Lysine Requirements of Pre-lay Broiler Breed- Ers as Determined by the Indicator Amino Acid Oxidation Re-evaluation of the Lysine Requirement of the Commercial Laying Hen in a Corn-soybean Meal Diet. Dou- Reevaluation of the Isoleucine Requirement of the Commercial

s of papers 59 IBDV as a possible cause of proventriculitis. SPF leghorns were divided into 6 groups. At 4 weeks of age, the birds were challenged with Ark homogenate (Group 6), Ark + 1:10 Anti-Reovirus antibody (Group 5), Ark + undiluted Anti-Reovirus antibody (Group 4), Ark + 1:10 antiIBDV antibody (R63) (Group 3), Ark + undiluted anti-IBDV antibody (R63) (Group 2), and diluent (Group 1). Anti-Reovirus antibody is a commercial antibody against Reovirus, whereas R63 is a monoclonal antibody against IBDV. The antibodies were incubated with the Ark homogenate for virus neutralization before inoculating into the birds. At seven days post-infection, all groups except group 1 (control) had bursal atrophy. The mean proventriculus weight of group 2 was significantly smaller than all other groups and only 15% of the birds had proventricular lesions compared to the other groups having more than 50%. All of the Ark homogenate inoculated birds produced antibodies against IBDV as measured by ELISA, with Group 6 inoculated with Ark alone, having the highest titer. Undiluted R63 antibody significantly reduced the incidence of proventriculitis based on visual examination and prevented enlargement of the proventriculus based on weight. Anti-Reovirus antibody did not have any effect on the incidence or severity of proventriculitis.