Rao Zahid Abbas

Acaricide resistance in cattle ticks and approaches to its management: The state of play

Cattle ticks are an important constraint on livestock production, particularly in tropical and subtropical areas. Use of synthetic acaricides is the primary method of tick control; therefore, it would be imperative to develop strategies to preserve the efficacy of existing acaricides. This paper summarizes the status of acaricide resistance in cattle ticks from different parts of the world and reviews modes of action of currently used acaricides, mechanism of resistance development, contributory factors for the development and spread of resistance, management of resistant strains and strategies to prolong the effect of the available acaricides. Use of vaccines, synthetic and botanical acaricides and educating farmers about recommended tick control practices are discussed, along with the integration of currently available options for the management of drug resistance and, ultimately, the control of cattle ticks.

Botanicals: an alternative approach for the control of avian coccidiosis

Coccidiosis is recognized as the major parasitic disease of poultry and is caused by the apicomplexan protozoan Eimeria. In the past, conventional disease control strategies have depended mainly on anticoccidial drugs and, to a certain extent, live vaccines. Anticoccidial drugs have played a major role in the effective control of avian coccidiosis, but, their extensive use has resulted in the emergence of drug resistant coccidian strains. In such situations, new drugs should be available to replace the older ones against which resistance has developed, however it takes a long time to develop any new compounds. Because of the high cost of developing new drugs and vaccines, development of drug resistance and concerns over drug residues associated with the continuous use of these chemicals, there is a renewed interest in the use of botanicals for safe, effective and cheap control of avian coccidiosis. Several poultry scientists all over the world are now actively engaged in research into the use of plants and plant derived products to fight and reduce the heavy economic losses in poultry industry caused by coccidiosis. This paper reviews the research on botanicals, herbal complexes and commercially available botanical products having anticoccidial properties against avian coccidiosis. Information regarding active compounds, doses and mechanism of action of plants provided in this paper may serve as a guideline for the use of botanical anticoccidial agents as a part of integrated control strategies for the effective control of resistant coccidian parasites.

Anticoccidial drug resistance in fowl coccidia: the state of play revisited

The development of drug resistance in Eimeria is common because of extensive use of anticoccidial drugs for the control of avian coccidiosis. The significance of chemotherapy is evident from the fact that, in spite of advancement in the field of immunological, biotechnological and genetic methods, prophylactic chemotherapy with anticoccidial drugs is still widely used for the control of coccidiosis. In such situations, new drugs should be available to replace the older ones against which resistance has developed, however it takes a long time to develop any new compounds. It is therefore currently necessary to develop strategies to minimise the emergence of resistance in Eimeria strains and to prolong the effect of available anticoccidial drugs. This paper summarises the resistance status of Eimeria species in different parts of the world and reviews different types of resistance, mechanism of resistance development, factors involved in the development and spread of resistance, management of resistant strains and strategies to preserve the efficacy of the available anticoccidial drugs. Use of vaccines, synthetic and botanical anticoccidials and educating farmers about recommended coccidiosis control practices are discussed in this review, along with the integration of currently available options for the management of drug resistance and, ultimately, the control of coccidiosis.

Epidemiology of Eimeria and associated risk factors in cattle of district Toba Tek Singh, Pakistan

A cross-sectional study was carried out to determine the prevalence, species characterization, and associated risk factors with Eimeria of cattle of district Toba Tek Singh from April, 2009 to March, 2010. Of the total 584 fecal samples examined for Eimeria, 275 (47.09%) were found infected with six species of Eimeria. Among the identified species of Eimeria, Eimeria bovis was found to be the highest prevalent species (52.36%), followed in order by Eimeria zuernii, Eimeria canadensis, Eimeria ellipsoidalis, Eimeria alabamensis, and Eimeria cylindrica with prevalence of 48.27%, 34.83%, 29.31%, 24.14%, and 8.62% respectively. Peak prevalence was observed in August. Cattle were infected more frequently during rainy (60.32%) and post-rainy seasons (59.25%). Calves had significantly higher prevalence (P < 0.05) of Eimeria than adults while higher prevalence of Eimeria was observed in female cattle. Among management and husbandry practices, feeding system, watering system, housing system, floor type, and herd size strongly influenced the prevalence of Eimeria in cattle. Coccidiosis was more prevalent in ground feeding system, pond-watered animals, closed housing system, and non-cemented floor type (P < 0.05) as compared to trough feeding system, tap watered animals, open housing system, and partially cemented floor types, respectively. Breed and body condition of animals were not found risk factors (P > 0.05) influencing prevalence of Eimeria.

Anticoccidial activity of herbal complex in broiler chickens challenged with Eimeria tenella

The objective of the present study was to evaluate the anticoccidial effect of different concentrations of the herbal complex of 4 plants (leaves of Azadirachta indica and Nicotiana tabacum, flowers of Calotropis procera and seeds of Trachyspermum ammi) in broiler chickens in comparison with amprolium anticoccidial. Three concentrations (2 g, 4 g and 6 g) of herbal complex were given to the experimental groups once a day and amprolium (at the dose rate of 125 ppm) was given orally in drinking water from the 14th to the 21st days of age. One group was kept as infected, non-medicated control and one as non-infected, non-medicated control. All groups were inoculated orally with 75,000 sporulated oocysts on the 14th day of age except the non-infected, non-medicated control. Among herbal complex medicated groups, the maximum anticoccidial effect was seen in the group medicated with 6 g herbal complex followed by 4 g and 2 g herbal complex medicated groups. Treatment with 6 g of the herbal complex significantly reduced the negative performance and pathogenic effects associated with Eimeria tenella challenge at a level that was comparable with amprolium when using a largely susceptible recent field isolate. In summary, concentration-dependent anticoccidial activity of the studied herbal complex suggests its use as an alternative anticoccidial agent to chemotherapeutic drugs for Eimeria tenella control.

