Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Est&Eacute Van Marle-KÖSter has a total of 153 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Precision livestock farming technologies to support sustainable beef cattle production: A South African perspective

    by Anton Gresse, Este van Marle-Köster

    The global livestock sector is undergoing substantial transformation, driven by the need to improve production efficiency, environmental sustainability, and animal welfare in response to growing demand for animal-derived protein. Precision livestock farming (PLF) has emerged as a paradigm shift from conventional herd-level management to data-driven systems that enable continuous monitoring and management of individual animals. This review synthesises current knowledge and emerging applications of PLF technologies worldwide, with a focus on the South African beef industry, which exhibits a dual production structure comprising both emerging and commercial farming systems. The integration of sensor technologies, automated systems, and advanced data analytics facilitates real-time monitoring of physiological, behavioural, and environmental parameters. Key applications, including radio frequency identification for animal identification and traceability, global positioning system technologies and accelerometers for spatial and behavioural monitoring, and automated feeding systems, are discussed in relation to intensive feedlot operations and extensive rangeland systems. The contribution of these technologies to improving traceability, supporting quality assurance, and enhancing biosecurity within the beef value chain is also highlighted. Strategies addressing the challenges of commercial rangeland systems and emerging smallholder farms are reviewed, highlighting current limitations. Despite challenges associated with implementation costs, data integration, and rural connectivity, PLF offers opportunities to enhance productivity, resource-use efficiency, and sustainability. Adoption of these technologies is critical for the South African beef industry to meet national production goals, strengthen competitiveness, and respond to global market and sustainability demands. The benefits of PLF technology can be made available to the smallholder and emerging sectors through tailor-made financing and technical support. (Submitted 15 January 2026; Accepted 9 April 2026; Published 03 June 2026)

  • Open Access

    Measurement of pregnancy rate and foetal loss, and their associations with management practices on reproductive performance of smallholder beef cattle heifers in South Africa

    by Marble Nkadimeng, Este van Marle-Köster, Nkhanedzeni B. Nengovhela, Fhulufhelo V. Ramukhithi, Johannes M. Rust, Mahlako L. Makgahlela

    Understanding reproductive performance of replacement heifers is pivotal for sustainable and profitable farming in any cattle production system. The study assessed reproductive performance of smallholder beef cattle heifers focusing on pregnancy rate (PR); and fetal and calf loss (FCL). Additionally, it investigated herd management factors that influence these traits. A total of 538 heifer records were collected from 40 herds representing five provinces between 2018 and 2019. A secondary application of established seasonal pregnancy diagnosis methods was used to measure PR and FCL. Management factors including body condition score (BCS), age at first mating and calving, breed type, heifer selection, record-keeping, frame size, breeding and calving season were recorded. The Kaplan-Meier method analysed reproductive outcomes, while the Cox proportional hazards model assessed management factors influencing PR and FCL. Results indicated an average of 47% PR and 11% FCL with achievable levels of 60% PR and 0.9% FCL. Majority of heifers conceived between ages four and five years. At three years, 96.19% of heifers had not experienced loss, however, the calf survival probability decreased to 68.17% by five years. The median age for first calving was four, by age five, 72.96% of heifers had calved. The results showed significant effects ( P < 0.05) for breed type, breeding season, BCS, frame size and heifer selection on PR and FCL. Optimizing PR and FCL in smallholder heifers may depend on improving management practices including selection practices of heifers prior to breeding, maintaining optimum BCS and breeding during favourable environmental conditions.

  • Open Access

    Behaviour of commercial layer hens in enriched cages and floor systems examined using human and video-based observations

