Resumo

RODRIGUEZ NEIRA, Juan Diego; CORREA LONDONO, Guillermo Antonio  e  ECHEVERRI ZULUAGA, José Julián. Prediction Models for Total Milk Yield and Fat Percentage Using Partial Samples. Rev. Fac. Nac. Agron. Medellín [online]. 2013, vol.66, n.1, pp.6909-6917. ISSN 0304-2847.

This research aimed to present prediction models for daily total milk yield and percentage of total fat from the partial productions in the morning (a.m.) and the afternoon (p.m.). This research was carried out with three dairy herds in Antioquia. 182 Holstein dairy cows milked twice a day were sampled monthly over a year. Recorded data included: information on entering time, milk yield, fat percentage, parity, days in milk, calving season and milking intervals. Predictive models were created from multiple regression analysis. The effects of duration of days in milk, milking interval, birth number, fat percentage and the quadratic terms of the previously mentioned effects were significant for the percentage of fat per day and the total milk production per day. Fat percentage and total milk production are affected by different environmental factors. In order to have more accurate estimates of production, it is necessary to consider adjustment factors for the known effects.

Palavras-chave : Environmental effects; mathematical models; adjustment factors; genetic improvement.

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