Currently TIM is the accepted procedure in the US for estimating lactation yield from test day data.Daily yields from 658 Canadian Holsteins and information on US testing frequencies from 100,000 cows were used to determine whether BP methods could estimate lactation yields more accurately than TIM.For the traditional environment of MN tests, a moderate decrease in estimation error (4%) was found for BP methods compared with TIM in estimating 305-d actual milk yield. For AP and TRI testing, the decreases in estimation error were 6 and 10%, respectively. Because 60% of the US cows on test are en-rolled in an AP plan in which intervals between test shave increased and components are not sampled at each test, new procedures that more accurately predict lactation yields for such plans (such as the BP method) should be considered as replacements for TIM. However, further research is needed to examine the accuracy of BP for projecting records in progress to 305 d
Comparison of Test Interval and Best Prediction Methods for Estimation of Lactation Yield from Monthly, a.m.–p.m., and Trimonthly Testing (PDF Download Available). Available from: https://www.researchgate.net/publication/13221765_Comparison_of_Test_Interval_and_Best_Prediction_Methods_for_Estimation_of_Lactation_Yield_from_Monthly_am-pm_and_Trimonthly_Testing [accessed May 8, 2016].