    by T Chilemba, E van Marle-Köster, A Masenge, M Cromhout, T Nkukwana

    There is considerable pressure to eliminate the use of conventional cages in commercial layer hen production systems. However, the assessment of alternative systems that can ensure the hen’s ability to perform natural behaviours, while simultaneously enhancing farm productivity and economic efficiency, remains incomplete. This study assessed layer behaviour in a floor system and in enriched cages on a commercial layer farm using human and video-based observations. The study focused on dust bathing, nesting, feather pecking, and perching behaviours, and on the formation of mud balls on the feet. A large proportion (72.9%) of the hens exhibited dust-bathing behaviour, with an average duration of 22.63 minutes. Feather pecking was exhibited by 35.4% of layers in the enriched cages, compared to 58.3% of layers in the floor system. Overall, feather pecking was the least observed behaviour. Layers in enriched cages used perches more (47%) than layers in the floor system (27%), and a negative association was found between body weight and perching in layers in the floor system. At the end of the six-week trial period, 41.67% of the hens had developed mud balls on their toes that exceeded 3 cm in length. The results of this study provide evidence of the relationships between poultry behaviour, welfare, and production. Video-based observations confirmed that farm managers may not be able to identify certain welfare-related behavioural aspects unless they are closely monitored. The results of this study may be used to inform stakeholders about behaviour and welfare considerations in the management of commercial layers. Submitted 28 August 2024; Accepted 27 January 2025; Published March 2025 ------------------------------------------------------------------- Significance of research to South African science The article contributes meaningfully to the advancement of animal welfare science in South Africa. It represents the first field-based study in the country to comprehensively assess layer hen behaviour under commercial farming conditions using both human and video-based observation techniques. By analysing welfare indicators such as dust bathing, perching, feather pecking, and nesting behaviours, the study offers crucial evidence on how different housing systems affect hen welfare and productivity. These insights are particularly significant as South Africa navigates global pressures to transition away from conventional cages toward more humane and sustainable egg production systems. The findings inform policymakers, producers, and animal welfare advocates, supporting evidence-based decisions for improving poultry housing standards and aligning with both local industry realities and international welfare trends.

  • Open Access

    Heat stress in dairy cows: A review of abiotic and biotic factors, with reference to the subtropics

    by L.M. Erasmus, E. Van Marle-Köster

    Heat stress has been identified as one of the major challenges for livestock production. Global temperatures are steadily increasing, with South African temperatures increasing at nearly twice the global rate. Of the livestock used for food production, dairy cows are the most sensitive to thermal changes, which have detrimental effects on their health, welfare, and overall productivity. Several abiotic factors that influence the heat load experienced by the cow are not commonly included in thermal indices used to measure heat stress; these include solar radiation, wind speed, and soil quality. Furthermore, the thermal comfort zone of cows has been altered by years of intense selection for increased milk yield, causing cows to become heat stressed at lower temperatures. Considering the abiotic and biotic factors affecting the cow’s heat load, it can be argued that dairy cows in tropical and subtropical climates are experiencing constant heat stress. In this review, the abiotic and biotic factors influencing the heat load experienced by dairy cows are reviewed, along with the available thermal indices that can be utilised at farm level.


  • Open Access

    Risk factors underlining reproductive performance in smallholder beef cattle herds of South Africa

    by Marble Nkadimeng, Este Van Marle-Köster, Nkhanedzeni B. Nengovhela, Fhulufhelo V. Ramukhithi, Masindi L. Mphaphathi, Johannes M. Rust, Mahlako L. Makgahlela

    Improving the historically low reproductive performance of beef cattle in smallholder systems is essential for its productivity and profitability. Therefore, identifying and addressing risk factors associated with low performance in this system present an opportunity for improvement. The study aimed to evaluate the effect of animal and management risk factors on pregnancy rate (PR), fetal and calf loss (FC), calving interval (CI) and days open (DO) in smallholder beef cattle farms. A multi-stage selection approach was conducted in five provinces of South Africa. Cow records (3694) collected from 40 smallholder herds over two years (2018–2019) were analysed. Data on animal and herd management factors including body condition score (BCS), cow age class, breed type, lactation status, culling old/non-productive cows, record-keeping, and breeding and calving seasons were recorded. The GLIMMIX procedure was computed to determine risk factors associated with performance indicators (PR, FC, CI and DO). Risk factors highly associated with performance were breed type, BCS, cow-age class and breeding/calving season (P ≤ 0.05). Indicators FC, DO and CI increased with decreased BCS, autumn calving seasons, and in first calvers and aged cows. Whereas, PR increased with increasing odds of BCS and breeding seasons between December-March, November-February and January-March. Optimizing reproductive performance in smallholder beef cattle herds may involve managing cow body condition, breeding with adapted genotypes and synchronizing breeding with favourable seasons. Therefore, record keeping and regular monitoring of herd nutrition, climate and breed performance may be significant in improving reproductive performance in smallholder herds.


