Abstract :
Milk production data from Holstein3Zebu cows in small farms (2.4 cows per farm on average) in Maharashtra, India, followed
by Bharatiya Agro Industries Foundation (BAIF), an Indian non-governmental organisation, were analysed to evaluate the impact
of simplified milk-recording systems. The aim was to investigate, in developing tropical areas, less-costly protocols compared
with the one currently implemented at BAIF, used as a reference. The latter can be considered an ‘AT2’ protocol with the
recording made by specialised technicians at 2-week intervals. The simplified protocols were simulated from an initial data file
by sampling test days according to each protocol. Bias and accuracy on the 305-day cow milk production and on the resulting
reliability of the estimated breeding value of bulls were the criteria used in the comparison with the reference protocol. One
type of simplified protocol considered an increase in the interval between two tests to at least 4 and up to 8 weeks. Another
alternative studied corresponded to the situation where milk yield information measured by the farmer is collected by the
artificial insemination technicians themselves when visiting a farm. This could be an option in the case of very small herd sizes
(two or three cows). The results suggest that simplifying the current milk-recording protocol leads to a clear decrease in
accuracy of estimating 305-day cow production but it has a limited effect on the reliability of bull proofs. No economic
comparison was carried out, but the results strongly suggest that properly managed simplified milk-recording schemes could
permit a substantial decrease of costs of milk recording per cow without damaging the efficiency of progeny testing in tropical
areas with small herd size. Moreover, with the proposed simplified milk-recording protocols, up to three to four times more
bulls could be tested with the same number of records.
Keywords :
dairy cows , India , Milk recording designs , Tropics