Achmad Fadillah

Mastitis adversely affects milk composition as well as milk processing by dairy factories and poses a costly problem for dairy farms worldwide. Mastitis reduces milk production and milk quality, increases the risk of culling, raises treatment and labour costs, and may have long-term animal health and economic consequences on the dairy farm. Improving milk quality can be achieved by enhancing udder health through effective mastitis management.

Smallholder dairy farming plays a pivotal role in milk production globally. Approximately 53% of the world’s dairy production takes place in low- and middle-income countries, predominantly produced by smallholder farmers, with Asian countries accounting for 42% of this global production. Mitigating mastitis in these regions can have a considerable impact on total milk production, milk quality, and costs of production. However, improving milk quality and mitigating mastitis in smallholder dairy farms presents numerous challenges. Much of our current knowledge on mastitis, its economic impact, and intervention and monitoring strategies comes from high-income countries with generally larger dairy farms, while similar research in smallholder farms in low- and middle-income countries remains limited.

Indonesia is one of the countries dominated by smallholder dairy farms and faces significant challenges with mastitis, with a high subclinical mastitis prevalence. This high prevalence can be attributed to the absence of udder health monitoring, inadequate hygiene practices, poor udder health management, and a lack of knowledge and training in mastitis prevention and treatment. Milk quality, udder health status, and the potential for reducing the economic burden of mastitis have been studied in many countries throughout the world. However, such knowledge remains limited in smallholder dairy systems across Southeast Asian countries, including Indonesia. This underscores the need for interdisciplinary research, combining epidemiology and economics, to support smallholder dairy farmers in enhancing milk quality and mastitis management, thereby improving their livelihoods and achieving sustainability in dairy farming.

There is insufficient knowledge of milk quality, udder health, and the economic impact of mastitis in Indonesian smallholder dairy farms. Therefore, the overall objective of this thesis is to investigate milk quality, mastitis management, and economic performance in Indonesian smallholder dairy farms. This research aims to provide comprehensive insights and practical solutions to support smallholder dairy farmers. The overall research objective of this thesis was divided into five specific objectives:
1. To assess smallholder dairy farmers' awareness regarding milk quality parameters, and to identify factors associated with these awareness levels.
2. To identify risk factors associated with milk quality parameters (somatic cell count; SCC and total plate count; TPC) in smallholder dairy farms.
3. To analyse the economic performance of smallholder dairy farms related to milk quality parameters (SCC and TPC), dairy farm characteristics, and management practices.
4. To estimate the costs of mastitis in smallholder dairy farms and to assess the cost-efficiency of different mastitis control strategies.
5. To assess the cost-effectiveness of SCC monitoring systems in smallholder dairy farms by dairy cooperatives.

Applying empirical study, Chapter 2 focuses on Indonesian smallholder dairy farmers' awareness of milk quality parameters. It provides foundational insights into the current level of milk quality awareness and identifies factors influencing this awareness, thereby setting the stage for targeted awareness programs by dairy cooperatives. A cross-sectional study of 600 smallholder dairy farming households was conducted in West Java, Indonesia from August to September 2017. Factors putatively associated with awareness of TPC were investigated with multinomial regression models while a Firth-type logistic regression was applied to identify factors associated with SCC awareness. The study found that factors such as the milk cooperative, distance to other farmers, technology adoption, buyer priority on TPC, milk production information, and cow health information were associated with farmers' awareness of TPC. Additionally, milk cooperatives, dairy business experience, and milk quality test adoption were associated with farmers' awareness of SCC. Cooperative was the only variable that was significant in both final statistical models. This indicates that cooperatives play an important role in increasing farmers' awareness of milk quality parameters in these smallholder dairies.

Chapter 3 describes an epidemiological study that evaluated risk factors putatively associated with two milk quality parameters, SCC and TPC, in Indonesian smallholder dairy farms. Identifying these risk factors is crucial for developing effective management strategies to improve udder health and milk quality. A cross-sectional study of 119 smallholder dairy farmers in Cianjur District, West Java, Indonesia was conducted in April 2022. Risk factors associated with dairy farms’ SCC and TPC were investigated using multivariable population-averaged generalized estimating equations (GEE) models. Several factors were associated with SCC, including manure removal frequency, mastitis treatment training, washing udders with soap, the number of workers on the farm, and pasture area ownership. Furthermore, manure removal frequency and the contribution of dairy farming to household income were associated with TPC. These findings be used as a starting point to improve udder health and milk quality in Indonesia.

