Work

Culling Reasons in Industrial Dairy Farms of Western Tehran Province, Iran: A Herd‐Size Stratified Analysis and Management Implications

Year: 2026

Type: article

Abstract: This study investigated culling reasons in 27 industrial and semiindustrial dairy farms (15,907 cattle) in western Tehran Province, Iran, using records from 2010-2014 (with detailed analysis for 2012-2014). Herds were stratified by size: 20-100, 101-200, 201-500, and > 500 head. Milk yield increased with herd size (6955 to 8750 kg), while fat (4.06% to 3.86%) and protein (3.28% to 3.20%) decreased, showing strong negative correlations with yield (-0.79 to -0.89 for fat; -0.77 to -0.88 for protein) and positive correlations between fat and protein (0.91-0.94). Involuntary culling predominated (70%-76%), with reproductive disorders (15%-20%), mastitis (13%-15%), lameness (15%), and low milk yield as primary causes. Larger herds exhibited higher involuntary culling for health-related issues, consistent with findings that high milk yield is associated with deteriorated cow health and fertility. Herds of 201-500 head demonstrated optimal balance between productivity (mean 32 kg/day, 3.1% fat) and lower culling rates for mastitis, udder disorders, and lameness compared to larger herds. These findings indicate that targeted management and breeding strategies-including fertility-focused selection and proactive health monitoring-could reduce involuntary culling by 10%-15% and enhance herd sustainability in Tehran's dairy industry.

Source: Scientifica

DOI: 10.1155/sci5/9580301

Authors: Ahlam Advay, Mohammad Reza Sanjabi, Mohammad Zandi, Hamed Mohammadi

Institutions: Iranian Research Organization for Science and Technology, Payame Noor University

Language: English

Topic: Genetic and phenotypic traits in livestock

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $1,000