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Culling reasons relationship with milk yield, type and parity of Iranian Holstein cows
Published online by Cambridge University Press: 22 November 2017
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Culling is the act of identifying and removing a cow from a herd and, assuming a constant or expanding herd size, replacing the cow with another cow, often a first-lactation heifer. The culling rate describes the percentage of cows removed from a herd. Understanding culling rates is important for managing dairy production response and profitability. When dairy farm managers cull cattle too often or too quickly, replacement expenditures are excessive. When managers keep cattle for too long, milk production, reproduction, or genetic improvement may be impaired. Past research has consistently estimated optimal herd-level culling rates ranging from 19 to 29%. Researches found that poor reproduction rate was the primary reason for culling, followed by low production and mastitis. Higher milk producing herds were more likely to cull a cow for abortion and reproduction, but less likely to cull for mastitis. So the objective of this study was to investigate the relationships between different reasons of culling and age at time of culling, mean type score of cows, parity at the time of culling, total milk production at 1st parity.
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- Copyright © The British Society of Animal Science 2008