Effect of time on response to Eimeria adenoeides and Eimeria meleagrimitis infection in young turkeys.

Physiologic characteristics were measured on day 7 postinoculation (PI) in 2-week-old turkeys inoculated with 10(5) Eimeria adenoeides oocysts, in pair-fed controls, and in control turkeys fed ad libitum. Pathophysiologic responses were measured in turkeys inoculated with 7 x 10(4) E. adenoeides oocysts or 1.2 x 10(5) E. meleagrimitis oocysts and necropsied 2, 4, 6, 8, 10, 15, and 21 days PI. At day 7 PI, weight gains and heart weights (as a percentage of body weight) of E. adenoeides-infected turkeys were significantly lower and plasma glucose levels significantly higher than those of pair-fed counterparts. Plasma carotenoid and protein levels of the infected turkeys were significantly lower than those of the controls fed ad libitum and were consistently, but not always significantly, lower that those of the pair-fed controls. Significant responses were first observed in E. meleagrimitis-infected turkeys on day 4 PI and in E. adenoeides-infected birds on day 6 PI. Birds infected with both species commonly had reduced weight gains, heart weights, and plasma carotenoid levels and increased plasma aspartate aminotransferase levels. Plasma carotenoids in E. adenoeides-infected turkeys were significantly reduced on day 6 PI only, whereas plasma carotenoids in E. meleagrimitis-infected turkeys were sometimes reduced significantly as early as day 2 PI and remained significantly lower than control values through day 21 PI.