Application of peracetic acid and quarternary ammonium disinfectants as a part of sanitary treatment in a poultry house and poultry processing plant

Hygiene and sanitation play a major role in any effective disease control programme for poultry production and processing premises. Various deficiencies in disinfection may induce that chains of infections are not broken from one stock to another. The present study investigated the efficacy of disinfection on a broiler farm and in a plant processing poultry from the investigated farm. Besides inspection of disinfection, the influence of contamination on broiler carcasses and consequences of this contamination on sanitation of the processing lines were studied. Swabs from surfaces coming into contact with the handled raw material were taken and evaluated. The results obtained by a standard microbiological swab method were evaluated and compared with an ATP-bioluminescence method. The investigations included determination of total counts of microorganisms, coliform bacteria and moulds. When employing the standard plate-count method, the total counts of microorganisms (TCM) reached <1, 1-100 and >100 CFU in 0, 12 and 88% swabs on poultry farm and in 22%, 36% and 42% swabs in the processing plant, respectively. The bioluminescence method was used only in the processing plant and contamination corresponding to <100, 100-300 and >300 relative light units (RLU) was detected in 80%, 10% and 10% swabs respectively.     

Ureteral sarcoma in a dog

A ureteral sarcoma was diagnosed in a nine-year-old Weimaraner dog with gross haematuria, severe unilateral hydronephrosis, and hydroureter. Treatment consisted of unilateral nephrectomy and ureterectomy. This case was compared with 14 other ureteral tumours reported in the veterinary literature. Only three previous reports concerned a malignant ureteral tumour. Urinary tract neoplasms mainly involve the bladder and the kidney, and more rarely the urethra. The purpose of this paper is to report a rare case of malignant ureteral tumour in a dog.     

Clinical, humoral and IFNgamma responses of cattle to infection with Mycoplasma mycoides var. mycoides small colony and attempts to condition the pathogenesis of the infection

Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides var. mycoides small colony (MmmSC), is one of the most important diseases of cattle in Africa. The role of innate or acquired cell mediated and humoral immunity in conferring protection against MmmSC infection has not yet been elucidated. On the other hand, the pathological lesions caused by the aetiological agent have been considered indicative of an immunopathological process. In this study ten na?ve cattle were exposed to in-contact infection with animals infected by intubation with a strain of MmmSC. Clinical signs, antibody response, IFNgamma release and pathological changes at necropsy were analysed and compared with the events following in-contact infection of an equal number of animals kept under daily treatment with cyclosporine for the entire observation period of 84 days. Cyclosporine is a suppressor of the immune response related to the T-cell system. Under the conditions of the experiment, cyclosporine appeared to condition the pathogenesis of CBPP by delaying the events that follow infection, bringing further support to the possibility that the immune response may have an impact on the disease outcome.     

Enhancement of enrofloxacin serum antibacterial activity by calcium primed broilers

The aim of this trial was to assess the effect that calcium gluconate priming of 468 broilers has on the antibacterial activity of a standard dose of enrofloxacin. Hence, a series of oral pharmacokinetic studies were carried out in four groups of broilers medicated individually through an oral cannula as follows: group A, medicated only with enrofloxacin 10mg/kg; group B, receiving immediately one after the other, calcium gluconate (200mg/kg) and enrofloxacin 10mg/kg; group C, dosed first with calcium gluconate (200mg/kg) and 1h later enrofloxacin (10mg/kg); and group D, dosed first with calcium gluconate (200mg/kg) and 2h later enrofloxacin (10mg/kg). Broilers were bled at different times after the dose of enrofloxacin and antibacterial activity, measured as concentration of enrofloxacin, was measured by an agar diffusion assay. Results revealed that group D the greatest values of maximum serum concentration (Cs(max)), area under the concentration vs. time curve (AUC) and area under the moment curve (AUMC). These values were statistically higher than the corresponding ones derived from groups A, B and C (P<0.05). Taking Cs(max) and AUC values of group A as reference baseline, an increase of 24% and 50%, respectively, was obtained in group D. Group B had the lowest Cs(max), AUC, AUMC and elimination half life (T(1/2)beta) and these values were statistically different from groups A, C and D (P<0.05). The T(1/2)beta was statistically longer in groups C and D as compared with A and B, and the former groups were also different between each other (P<0.05). These results show that if calcium gluconate is first dosed to broilers and 2h later enrofloxacin is administered (as in group D), a more pronounced antibacterial activity of enrofloxacin can be obtained. A challenge of this sequential dosing scheme in a field trial may reveal its clinical value.     

