Comparative responses of White Leghorn and New Hampshire chickens to experimental infections with Histomonas meleagridis and Heterakis gallinarium.

Experimental infections with Histomonas melegridis and Heterakis gallinarum were produced in young White Leghorn (W.L.) and New Hampshire (N.H.) chickens and Beltsville Small White turkeys (B.S.W.T.). Although the histomonads caused liver lesions and high mortality in B.S.W.T., infections in chickens were not fatal and were confined to the ceca. Cecal involvement in the W.L. was slightly more severe, but also more transitory, than in the N.H. With regard to length, survival, and reproductive capacity, the heterakids thrived best in the W.L. Furthermore, the W.L. had the greatest potential for disseminating Histomonas-bearing heterakid eggs. These findings are similar to those of a previous study with the same breeds of birds but with a different strain of W.L. Thus, the differences in responses according to breed were quite consistent, whereas any difference according to strain was insignificantly by comparison.