Supplementing growing rabbit diets with chestnut hydrolyzable tannins: Effect on meat quality and oxidative status, nutrient digestibilities, and content of tannin metabolites.

The study investigated the effect of dietary inclusion of chestnut hydrolyzable tannin (CHT) in growing rabbit diets on nutrients digestibility, quality and oxidative status of meat, and content of tannin metabolites. At weaning, rabbits were assigned to 5 dietary groups (n = 72 rabbits/diet): control medication-free (Co), control with coccidiostat (Cc), and T200, T400 and T600 (diets supplemented with 200, 400 and 600 g/100 kg CHT extract). Sixteen carcasses/treatment were considered and hindleg meat and Longissimus thoracis et lumborum (LTL) muscle were used for analyses. L*a*b* color values, water holding capacity, Warner Bratzler shear force, haem iron content, oxidative status and nutritional quality were unaffected by dietary treatments. Saturated fatty acids (SFA) and monounsaturated FA (MUFA) in LTL meat were higher in T600 than Cc rabbits (P < .05), even though no differences were found for SFA and MUFA digestibility. Contrarily, polyunsaturated FA digestibility was lower in T400 and T600 than Co rabbits. No tannin metabolites traces were found in rabbit meat. Results of the present study showed that feeding CHT did not improve rabbit meat quality.

Influence of three coccidiostats on the pharmacokinetics of florfenicol in rabbits.

In-feed Medication has been used for a long time to prevent coccidiosis, a worldwide protozoal disease in rabbits. Florfenicol (FFC) has been widely used in veterinary clinics for bacterial diseases treatment. Therefore, the use of combinations of coccidiostats with FFC in rabbits is common. In the present study, we aimed to evaluate the effect of three coccidiostats, sulfaquinoxaline (SUL), robenidine (ROB), and toltrazuril (TOL), as feed additives on the pharmacokinetic profile of FFC in rabbits. The disposition kinetics of FFC in rabbits were investigated after a single intravenous injection (25 mg/kg) in rabbits fed anticoccidial-free diets or feeds containing SUL (250 ppm), ROB (66 ppm), or TOL (2 ppm), respectively, for 20 days. Plasma FFC concentrations were determined by the high performance liquid chromatography (HPLC) method. The pharmacokinetic parameters of FFC were analyzed using a non-compartmental analysis based on the statistical moment theory. The results demonstrated that ROB feeding resulted in an obvious decrease in plasma FFC level as compared with anticoccidial-free feeding. The terminal elimination half-life (t1/2z), area under the concentration-time curve (AUC), area under the first moment curve (AUMC), and mean residence time (MRT) significantly decreased, whereas the elimination rate constant (λz) and total body clearance (CLz) obviously increased in rabbits pretreated with ROB. However, we did not find that SUL or TOL feeding had any effect on the pharmacokinetic profile of FFC. Our findings suggested that more attention should be paid to the use of FFC in rabbits supplemented with ROB.

Effect of subcutaneously administered diclazuril on the output of Eimeria species oocysts by experimentally infected rabbits.

The effect of subcutaneously injected diclazuril on the output of Eimeria species oocysts was studied in experimentally infected rabbits. Diclazuril was administered either prophylactically at 0.5, 1 or 2 mg/kg bodyweight two days before each rabbit was inoculated with 20,000 oocysts of a mixed-species field isolate of Eimeria or therapeutically at 1, 2 or 4 mg/kg bodyweight five days after they were inoculated. The prophylactic treatments significantly reduced (P<0.05) the output of oocysts in faeces and the numbers in the rabbits' livers at all doses. The therapeutic treatment at 4 mg/kg also caused a significant reduction (P<0.05) in oocyst shedding, but the lower doses resulted in only a moderate reduction. The shedding of the pathogenic species Eimeria stiedae, Eimeria magna, Eimeria irresidua, Eimeria flavescens, Eimeria piriformis and Eimeria intestinalis was significantly reduced (P<0.05) in all the treated groups. The burden of oocysts in the livers of the therapeutic groups (4000 to 9000) were significantly lower (P<0.05) than in the inoculated but untreated control group (23,000), but higher than in the prophylactic groups (around 1000).

Sensitivity of Escherichia coli O157:H7 strain 932 to selected anticoccidial drugs in broiler chicks.

The ability of selected anticoccidial drugs to inhibit the colonization of day-old male broiler chicks (Cornish Rocks) by Escherichia coli O157:H7, strain 932 was examined. Chicks were challenged with 1.8 x 10(9) E. coli O157:H7 on Day 1, and fed diets supplemented with three selected anticoccidial drugs; monensin, nicarbazin, or robenidine. The cecal and colon fecal contents of the chicks were removed on Day 7, 14, and 21 postinoculation and examined for the concentration of E. coli O157: H7 per gram of contents. Monensin effectively reduced cecal and colon colonization of the chicks by E. coli O157:H7. By Day 7, there were significant reductions in the bacterial population of the cecal contents of chicks receiving the monensin-medicated feed, and by Day 21 no E. coli O157:H7 was recovered from the cecal and colon contents. The bacterial counts in the colon contents of the nicarbazin- and robenidine-medicated and unmedicated chicks were significantly higher than the monensin-treated chicks. Bacterial populations in the colon contents were high only when there were high bacterial concentrations in the cecal contents.

Chemotherapy of experimental toxoplasmosis with special reference to robenidine.

Robenidine as an anticoccidial agent alone (in doses of 50 and 100 mg/kg) or in association with two other antiprotozoal compounds--pyrimethamine and sulfadoxine (in doses of 2.5 and 250 mg/kg, respectively) were tested in the treatment of chronically infected mice with an avirulent cyst-forming HF strain of Toxoplasma gondii. The efficacy of the used drugs was evaluated by the cysts number in the brains of treated mice versus control group, antibody level and viability of survived cysts by the consecutive infection of mice. According to these criteria none of the tested drugs alone or combined exhibited to be able to produce an effective cure of cyst-stage of toxoplasmosis in experimental mice.

The influence of nutrient density of broiler rations on the effective dose of anticoccidial drugs.

Anticoccidial drugs were added to diets formulated with a nutrient density of 1479 kcal/lb and 24% protein or with 80% of those energy and protein levels (low density) to determine whether rate of feed intake influences efficacy of drugs in broilers infected with coccidiosis. In four experiments with monensin, broilers receiving 60 or 100 ppm of monensin in the lower-density ration consumed more feed per unit of gain but gained less weight than those on the control diet. Coccidiosis (Eimeria tenella) was better controlled by 60 ppm of monensin in the low-density diet than in the high-density diet. There was some evidence of a similar efficacy-enhancing effect with nicarbazin, salinomycin, and lasalocid but not with robenidine. When drug intake was calculated as mg/kg of weight gain, there was a strikingly higher rate of intake of most drugs in the low-density diet, accounting for the apparent increase in activity. These results suggest that in countries where nutrient density of feeds varies significantly from those used in the United States, some compensation in levels of certain feed additives might be considered.