The Influence of Disease on the Performance of Beef Cattle

Abstract

Data obtained from three of the Milk Marketing Board's beef progeny tests, for which a careful monitor of individual health records is undertaken, have been used to examine the influence of certain disease categories on the performance of 935 beef steers. Eight categories were identified including salmonella infections, and were associated with reduced weights for age in the early growth period. There was evidence of compensatory growth in later life among animals affected with five of these, including enzootic pneumonia, enteric disease and infectious bovine keratoconjunctivitis. Production loss among Charolais × Friesian calves fed intensively in 1971 was 2.64%; among Aberdeen Angus × Friesian calves fed semi-intensively (1970) it was 3·06%; and among Hereford × Friesian calves fed semi-intensively (1971/72) it was 0·78%. Enzootic pneumonia, pneumonic consolidation and pleurisy together accounted for more than half of these losses, and for the majority of losses from fatal disease. Low serum immune globulin (Ig) levels in newly arrived calves were associated with increased susceptibility to respiratory disease, and two other syndromes. No correlation of Ig levels with enteric disease was demonstrated.