AN EVALUATION OF THE GROWTH-PERFORMANCE, CARCASS CHARACTERISTICS, ANDMEAT QUALITY OF SAHIWAL-FRIESIAN CROSS BULLS

Sahiwal-Friesian cross (Sa-X) bulls (n = 39) were run with Friesian (F r) bulls (n = 40), Hereford-Friesian cross (He-X) bulls (n = 39), and either Charolais-cross (year 1) or Simmental-cross steers (n = 40) in an all-pasture system on hill country in New Zealand from an age of ab out 4 months. The heavier half of each group was slaughtered at an age of about 20 months and the remainder at about 28 months. The Sa-X bul ls along with the two other bull groups grew faster than the steers, b ut within the bull groups the Sa-X group grew more slowly over some pe riods. Differences in dressing-out percentage between the groups were small, but slightly higher for the Sa-X group relative to the Fr bulls . All bull groups were less fat than the steers, and the Sa-X bulls ha d more kidney and pelvic fat than the Fr bulls. Beef from the M. longi ssimus thoracis of Sa-X bulls was tougher (higher shear force values) than that from the other two bull groups, but not significantly differ ent from beef of the steers. These differences in shear force were ass ociated with differences in ultimate pH, with mean values for the stee rs being lower than the Sa-X bulls, which were lower than for the othe r two bull groups. After adjustment for pH differences, Warner-Bratzle r peak force values remained higher for the Sa-X group, but there were no differences between the other three groups. Shear force values for the 28-month age group were higher than for the 20-month group both b efore and after adjustment for pH differences. These patterns were sim ilar for meat aged for either 1 or 20 days. It is concluded that that Sa-X bulls will grow slightly more slowly than Fr or He-X bulls on hil l country, and that beef from such bulls is more likely to be tough.