Strategic test-day recording regimes to estimate lactation yield in tropical dairy animals

Table 1 Comparison of different estimation methods and sampling protocols

Sampling protocol	Average peak and persistent tail		High peak and less persistent tail
Sampling protocol	Top 100_Med	MSPE_Med	Top 100_Med	MSPE_Med
Test-interval method
Weekly^†	96	2936	96	3112
Monthly^†	85	12385	88	13587
Quarterly^†	73	43621	77	71631
6 Test-days/lact^‡	82	26829	87	32229
5 Test-days/lact^‡	81	30649	86	35479
4 Test-days/lact^‡	81	35767	85	47048
Wood model estimation
Weekly^†	96	2613	96	2945
Monthly^†	87	10530	90	12098
Quarterly^†	73	31334	82	34508
6 Test-days/lact^‡	82	18511	87	20666
5 Test-days/lact^‡	81	21654	85	24964
4 Test-days/lact^‡	81	25306	84	30324

^†For the equally spaced estimation methods (weekly, monthly, quarterly) only one regime was tested and this value is reported here; ^‡for the different TDSR (m = 4, 5 and 6 test-days/lactation), the values presented here are the median top100 and MSPE values for all the TDSR tested that have at least 80 animals in common in the top 100 compared to the ‘true’ EBV.

ISSN: 1297-9686