Cow-level Production Traits and Their Association with Mastitis and Metabolic Disorders in Dairy Cows Raised in an Intensive Farming System under Tropical Weather

Abstract

Aims: This study aimed to assess farm and cow-level production characteristics and identify factors associated with milk yield and mastitis occurrence in dairy cows managed under intensive systems in Dhaka, Bangladesh. Study Design: A cross-sectional observational study. Place and Duration of the Study: Five dairy farms located in different regions of Dhaka district, Bangladesh, and data collected from 1 January to 31 December 2023. Methodology: Data was collected through face-to-face interviews with farmers and by reviewing farm register books. A structured, pretested questionnaire was used to record farm-level variables (roughage and concentrate quantities, number of lactating cows, daily milk yield) and cow-level characteristics (breed, age, body weight, BCS, parity, lactation stage, feed intake, and disease frequency). Twenty-five cows (five per farm) were randomly selected. Descriptive statistics were performed, and categorical variables were expressed as percentages. Univariable linear regression was conducted using milk yield as the outcome variable, with significance set at p ≤ 0.20. Results: The farms averaged 45 lactating cows producing 670 litres per day (15 litres/cow/day), with mean daily roughage and concentrate intake of 934.4 kg (20.76 kg/cow/day) and 475.4 kg (10.56 kg/cow/day), respectively. Most cows were crossbred (96%), aged ≤6.4 years (52%), and had good BCS (60%). Milk fever (96%), acidosis (72%), and mastitis (60%) were common. Body weight (β=1.4) and roughage intake (β=1.5) showed positive associations with milk yield, whereas BCS and mastitis showed negative trends. Mastitis was more frequent among cows with higher milk yield, higher parity, and roughage intake of 21.1–30 kg/day. Conclusion: Cow-level traits, nutritional intake, and lactation factors influence milk yield and mastitis risk in intensive dairy systems, indicating the need for improved feeding management and targeted health interventions.