The effects of different levels of oocyst inocula of Eimeria acervulina, E. tenella, or E. maxima on plasma carotenoids, total plasma lipids, total plasma proteins, packed cell volume (PCV), bird performance, and coccidial lesion scores were determined in male Hubbard chickens. Each test consisted of an uninfected treatment and either four levels (E. tenella and E. maxima) or five levels (E. acervulina) of inocula. Carotenoids and lipids were significantly (P < or = 0.05) depressed by E. acervulina starting at 10(2) oocysts per bird, whereas 10(4) and higher inoculum levels significantly depressed plasma protein. Carotenoids and lipids were significantly depressed by E. tenella beginning at 10(4) oocysts per bird, whereas 10(2) oocysts per bird and greater levels significantly depressed plasma protein. E. maxima significantly depressed carotenoids and lipids beginning at 6.7 x 10(2) oocysts per bird and plasma protein at 6.7 x 10(4) oocysts per bird. PCV was depressed by E. acervulina and E. tenella starting at 10(4) oocysts per bird but was not affected by E. maxima. Weight gain was significantly depressed by E. acervulina beginning at 10(5) oocysts per bird, by E. tenella at 10(4) oocysts per bird, and by E. maxima at 6.7 x 10(4) oocysts per bird. Coefficients of determination (R2) were highest for carotenoids (0.96-0.99), followed by lipids (0.93-0.96), weight gain (0.89-0.91), feed:weight gain ratio (0.89-0.91), and protein and PCV (0.65-0.92). Results demonstrated that plasma carotenoids and lipids were excellent response variables for measuring the effects on broiler chickens of each of the Eimeria spp. tested.

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The volume of blood consumed by actively reproducing female cat fleas, Ctenocephalides felis (Bouché), while feeding in confinement feeding chambers on cats for 3 h, was investigated using two radionuclide blood tags (51Cr-erythrocyte and 125I-albumin) and the gravimetric method. Female fleas consumed an average of 0.110 ml (+/- 0.026 ml) of blood per 100 females in 3 h as determined using the dual radionuclide system. The single 51Cr-erythrocyte tag overestimated blood consumption by 11.3% and the single 125I-albumin tag underestimated blood consumption by 6.4%. The gravimetric method underestimated blood consumption by 72.2% compared with the dual radionuclide value. Investigations of blood consumption of nonconfined female fleas were conducted with cats housed in metabolic cages and restricted from grooming. These investigations were conducted using the single 51Cr-erythrocyte tag, and the data obtained were corrected to compensate for using a single erythrocyte tag. Female cat fleas consumed an average of 13.6 microliters (+/- 2.7 microliters) of blood per day, which was equivalent to 15.15 times their body weight. In an additional study, direct exposure to 40 kHz ultrasound did not reduce blood consumption by the fleas.

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