India’s economy is largely agrarian, with dairy farming serving as a vital contributor to agricultural growth and expansion. The income generated from dairy animals supports rural livelihoods and strengthens the sector’s sustainability. The livestock industry represents 5 per cent of the total GDP and contributes 18 per cent to the agricultural GDP (Press Information Bureau, 2024). The dairy industry in India is an alternate means of generating money and ensuring food security. Furthermore, it significantly contributes to the socio-economic development of rural areas by enhancing household incomes and generating sustainable employment opportunities, particularly for landless individuals and small or marginal farmers (Dash, 2017). The dairy industry encounters several disease-related challenges that contribute to significant economic losses from animal deaths and reduced output (Singh and Prasad, 2008). The livestock sector has faced significant challenges, including reduced investment, diminished resource efficiency and lower animal productivity due to disease outbreaks. Mastitis, a multifaceted and financially burdensome disease, is considered one of the most significant ailments affecting dairy herds (Beheshti et al., 2010). Ranked second to foot and mouth disease (Varshney and Mukherjee, 2002), this disease poses a significant challenge in high-yielding dairy animals. The study was conducted in the Ahmednagar district, which has the highest percentage share (9.2 per cent) of the cattle population in the state (20^th Livestock Census, 2019). The crossbred cattle are meant for milk production in the area. Hence, the present study aimed to analyze economic losses due to clinical mastitis in the crossbred cattle in the Ahmednagar district in Maharashtra state.
 
Study type, duration and questionnaire development
 
The present study utilized a combination of stratified sampling (based on rainfall levels) and multi-stage sampling (tehsil ® village ® household) from June 2015 to December 2016 in the Ahmednagar district of Maharashtra state.
       
The questionnaire was developed based on expert consultations with academicians from the National Dairy Research Institute, Karnal, India and a veterinarian from Rahuri Vidyapeeth, Ahmednagar. The questionnaire was structured to address socioeconomic profile, animal inventory, milk production data, clinical history, treatment cost, replacement cost of animals and other information, including closed and open-ended questions. The initial draft of the questionnaire underwent evaluation by three expert researchers to assess content validity and identify ambiguities. After a pilot test with ten dairy farmers and ten agriculture economics postgraduate students to refine its length, clarity and sequence, ambiguous or non-relevant items were removed, resulting in a final version.
 
Sample size
 
 The study targeted dairy farmers as the source population, with inclusion criteria requiring participants to own at least five dairy animals, regardless of land ownership.
       
Using the Raosoft sample size calculator (http://www.raosoft.com/samplesize.html?nosurvey), a sample size of 643 dairy milch population was estimated based on a 50% response distribution, a 5% margin of error and a 99% confidence level.  Fourteen tehsils of Ahmednagar district were categorized into three groups based on their precipitation levels: low, medium and high rainfall areas. From these categories, three tehsils were randomly selected from the low rainfall zone, two from the medium rainfall zone and one from the high rainfall zone. Two villages were chosen randomly from the selected tehsil. All households in the particular village were screened for clinical mastitis; those with complete information on all parameters were considered for the economic loss study.
 
Ethical considerations
 
The research adhered to the Declaration of Helsinki and complied with national standards. Participation in the study was voluntary, with participants being fully informed about the study’s objectives. They were assured that their personal information would remain confidential and be used exclusively for research.
 
Statistical analysis
 
The survey data were compiled in Microsoft Excel 2010, cleaned for inconsistencies and further analyzed using SPSS version 21.0 (SPSS Inc., IBM, Armonk, NY, USA).

The prevalence of clinical mastitis was calculated as,
   
Economic Loss Estimation
 
Economic losses due to clinical mastitis were estimated by summing up three components: milk loss, treatment loss and replacement loss cost, which were calculated as follows;
   
       
The present study assumed an average milk loss of 1 litre per day per affected animal due to mastitis, calculated for an average of 5 days at the milk rate of  ₹ 25 per litre to standardize calculations. This assumption was made to simplify the estimation process and represents a generalized average across lactation stages, severity of mastitis and regional variations. While actual milk loss may vary, ranging from 1.5-3 litres/day based on lactation stage and disease severity, this standardized value was chosen to facilitate uniformity in data analysis and reporting.
   
