Knowledge and practices of smallholder farmers and herdsmen in the use of acaricides and gastrointestinal anthelminthes in Ghana

W Addah, J Baah*, S Tia** and E Okine

Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB Canada
addah@ualberta.ca
* Agriculture and Agri-Food Canada, Lethbridge Research Centre, AB Canada
** University for Development Studies, P. O. Box TL 1882, Tamale, Ghana

Abstract

A survey was conducted to assess the label information of acaricides and gastrointestinal anthelminthes used by farmers (n = 70) and herdsmen (n = 30) and their knowledge and practices in the administration of these parasiticides in the Sissila East district of the Upper West region of Ghana. Respondents were interviewed with semi-structured questionnaires and data analyzed using Statistical Package for Social Sciences (SPSS 11).

Examination of the labels on the packages showed that a significant number of acaricides (14%; n = 45) and anthelminthes (30%; n = 102) were not certified by the Food and Drugs Board of Ghana as required by law (P<0.05). Administration of both parasiticides was done by veterinary personnel (9%), community-based livestock health workers (11%), livestock farmers (30%) or herdsmen (50%; P<0.05). The herdsmen were neither literate in the English language nor had any formal training in the use of agro-parasiticides. Both parasiticides were used by majority of respondents at levels below the recommended rate. There was also widespread cross-application of crop-designated pesticides and petroleum products in the control of ticks. Animals that did not respond to treatment were slaughtered and consumed in the household (65%; P<0.05). In addition, a significant number of farmers (35%; P<0.05) did not practice parasiticide withdrawal prior to slaughter or sale of livestock.

Our results indicate that inappropriate handling and use of livestock parasiticides were prevalent and raised serious public health and food safety concerns in the Sissila East district of the Upper West region of Ghana.

Keywords: Food safety, label information, livestock, parasiticides, withdrawal period

Introduction

Ticks and helminths have a wide host and geographic diversity and hence constitute a major constraint to livestock production in the tropics and subtropics (Keyyu et al 2003; Githiori 2004; Swai et al 2005).  In Ghana, the control of ticks (Koney et al 2004) and helminths (Agyei et al 2005; Addah and Yakubu 2008) is currently reliant on acaricides and anthelminthes, respectively. The provision of primary animal heath care in most developing and under-developed countries is constrained by inadequate veterinary personnel, infrastructure and cost of veterinary medicines. Smallholder livestock farmers dependant on indigenous knowledge in the health management of their livestock are often compelled to extend such knowledge and practices to orthodox medications without adequate knowledge of the mode of application, pathway of action and side effects of the latter (Awumbila and Bokuma 1994; Keyyu et al 2003; Githiori 2004). Herbal or traditional medicines are biodegradable and less toxic therefore farmers can administer them based on their knowledge of ethno-veterinary medicine without much health risk.  However, the importance of administration of orthodox medicines by either a veterinarian or trained personnel cannot be overemphasized since many orthodox medicines are very persistent, toxic and potentially hazardous and require strict adherence to label instructions (Hoopes and Thwaits 1997). Under-dosing of parasiticides exposes parasites to sub-lethal levels of active ingredients leading to possible development of resistance and resultant treatment failures. Overdosing on the other hand may lead to poisoning of the treated animal, the producer or both, and in some cases even consumers of products from treated animals as well as pollution of the environment (Awumbila and Bokuma 1994; Githiori 2004; Kambarage et al 2004). The problem of improper use of parasiticides in under-developed countries is further worsened by high illiteracy rates among farmers, repackaging of large volumes of imported parasiticides into smaller units and subsequent retailing of these drugs which rarely carry adequate or any labeling, and the lack of adequate capacity of regulatory agencies to enforce regulatory laws (FAO 2002; Williamson 2003). Some parasiticides imported into developing countries are therefore improperly labeled with some active ingredients deliberately not indicated, understated or overstated depending on the economic interest of the manufacturer or distributor. According to FAO/WHO (2001), poor farmers in developing countries are paying an estimated US$300 million per annum for pesticides of which 30% do not meet internationally accepted quality standards and whose use has already been banned or severely restricted elsewhere because of hazardous substances and impurities.   

