Daily in-line milk analysis with a real-time milk analyzer, such as Afimilk's AfiLab system, may be more useful in predicting a cow's future lactation than monthly Dairy Herd Improvement Assn. (DHIA) tests, according to a recently published study of 37,486 Holstein cows conducted over a two-year period.
The study -- "Genetic & Phenotypic Analysis of Daily Israeli Holstein Milk, Fat & Protein Production as Determined by a Real-Time Milk Analyzer," selected for "Editor's Choice" in the December 2016 issue of the Journal of Dairy Science -- appears to validate the hypothesis that AfiLab's daily analyses of milk components provide a more representative measure of a cow's total lactation compared with monthly DHIA tests.
Joel Weller and Ephraim Ezra from the Agricultural Research Organization in Volcani Center, Israel, compared daily records of milk production, protein and fat concentration collected by the AfiLab with monthly test day records of the same statistics derived from the central laboratory of the Israel Cattle Breeders Assn. They concluded that real-time daily recording may be preferable to monthly DHIA testing based on several findings:
* Lactation means were similar for the two methods for all traits except fat production, with minor differences of up to 0.1%.
* First-parity heritabilities were higher for lactations computed from daily records for all traits except protein percentage, but differences were not significant.
* At only 30 days in milk (DIM), high genetic correlations ranging from 0.73 to 0.79 were observed between predicted and actual lactations using in-line milk sampling.
* Daily first-parity partial lactations for milk, fat and protein production with fewer than 150 DIM predicted future lactation more accurately than corresponding monthly partial lactations.