evaluation of protein/fat ratio in first DHI test milk for prediction of subsequent displaced abomasum in dairy cows

First DHI test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to evaluate milk protein/fat ratio (PFR) for prediction of subsequent DA in dairy cows. Odds ratio, sensitivity, specificity, and likelihood ratio were determined. Twenty-seven DA cases were matched to 3 control...

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Bibliographic Details
Published in:	Canadian journal of veterinary research Vol. 62; no. 2; pp. 144 - 147
Main Authors:	Geishauser, T.D, Leslie, K.E, Duffield, T.F.B, Edge, V.L
Format:	Journal Article
Language:	English
Published:	Canada 01-04-1998
Subjects:	abomasum Abomasum - abnormalities Animals Cattle - abnormalities Cattle Diseases - epidemiology clinical aspects dairy cows dairy herd improvement corporation dairy protein disease diagnosis evaluation False Positive Reactions Female lactation Lipids - analysis milk Milk - chemistry milk fat Milk Proteins - analysis Ontario parturition prediction Prognosis ratios Reproducibility of Results Sensitivity and Specificity Stomach Diseases - epidemiology Stomach Diseases - veterinary Ontario
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Summary:	First DHI test milk that was sampled prior to displaced abomasum (DA) diagnosis was used to evaluate milk protein/fat ratio (PFR) for prediction of subsequent DA in dairy cows. Odds ratio, sensitivity, specificity, and likelihood ratio were determined. Twenty-seven DA cases were matched to 3 controls per case by herd and calving date. Milk was tested at a median of 19 d after calving, which was 8 d prior to the median time of DA diagnosis. Adjusted for parity and days in milk, a protein/fat ratio < or = 0.72 was 8.2 times more likely to come from a cow subsequently diagnosed with DA than a protein/fat ratio > 0.72. Using the cut off value of 0.72, the sensitivity of PFR for DA was 80% and the specificity was 68%. A receiver operating characteristics curve indicated that the minimum sum of false negative and false positive results was at a PFR cut off value of 0.72. The likelihood ratio indicated that protein/fat ratios < or = 0.62 are 3.8 times more likely to come from cows that are diagnosed subsequently with DA than from cows without DA. The protein/fat ratio in 1st DHI test milk may predict subsequent DA in dairy cows.
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0830-9000