Genetic parameters for pre-fresh intake and the effects of lameness on feed intake and milk production in dairy cattle

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2014-01-01
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Shonka, Brittany
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Diane M. Spurlock
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Animal Science

The Department of Animal Science originally concerned itself with teaching the selection, breeding, feeding and care of livestock. Today it continues this study of the symbiotic relationship between animals and humans, with practical focuses on agribusiness, science, and animal management.

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The Department of Animal Husbandry was established in 1898. The name of the department was changed to the Department of Animal Science in 1962. The Department of Poultry Science was merged into the department in 1971.

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Dry matter intake (DMI) is an important topic of research in dairy cattle. It is often studied relative to feed efficiency and disease. However, there are gaps in the current knowledge of DMI that remain to be filled. The objectives of the current study aimed to fill these gaps by estimating genetic parameters for DMI during the pre-fresh transition period, as well as examining the impact of lameness on DMI and milk production. In the current study, DMI during the dry period was moderately heritable, and had a high genetic correlation with lactating intake. This finding indicates DMI may be under similar genetic regulation during the dry period and lactation. Also, a low genetic correlation was found between the magnitude of intake depression before calving and other DMI traits, suggesting that the decline in DMI at parturition would be minimally affected by selection for DMI at other time points. It was confirmed that lameness has a negative effect on milk production and feed intake in lactating dairy cattle. Milk production decreased earlier than intake when comparing daily averages in the days before treatment, suggesting that decreased intake may not be the cause of decreased production surrounding a lameness event. Milk production also did not return to pre-treatment levels, indicating a lasting effect of lameness. When compared to the average of healthy cows, lame cows deviated in both intake and milk production for the days surrounding treatment for lameness. After treatment, milk production of multiparous cows gradually returned to pre-treatment levels, whereas primiparous cows recovered more quickly. The effects of lameness can be seen for at least two months after treatment for both DMI and milk production.

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Wed Jan 01 00:00:00 UTC 2014