延胡索酸泰妙菌素对支原体和大肠杆菌混合感染的治疗试验

以人工诱发鸡毒支原体和大肠杆菌混合感染为模型,以酒石酸泰乐菌素为对照药物,评价了延胡索酸泰妙菌素的疗效.按每1 L水中分别加入312.5、468、625 mg延胡索酸泰妙菌素及500 mg酒石酸泰乐菌素的用量给病鸡饮水给药,连用5 d.试验表明,用药组的成活率、日增重、料肉比、气囊损伤度与感染对照组比较差异极显著(P＜0.01);延胡索酸泰妙菌素大剂量组日增重与小剂量组比较差异显著(P＜0.05),与其他各用药组比较差异极显著(P＜0.01),料肉比与其他各用药组比较差异极显著(P＜0.01);酒石酸泰乐菌素组的料肉比与延胡索酸泰妙菌素小剂量组比较差异不显著(P＞0.05);而与其他各组比较差异极显著(P＜0.01).数据分析表明,延胡索酸泰妙菌素大剂量组能有效地降低气囊损伤度,提高饲料转化率.     

Evaluation of fenbendazole as an extended anthelmintic treatment regimen for swine

Fenbendazole was given in the feed to swine at a cumulative dosage of 9 mg/kg of body weight over a period of 3, 6, and 12 days to compare efficacy. Four treatment groups of ten 2- to 3-month-old pigs each, with a mean of 15 kg of body weight per group, received 3 mg of fenbendazole/kg/day for 3 days, 1.5 mg/kg/day for 6 days, 0.75 mg/kg/day for 12 days, and no medication. Medicated feed was scheduled so that all treated pigs reached the last day of treatment on the same day, thus making the time between the last treatment and necropsy equal for all groups. Ascaris suum and Trichuris suis were the target species, their presence before treatment being determined by fecal egg counts and at necropsy by worm counts. At necropsy, 9 control pigs were infected with A suum (mean of 18.0 worms/pig), and all control pigs had T suis infection (mean of 36.5 worms/pig). All 3 treatment schedules were 100% effective in removal of A suum; and for T suis, the 3-day regimen was 100% effective, the 6-day regimen, 99.2%, and the 12-day regimen, 91.0%.     

Determination of the dosage of clomipramine for the treatment of urine spraying in cats

OBJECTIVE: To determine the optimal dosage of clomipramine for the treatment of urine spraying in cats. DESIGN: Randomized controlled multicenter clinical trial. ANIMALS: 67 neutered cats. PROCEDURE: Cats with a minimum 1-month history of spraying urine against vertical surfaces at least twice per week were randomly assigned to be treated with a placebo or with clomipramine at a dosage of 0.125 to 0.25 mg/kg (0.057 to 0.11 mg/lb), 0.25 to 0.5 mg/kg (0.11 to 0.23 mg/lb), or 0.5 to 1 mg/kg (0.23 to 0.45 mg/lb), p.o., every 24 hours for up to 12 weeks. Owners of all cats were given information on behavioral treatment and environmental modification. RESULTS: Prior to treatment, mean number of urine spraying events ranged from 0.9 to 1.3 urine spraying events/d for the 4 groups, and mean percentage of days with urine spraying events ranged from 62% to 69%. All 3 dosages of clomipramine were associated with significant reductions in frequency of urine spraying. Sedation was the most common adverse effect and was identified in 27 of the 50 cats treated with clomipramine; however, treatment was not discontinued in any cat because of sedation. CONCLUSIONS AND CLINICAL RELEVANCE: Results of the present study suggest that compared with a placebo, clomipramine significantly reduces the frequency of urine spraying in cats in terms of the number of urine spraying events per day and the number of days with urine spraying events. For cats with urine spraying, the recommended initial dosage of clomipramine is 0.25 to 0.5 mg/kg, p.o., every 24 hours.     