Previous studies on livestock parasiticides in Africa have focused on comparative efficacies (Githori 2004; Keyyu et al 2003; Addah and Yakubu 2008) and their impact on the biosphere (Awumbila and Bokuma 1994; Darko and Acquaah 2007). However, little attention has been paid to the efficacy of agro-chemicals under rural settings.  The present study investigated the knowledge and practices of smallholder livestock farmers and herdsmen in the use of acaricides and anthelminthes, and the characteristics of these parasiticides based on their label information in the Sissila East district of the Upper West region of Ghana.

Materials and methods    

Study location, data collection and analysis

Semi-structured questionnaires were administered to 70 smallholder livestock farmers and 30 herdsmen randomly sampled from 20 selected farming communities in the Sissila East District of the Upper West region of Ghana through Participatory Rural Appraisal (PRA) techniques (Temu and Due 2000). The district is located in the north-eastern part of the Upper West region of Ghana between Longitude 1.30° W and Latitude 10.00° N and 11.00° N. It is bounded to the north by Burkina Faso and to the east, west and south by 5 other administrative districts in Ghana. It is separated from Cote d’Ivoire in the west by the Sissila West district and consists of a total of 46 communities. Secondary data were obtained from the district directorate of the Ministry of Food and Agriculture (MoFA). The study was conducted between April and July 2007. Livestock farmers were asked to submit acaricides and anthelminthes (in their original containers) used for treating their animals for inspection. The following information on labels of containers were collected: trade name, country of origin, manufacturer, active ingredients, expiry date, language of instruction/inscription, recommended dosage, mode of administration and official certifying agency. The containers used to measure each parasiticide and water for dilution when indicated, were also used to determine whether the product was used as recommended  on the label, over-dosed or under-dosed. In some instances, respondents were asked to demonstrate how they used either parasiticide. Tick and helminths control practices of farmers were also observed during visits.

Data were analyzed by nonparametric methods with Statistical Package for Social Sciences^® (SPSS 11.0) software. The Chi square goodness of fit was used to test whether the observed proportions of each categorical variable differed. Differences in proportion for each variable between farmers and herdsmen were determined by non-parametric binomial test for categorical data. Statistical significance was declared at P <0.05.

Results and discussion 

Characteristics of acaricides and anthelminthes used by farmers and herdsmen

The characteristics of acaricides and anthelminthes used by both farmers and herdsmen in the district are indicated in Tables 1 and 2, respectively.

A total of 315 acaricides and 340 anthelminthes were inspected for label information. Examination of the labels indicated that 75% of acaricides (P<0.05) and 53% of anthelminthes (P>0.05) used by farmers and herdsmen in the district had not exceeded the inscribed expiry dates. All of the anthelminthes and most of the orthodox acaricides (91%, n = 188; P<0.05) inspected were imported products. The labels indicated that 14% of acaricides (n = 45) and 30% of anthelminthes (n = 102; P<0.05) were not certified by the Food and Drugs Board (FDB) of Ghana as required by law. It is likely that the certification of these products may have been inscribed on the bulk cartons used for packaging rather than on the individual bottles or containers. However, it is also likely that these products were illegally imported.  The quality and safe handling of such repackaged products can be difficult to ascertain especially when reference is not made on each individual bottle/container to the bulk packaging material for instruction on the use of the product.  The retailing of repackaged parasiticides in smaller units is widespread in Ghana because smallholder farmers often do not require or cannot afford larger volumes (Williamson 2003).  This has contributed to restricted and banned pesticides still being purchased and used in Africa (Williamson 2001; FAO 2002). Nearly two-third of all anthelminthes (n =30; 67%) and 20% (n= 68) of all acaricides not certified by the FDB bore labels written in French (P<0.05) which is not the official language of instruction in Ghana. Both farmers and herdsmen who used them said they were comparatively cheaper than those sold in Ghana. Illegal cross-border trading in agro-chemicals is reported to be prevalent between Ghana and its  French neighbours (Togo, Cote d’Ivoire and Burkina Faso) because registered pesticides in Ghana can sometimes cost ten times more than their francophone counterpart products in Cote d’Ivoire (Williamson 2003). The repackaging of products and prevalence of French-labeled products contravenes the FAO Code of Conduct on the Distribution and Use of Pesticides. The code stipulates that the pesticide industry should provide products consistent with national requirements; a range of pack sizes and types that are appropriate for the needs of small-scale farmers and other local users, in order to reduce risks and discourage sellers from repackaging products into unlabelled or inappropriate containers (Article 8.2.8; FAO 2002). The code also requires that each package of pesticides should contain information and instruction in a form and language appropriate and adequate to ensure effective use and reduce risks during handling (Article 3.4.4; FAO 2002).

