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Milk from eight Bos Taurus and Bos indicus × Bos Taurus breed types (n=128) was evaluated for percentage butterfat, protein, lactose and solids- non-fat. Milk samples were collected at approximately 60, 105, and 150 d after the onset of lactation by hand-milking the left front quarter following a 30-IU injection of oxytocin. Breed type variation was significant for some milk component traits at each stage of lactation. Brahman × Angus dams increased in component yields (kg) as lactation progressed; production levels of other breed types remained approximately the same or declined. Sex of calf influenced (P<.05) yield (kg) of protein, butterfat and solids-non-fat at 105 d only. Mastitis effects caused a reduction (P<.01) in percentage of lactose. Residual correlations between yield (kg) of milk components and weaning weight were all positive and significant.