Metaanalysis of ketosis milk indicators in terms of their threshold estimation

Abstract

Real time analyses of main milk components are attended in milking parlours today. Regular day information without delay is advantageous. Farmers can know milk composition every day. They can calculate milk energy quotients, identified subclinical ketosis in early lactation of dairy cows and thus improve ketosis prevention and avoid economical losses. Aim was to improve the estimation reliability of thresholds of milk indicators of energy metabolism for subclinical ketosis detection and its prevention support by metaanalysis. This can have higher result reliability than individual studies. Results of similar papers were analysed. These were focused on ketosis indicators in milk (acetone (AC) and milk energy quotients (fat/crude protein, F/CP; fat/lactose, F/L)) and their thresholds for subclinical ketosis. Methods for threshold derivation were specified: – statistically to reference procedure; – calculation according to relevant data frequency distribution; – qualified estimation; – combinations of mentioned procedures. This was as weight source. Variability in AC subclinical ketosis cut–off values was high (78.5%) and in ketosis milk quotients was low (from 5 to 8%). The value 10.57 mg.l−1 could be the validated estimation of milk AC cut–off limit for subclinical ketosis identification. Similarly the milk quotients F/CP and F/L 1.276 and 0.82. The F/CP F/L relationship is closer in 1st third of lactation (0.89; P < 0.001) than in whole lactation (0.86; P < 0.001). This could be one of proofs of ability for subclinical ketosis identification because the majority of cases occurs in early lactation. The improved estimations of thresholds of milk indicators in early lactation for subclinical ketosis can be used at this technological innovation. Combined use of both quotients could bring an improvement of regular diagnosis of subclinical ketosis.

Keywords

• dairy cow
• health
• individual milk sample
• acetone
• milk energy quotients
• subclinical ketosis identification