The correlation between the average daily gain of calves and the reconception of their dams as a screening test when investigating problems with fertility in beef herds.

A regression line (y = 32,025 + 140,223 x) between the average daily gain of groups of beef calves from birth to weaning and the reconception of their dams during a breeding season of three months within the lactation period was calculated by means of a weighted regression analysis. The records of five herds of Africander x exotic breed crosses from different owners in the central and northern Transvaal were used for this purpose. The 80% prediction band was also calculated. This band included all the observation points from apparently normal herds under varying nutritional levels. The points calculated from herds infected with venereal disease or where a bull was infertile fell outside the band while values from herds where the growth rate of the calves was restricted by pathological conditions fell on the other side of the band. It is suggested that setting out data in this manner may be of value as a screening test when investigating fertility problems in beef herds.