The effect of beta-carotene on thyroxine and cholesterol levels in pregnant heifers before and after parturition

Thyroxine (T4) and cholesterol concentrations and their dynamic changes and differences were studied in 20 pregnant heifers 10 days before calving until 56 days after calving. Ten control heifers were fed the feed ration for pregnant heifers according to Czechoslovak Standard CSN 46 7070. The feed ration given to another ten (experimental) heifers was fortified with 300 mg of synthetic beta-carotene per head/day within the period of five months before insemination, during pregnancy and till the 56th day after parturition. As suggested by the regression function of straight line, no obvious differences were recorded in the dynamic changes of T4 before parturition and during the first days after parturition. T4 concentrations had a generally descending tendency in both groups, the lowest values being recorded in the 48th hour in the experimental group and the 24th hour in the control. A marked increase of T4 concentrations with the values significantly higher in the control group than in the experimental group was observed between the 21st and 35th day after calving. A medium increase of cholesterol concentrations was found in the heifers given rations fortified with beta-carotene. No significant differences in cholesterol concentrations were observed between the two groups, except in the 72nd hour and the seventh day. Significant T4: cholesterol correlations were recorded in the experimental animals in the first and second hours, on the 42nd day (P less than 0.05), and in the 72nd hour (P less than 0.001); in the control group these observations were made the seventh day before calving and in the sixth hour and on the 14th, 21st and 56th days (P less than 0.05) after calving. It is inferred from the results that beta-carotene interferes with the activity of the thyroid gland and the production of its hormones, and that the increases or decreases of the activity of this gland, caused by beta-carotene, influence the metabolism of cholesterol in the body.     

凝结芽孢杆菌对蛋鸭产蛋性能、蛋品质及血清生化指标的影响

 试验旨在研究饲粮中添加不同水平凝结芽孢杆菌对蛋鸭产蛋性能、蛋品质及血清生化指标的影响。选取200日龄,产蛋率约80%的临武鸭240羽,随机分成4组,每组6个重复,每个重复10羽鸭,对照组饲喂基础饲粮,试验组在基础饲粮中分别添加100 mg/kg、150 mg/kg和200 mg/kg凝结芽孢杆菌,预试期7 d,正试期28 d。结果表明：（1）饲粮添加凝结芽孢杆菌可提高蛋鸭产蛋率、平均日产蛋量、平均蛋重和饲料转化率,但未达显著水平（P>0.05）;添加100 mg/kg和150 mg/kg凝结芽孢杆菌可显著降低产蛋鸭采食量（P<0.05）,添加200 mg/kg与各组间均无显著差异（P>0.05）;(2）饲粮添加凝结芽孢杆菌可显著降低鸭蛋蛋壳厚度（P<0.05）,当添加150 mg/kg和200 mg/kg时,差异达极显著水平（P<0.01）,凝结芽孢杆菌还可显著提高鸭蛋蛋黄颜色,蛋白高度和哈氏单位（P<0.05）;（3）芽孢杆菌对产蛋鸭血清中血糖、总蛋白、总胆固醇、甘油三脂等血清生化指标均无显著影响（P>0.05）。由此可知,饲粮中添加凝结芽孢杆菌能在一定程度上提高蛋鸭饲料转化率和产蛋性能,虽会引起蛋壳厚度降低,但不影响合格蛋率,还可提高蛋黄颜色和哈氏单位,对蛋品质有一定改善。综合考虑,蛋鸭饲粮中凝结芽孢杆菌的添加量以150 mg/kg较为适宜。     

Metabolism and excretion of ochratoxin A fed to sheep.

Hydrolysis of the mycotoxin ochratoxin A (OA) to ochratoxin alpha (Oalpha) by microorganisms within the gastrointestinal tract leads to the excretion of OA as the nontoxic alpha form. The Oalpha form is the principal means for the detoxification of OA. In the current experiment, three groups of four sheep were fed diets consisting of 70% concentrates and 30% hay (dry matter basis, energy to supply 1.1 times the requirement for maintenance) for 4 wk with three dietary concentrations of OA (0, 2, or 5 mg/kg of concentrate feed). The OA content did not affect feed intake or nutrient digestibility. In a preliminary experiment, an OA dose of 20 mg/kg of concentrate feed greatly reduced feed intake. After 1, 2, 3, and 4 wk of the trial, significant concentrations of OA were detected in the serum of the animals fed 2 or 5 mg of OA/kg feed. This suggested that even at a dosage of 2 mg of OA/kg of concentrate feed, considerable amounts of OA were not degraded by ruminal and intestinal microorganisms. The analysis of the feces and urine samples reflected these findings; OA and Oalpha were found in significant concentrations, escaping fermentation in the rumen and in the hindgut. The current experiment demonstrates that OA hydrolysis in the gastrointestinal tract of sheep is substantially less than previously described, especially if OA is ingested in combination with concentrate-rich diets.     

