全球禽肉生产和贸易中的沙门菌风险评估与控制

1 禽源沙门菌对公共卫生的影响 在许多国家,沙门菌仍是引发食源性肠道疾病的主要原因.沙门菌通常存在于家畜、家禽中,也可在啮齿类、爬行类和鸟类等野生动物中发现.当农场的禽群感染沙门菌后,通常会有一部分家禽的消化道中携带沙门菌,但并无症状.随后,沙门菌可能会通过粪便污染感染动物屠体.     

Morphologic studies of uveoscleral outflow in normotensive and glaucomatous beagles with fluorescein-labeled dextran

Aqueous humor leaves the anterior chamber through 2 pathways: the trabecular meshwork of the iridocorneal angle and the unconventional uveoscleral route. In the latter route, aqueous humor leaves the anterior chamber, passes caudally through the trabecular meshwork and sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is absorbed by the choroidal and scleral circulation. Fluorescein-labeled dextran was slowly infused into the posterior chamber of healthy and glaucomatous Beagles for 30 minutes. The eyes were fixed in a mixture of 70% alcohol and formalin, placed in epoxy resin for histologic evaluation, and examined by fluorescent microscopy. Fluorescence was detected in the healthy dogs throughout the uveoscleral pathway. In the glaucomatous dogs, the uveoscleral outflow was decreased or completely absent.     

Digestibility of fiber components and reproductive performance of sows fed high levels of alfalfa meal

Two experiments were conducted with second-parity sows fed either 5 or 50% alfalfa meal diets (Exp. 1) or 5, 50 or 95% alfalfa meal diets (Exp. 2) beginning 30 d after breeding and continuing through lactation, 21 d postpartum. Diets in both experiments were calculated to be equal in crude protein, but different in metabolizable energy content. Feed intake was restricted to 2 kg/d during gestation and ad libitum during lactation. Sows were tethered in metabolism crates 45 d after breeding. Total feces were collected during two 5-d collection periods, 60 and 100 d after breeding. Digestibilities of dry matter, fiber components (neutral detergent fiber, acid detergent fiber, hemicellulose and cellulose), protein and energy were determined in both experiments for all diets and periods of gestation. In both experiments, there was a reduction (P less than .05) in digestibility of dry matter, fiber components, protein and energy with increasing fiber levels for both periods of gestation. In Exp. 1, the decrease in digestibility of dry matter, neutral detergent fiber, acid detergent fiber, cellulose and energy was greater at 100 d gestation than at 60 d in sows fed 50% alfalfa. In Exp. 2, 50 and 95% dietary alfalfa reduced 60-d digestibilities of dry matter, all fiber constituents, energy and protein; these digestibilities were further reduced (P less than .05) at 100 d of gestation. In Exp. 1, weight gains of sows fed 5 and 50% alfalfa diets from breeding to 109 d gestation, were 42 and 18 kg/sow (5 greater than 50% level, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Infectious dermatitis in a ball python (Python regius) colony.

Seven wild-caught ball pythons (Python regius), including six gravid females and one male, were obtained from Africa and were housed in a government animal facility in Research Triangle Park, North Carolina. Upon arrival, the snakes were found to be infested with ticks (Aponomma latus), which were manually removed. Four weeks following arrival, vesicular skin lesions began to appear on the snakes. Despite treatment of all affected female snakes with amikacin (5 mg/kg i.m., every 3 days) and cefotaxime (25 mg/kg i.m., every 3 days), the condition progressed and five of the female snakes died 7 wk after arrival. The remaining male and one female improved after an increase in environmental temperature, with ecdysis followed by healing. Physiologic stress, ectoparasites, and shipping may have predisposed the snakes to sepsis.     

The epidemiology of echinococcus infection in Kaduna State, Nigeria

Infection of dogs with Echinococcus gramulosus is recorded for the first time in Kaduna State. Observations on 330 dogs from different suburbs revealed an incidence of 1.2 per cent. Of slaughtered stock examined, hydatid cyst infections were found in sheep (7.1 per cent), goats (18.4 per cent), cattle (1.5 per cent), camels (70.9 per cent) and pigs (5 per cent).     

Technical note: Development of an enzyme-linked immunosorbent assay for the determination of florfenicol and thiamphenicol in swine feed

One polyclonal antibody against florfenicol and thiamphenicol was produced and a competitive ELISA was developed for the detection of florfenicol and thiamphenicol in swine feed. The ELISA gave a 50% inhibiting concentration of 1.02 ng/mL for florfenicol. For swine feed fortified with 0.05 to 3.0 mg/kg, the interassay recoveries of florfenicol and thiamphenicol ranged from 86.4 to 118.6%, whereas intraassay recoveries of both drug ranged from 90.1 to 126.5% with less than 15% CV. Results obtained from HPLC-tandem mass spectrometry indicated this ELISA procedure could be used as a convenient method for rapid screening of florfenicol and thiamphenicol in swine feed.     

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method

Determination and kinetics of enrofloxacin and ciprofloxacin in Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a liquid chromatography/mass spectrometry method. J. vet. Pharmacol. Therap. 34, 142-152. The fluoroquinolones enrofloxacin (EF) and ciprofloxacin (CF) residues were investigated in the edible tissues of two important Asian aquacultured species such as Tra catfish (Pangasianodon hypophthalmus) and giant freshwater prawn (Macrobrachium rosenbergii) using a sensitive liquid chromatography-electrospray ionization-tandem mass spectrometry method. Fish and prawn were treated with medicated feed with multiple doses of EF, in field conditions. A validation study of the analytical method was realized in terms of linearity, specificity, precision (repeatability and within-laboratory reproducibility), recovery and decision limit (CCα). The time needed before the antibiotic disappears from animal tissues or reach the maximum residue limit (MRL, 100μg/kg) was assessed. The concentration values of EF detected in Tra catfish tissue were between the MRL and 2×MRL concentrations, according to the fish density, 7days following the end of the enrofloxacin treatment (20mg/kg body weight per day, for seven consecutive days). The concentration value of ER in prawn tissue was lower than the MRL and the limit of quantification (LOQ, 14μg/kg) 5 and 7days after the stop of the EF treatment (50mg/kg body weight per day, for five consecutive days), respectively. The mean detected levels of CF was much lower in comparison with that of EF, indicating that only a small part of EF is metabolized into CF (<5%) in both Tra catfish and prawn.     

Effect of long- or short-term feeding of alpha-tocopheryl acetate to Holstein and crossbred beef steers on performance, carcass characteristics, and beef color stability.

Three experiments were conducted to examine the effects of vitamin E supplementation on feedlot cattle. Vitamin E supplementation did not affect feedlot performance or carcass characteristics of cattle fed a high-concentrate diet (P greater than .1). The major finding was the effectiveness of vitamin E in extending the color stability of displayed beef (P less than .01). Color stability during display of longissimus lumborum steaks from cattle supplemented with 300 IU/d for 266 d, 1,140 IU/d for 67 d, or 1,200 IU/d for 38 d was extended by 2.5 to 4.8 d. Gluteus medius steaks had an extended color display life of 1.6 to 3.8 d. The accumulation of lipid oxidation products, but not aerobic microbes, associated with displayed longissimus lumborum was suppressed for muscle from vitamin E-supplemented steers. Taste panelists detected no difference among longissimus lumborum steaks from control and vitamin E-supplemented steers but found (P less than .01) steaks aged for 21 d to be more tender than steaks aged for 7 d. Supplementing cattle with vitamin E should reduce economic losses associated with discolored beef during retail display.