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

dc.contributor.advisor Diane M. Spurlock
dc.contributor.author Shonka, Brittany
dc.contributor.department Animal Science
dc.date 2018-08-11T04:02:18.000
dc.date.accessioned 2020-06-30T02:55:33Z
dc.date.available 2020-06-30T02:55:33Z
dc.date.copyright Wed Jan 01 00:00:00 UTC 2014
dc.date.embargo 2015-11-13
dc.date.issued 2014-01-01
dc.description.abstract <p>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.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/etd/14269/
dc.identifier.articleid 5276
dc.identifier.contextkey 7842455
dc.identifier.doi https://doi.org/10.31274/etd-180810-3821
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath etd/14269
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/28455
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/etd/14269/Shonka_iastate_0097M_14559.pdf|||Fri Jan 14 20:17:21 UTC 2022
dc.subject.disciplines Agriculture
dc.subject.disciplines Animal Sciences
dc.subject.keywords Animal Breeding and Genetics
dc.subject.keywords dry matter intake
dc.subject.keywords heritability
dc.subject.keywords Holstein cow
dc.subject.keywords lameness
dc.subject.keywords pre-calving intake
dc.title Genetic parameters for pre-fresh intake and the effects of lameness on feed intake and milk production in dairy cattle
dc.type article
dc.type.genre thesis
dspace.entity.type Publication
relation.isOrgUnitOfPublication 85ecce08-311a-441b-9c4d-ee2a3569506f
thesis.degree.level thesis
thesis.degree.name Master of Science
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