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The Effect of Eimeria tenella Infection and Testosterone Treatment on the Weight of the Bursa of Fabricius in Young Chickens

1973; Elsevier BV; Volume: 52; Issue: 3 Linguagem: Inglês

10.3382/ps.0521034

1525-3171

R. J. Visco,

Bird parasitology and diseases

E. tenella infections of young male and female chicks caused a premature regression of the bursa of Fabricius. Seven or 11 days after infection, the mean uncorrected bursa weights of parasitized male and female chicks were significantly less than those of uninfected control chicks. The mean corrected bursa weights (per 100 gm. total body weight) were also significantly less in E. tenella-infected chicks than in uninfected controls, but, since the growth of infected chicks was significantly retarded, these differences were not as great as those between mean uncorrected bursa weights. Intraperitoneal injection of testosterone also caused significant reduction in the mean corrected and uncorrected bursa weights of male and female chicks when compared to oil-injected controls. Weight gain was reduced in the testosterone-injected chicks and, 12 days after injection, the “growth indices” of testosterone-treated male and female chicks were significantly less than those of oil-injected controls. After both E. tenella infection and testosterone injection of young male and female fowl, the mean uncorrected weights of their bursae were lower than those of either E. tenella-infected or testosterone-treated birds. The corrected mean bursa weights of infected, testosterone-injected chicks were similar to those of uninfected testosterone-injected controls and less than those of E. tenella-infected oil-injected chicks. In 2 of 3 trials, infected, testosterone-treated male birds had corrected mean bursa weights significantly less than those of infected, oil-injected males. The mean bursa weight of female chicks in all groups tended to be less than those of similarly treated males but in no cases were their corrected mean bursa weights significantly different.