In an effort to regulate the importation of dangerous and unregistered agro-chemicals, Ghana was one of the first countries in Africa to sign the Rotterdam Convention on Prior Informed Consent for importation of pesticides (Williamson 2001). The FDB is mandated by law (PNDC 305b; Act 523) to register and license all medicines. The Act is jointly enforced by the Environmental Protection Agency (EPA) and Custom Excise and Preventive Service (CEPS) but logistical constraints limit their capacity to effectively monitor non-commercial borders and unapproved routes such as those in Northern Ghana. In 2001, officials of the EPA estimated that 20% of pesticides used by farmers in Ghana were obtained from unauthorized trading sources (Williamson 2003).

Availability and use of acaricides and anthelminthes

Private veterinary shops were the main sources of both parasiticides (41%); others were bought from village markets (32%), the district MoFA veterinary clinics (25%) and chemical peddlers (2%; P<0.05). Farmers and herdsmen are normally educated on the right use of drugs when they are supplied by the MoFA clinics. Cumulatively, 75% obtained their medicines from sources other than the MoFA based on the following reasons: unavailability of drugs at MoFA (51%), long distance from the community (28%), higher prices (16%) and the unwillingness of the MoFA to retail medicines in smaller volumes (5%). Provision of animal health care in Ghana has been liberalized and privaterized and is now based on a cash-and-carry system. Most district extension agents also own private veterinary shops and therefore often sell these products to farmers unless the farmers go directly to the district MoFA veterinary clinic. All the private veterinary shops owned by veterinary extension agents, were located in the district capital, Tumu, which is far away from most farming communities. Keyyu et al (2003) also reported that private drug shops were the primary sources of veterinary drugs for 66.7% of smallholder dairy farmers compared to only 33.3% from official Government extension agents in Tanzania.

The current study indicated that there was no routine parasite control programmes but acaricides were used when high infestations were observed while helminths control was initiated when animals continuously lost weight or shed worms in their feces. On-the-spot hand dressing (80%), dipping/washing (15%) and pour-on (5%) were the methods used to administer acaricides in the study area (P<0.05). Small ruminants were dipped in large vehicle tires cut out for that purpose or in small metal barrels.  On-the-spot application was the most preferred method for cattle. The administration of acaricides and anthelminthes was done by pastoral herdsmen (50%), livestock farmers (30%), community livestock workers (11%) and veterinary personnel (9%; P<0.05).  The pastoral herdsmen have enormous indigenous knowledge and skills in handling cattle therefore they are often called upon by farmers to administer veterinary medicines. However as nomadic pastoralist, they lack formal education and are unable to read and write English or French which were the two languages of instruction on the labels examined. In the present study, 8% of farmers and none of the herdsmen had any formal education (P<0.05). Inadequate veterinary personnel and registered drug shops in rural areas have also been associated with improper use of acaricides in Africa; studies among nomadic Massais in Tanzania also showed that 76% of them administered acaricides themselves and did so at the wrong dosage rates (Swai et al 2005).

Orthodox methods of controlling both ticks and gastrointestinal helminths were generally higher than anticipated. As shown in Figure 1, none of the respondent used unorthodox anthelminthes.

Generally, response to herbal medicinal treatment is not as rapid as orthodox medicinal treatment therefore herbal medicines are often preferred for prophylactic treatment.  A survey of 175 small-scale dairy farmers in Tanzania similarly indicated more orthodox anthelmintic worm control than herbal control (94% vs. 1%; Keyyu et al 2003).

Majority of farmers (66%) preferred Cyprin EC because it was recommended by the district extension agents.  Cypermethrin and albendazole were the main active ingredients in most of the orthodox acaricides and all anthelminthes, respectively (see Tables 1 and 2).

