Effect of thymectomy on growth, hematology, and immunological response of dairy calves.

Abstract Twelve Holstein and seven Brown Swiss were thymeetomized, and 12 Holsteins were sham-operated 24 to 48 hours after birth. All were raised to 18 to 20 weeks of age. In Experiment I (six thymeetomized and six sham-operated Holsteins) lymphocyte counts increased in both groups following injections of whole sheep blood at 13 weeks. Sham-operated calves showed the greatest increase (P