Pharmacokinetics of ciprofloxacin in ponies

The pharmacokinetics of ciprofloxacin was investigated in healthy, mature ponies. Ciprofloxacin was administered intravenously to six ponies at a dose of 5 mg per kg body weight. Seven days later, ciprofloxacin was administered orally to each pony at the same dose. Intravenous ciprofloxacin concentration vs. time data best fit a two-compartment open model with first-order elimination from the central compartment. Mean plasma half-life, based on the terminal phase, was 15 7.8 9 min (harmonic mean). Total body clearance of ciprofloxacin was 18.12 ± 3.99 mL/min/kg. Volume of distribution at steady-state was 3.45 ± 0.72 L/kg. From the pharmacokinetic data and reported minimum inhibitory concentrations for equine gram-negative pathogens, the appropriate dosage of ciprofloxacin was determined to be 5.32 mg per kg body weight at 12 h intervals. Bioavailability of oral ciprofloxacin in ponies was 6.8 ± 5.33%. Owing to the poor bioavailability, a dosage regimen could not be proposed for oral ciprofloxacin administration in horses. Ciprofloxacin concentrations were determined in tissues and body fluids at 1, 2 and 4 h after intravenous administration. At all times, tissue concentrations exceeded plasma concentrations of ciprofloxacin. Highest concentrations were achieved in kidneys and urine. Potentially therapeutic concentrations were obtained in cerebrospinal and joint fluid, but low concentrations were achieved in aqueous humour.     

Renal effects of carprofen administered to healthy dogs anesthetized with propofol and isoflurane

OBJECTIVE: To evaluate renal effects of carprofen in healthy dogs following general anesthesia. DESIGN: Randomized clinical trial. ANIMALS: 10 English hound dogs (6 females and 4 males). PROCEDURE: Dogs were randomly assigned to control (n = 5) or carprofen (5) groups. Anesthesia was induced with propofol (6 to 8 mg/kg [2.7 to 3.6 mg/lb] of body weight, i.v.) and maintained with isoflurane (end-tidal concentration, 2.0%). Each dog underwent two 60-minute anesthetic episodes with 1 week between episodes, and mean arterial blood pressure was maintained between 60 and 90 mm Hg during each episode. Dogs in the carprofen group received carprofen (2.2 mg/kg [1 mg/lb], p.o.) at 9:00 AM and 6:00 PM the day before and at 7:00 AM the day of the second anesthetic episode. Glomerular filtration rates (GFR) were determined during each anesthetic episode by use of renal scintigraphy. Serum creatinine and BUN concentrations and the urine gamma-glutamyltransferase-to-creatinine concentration (urine GGT:creatinine) ratio were determined daily for 2 days before and 5 days after general anesthesia. RESULTS: Significant differences were not detected in BUN and serum creatinine concentrations, urine GGT:creatinine ratio, and GFR either between or within treatment groups over time. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen did not significantly alter renal function in healthy dogs anesthetized with propofol and isoflurane. These results suggest that carprofen may be safe to use for preemptive perioperative analgesia, provided that normal cardiorespiratory function is maintained.     

Urinary delta-aminolevulinic acid levels in dairy cows during lead loading from feed rations under normal conditions of rearing in the Western Slovakia Region

