Milk production and calf growth rate in Hereford, Africander - Shorthorn and Brahman - Shorthorn cattle in Queensland.

The daily -milk production of 67 Hereford cows at the C.S.I.R.O. Pasture Research Station, Samford, near Brisbane, and of 24 F1 Africander-Shorthorn and 19 F1 Brahman-Shorthorn cows at the National Cattle Breeding Station “Belmont”, near Rockhampton, was estimated at monthly intervals during summer and autumn by measuring the amount of milk secreted in 6 hr. intervals between injections of oxytocin. At Samford, there were positive correlations between estimated daily milk production and calf growth in successive months of 0.66, 0.66, 0.57, 0.30 and 0.67. The correlation of total milk production with calf growth rate to six months was 0.82. At “Belmont” there was a similar relationship between estimated daily milk production and calf growth rate. Lactation curves of the crossbred cattle were more varied and their milk yields were significantly higher than those of the Herefords at Samford. The Africander crossbreds had higher initial ‘milk yield than the Brahman crossbreds, but declined in yield more rapidly.