Effect of testosterone on the pharmacokinetics of sulphadimidine and sulphachloropyrazine in roosters--a preliminary report

Determination of sulphachloropyrazine-diaveridine residues by high performance liquid chromatography in broiler edible tissues

Diaveridine (DVD) is used in combination with sulphachloropyrazine (SPZ) as an effective antibacterial agent and antiprotozoal agent, respectively, in humans and animals. To gain a better understanding of the metabolism of SPZ and DVD in the food-producing animals, a high performance liquid chromatography (HPLC) method to determine and quantify sulphachloropyrazine (SPZ) and diaveridine (DVD) suspension residues from broilers is reported. Thirty healthy chickens were orally administered with sulphachloropyrazine-diaveridine (SPZ-DVD) suspension in water of 300 mg/l (SPZ) per day for seven successive days. Six chickens per day were slaughtered at 0, 1, 3, 5 and 7 days after the last administration. This procedure permitted SPZ and DVD to be separated from muscle tissue, liver, kidneys and skin with fat after extraction with acetonitrile and acetone under slightly acidic conditions. From the detected residuals in different tissues, we found that SPZ was quickly eliminated in liver and muscle, and slowly eliminated in kidney and skin with fat. DVD was quickly eliminated in liver and slowly eliminated in kidney. The withdrawal period of SPZ was 3.26, 3.72, 4.39 and 5.43 days in muscle, liver, kidney and skin with fat, respectively. The withdrawal period of DVD was 4.77, 4.94, 6.74 and 4.58 days in muscle, liver, kidney and skin with fat, respectively. Therefore, the suggested withdrawal period for SPZ-DVD suspension should be 7 days after dosing for seven successive days.

The blood parasite Haemoproteus reduces survival in a wild bird: a medication experiment

While avian chronic haemoparasite infections induce reproductive costs, infection has not previously been shown to affect survival. Here, we experimentally reduced, through medication, the intensity of infection by Haemoproteus parasites in wild-breeding female blue tits Cyanistes caeruleus. However, this treatment did not reduce the intensity of infection in males or the intensity of infection by Leucocytozoon. Medicated females, but not males, showed increased local survival until the next breeding season compared with control birds. To our knowledge, this is the first empirical evidence showing long-term direct survival costs of chronic Haemoproteus infections in wild birds.

Pharmacokinetic of sulfaclozine in broiler chickens

In this study, 30-day-old, 14 male broiler chickens were used. Two groups, each comprising 7 animals, were established. While each animal included in the first group was administered sulfaclozine at a dose of 60 mg/kg bw by intravenous route (IV), group 2 was administered sulfaclozine at the same dose but by intracrop route (IC). In group 1, serum sulfaclozine concentrations at 0.083, 0.50, 2, 6, 24 and 72h were determined to be 99.62+/-3.31, 83.50+/-4.22, 72.68+/-5.02, 58.43+/-5.39, 38.66+/-4.04 and 13.14+/-1.64 microg/ml, respectively, via HPLC. In group 2, serum drug concentrations at 0.083, 0.50, 2, 6, 24 and 72h were determined as 4.33+/-0.45, 7.95+/-0.72, 16.46+/-2.68, 22.88+/-3.00, 16.03+/-3.53 and 5.74+/-0.98 microg/ml, respectively. Statistical analyses revealed that, of all the parameters studied, only A(1)( *), A(2)( *), alpha, beta, t(1/2)(alpha), t(1/2)(beta), MRT, Vd(area), k(12), k(21), AUC(0-->72) and AUC(0-->infinity) differed significantly between the groups (p<0.05). Compared to intravenous administration, significant increase in t(1/2)(alpha), t(1/2)(beta), MRT and Vd(area), and significant decrease in A(1)( *), A(2)( *), alpha, beta, k(12), k(21), AUC(0-->72) and AUC(0-->infinity) were observed in the group, which was administered sulfaclozine by intracrop route.