The concentration of delta-amino levulinic acid (ALA) was determined in the urine of clinically healthy cows of 14 herds in the West-Slovakian region. The content of lead was determined at the same time in the components of feed rations. The ALA concentration values were converted to values per uniform specific weight of urine and per gram of secreted creatinine to match literary sources where the ALA concentration is given in these two quantities. The approximate intake of lead by the animal bodies in milligrams per head/day and per kg of live weight was calculated from lead content in feed rations. The average ALA concentration in the urine of dairy cows was 42.7 +/- 20.2 mu mol per 1 of urine (36.8 +/- 18.7 mu mol per g of creatinine), the average lead intake from feed being 0.157 mg per kg of live weight. The ALA concentrations in urine refer to animals given normal feeds with no lead contamination and as such can be considered as physiological values. Statistically significant correlations were recorded between ALA concentrations per litre of urine at the uniform specific weight of 1030 g per litre and the values converted per gram of secreted creatinine (r = 0.789). The upper biological tolerance limit of ALA concentration in urine (105.0 mu mol per litre) was determined by mathematico-statistical methods. Values above this limit could be indicative of an increased lead stress of the cows' bodies.     

Estimation of daily urinary potassium excretion using urinary creatinine as an index substance in prepartum dairy cows

In the present study, the daily excretion of potassium (K) in urine (urinary K(UK)) was estimated from a 6 h urine sample using urinary creatinine (UC) as the index substance. All urine was collected from six pregnant Holstein cows at 6 h intervals for 24 h on 3 days of the 4th, 2nd and final week before the expected date of parturition. In total, 72 6 h urine samples were obtained. Daily UC excretion (mg/day per kg bodyweight (BW)) was almost the same for the three sampling days. Daily UC excretion varied among cows from 22.1 to 24.3 mg/day per kg BW with a mean of 22.8 mg/day per kg BW with no significant difference. Thus, daily UC excretion was confirmed to be constant throughout the prepartum period with no differences among individuals. The concentration ratios of K to creatinine ((UK mg/dL)/(UC mg/dL) (UK/UC)) correlated strongly to the hourly K excretions (mg/h per kg BW) (r = 0.952, P < 0.01) in the 6 h urine samples. The differences in the UK/UC ratio between sampling periods were not significant within each cow. Therefore, daily UK excretion (mg/day) can be estimated using the equation: daily UK excretion (mg/day) = daily UC excretion (mg/day per kg BW) × BW (kg) × 6 h urine sample UK/UC, where daily UC excretion can be a given value.     

Chronic Vanadium Poisoning in Calves and Its Treatment with Calcium Disodium Ethylenediaminetetraacetate

Sixteen Friesland heifer calves aged between 96 and 157 days were removed from a dairy farm that had been polluted with vanadium and randomly allocated into two equal groups (n = 8). The objective of the trial was to determine whether calcium disodium ethylenediaminetetraacetate (CaNa₂EDTA) could be used as a treatment for cattle running in environments high in background vanadium. The treatment group received 80 mg CaNa₂EDTA per kg body weight intraperitonealy (i.p.) twice a week over a 10-week period. The control group received normal saline i.p. over the same period. During the trial calves were exposed to a daily intake of vanadium in the form of contaminated tef hay derived from the farm of origin. In addition, the total mixed ration was spiked with a further 20 mg V₂O₅/kg feed to compensate for possible on-farm inhalation exposure. A stochastic model was used to estimate daily intake of vanadium as a distribution function. The model estimated that the daily intake of vanadium varied between an absolute minimum of 33 mg/day to an absolute maximum of 124 mg/day. The average intake of vanadium was 71.8 mg per day per calf. Various chemical pathology parameters were measured throughout the trial as well as urine excretion rates of vanadium and lymphocyte stimulation counts. All calves were slaughtered and necropsied in cohorts of 4–6 animals at monthly intervals after completion of the trial and withdrawal of vanadium from the ration. Tissue concentrations of vanadium were determined and necropsy findings were noted. The study found that CaNa₂EDTA appears to enhance the excretion of vanadium in calves, but could not prove that the treatment had a protective effect against vanadium exposure. Calves were able to tolerate the prolonged treatment with CaNa₂EDTA without side-effects.     