  • Open Access

    Brainstem auditory evoked responses: Objective hearing threshold assessment in Holstein cows

    by Alida Naudé, Lize-Mari Erasmus, Liesl de Swardt, Juan Bornman, Este van Marlé-Köster

    Background: Animal audiology utilizes brainstem auditory evoked responses (BAER) as a non-invasive tool to assess hearing in animals, including Holstein dairy cows. Understanding cows’ auditory capabilities is critical for their welfare, especially given their exposure to farm noise. Objectives: This study provides preliminary normative BAER data for Holstein cows by focusing on absolute and interpeak wave latencies. The objective is to assess the impact of farm noise and expand audiologists’ practice scope. Method: Ten Holstein cows were tested using monoaural broadband click stimuli with contralateral masking. Earphones with foam ear tips were used to minimize environmental noise interference. The BAER responses were recorded via subdermal needle electrodes placed at standardized locations on the cows’ heads. The data were analysed using descriptive statistics to determine auditory thresholds and wave latencies. Results: The cows exhibited auditory thresholds at 90 dB SPL (55 dB nHL). Detailed wave and interpeak latencies were recorded at intensities from 85 to 105 dB SPL. At 90 dB SPL, the average latency for wave V was 5.17 ms, marking the auditory threshold for Holstein cows. Conclusion: These findings provide key insights into the auditory sensitivity of Holstein cows, highlighting BAER’s potential for monitoring auditory health and evaluating the effects of noise pollution on animal welfare. This research underscores the value of integrating animal audiology into the audiologist’s scope, ultimately enhancing both animal welfare and farming sustainability. Contribution: This study adds to the limited literature on farm animal auditory health and suggests strategies to improve welfare through better auditory management.


  • Open Access

    316 Routine Claw Trimming Data Provides Insight into the Occurrence of Claw Lesions Holstein Herds in the Central Region of South Africa

    by Robyn C Joubert, EstÉ Van Marle-KÖSter, H F Strydom

    Claw lesions in dairy cows are a primary contributor to lameness, posing severe welfare concerns due to the distress and discomfort experienced by affected cows. Claw disorders have a significant negative impact on herd efficiency, milk yield, reproductive performance, and involuntary culling. Despite increased awareness of the detrimental effects of lameness, its incidence has continued to rise. Reducing the occurrence of lameness remains a major challenge, especially in defining and recording of claw traits. In South Africa (SA), claw data is limited to private hoof trimmers with paper-based recording. The objective of this research was to examine the occurrence and recording of claw lesions in Holstein cattle from the central region of South Africa. Claw-trimming data from five intensively managed dairy farms (average herd size: 1,073) using both dirt lot (DL) and free-stall (FS) housing systems were analyzed over a six-year period (2014 to 2019). The Claw Lesion Identification in Dairy Cattle brochure, co-developed by Zinpro Corporation and the International Lameness Committee, was used as the reference for lesion identification by a local hoof trimmer. Digital dermatitis (D) showed the greatest prevalence (64.02% of all recorded lesions), followed by sole ulcers (U; 8.59%), white line disease (W; 6.27%), and sole hemorrhage (H; 4.28%), with most lesions occurring in the rear feet. A chi-square test of independence between lesion and housing was rejected (P < 0.0001). Correspondence analysis (CA) was then used to explore these dependencies. The first dimension of the graphical display explained 90.7% of the variation in the data. The CA indicated that the prevalence of D and F are strongly associated, and closely associated with U. The prevalence of these lesions is also associated with housing systems DL and FS. The CA also confirmed a close association between W and H, and the prevalence of these lesions in housing system DL+FS. Improving the precision of claw lesion identification and recording, especially with regard to lesions that tend to occur together, can furnish essential data to identify the most prevalent lesions in a population. This will enhance our comprehension of the causal factors behind these significant lesions and offer producers practical recommendations to use these data for prevention, early detection, management, and improvement of lameness.