Replacement loss cost (₹) = Cost of new animal - Selling value of mastitis-affected animal
 
       
Replacement loss cost was only considered for those animals whose productivity and reproductive performance declined significantly due to mastitis, making them economically unviable to retain.
     
       
The present study obtained 211 (87.9%) responses out of 240 targeted surveys, with 180 (75%) respondents providing complete information. Surveys with incomplete information were eliminated from the study.
 
Demographic details
 
Most respondents (47.2%) of the present study were between 25-50 years old, whereas only 15% were below 25 years (Table 1). 


       
The majority of male respondents (66.1%) actively participated in the study. The survey showed that 32.2% of respondents were graduates and the majority of respondents were in the agriculture and dairy industry, but a considerable proportion of respondents (43.3%) were also active in other types of employment activities in addition to dairy farming (Table 1). The medium (36.1%) and large (30%) landholders had more than ten animals reported in the study.
 
Prevalence of clinical mastitis in different rainfall regions
 
The prevalence of clinical mastitis in high, medium and low rainfall regions was found to be 22.98% (n=315, milch crossbred population (MCBP)=1371), 17.88% (n=480, MCBP=2685) and 14.95% (n=578, MCBP=3865), respectively.
       
Higher prevalence in high rainfall areas due to increased moisture and muddy conditions, which promote bacterial contamination in bedding and milking environments. Damp conditions make it harder to maintain udder hygiene, while high humidity encourages bacterial growth, weakening animals’ immune defences. Proper barn drainage and improved hygiene practices can help mitigate the risks.
 
Economic losses due to clinical mastitis
 
The total economic loss due to clinical mastitis in regions with high, medium and low rainfall is shown in Table 2.  The milk loss resulting from mastitis in the crossbred cattle population observed in these rainfall regions amounted to ₹ 41879, ₹ 68861 and ₹ 81486, respectively.  Clinical mastitis in high-yielding animals results in significant milk losses and the current study noted a higher number (n=578) of clinical mastitis cases in low rainfall regions compared to other areas. This increased occurrence contributes to the higher associated costs in these regions. The calculation of milk loss in the current study used a standardized value of 1 litre per day per affected animal. This approach may underestimate actual losses in specific scenarios, such as acute cases during early lactation, where losses can be higher. Future studies could benefit from more precise data to capture variations in milk yield loss across different stages of lactation and clinical presentations.


       
The treatment costs for mastitis cases in high, medium and low rainfall regions were ₹ 281280, ₹ 422393 and ₹ 514162, respectively. The variation in treatment costs across different rainfall zones can be attributed to differences in accessibility and the frequency of veterinary visits. Although the unit cost of treatment per animal is relatively similar across regions- ₹ 892.95 in high rainfall areas, ₹ 880.98 in medium rainfall areas and ₹ 889.55 in low rainfall areas-the total treatment cost is higher in low rainfall zones due to a larger number of animals requiring treatment in these areas.
       
The replacement loss cost was calculated for those animals suffering from clinical mastitis whose production and reproduction performance had decreased and retaining such animals would result in a loss instead of a profit to the farmer. The replacement cost in high, medium and low rainfall regions was ₹ 146000, ₹ 232000 and ₹ 401000, respectively.  The number of animals replaced reported by the current study was 80, 120 and 145 from high, medium and low rainfall regions, respectively. The replacement loss cost varied from ₹ 1825 to ₹ 2766 across regions. The total replacement loss cost is higher in low rainfall areas because more animals were replaced than in other areas. The replacement cost difference is lower as farmers often sell animals during the subsequent lactation, or sell pregnant animals or recently calved animals, which fetch higher prices in the market.
       
