Search results for "genetic evaluation"
showing 2 items of 2 documents
Suitability of simplified milk recording methods for genetic evaluations using test-day models in dairy sheep
2008
Nowadays in dairy sheep, test-day records are collected monthly under an alternate morning/evening system. This alternate system was implemented because of the steady increase in recording cost per sheep observed in the last few decades. Furthermore, additional modifications to the testing schemes have been proposed to reduce the costs of milk recording. In dairy sheep, the cost for milk recording is indeed too high compared both with individual outputs and with other dairy species. Therefore, the purposes of the present study were: i) to compare estimated breeding values (EBVs) for milk yield using different simplified testing schemes with a test-day sire model; ii) to evaluate the effect …
Effects of different simplified milk recording methods on genetic evaluation with Test-Day animal model
2007
The aims of the present study were to compare estimated breeding values (EBV) for milk yield using different testing schemes with a test-day animal model and to evaluate the effect of different testing schemes on the ranking of top sheep. Alternative recording schemes that use less information than that currently obtained with a monthly test-day schedule were employed to estimate breeding values. A random regression animal mixed model that used a spline function of days in milk was fitted. EBVs obtained with alternative recording schemes showed different degrees of Spearman correlation with EBVs obtained using the monthly recording scheme. These correlations ranged from 0.77 to 0.92. A redu…