Plasma concentrations of an angiotensin-converting enzyme inhibitor, benazepril, and its active metabolite, benazeprilat, after repeated administrations of benazepril in dogs with experimental kidney impairment

In order to examine the safety of an angiotensin-converting enzyme (ACE) inhibitor in dogs with impaired renal excretion route, benazepril was administered orally, and plasma concentrations of benazeprilat, the active metabolite of benazepril, were determined in dogs with renal mass reduction (1/4th kidney) created by right-side nephrectomy and ligation of branches of the left renal arteries. Five dogs were administered benazepril orally at a given dose (0.5 mg/kg body weight) and 4 other dogs received 20 times that dose (10 mg/kg body weight) once daily for 15 consecutive days before (intact kidney period) and after (1/4th kidney period) creation of kidney impairment. Six control dogs received surgical treatment, but no drug. After creating a 1/4th kidney, plasma urea nitrogen and creatinine concentrations increased to approximately 30 mg/dl and 2.0 mg/dl, respectively, and renal plasma flow and glomerular filtration rate decreased to 37% and 30% of pre-treatment values, respectively. However, these parameters did not change significantly during the 1/4th kidney period both in the 0.5 mg/kg and 10 mg/kg groups. In the 0.5 mg/kg group, plasma benazeprilat concentrations increased to approximately 20 ng/ml to 340 ng/ml 2 hr after each administration, and there were no significant differences between the plasma benazeprilat concentrations during the intact and 1/4th kidney periods. In the 10 mg/kg group, plasma benazeprilat concentrations varied in the individual dog, but did not increase with the days of administration, and were not significantly different on each administration day between the intact and 1/4th kidney periods in either dose group. The AUCs(0-24) of plasma benazeprilat concentrations determined on the 15th administration day were not different between the intact and 1/4th kidney periods in dogs of either dose group. Plasma ACE activities decreased after drug administration in dogs of both groups. Benazepril seemed to have a high safety, and the adjustment of dosage regimen might not be needed in dogs with mild to moderate renal function impairment because the drug was excreted both from the kidneys and liver.     

Thiacetarsamide in dogs with Dirofilaria immitis: influence of decreased liver function on drug efficacy

The influence that decreased functional hepatic mass had on blood arsenic concentrations in dogs after they were treated with thiacetarsamide, on the clearance of indocyanine green (ICG), on arsenic concentrations in the heartworm (Dirofilaria immitis), and on drug efficacy was studied. Dogs which were partially hepatectomized and treated with thiacetarsamide (1.76 mg/kg, 2 times a day for 2 days) had a significantly (P less than 0.01) reduced ICG clearance, significantly (P less than 0.01) higher arsenic levels in heartworms, and a significantly (P less than 0.01) higher proportion of heartworms killed than did dogs that were sham operated and treated with thiacetarsamide or sham operated and untreated. There were no significant differences in blood arsenic (thiacetarsamide) concentrations 2 minutes after injection between hepatectomized and nonhepatectomized groups. More male heartworms were killed than were female worms in the thiacetarsamide-treated groups. Indocyanine green half-life was longer (12.43 minutes) in the hepatectomized group than it was in the nonhepatectomized sham-operated groups (5.09 and 4.94 minutes). Indocyanine green clearance rate was lower in the hepatectomized group (0.54 ml/min/kg) than that in the nonhepatectomized groups (1.36 and 1.56 ml/min/kg). A parallel seemed to exist between ICG and thiacetarsamide removal from the blood by the liver. This parallel also was suggested in the higher worm arsenic (thiacetarsamide) concentrations for the hepatectomized group vs that for nonhepatectomized groups. Apparently, the slower the removal of thiacetarsamide from the blood by the liver, the higher the worm arsenic level and, consequently, the higher the worm kill.     