The total economic losses in high, medium and low rainfall regions were calculated as ₹ 469159, ₹ 723254 and ₹ 996648, respectively. The per animal cost affected by clinical mastitis was ₹ 1489.39, ₹ 1506.78 and ₹ 1724.31 in high, medium and low rainfall regions, respectively.
 
Projected economic losses of clinical mastitis in Maharashtra state
 
The projected economic losses due to clinical mastitis in crossbred cows in Ahmednagar district were calculated based on the observed prevalence rate multiplied by the milch crossbred population and estimated loss per animal in the respective rainfall region of Ahmednagar district. The projected economic losses in the high rainfall region were ₹ 2.08 crore. The corresponding figure was ₹ 6.14 crore in the medium rainfall region and ₹ 5.9 crore in the low rainfall region of Ahmednagar district. A total projected economic loss due to clinical mastitis in the Ahmednagar district was reported to be ₹ 14.12 crore (Table 3).


       
The projected economic losses due to clinical mastitis in the high rainfall region of Maharashtra state were ₹ 4.67 crore; in the medium rainfall region were ₹ 18.35 crore and in the low rainfall region were ₹ 31.45 crore. A total projected economic loss in the crossbred cattle in Maharashtra state is estimated to be ₹ 54.47 crore (Table 3). It is important to understand that calculating exact losses is not feasible, as all figures are inherently estimates or projections. However, having a specific benchmark is essential for evaluating potential losses. This benchmark can be established by expected economic losses, providing a reference point for assessment. According to an estimate by Bansal and Gupta (2009), the total annual economic loss due to mastitis in India amounts to ₹ 7165.51 crores, with ₹ 503.49 crores attributed specifically to the Punjab region. In the current study, the estimated costs are significantly lower as the focus is solely on the crossbred cattle population, excluding buffaloes, non-descript cattle and indigenous breeds. Another researcher, Dua (2001), estimated the overall economic impact of mastitis in cows in Punjab at ₹ 46.57 crores. In comparison, the present study reports slightly higher economic losses of ₹ 54.47 crores, which may be attributed to differences in the timeline or the parameters used for economic estimation.
       
Christy (2014) estimated the annual economic loss due to mastitis in the Villupuram district at ₹ 7.07 crores, with a weighted average total direct economic loss of ₹  2086.96 per case. In contrast, the present study reported an average cost of ₹ 1573.49 per clinical mastitis case in the crossbred population of Ahmednagar district. This lower cost could be attributed to differences in timelines or variations in the livestock population considered in the studies. Another study by Rakesh et al., (2011) reported an economic loss of 124.88 crores in Uttar Pradesh due to clinical mastitis; in contrast, the present study noted the economic loss of ₹ 54.47 crores in the crossbred cattle population.
       
In the present study, the average economic loss per animal is significantly lower compared to Bardhan’s (2013) findings, which reported an average monthly loss due to mastitis per crossbred cow at ` 3206.55 in an optimistic scenario and ₹ 3549.59 in a pessimistic scenario. This difference may be attributed to regional variations in milk prices, differences in milk production across species and breeds, as well as varying agro-climatic conditions. Singh et al., (2014) reported an economic loss of ₹ 1314 per animal per lactation in crossbred cattle in Uttar Pradesh, which aligns closely with the findings of the current study. In contrast, Pvk et al., (2002) reported a much lower loss of ₹ 326 per infected cow from an organized dairy farm in Hyderabad and Fareed et al., (2017) noticed per animal economic loss of 640 Pakistan rupees in water buffaloes in Pakistan. This lower loss can be attributed to the implementation of best management practices and stringent herd health measures typically observed in organized dairy farms. Several researchers have observed discrepancies in production, treatment and total loss. These variances could be attributed to disparities in the calculating methodologies employed and differences in the periods under consideration. The occurrence of significant losses in crossbred cows highlights the need for specific attention to be given to the prevention of mastitis in dairy farms.