The potential of mini-ridging for controlling intrarow weeds: estimating minimum lethal burial depth

Weed management using synthetic herbicides is undergoing a global decline, necessitating a re-evaluation of existing control measures and the development of novel weed management tools. ‘Mini-ridging’ is a non-discriminatory, physical weeding method that functions by burying weeds in the intrarow with a laterally shifted ridge of soil. In glasshouse trials using potted plants, we found that plant recovery after soil application was influenced by plant size, which in turn was influenced by plant species, developmental stage and/or age. The likelihood of plant recovery after soil application was negatively related to the depth of soil applied: very few plants survived total coverage by soil but, conversely, survival could be substantial if some parts of the plants were not covered. The results suggest that burial under a depth of 6 cm of soil would eliminate most plants regardless of species or growth stage. Larger plants would require the application of a greater total depth of soil to achieve this 6 cm of soil cover, and weed management would, therefore, tend to be more successful and more practical if weeds were targeted when still small. This research demonstrates the potential of plant burial as a simple and reliable means of non-chemical weed management, and re-emphasises that, for weed control to be effective, the applied soil layer must cover the whole plant.     

Tomato brown rugose fruit disease: current distribution,knowledge and future prospects

Tomato is the most economically important fruit/vegetable crop grown worldwide. However, viral diseases remain an important factor limiting its productivity, with estimated quantitative and qualitative yield losses in tomato crops often reaching up to 100%. Many viruses infecting tomato have been reported, while new viral diseases have also emerged. The climatic changes the world is experiencing can be a contributing factor to the successful spread of newly emerging viruses, as well as the establishment of disease in areas that were previously either unfavourable or where the disease was absent. Because antiviral products are not available, strategies to mitigate viral diseases rely on genetic resistance/tolerance to infection, control of vectors, improvement in crop hygiene, roguing of infected plants and seed certification. Tomato brown rugose fruit virus (ToBRFV) is an emerging viral threat to tomato productivity and is currently spreading into new areas, which is of great concern to the growing global production in the absence of mitigation measures. This review presents the current knowledge about ToBRFV and future prospects for an improved understanding of the virus, which will be needed to support effective control and mitigation of the impact it is likely to cause.     

Maturity, fecundity and the effect of reduced rainfall on the spawning rhythm of a siluroid catfish, Clarias mossambicus (Peters)

Abstract. Five maturity stages in the male and six in the female Clarias mossambicus (Peters) are described based on macroscopic and histological analysis of the gonads. During the study period (September 1984-August 1985) the species spawned only once instead of the usual biannual spawnings which coincide with the two rainy seasons in the gulf region. The reduction in the spawning rhythm is associated with the reduced rainfall which the Nyanza district experienced during October-December 1984. Rainfall, therefore, acts as a spawning stimulus in the species. Ripe ovaries which could not be released due to lack of spawning underwent atresia. The fecundity of fish measuring 46 0-87-Ocm TL ranged from 7966-229648 with a mean of 78152 eggs and it increased lineariy with total length (r = 0-9165) and body weight (r = 0.9371). The overall ratio of male to female was 1:1. First sexual maturity is attained in the length range of 41-45cm TL in both sexes.     

Compensatory growth in Atlantic halibut: Effect of starvation and subsequent feeding on growth, maturation, feed utilization and flesh quality

A group of juvenile Atlantic halibut (mean, SD, 199.5 g, 44.7) was split into two experimental groups: one group was fed in excess twice a day and later five days a week (i.e. Control group), and the other group was starved for 5 weeks and then subsequently re-fed for 10 weeks (i.e. 5/10 starvation/re-fed group). This treatment was repeated for three years until the fish were harvested (mean final weight, 4.4 kg). A size +specific compensatory response was seen; partial compensation was observed in halibut weighing less than 500 g whereas full recovery growth was seen in halibut over 2 kg. Food consumption and feed conversion efficiency was measured during two full 5/10 starvation/re-fed cycles. The Control group consumed 86% more food in the measurement period, whereas the FCE 40% higher in the 5/10 starvation/re-fed group (FCE = 0.95) compared to the Control group (FCE = 0.68). In males lower gonadosomatic index (2.2 vs. 3.0) and plasma 11-ketotestosterone (0.22 vs. 1.26 ng ml^− 1) levels in the 5/10 starvation/re-fed group were observed during late winter and spring of 2006 (age 3 years) indicating higher age at 1st maturity. Starvation had a significant effect for improving the quality as starved fish had higher muscle pH (6.4 vs. 6.2), less gaping (0.1 vs. 0.3) and harder texture (61.4 vs. 57.6 N). Overall, the rearing on a repeated 5/10 starvation/re-fed regime for 3 years led to full growth compensation, higher feed conversion efficiency, lower male maturation and improved flesh quality.