Fasciola hepatica and rumen flukes - in vitro evaluation of main commercial anthelmintics

Background: Trematode infections are of great importance as they affect the health of many species of mammals as cattle, sheep and goat. Fasciola hepatica represents the main trematode zoonosis and risks to human and cattle and paramphistomosis is one emerging parasitic diseases of ruminants widely distributed in the world. The economic expenses are incurred by the use of ineffective anthelmintics for trematode control. Besides to faecal egg count reduction test (FECRT) to determine the anthelmintic efficacy, can be used in vitro assays, by this the aim of the study was to determine the lethal doses (LD) with hatching egg test (EHT) of the main commercial anthelmintics used for the control of trematodes in cattle. Materials, Methods & Results: Liver and rumen were examined from cattle slaughtered in Tabasco, Chiapas and Campeche states from Mexico. F. hepatica eggs were recovered from gallbladder and rumen fluke eggs collected from adult parasites in saline solution. Subsequently, the hatching egg assays were performed placing 100 trematode eggs in distilled water in each one of 96 wells of polystyrene plates. After making the appropriate dilutions, several concentrations of commercial anthelmintics were evaluated, ranging from 0.04 to 80.63 mM for triclabendazole + 0.046 to 96.87 mM febendazole (TC+FBZ), from 0.04 to 91 mM for rafoxanide (RAFOX), from 0.02 to 43.74 mM for closantel (CLOS), from 0.036 to 76.18 mM for clorsulon + 0.002 to 3.31 mM ivermectin (CLORS+ IVM) and from 0.163 to 334.47 mM for nitroxynil (NITROX). A control group (water) was included in each plate. Lethal doses were obtained using the Probit procedure and analysis of the means with a one-way statistical design. Most drugs used against rumen fluke eggs presented a high LD50 and therefore were ineffective to cause egg mortality, such was the case of RAFOX that presented LD50 from 4,580 to 10,790 µg/mL (7 to 17 mM). CLOS presented the lowest LD50 (80 µg/mL or 0.12 mM) on rumen fluke eggs. TC+FBZ was found to be effective drug against the development of F. hepatica eggs in many samples. In the same way NITROX showed a low LD50 (37 to 63 µg/mL or 0.13 to 0.22 mM), but RAFOX presented a highest LD50 (1,450 µg/mL or 2.32 mM). Discussion: The present study focused on screen the ovicidal activity and determining in vitro lethal doses 50 of main commercial anthelmintics used to control F. hepatica and rumen fluke as rapid tests in a tropical region from Mexico. The FECRT is the main method to detect effectiveness of anthelmintic and other method is the coproantigen reduction test (CRT) by ELISA. Both tests require many infected animals depending the number of treatments and by this the egg hatch assay (EHA) represent a complementary diagnosis of effectiveness of anthelmintic products to compare between regions and even between farms, because few animals are required from the farm to collect trematode eggs, and it is possible to know the effectiveness against various anthelmintics at the same time. Efficacy studies on trematodes using egg hatching tests are scarce, although they have the advantage that they can be applied to both F. hepatica and rumen fluke. TC+FBZ was one of the most effective products in inhibiting the development of F. hepatica eggs. However, RAFOX showed low effectiveness against trematode eggs, with very high lethal doses. These results agree with a study that show low efficacy against the development of Paramphistomum cervi eggs and with the FECRT test reductions of 75% and 80.58% were obtained, in times from 7 to 84 days after treatment with RAFOX. NITROX and CLORS were drugs that had good efficacy on the development of F. hepatica eggs. A differential response between liver and rumen fluke was observed. The anthelmintics used against rumen fluke eggs show low ovicidal activity and in Fasciola hepatica TC+FBZ show the best activity

Activities and Ergonomics of Workers in Broiler Hatcheries

The objective this study was to assess ergonomic factors, posture and biomechanics of workers of a broiler egg hatchery. The analysis of ergonomic factors was based on physical work load, thermal environment, and exposure to light and noise. The posture of workers was analyzed using photographic records which were evaluated by the software program OWAS (Ovako Working Posture Analysing System). A biomechanics analysis was also performed based on the photographs taken of the employee at various angles, which were used as inputs to the Michigan two-dimensional biomechanical model software program. The results show that certain activities can be considered unhealthy due to the exposure of employees to physical and thermal overload. The continuous noise levels and lighting were outside the range considered adequate by the regulations of the Brazilian Ministry of Labor. The manner in which certain activities are carried out when associated with weight and poor posture can result in body lesions in broiler hatchery employees. It is therefore necessary to apply specific ergonomic programs, including scheduled breaks, training, and other measures in order to reduce or to eliminate the risks involved in these activities.(AU)