The unorthodox parasiticides included herbal preparations (60%) and other chemicals (40%) such as used engine oil, kerosene and crop-designated pesticides including Gamatox (lindane) and endosulfan. Direct exposure to or residual effects of herbal medicines may be minimal because they are organic substances with relatively lower toxicity. Used engine oil, the most common petroleum product used, is cheaper and readily accessible but its efficacy for controlling ticks and scabies has not been scientifically assessed. Prolonged use of engine oils may also pose a risk of lead poisoning in meat and milk because engine oils are reported to contain lead at about 500mg/100mls (Masika et al 1997) while repeated exposure to petroleum can cause skin irritations and inflammation (Freeman et al 1990).   

As shown in Figures 2 and 3, 52% and 72% of respondents used acaricides and anthelminthes at levels below the recommended dosages, respectively.

None of the herdsmen used anthelminthes at the recommended rate (Figure 3; P<0.05). This observation has significant implications for livestock health management since the predominant group responsible for administering veterinary drugs (50%) in this study was the herdsmen who had limited knowledge in the use of orthodox veterinary drugs. All anthelminthes except Albevet GR-2500 (bolus) were administered by drenching with a syringe. Both acaricides and anthelminthes were similarly over-dosed by equal proportions of farmers and herdsmen. Our estimates showed that this practice was associated with younger animals since farmers did not take into account the age and weight of the animals when administering the drugs.  Bolus albendazole (Albevet GR-2500) was the commonest anthelminthes (30%) because it was reported to be handy and comparatively cheaper. However, it has been reported to have a limited parasite spectrum and questionable efficacy (Keyyu et al 2003).  The main factors accounting for under-dosing of veterinary drugs are; illiteracy and unfamiliarity with the drug (Damø and Bøgh 1999) and high cost (Awumbila and Bokuma 1994; Forse 1999). Over-dilution, which is the main cause of under-dosing associated with medicines that require dilution at the farm level, is a way of economizing on the use of the product to serve a large number of animals (Awumbila and Bokuma 1994; Swai et al 2005).  The efficacy of  most parasiticides used in Africa are already lowered by adulteration, dilution and other illegal tempering by distributors and retailers (Williamson 2001) therefore over-dilution by farmers is expected to further reduce the concentration of essential active ingredients to non-lethal levels. This can expose parasites to sub-lethal levels of active ingredients leading to the development of resistance in the parasites and resultant treatment failures. Overdosing on the other hand is a waste of resources and may lead to poisoning of the treated animal, the user or environmental pollution.

Cross-application of crop pesticides such as lindane and endosulfan to ruminants was a common practice among cotton and cowpea farmers who also kept livestock. Under the cotton out-grower scheme, cotton companies in Northern Ghana supply pesticides to farmers as part of a package of farm inputs for growing cotton. Reasons for diversion of cotton pesticides in Northern Ghana have been extensively studied (Williamson 2003). Thirty percent (n = 27; P<0.05) and 6% (n = 5; P<0.05) of all unorthodox acaricides used by farmers and Fulani herdsmen respectively were designated as crop pesticides.  Because lindane and endosulfan are cheaper and highly persistent organochlorines, previous studies have found that many farmers (75%) and herdsmen (36%) prefer them to other parasiticides in the control of ticks in Ghana (Awumbila and Bokuma 1994).  Cheaper lindane is still procured from cocoa farmers in southern Ghana and neighboring Francophone countries where it is being used to control resistant cotton bollworms (Williamson 2003). Lindane and endosulfan are however, highly toxic and their use was banned by the European Union in 2006 and 2003, respectively (PAN 2008). High livestock fatalities due to crop pesticides have been reported in cotton, cowpea and cereal farming communities of Ghana (PAN 2007; Williamson 2005).

Public health concerns and food safety

Neither farmers nor herdsmen wore any protective clothing during the administration of both parasiticides. Dermal exposure to veterinary drugs are usually overlooked or underestimated by farmers in developing countries although the drugs are capable of binding to the skin, extracting lipids out of the skin or rendering it permeable to other similar toxic chemicals (Muhammad et al 2009).

As shown in Figure 4, 35% (P<0.05) of farmers did not  practise withdrawal prior to slaughter, milking or sale of treated animals while a similar percentage observed it for only 7 days (32%; P>0.05).

