Weights for the Maternal Relatives of Sires

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Abstract
An intraherd selection index for fat-corrected milk was developed both for 1st records and for all records utilizing the regressed AI proofs of 126 Holstein bulls as the dependent variable with the independent variables being the cow (dam of the bull), her dam (79), daughters (258), maternal sisters (171), and paternal sisters (5910). All records of the cows averaged 1420 lb of milk above herd average and 1st records were 1847 lb above herd average. The weights for the dam and the paternal sisters were negative. The weights for all records of the cow were negative when large numbers of relatives were available. The index using 1st records was superior to the index using all records in predicting a cow''s breeding value when a large and small number of relatives were available. The index using all records was superior when an intermediate number of relatives were available.