Activities and Ergonomics of Workers in Broiler Hatcheries

The objective this study was to assess ergonomic factors, posture and biomechanics of workers of a broiler egg hatchery. The analysis of ergonomic factors was based on physical work load, thermal environment, and exposure to light and noise. The posture of workers was analyzed using photographic records which were evaluated by the software program OWAS (Ovako Working Posture Analysing System). A biomechanics analysis was also performed based on the photographs taken of the employee at various angles, which were used as inputs to the Michigan two-dimensional biomechanical model software program. The results show that certain activities can be considered unhealthy due to the exposure of employees to physical and thermal overload. The continuous noise levels and lighting were outside the range considered adequate by the regulations of the Brazilian Ministry of Labor. The manner in which certain activities are carried out when associated with weight and poor posture can result in body lesions in broiler hatchery employees. It is therefore necessary to apply specific ergonomic programs, including scheduled breaks, training, and other measures in order to reduce or to eliminate the risks involved in these activities.

The effect of abiotic factors on the hatching of Moina micrura Kurz, 1874 (Crustacea: Cladocera) ephippial eggs

The roles of some abiotic factors in controlling the hatching rates of Moina micrura ephippial eggs were investigated. Determination of optimum hatching conditions would be important in developing the use of this species as a food for fish larvae in aquaculture. Ephippia were exposed to different treatments in the laboratory, and monitored for hatching over a period of seven days. Optimum hatching conditions were: pH 5-9, temperature 25ºC, photoperiod eight or more hours light per day and light intensity equal to or greater than 850 lux. Differences in water ionic concentrations (from deionized water to 880 mg.L FONT FACE=Symbol>- /FONT>1 of selected salts) had no effect.

Foram investigados os efeitos de alguns fatores abióticos na taxa de eclosão dos ovos efipiais de Moina micrura. O conhecimento das melhores condições para a eclosão desses ovos pode ser importante na utilização dessa espécie para a aqüicultura, como alimento para larvas de peixes. Os efípios foram expostos a diferentes experimentos em laboratório por um período de sete dias. As melhores condições de eclosão foram: pH de 5 a 9, temperatura de 25ºC, fotoperíodo de oito ou mais horas de luz e intensidade luminosa igual ou maior que 850 lux. Diferentes concentrações de íons na água (de água deionizada e até 880 mg.L FONT FACE=Symbol>- /FONT>1 de sais selecionados) não influenciaram a eclosão.

The effect of abiotic factors on the hatching of Moina micrura Kurz, 1874 (Crustacea: Cladocera) ephippial eggs

The roles of some abiotic factors in controlling the hatching rates of Moina micrura ephippial eggs were investigated. Determination of optimum hatching conditions would be important in developing the use of this species as a food for fish larvae in aquaculture. Ephippia were exposed to different treatments in the laboratory, and monitored for hatching over a period of seven days. Optimum hatching conditions were: pH 5-9, temperature 25ºC, photoperiod eight or more hours light per day and light intensity equal to or greater than 850 lux. Differences in water ionic concentrations (from deionized water to 880 mg.L FONT FACE=Symbol>- /FONT>1 of selected salts) had no effect.

Foram investigados os efeitos de alguns fatores abióticos na taxa de eclosão dos ovos efipiais de Moina micrura. O conhecimento das melhores condições para a eclosão desses ovos pode ser importante na utilização dessa espécie para a aqüicultura, como alimento para larvas de peixes. Os efípios foram expostos a diferentes experimentos em laboratório por um período de sete dias. As melhores condições de eclosão foram: pH de 5 a 9, temperatura de 25ºC, fotoperíodo de oito ou mais horas de luz e intensidade luminosa igual ou maior que 850 lux. Diferentes concentrações de íons na água (de água deionizada e até 880 mg.L FONT FACE=Symbol>- /FONT>1 de sais selecionados) não influenciaram a eclosão.