紫花苜蓿粗多糖对蛋鸡生产性能、蛋品质及盲肠微生物数量的影响

本试验旨在研究饲粮中添加不同水平紫花苜蓿粗多糖对蛋鸡生产性能、蛋品质及盲肠微生物数量的影响。选取540只30周龄的海兰褐壳蛋鸡,随机分为6组,每组6个重复,每个重复15只鸡。对照组饲喂玉米-豆粕型基础饲粮,试验组分别在基础饲粮中添加250、500、1 000、2 000、4 000 mg/kg紫花苜蓿粗多糖。试验期144 d。结果表明:1)试验第1~8周,2 000、4 000 mg/kg紫花苜蓿粗多糖组产蛋率显著高于对照组和250 mg/kg紫花苜蓿粗多糖组(P0.05);试验第17~20周,2 000 mg/kg紫花苜蓿粗多糖组平均日采食量显著高于对照组和250 mg/kg紫花苜蓿粗多糖组(P0.05),同时250 mg/kg紫花苜蓿粗多糖组料蛋比显著低于对照组和500 mg/kg紫花苜蓿粗多糖组(P0.05)。2)与对照组相比,试验第144天,各紫花苜蓿粗多糖组蛋黄颜色均显著加深(P0.05);试验第90天,4 000 mg/kg紫花苜蓿粗多糖组哈夫单位显著降低(P0.05);试验第60天,2 000、4 000 mg/kg紫花苜蓿粗多糖组蛋形指数显著降低(P0.05),试验第120天,1 000 mg/kg紫花苜蓿粗多糖组蛋形指数亦显著降低(P0.05);试验第61~90天,250、1 000 mg/kg紫花苜蓿粗多糖组软破壳蛋率显著降低(P0.05)。3)与对照组相比,试验第80天,500、2 000 mg/kg紫花苜蓿粗多糖组盲肠大肠杆菌数量显著降低(P0.05),盲肠乳酸杆菌数量显著增加(P0.05),同时4 000 mg/kg紫花苜蓿粗多糖组盲肠乳酸杆菌数量也显著增加(P0.05);试验第144天,1 000 mg/kg紫花苜蓿粗多糖组盲肠沙门氏菌数量显著降低(P0.05);试验第40、80、120、144天,500、1 000 mg/kg紫花苜蓿粗多糖组盲肠双歧杆菌数量均有所升高,但差异不显著(P0.05)。由此可见,饲粮中添加适宜水平的紫花苜蓿粗多糖可以显著提高产蛋期蛋鸡生产性能,改善蛋品质,优化盲肠菌群结构,且500 mg/kg为适宜添加水平。     

The effect of straw meal on the crude protein and amino acid metabolism and digestibility of crude nutrients in broiler hen breeds. 1. Problems, experimental review and N-excretion in the urine

The metabolization of the straw N and the influence of the straw on N excretion in urine were studied in 2 experiments with colostomized broiler hens and with 15N labelled wheat straw as well as 15N labelled wheat. In experiment 1 the test animals divided up into 4 groups received 0 g, 20 g, 30 g and 40 g straw meal per animal and day in addition to 120 g mixed feed. The daily 15N-excess (15N') intake from the straw was 18.4 mg, 27.5 mg and 36.7 mg. The amount of 15N' daily consumed with the labelled wheat in experiment 2 was 119.7 mg. 40 g straw meal resulted in a significantly increased amount of urine (p less than 0.05). The amounts of urine N and uric acid N were only increased as a tendency. On average the productive N decreased as a consequence of the straw meal supplement from 1070 mg/animal and day (control) to 764 mg/animal and day after 40 g straw meal supplement. The productive 15N' of the labelled wheat was not influenced by the straw meal supplement. The productive 15N' of the straw increased from 3.8 mg/animal and day (20 g straw) to 13.4 mg/animal and day (40 g straw). In contrast to 15N wheat, straw as a 15N source resulted in a lower labelling of uric acid N in comparison with urine N. It can be assumed that the changed metabolization of the straw N is influenced by microbial processes in the intestines.     

The effect of salinomycin on certain blood parameters and milk quality of lactating sows

