Performance of Holstein and crossbred dairy cattle in Louisiana. III. Health and viability.

Viability and health disorders were compared for straightbred Holsteins and crosses between Holsteins, Brown Swiss, Jerseys, and Red Sindhis. In addition, effects of mating systems and effects of various parts of Red Sindhi heredity on these traits were evaluated. Losses before first calving per 100 females born alive were: Holsteins 22; Holstein-sired crosses 20: Brown Swiss-sired crosses 26; daughters of crossbred sires group I (sires had from 1/4 to 1/16 Red Sindhi heredity) 24; and group II (sires were all European breeds) 31. Losses in first-gestation from abortions and stillbirths were: Holsteins 20% and crossbreds 9%. In first lactation, incidence of foot rot and anaplasmosis was higher among Holsteins (13% and 16%) than in crossbreds (5% and 8%) whereas the incidence was less among crosses with Red Sindhi heredity (3% and 2%) than in all European breed crosses (9% and 17%). When progeny produced by criss-crossing to purebred sires were compared with progeny from random mating to crossbred sires, the former had a greater incidence of mastitis (30% versus 19%) and anaplasmosis (11% versus 2%). There was no differences between Holsteins and crossbreds in overall viability. However, there was considerable variation between breeds at the various ages.