  • Open Access

    Whole-Genome SNP Characterisation Provides Insight for Sustainable Use of Local South African Livestock Populations

    by Esté van Marle-Köster, Simon Frederick Lashmar, Anel Retief, Carina Visser

    Local cattle and sheep populations are important for animal production and food security in South Africa. These genetic resources are well adapted to the diverse climatic conditions and hold potential to be utilized in production systems subjected to climate change. The local beef breeds are well integrated into commercial livestock production systems with access to performance recording and genetic evaluations, while local sheep breeds are mainly utilised in smallholder and communal systems. The GeneSeek® Genomic Profiler™ Bovine 150 K SNP genotyping array was used to evaluate the diversity and inbreeding status of four indigenous (Boran, Drakensberger, Nguni, Tuli), two composite (Bonsmara and Beefmaster) and two exotic (SA Hereford and Charolais) beef breeds. The Illumina® Ovine 50 K SNP BeadChip was used to investigate five indigenous (Black Head Persian, Damara, Fat tail, Namaqua Afrikaner, Pedi) and three commercial (Dorper, Dohne Merino and SA Merino) populations. Although ascertainment bias was indicated by the low MAF (the autosome-wide proportion of SNPs with MAF< 0.05 ranged from 6.18 to 9.97% for cattle, and 7.59–13.81% for sheep), moderate genomic diversity was observed (mean Ho ranged from 0.296 to 0.403 for cattle, and 0.327 to 0.367 for sheep). Slightly higher levels of ROH-based inbreeding were calculated for cattle (FROH range: 0.018–0.104), than for sheep populations (FROH range: 0.002–0.031). The abundance of short ROH fragments (mean proportion of <4 Mb fragments: 0.405 for cattle, and 0.794 for sheep) indicated ancient inbreeding in both species. The eight cattle populations were categorized into indicine, taurine or Sanga subspecies based on principal component, model-based clustering and phylogenetic analyses, with high levels of admixture observed within the Drakensberger, Nguni and Tuli breeds. Within the sheep populations, a clear distinction could be seen between the dual-purpose breeds, the meat breed and the indigenous breeds. Despite directional selection practiced in the cattle breeds, genomic diversity was moderate with low inbreeding. The non-commercialized, indigenous sheep populations are more vulnerable with small effective populations. These results emphasise the value of genomic information for effective management to exploit the potential contribution of local genetic cattle and sheep resources in a changing environment.


  • Moving towards sustainable breeding objectives and cow welfare in dairy production: a South African perspective

    by Lize-Mari Erasmus, E. van Marle-Köster

    Genetic advancements have resulted in improved dairy production over many decades, due to the focus of breeding objectives on production as the driving force for genetic progress and overall farm profitability. Major advancements were made in the easy-to-measure traits with moderate to high heritability, which resulted in unintended consequences on herd fertility, health, and welfare of cows. In addition, climate change and animal welfare concerns demanded balanced breeding objectives and selection approaches for sustainable production—including health and longevity. The inclusion of genomic information into genetic evaluations has been proved to benefit traits associated with welfare and sustainable production. Cow welfare traits remain complex and suitable phenotypes are not always easy to measure or readily available for genetic evaluations. The challenge for improvement of cow welfare often lies within implementation of sensitive and measurable parameters. The aim of this review was to explore the reconsideration of breeding objectives in the dairy industry towards sustainable dairy production and cow welfare with reference to selection of dairy animals in South Africa.


  • Open Access

    Unintended consequences of selection for increased production on the health and welfare of livestock

    by Este van Marle-Köster, Carina Visser

    Modern farming technologies, including quantitative selection and breeding methods in farm animal species, resulted in increased production and efficiency. Selection for increased output in both intensive and extensive production systems has trade-offs and negative outcomes, often more pronounced in intensive systems. Animal welfare and health are often adversely affected and this influences sustainable production. The relative importance of animal welfare differs among developed and developing countries due to the level of economic development, food security and education, as well as religious and cultural practices which presents challenges for sound scientific research. Due to breeding goals in the past set on growth performance, traits such as fertility, welfare and health have been neglected. Fertility is the single most important trait in all livestock species. Reduced fertility and lameness, claw health and mastitis results in unnecessary culling and reduced longevity. Selection pressure for growth accompanied with inbreeding has resulted in a number of genetic defects in beef, sheep and pigs. This review demonstrated the importance of inclusion of animal welfare concepts into breeding objectives and selection strategies. Accurate phenotyping of welfare traits is a limiting factor in the implementation of mitigating strategies, which include diagnostic testing, control of inbreeding and genomic selection.