Twenty-five gilts and sows, after pregnancy confirmation using the ultrasonic method, were randomly divided and allocated to the following five experimental groups: SAL0 = negative controls, SAL20 = 20 mg salinomycin per kg of feed, SAL40 = 40 mg salinomycin per kg of feed, SAL60 = 60 mg salinomycin per kg of feed and SAL80 = 80 mg salinomycin per kg of feed. All animals remained under treatment for two consecutive breeding cycles. The sows were fed a home-mixed balanced feed during gestations and lactations. At the third, tenth and eighteenth day of each lactation, blood and milk samples were collected. Blood samples were analysed for cholesterol and total lipids and milk samples were analysed for the determination of the fat, lactose, protein, ash and totals solids concentrations. In all treated groups, cholesterol concentrations were significantly higher (P < 0.05) compared with the controls. Total lipid concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups in comparison with SAL0 and SAL20 groups, during both cycles. Milk fat concentrations were higher (P < 0.05) in treated groups than in the control group; the highest concentrations were observed at SAL40 and SAL60 groups. In all treated groups, concentrations of milk lactose were significantly higher (P < 0.05) than those observed in the negative control group. Milk protein concentrations were significantly higher (P < 0.05) in SAL40 and SAL60 groups compared with the SAL0 group, but there was no significant difference in SAL20 and SAL80 groups in comparison with the SAL0 group. No significant differences were observed concerning milk ash concentrations between all groups. In all treated groups, concentrations of total solids were significantly higher (P < 0.05) in comparison with the control group; the highest concentrations were observed in the SAL40 and SAL60 groups. It is concluded that the use of salinomycin in sow diet, increases concentrations of blood triglycerides and cholesterol and improves the quality of milk, thus reflecting on higher weight gain and survival rate of suckling piglets.     

Comparative pharmacokinetics of two intravenous administration regimens of tiludronate in healthy adult horses and effects on the bone resorption marker CTX-1

Bioavailability and pharmacological effects of tiludronate were compared when administered as an intravenous (i.v.) bolus at a dosage of 0.1 mg/kg body weight (b.w.) once daily for 10 consecutive days (group 1, n  = 6) and as a single constant rate infusion (CRI) at a total dose of 1 mg/kg b.w. (group 2, n  = 6) in healthy adult horses.
Tiludronate and carboxy-terminal cross-linking telopeptide of type I collagen (CTX-1) were measured in plasma and urine.
There was no statistically significant difference in area under the curve ( AUC ) and clearance ( Cl ) between the two groups. Bioavailability of the CRI was 103% (not significantly different) that of the 10 daily i.v. bolus doses. Cumulative urine tiludronate excretion could not be compared between groups because of poor sensitivity of the assay in urine. Plasma and urine CTX-1 levels were not different between groups throughout the study. However, interindividual variations were greater in group 1 than in group 2. A significant decrease in CTX-1 levels was observed in plasma after the first administration in group 1, but not in urine; while in group 2, a significant decrease in CTX-1 concentrations was observed after treatment in both plasma and urine.
In conclusion, both dosage regimens of tiludronate produced similar plasma exposure and pharmacological effects in adult healthy horses.     

Pharmacokinetics of gentamicin at steady-state in ponies: serum, urine, and endometrial concentrations

Gentamicin (GT) was administered IM to 6 healthy mature mare ponies at a dosage of 5 mg/kg of body weight every 8 hours for 7 consecutive days (total, 21 doses). Two venous blood samples were collected before (trough) and at 1 hour (peak) after the 5th, 10th, 14th, and 19th doses. An endometrial biopsy was done of each mare on days 4 and 7. On the 7th day, just before the 21st administration of GT, base-line blood samples were collected, and 22 blood samples were collected over a period of 48 hours after GT was given. The mares were catheterized on the 7th day, and urine was collected for 24 hours. Serum, urine, and endometrial GT concentrations were determined by a radioimmunoassay technique (sensitivity of 0.3 micrograms/ml of serum). Serum GT concentration data obtained from the terminal phase were best fitted by a 1-compartment open model with a biological half-life of 2.13 +/- 0.43 hours. Total body clearance and renal clearance were 1.69 +/- 0.41 and 1.40 +/- 0.26 ml/min/kg, respectively. Mean endometrial concentrations on day 4 and day 7 were 5.02 +/- 3.3 and 12.75 +/- 1.6 micrograms/g. To achieve mean serum GT concentrations (micrograms/ml) at steady state of 6.47 +/- 1.51, a maximum steady-state concentration of 12.74 +/- 1.60, and a minimum steady-state concentration of 1.43 +/- 0.57, a dosage of 5 mg/kg every 8 hours is recommended. Serum urea nitrogen, serum creatinine, and the fractional clearance of sodium sulfanilate were determined before and after GT treatment. Renal function remained within the base-line range during 7 days of GT administration.     

