Cross validation of cut–off limit estimations for milk indicators of subclinical ketosis

Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis

Petr Roubal¹  Oto Hanuš¹  Marcela Klimešová Vyletělová¹  Gustav Chládek²  Daniel Falta²  Eva Samková³ 

[1] Dairy Research Institute, Ltd., Prague, Ke Dvoru 12a, 160 00 Praha 6 - Vokovice, Czech Republic;Department of Animal Breeding, Mendel University in Brno, 613 00 Brno, Zemědělská 1, Czech Republic;Faculty of Agriculture, University of South Bohemia České Budějovice, Branišovská 1, 370 05 České Budějovice, Czech Republic;

关键词: dairy cow;    individual milk sample;    milk composition;    energy quotient;    subclinical ketosis identification;   

DOI  :  10.11118/actaun201361061661

来源: DOAJ

【 摘 要 】

Real time analyses of main milk components are attended in milking parlours today. Breeders can know milk composition regularly. Energy (ketosis) milk quotients such as fat/crude protein (F/CP) and fat/lactose (F/L) could be essential for ketosis prevention and losses which can be linked with it. Aim was to do a reciprocal validation of reliability of milk indicators for subclinical ketosis (SK) identification. There were: dairy cows on 1st and other lactations free of clinical and superior subclinical mastitis; 3 herds of Czech Fleckvieh (CF) breed, 3 herds of Holstein (H) breed and 1 herd with CF and H; 329 individual milk samples from summer and winter season and 1st third of lactation. Average milk yield varied from 5,500 to 10,000 kg per lactation. Thresholds of F/CP and F/L were estimated (P < 0.05) according to SK milk acetone cut–off limit (≥10 mg.l−1). These were: for first lactation 1.27 (CF) and 1.32 (H), for other lactations 1.52 (CF) and 1.42 (H) in F/CP; for first lactation 0.84 (CF) and 0.84 (H), for other lactations 0.87 (CF) and 0.85 (H) in F/L. They were used for cross validation (P < 0.001) in the same order: 1.251, 1.31, 1.31 and 1.383 in F/CP; 0.831, 0.821, 0.989 and 0.852 in F/L. Validated cut–off limits are quite similar to their original values. It confirmes good reliability of original limits. The validated cut–off limits of milk indicators (F/CP and F/L) for SK in early lactation can be used at technological innovation in animal husbandry. Use of both quotients could improve the regular investigation of SK in practice.

【 授权许可】

Unknown