te bly. Suiwelprodusente is dus genoodsaak om kuddegrootte te vergroot en die intensifisering van produksie te verhoog om die hoër insetkoste te verreken. Een van die nadele van hierdie intensifisering is dat suiwelproduksiestelsels gekenmerk word deur 'n kort reproduksieleeftyd van Holstein koeie (± 2.3 laktasies), wat die vraag na vervangingsverse verhoog. Dit is bekend dat 'n swaarder speengewig die laktasieprestasie van verse positief beïnvloed. Daarom het hierdie studie die potensiaal van melkvervanger (MR) volume gevoer (d.i. 4L/dag, 6L/dag en 9L/dag) en kalf aanvangsdieet (CS) ruproteïenvlak (d.i. 210 g/kg DM en 260 g/kg DM) op voormaag- en spysverteringskanaal funksie, groei en kalfwelstand ondersoek in 48 Holstein verskalwers gedurende die voorspeen tydperk. Die aanvang van SVK-funksie is bestudeer met behulp van ultraklank skandering van die abomasum vir die eerste vier uur na die inname van biesmelk. 'n Interaksie tussen klontgrootte en passiewe immuniteitsoordrag was waargeneem, met ʼn toename in klontgrootte, as 'n persentasie van abomasumgrootte, wat geassosieer word met meer effektiewe immunoglobulien (Ig) G-oordrag. Die witbloedselprofiel, en meer spesifiek neutrofiel tot limfosiet verhouding, en BHBA vlakke, is gebruik as fisiologiese aanwysers van kalfwelstand. Gebaseer op die bevindinge van hierdie studie, kan verskalwers suksesvol tot 9L MR gevoer per dag inneem en verteer, sonder om druk op die spysverteringskapasiteit van die SVK te plaas. Allometriese groeiparameters en ander groeiverwante parameters soos gemiddelde daaglikse toename en voeromsetverhouding is aangeteken as aanwysers van kalfprestasie. Kalf prestasie en groei parameters is beïnvloed deur die MR volume gevoer en CS ruproteïen vlak, maar geen interaksie is waargeneem nie. Net so is geen interaksie tussen MR volume gevoer en CS voer ruproteïen vlak waargeneem wanneer die aanvang van rumen ontwikkeling en -funksie gemonitor is nie. Kalf-aanvangsvoerinname is beïnvloed deur MR volume gevoer, met 'n afname in voorspeense CS voerinname waargeneem met 'n toename in die MR volume gevoer. Daar is ook gevind dat CS ruproteïenvlakke 'n invloed op kalf-aanvangsinname het, met hoër ruproteïenvlakke wat gekoppel is aan 'n toename in CS voerinname. Rumenwand dikte is gemonitor deur ultraklank skandering te gebruik en 'n positiewe verband tussen kumulatiewe rumenwandgroei en kumulatiewe kalf-aanvangsvoerinname is gevind. Geen verskille in rumenwanddikte of groeitempo is waargeneem tussen verskillende MR-volumes gevoer of CS voer ruproteïenvlakke nie. Melkvoervolumes en CS ruproteïeninhoud het beide kalfprestasie en voormaag inisiasie en -ontwikkeling onafhanklik beïnvloed. Die resultate van hierdie studie bring die behoefte aan verdere ondersoek na die begrip. Masters 2025-06-02T08:40:50Z 2025-06-02T08:40:50Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132267 en Stellenbosch University 171 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Heifer calves -- Growth Calves -- Performance records Calves -- Feeding and feeds -- Nutritional aspects. Animal nutrition -- Measurement Ruminants -- Feeding and feeds -- Monitoring Dairy cattle -- South Africa -- Management UCTD Rice, Joshua Arthur Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title | Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title_full | Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title_fullStr | Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title_full_unstemmed | Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title_short | Different feeding strategies and their effect on heifer calf performance, forestomach function and metabolic indicators |
| title_sort | different feeding strategies and their effect on heifer calf performance forestomach function and metabolic indicators |
| topic | Heifer calves -- Growth Calves -- Performance records Calves -- Feeding and feeds -- Nutritional aspects. Animal nutrition -- Measurement Ruminants -- Feeding and feeds -- Monitoring Dairy cattle -- South Africa -- Management UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132267 |
| work_keys_str_mv | AT ricejoshuaarthur differentfeedingstrategiesandtheireffectonheifercalfperformanceforestomachfunctionandmetabolicindicators |