Chapter 4 describes a study that examined the economic performance of smallholder dairy farms in relation to milk quality parameters. It explores the associations between SCC, TPC, and economic outcomes. Data from 118 farms in Cianjur District, West Java, Indonesia, were collected in April 2022 through surveys, bulk milk tests, and dairy cooperative records. Data envelopment analysis was used to calculate the technical efficiency score for each farm. Generalized estimating equations and bootstrap truncated regression modelling were used to explore the association of 62 independent variables with the gross margin and the technical efficiency, respectively. The economic analysis in Chapter 4 reveals that improved milk quality, better udder health, a higher ratio of adult cows per livestock unit, and more frequent mastitis treatment trainings were associated with increased gross margins. Moreover, improved udder health and more frequent mastitis treatment trainings were also linked to increased technical efficiency. These findings are useful for informing Indonesian smallholder farmers about the economic benefits of actively improving udder health practices.

Utilizing a stochastic Monte Carlo bio-economic simulation modelling, Chapter 5 describes a study that estimated the economic impact of mastitis in Indonesian dairy farms and evaluated various mastitis management interventions. The model simulates the dynamics of individual cows, herd demographics, mastitis incidence, the economic consequences of mastitis, and the effects of mastitis control strategies. Input data parameters were collected from literature, experts’ insights, and the author's expertise. Chapter 5 underscores the significant economic burden of mastitis on smallholder farms, emphasizing the need for effective control strategies to enhance profitability. The total costs of mastitis was €175 per farm per year. Among the evaluated strategies, post-milking teat disinfection emerged as the only cost-efficient intervention for reducing mastitis incidence and associated costs. Chapter 5 offers evidence-based recommendations on the cost-efficiency of udder health improvement strategies, helping farmers to make informed decisions on mastitis control.

Building on the simulations of Chapter 5, Chapter 6 describes a stochastic Monte Carlo bio-economic simulation model that assessed the cost-effectiveness of SCC monitoring systems in Indonesian smallholder dairy farms. The model mimics the SCC dynamics of individual cows across 100 farms within a single MCP. Subsequently, various SCC monitoring systems based on two diagnostic equipment, three alert algorithms, and three measurement frequencies were assessed for their diagnostic performance and total costs. This study found that the SCC monitoring system using a theoretical future diagnostic equipment with weekly measurements and applying the first algorithm demonstrated the lowest mean cost-effectiveness ratio, making it the most cost-efficient monitoring system for smallholder dairy farms in Indonesia. Chapter 6 highlights the importance of evaluating both sensitivity and costs when selecting SCC monitoring strategies.

In Chapter 7, the findings in this thesis are integrated and the results are combined to offer practical guidance for dairy farmers and cooperatives to enhance milk quality and improve mastitis management in smallholder dairy farms.

Based on all findings, the most important conclusions of this thesis are as follows:
- Combining empirical studies (Chapters 2-4) and simulation studies (Chapters 5-6) provides a comprehensive understanding of milk quality and mastitis control in smallholder dairy farms, highlighting the value of an interdisciplinary approach that integrates epidemiological and economic analyses to address complex challenges and offers practical solutions.
- Findings from Chapter 2 highlight the need to enhance farmers’ awareness of milk quality (SCC and TPC) as a precursor to successful milk quality and udder health improvement efforts in smallholder dairy farms.
- Chapter 3 identified five risk factors—manure removal frequency, receiving mastitis treatment training, washing the udder with soap, number of labour, and ownership of the pasture area—that are associated with SCC. Additionally, manure removal frequency and dairy income contribution were found to be associated with TPC. These epidemiological findings lay the foundation for economic performance analysis (Chapter 4), ensuring a clear understanding of the risk factors associated with milk quality and udder health in Indonesian smallholder dairy farms.
- Chapter 4 reveals that improving milk quality and udder health can increase technical efficiency and the gross margin of smallholder farms. These findings complement the epidemiological findings from Chapter 3, offering more valuable insights for mastitis control in smallholder dairy farms.
- Chapter 5 quantifies the significant economic burden of mastitis on smallholder dairy farms, showing that the total cost of mastitis can represent up to 36% of the annual gross margin of farms (Chapter 4). This underscores the need for efficient control strategies in smallholder dairy farms. Among the evaluated strategies, post-milking teat disinfection was identified as the only cost-efficient strategy for reducing mastitis incidence, milk production losses, SCC, and mastitis-related costs.
- Investment in the development of an affordable yet accurate diagnostic monitoring system is advisable (Chapter 6). This SCC monitoring system should be combined with findings from empirical and modelling studies (Chapters 2-5) to generate greater benefits for smallholder dairy farmers and cooperatives.
- The findings from Chapters 2-6 can serve as a reference and guidance for developing and implementing national mastitis control programs in Indonesia and other tropical regions where smallholder farms play a significant role in dairy production. The proposed program addresses the constraints faced by smallholder farmers by prioritising cost-effectiveness, cooperative-led implementation of initiatives, and collective approaches to milk quality and mastitis monitoring and interventions.

These integrated findings provide practical recommendations for national mastitis control program implementation, aiming to improve mastitis control and milk quality in smallholder dairy systems, with broader implications for regional, national, and global level strategies.