Author
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Powell, Rex |
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Submitted to: California Dairy
Publication Type: Trade Journal Publication Acceptance Date: 10/29/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: In response to concern expressed about biases against some States in comparison with others attributed to heterogeneous variance, a study was undertaken of the distribution of cows designated elite or in the top 1000 or 10,000 cows based on the milk-fat-protein dollars (MFP$) index. State means and standard deviations (SD's) for predicted transmitting abilities (PTA's) for milk, fat, and protein yields also were examined in relation to percentage of cows designated elite. Percentage elite and PTA were related, but no clear relationship was found between SD and percentage elite. No unfairness among States in percentage of cows designated elite or in the top 1,000 or 10,000 was apparent, especially between California and Wisconsin. Although Washington had a higher percentage elite and Pennsylvania had a lower percentage elite, they were both about average for the top 1,000 cows for MFP$. Nothing was found to impact the portion of the elite cows from a given State more than the size of the population from which selections are made. |