In vitro and in vivo acaricidal activity of a herbal extract.

The anti-tick efficacy of combined aqueous herbal extracts of Azadirachta indica leaves, Nicotiana tabacum leaves, Calotropis procera flowers and Trachyspermum ammi seeds was evaluated using adult immersion test, larval packet test and ear bag method. The extract exhibited lethal effects on egg laying (index of egg laying=0.371404±0.00435), hatching (22.35%) and total larval mortality at 50 mg ml(-1) and reduced tick intensity on the infested calves (18 detached out of 35 at 45% (w/w) suspension, topically applied). The herbal extract exerted dose- and time-dependent response against all the developmental stages of Rhipicephalus (Boophilus) microplus considered in this study, thus justified their use in the traditional system of Pakistan.

Anticoccidial activity of Curcuma longa L. in broilers

Comparative efficacy of turmeric (Curcuma longa L.) crude powder and salinomycin sodium on the occurrence of coccidiosis and growth performance of broiler was evaluated. A total of 90, day-old chicks were randomly divided into six groups. From first day onward, ration was supplemented with 1, 2 and 3 % turmeric powder in groups 2, 3 and 4, respectively, group 1 received salinomycin sodium @ 12 g 50 kg-1 feed while groups 5 and 6 were kept as infected un-medicated and uninfected un-medicated controls. First five groups were infected with Eimeria tenella sporulated oocysts @ 1,00,000/chick at the age of 20 days. Body weight gain, feed consumption, feed conversion ratio were investigated throughout the experimental period, and bloody diarrhea and oocysts excretions were investigated at the first and the second week after infection. Maximum coccidiostatic effect was observed with turmeric (3%) showing mild bloody diarrhea as compared to other infected groups receiving turmeric containing rations. This effect was comparable with a standard coccidiostat i.e., salinomycin sodium. Similarly, the weight gain in the groups treated with salinomycin sodium (2280g) and 3% turmeric (2293g) were also significantly higher (p < 0.05) than that of infected control group (1955g). In the groups treated with ration supplemented with 3% turmeric powder and salinomycin sodium, the peak excretion of oocysts was delayed about 1 or 2 days relative to the control infected group. Concentration-dependent coccidiostatic effect of turmeric suggested that further studies should be carried out to determine the possible maximum safe levels of turmeric with least toxic effects to be used as coccidiostat.

Comparitive efficacy of five anthelmintics against trichostrongylid nematodes in sheep

The efficacy of levamisole, ivermectin and three different preparations of oxfendazole, applied at the recommended rate, were evaluated in flocks of sheep kept at two farms in Thal desert, Pakistan. Sixty animals on each farm were selected randomly on the basis of their weight and egg count of more than 150 eggs per gram of faeces. Three preparations of oxfendazole (fendamex, oxazole, syatamex), levamisole and ivermectin were given to five groups while one untreated group was kept as control. Faecal egg counts, faecal egg count reduction test, postmortem worm count and copro-culture were performed to assess the efficacy of selected anthelmintics. Levamisole and ivermectin preparations reduced (P ≤ 0.05) prevalent species of gastrointestinal nematodes in both flocks. Oxfendazole preparations exhibited low efficacy and some gastrointestinal nematodes (Haemonchus and Trichostrongylus) were suspected for resistance against these preparations, with resistance more pronounced in oxazole followed by systamex and...

Acaricidal drug resistance in poultry red mite (Dermanyssus gallinae) and approaches to its management

Poultry red mite (Dermanyssus gallinae), the haematophagous pest of egg laying hens, is an important problem in poultry production in many parts of the world. Control has typically relied on synthetic acaricides in spite of advancements in immunological, biotechnological and genetic approaches. However, the repeated long term use of these compounds has resulted in the development of drug resistant populations of poultry mites, therefore, the availability of effective acaricides is diminishing rapidly. Due to this, there is need for the continuous availability of new chemical acaricides to replace the older types, however the development and registration of new acaricides is a long expensive process, therefore, preserving and maintaining the effectiveness of available acaricides is essential. This review has two parts; the first is to provide the basic understanding of acaricide resistance in D. gallinae while the second part provides more detailed knowledge about the management of resistance to preserve the efficacy of available acaricides.

Anticoccidial effects of acetic acid on performance and pathogenic parameters in broiler chickens challenged with Eimeria tenella

The objective of the present study was to evaluate the anticoccidial effect of the different concentrations of the acetic acid in the broiler chickens in comparison with the amprolium anticoccidial. A total of 198 chicks were placed 11 per pen with three pens per treatment. The different concentrations (1%, 2% and 3%) of acetic acid and amproilum (at the dose rate of 125ppm) were given to the experimental groups in drinking water from 10-19th days of age. One group was kept as infected non medicated control and one as non infected non medicated control. All the groups were inoculated orally with 75,000 sporulated oocysts at the 12th day of age except non infected non medicated control. Anticoccidial effect was evaluated on the basis of performance (weight gain, feed conversion ratio) and pathogenic (oocyst score, lesion score and mortality %age) parameters. Among acetic acid medicated groups, the maximum anticoccidial effect was seen in the group medicated with 3% acetic acid followed by 2% and 1% acetic acid medicated groups. Amprolium and 3% acetic acid were almost equivalent in suppressing the negative performance and pathogenic effects associated with coccidiosis (Eimeria tenella) challenge. In summary, acetic acid has the potential to be used as alternative to chemotherapeutic drugs for Eimeria tenella control. Concentration-dependent anticoccidial effect of acetic acid suggests that further studies should be carried out to determine the possible maximum safe levels of acetic acid with least toxic effects to be used as anticoccidial.