Animals that did not respond to treatment were either slaughtered and consumed in the household (65%), died and were buried (25%), sold off quickly to butchers before they died (7%) or thrown away after death (3%) (P<0.05). It was considered unwise to bury the carcasses of especially cattle that could have been sold off to recover investments. Chronically sick animals where therefore sold to butchers who would usually slaughter such animals at unapproved  locations.  Meats from such animals however, eventually find their way into the market and human food chain despite the risks (Kambarage et al 2004).   Most farmers in developing countries do not often care about withdrawal periods in treated animals (Keyyu et al 2003) and cows are usually treated and milked at the same time in the morning before being let out to graze (Awumbila and Bokuma 1994). Drug residues in meat and milk are therefore likely to be higher in livestock products produced by smallholder rural farmers and herdsmen. Significant concentrations of organochlorines in milk and cheese samples have been observed in some urban areas of southern Ghana even though the levels did not exceed the maximum residual limits recommended by the WHO (Darko and Acquaah 2007).

 In Ghana and most West African countries, meat from small ruminants is prepared by burning off the hair and the carcass eviscerated without removing the skin. Meat prepared this way from animals treated with acaricides poses significant food safety risks since majority of farmers did not observe any withdrawal period or did it for 7 days or less (Figure 4). This practice is of greater concern especially when hazardous petroleum products and crop-designated pesticides which can accumulate in the subcutaneous tissue are used to treat animals.  Even though the level of drug residues in meat products was not determined in this study, Darko and Acquaah (2007) reported that 75% of all meat and milk samples examined in Ghana contained pesticide residues. Cypermethrin, the commonest active ingredient in most of the acaricides, is highly lipohpilic and is likely to bioaccumulate and biomagnify in higher organism like humans. In other studies, residual cypermethrin in whole milk diminished to control values only after 21 days post pour-on, while the level in subcutaneous tissue of sheep was 3,300 µg /kg after about one week of on-the-spot dosing compared to only 30-60 µg /kg in the muscle (WHO/FAO 2004). The method of meat preparation therefore predisposes consumers to greater risk of residual effects since the skin alone or skin plus subcutaneous fat is consumed as meat in Ghana. The FAO/WHO (2004) therefore recommends that maximum residue limit in fat should be 1000 µg/kg, 100 µg/kg in milk, 20 µg/kg in sheep muscle and 50 µg/kg in cattle muscle. These limits correspond to 0 - 20 µg/kg human body weight.

Acute toxic effects of parasiticides on animals and humans may easily be distinguished but long term exposures to lower doses are often difficult to recognize and can pose a risk to humans (Darko and Acquaah 2007). The US Environmental Protection Agency has classified cypermethrin as a possible human carcinogen though available information on its carcinogenic properties is inconclusive (EXOXNET 1996). Other studies by Morolli et al (2006); Kidds and James (1991), however, suggest that cypermethrin is water insoluble and easily absorbed and immobilized in the soil and is therefore unlikely to bioaccumulate or biomagnify in the food chain or cause ground water contamination.

To keep veterinary medicines out of reach of unintended users, farmers and herdsmen stored them under their beds (43%), in boxes (7%), in sheds outside their houses (26%), in polyethylene bags hanged on walls in pens (20%) or in store rooms (3%). No accidental ingestion of parasiticides was reported but farmers complained of itching after the application of acaricides.

Conclusion and recommendations 

• The survey found inappropriate trading, labeling and use of acaricides and anthelminthes in the study area which raises concerns about food safety and public health. Farmers and herdsmen tended to directly extend their knowledge and practices in ethno-veterinary medicines to potentially hazardous orthodox chemicals.

  
  

• To reduce inappropriate handling and improve usage of acaricides and anthelminthes at recommended doses, the labeling of parasiticides designated for used in developing countries with high rates of illiteracy should be packaged in suitable containers with instruction in the appropriate language, include the use of containers graduated by pictorial symbols or pictograms illustrating animal size and corresponding quantities of the drug required for treatment. Biological and integrated parasite management methods should be encouraged and taught to rural farmers and pastoralists to reduce the use of pervasive veterinary parasiticides.  Stringent policies and efforts by Governments of developing countries are also required to regulate the importation, distribution and marketing of agro-chemicals. 

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Received 9 July 2009; Accepted 16 September 2009; Published 1 November 2009

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