Serum Profiles of Luteinizing Hormone,Oestradiol and Cholesterol and Ovarian Functions in Layer Poultry Birds (Gallus domesticus) Fed Diets Containing Furazolidone

This study was carried out to assess the serum profiles of luteinizing hormone (LH), oestradiol, cholesterol and ovarian functions in layer poultry birds (Rhode Island Red: Gallus domesticus) fed a diet containing various concentrations of furazolidone (FZ). A total of 40 birds were randomly assigned to receive FZ 0, 200, 400 or 800 mg/kg feed (ppm) daily during the pre-laying age, i.e. 13-18 weeks (for 5 weeks). Blood samples were collected at weekly intervals. Concentrations of LH and oestradiol in serum were estimated at alternate weeks using radioimmunoassays. Serum cholesterol levels were analysed by an enzymatic calorimetric method. Furazolidone administration was terminated at the 18th week of age. The birds were sacrificed at 22nd week of age and ovarian tissues were processed for morphometric studies. Serum LH, oestradiol and cholesterol levels were affected by age (p < 0.001) and FZ dose (p < 0.001). Serum LH and oestradiol levels were lower (p < 0.05) in birds receiving FZ 800 mg/kg feed daily compared with the controls, whereas serum cholesterol profiles were lower (p < 0.05) in all FZ-administered groups than in the control group. The mean weight of ovaries having no yolky follicles observed in the group receiving FZ 400 or 800 mg/kg feed per day was reduced (p < 0.05) compared with the control group. Dosing FZ at 800 mg/kg feed per day reduced (p < 0.05) the mean volume of ovaries having no yolky follicles compared with the control group. In birds receiving FZ 800 mg/kg feed per day, the mean length of the oviduct was reduced (p < 0.05) as compared with the control group. Morphometric studies revealed that the mean number of oocytes with diameter in the range 401-800 microm decreased (p < 0.05) in birds fed FZ 400 or 800 mg/kg feed per day. Initial egg production was affected by age (p < 0.001) and dose (p < 0.001) of FZ. The mean number of eggs laid by different groups revealed that egg production was reduced (p < 0.05) in birds receiving FZ 800 mg/kg feed per day as compared with the controls. The present data suggest that FZ causes suppression in serum profiles of LH, oestradiol, cholesterol and ovarian functions in Rhode Island Red layer poultry birds. Therefore, great care must be taken with use of FZ in layer poultry birds (Gallius domesticus) with regard to dosage and duration of administration.     

Preliminary Assessment of the Tolerance and Efficacy of Florfenicol against Edwardsiella ictaluri Administered in Feed to Channel Catfish

Abstract

A tolerance study was conducted to determine the palatability of florfenicol to channel catfish Ictalurus punctatus. Four tanks of fish (20 fish/tank) were assigned to each of five treatments distinguished by the amount of florfenicol given in feed per kilogram of body weight, namely, 0, 10, 20, 40, or 100 mg. Fish were fed at a rate of 2.5% of body weight per day for 10 consecutive days. On day 11, all surviving fish were euthanatized, counted, and weighed as a group. Florfenicol- medicated feed was palatable to fish at doses of 10, 20, 40, and 100 mg for 10 consecutive days. All 400 fish were necropsied and examined by histopathology, and no treatment-related changes were observed. In a separate exploratory efficacy study, four tanks (20 fish/tank) were assigned to each of the following treatments: (1) not challenged with Edwardsiella ictaluri and fed unmedicated feed, (2) challenged with E. ictaluri and fed unmedicated feed, (3) challenged with E. ictaluri and fed florfenicol at 10 mg per kilogram of body weight, (4) challenged and fed florfenicol at 20 mg/kg, and (5) challenged and fed florfenicol at 40 mg/kg. Treatment was initiated the day after inoculation, and feed was administered by hand for five consecutive days at 2.5% of body weight. The cumulative mortality observed over a 17-d period in treatment groups 1–5 was 2.5, 57.5, 0, 1.25, and 1.25%, respectively. All 400 fish were necropsied and examined by histopathology. The results indicate that florfenicol was effective in controlling mortality from enteric septicemia of catfish with no adverse treatment-related tissue changes. Florfenicol was palatable, safe, and efficacious in controlling mortality due to infection by E. ictaluri in channel catfish.