A comparison of British breed crosses with F1 and F2 Zebu X British cattle on the basis of a productivity index.

Summary F1 and F2 Africander x Shorthorn and Hereford (AX), Brahman x Shorthorn and Hereford (BX), and Shorthorn x Hereford (HS) were evaluated on an index of kg beef produced per cow mated, at weaning (250 days) and at 820 days of age. In the F1 generation mean fertility of the AX was slightly higher than that of the BX, but their growth rate was lower. Both the AX and BX were superior to the SH for fertility and growth rates. Thus in the F1 generations there was very little difference between the AX and BX in terms of a production index, but both were superior to the HS. In the F2 generation there was a significant decline in the fertility of the BX, relative to the F1 BX and F1 and F2 AX, but no significant change in weight gains. In the F2 generations the AX were therefore superior to the BX for the production index.