In vivo comparative efficacy of indigenous plants against Trichostrongylus

Introduction

Balochistan is the largest province of Pakistan with atotal land mass of 347190sq. km. Out of the total landarea almost 92% consists of arid grazing lands, barrenRocky Mountains and deserts. Balochistan hasdiverse topography in elevation ranging from sea levelto 3520 meters. Physiographic units are mountainranges (52.6%), alluvial fans (21.9), piedmont plains(11.8%), sand plains (7.6%), valley bottom (3.3%),tidal plains (0.8%) and 2.0% plains (Saleem andAshiq, 2000). the average annual rain fall varies fromless than 50 mm in the southwest to above 400 mmin northeast. Cold winters and mild summerscharacterize the north region including District Zhob.Most winters receive snow, frost and rainfall rangingbetween 250 to 350 mm. In the southwestern desertregion, the annual rainfall ranges between 50 to 125mm and the region experiences the hottest summerwith temperatures rising occasionally to over 51°C.Animals are mostly dependant on open grazing.

The economy of Balochistan is dominated byagriculture, including livestock and fisheries. Itaccounts for 52% of the province's GDP and employs65% of the labour force. Of the total agriculture GDP,livestock contributes 40%, fruit 30%, field crops 17%,vegetables 12% and fisheries 1% (Annonymous, 2004-2005). The nomadic people solely depend onlivestock whereas; the transhumants and sedentarypeople derive up to 40% income from livestock. Sheeppopulation estimated at 27.4 million heads inPakistan (Annonymous, 2008-09) plays an importantrole in the national economy. 12.8 million (48%) ofthese, respectively are raised in Balochistan(Annonymous, 2006). In addition to food of highprotein value, products such as skin, wool, hair,pellets and goods made from them are a big source ofearning foreign exchange.

In developing countries like Pakistan, heavy economiclosses in livestock sector have been reported due toparasitic diseases. Theses parasitic diseases are one ofthe principal problems in the development of livestockindustry. Factors like constant exposure to parasiticinfection, variable climatic conditions lack ofknowledge on the part of livestock owners regardingparasitic infection play an important role in thedevelopment of ecto and endo parasites (Durani, 1991).

Throughout the world, internal parasites pose one of themajor health limitations for grazing animals. Sheep andgoats are more susceptible to internal parasites thanother livestock, due to their grazing behavior and poorimmunity (Martin 1983). The impact of parasiticdiseases varies greatly between countries and betweenregions, depending on climate and the intensification offarming in the area (Radostits et al., 1994). Parasitesexert adverse effects on the health and productivity ofanimals in Pakistan (Javed et al., 1992). Khan et al.(1988) reported 100% sheep in upland Balochistan getinfected with internal parasites. 

Trichostrongylid nematodes of sheep, because of theiradverse effect lead to lowered productivity, retardedgrowth rate and even death of lambs (FAO, 1974:Barger, 1982: Steel and Symons, 1982). Theprevalence of gastrointestinal nematodes of sheep hasalso been reported very high (25.1 to 92%) by manyworkers in Pakistan (Durrani et al., 1981; Mohiuddinet al., 1984; khan 1985; Iqbal et al., 1993; Qayyum,1996). Haemonchosis, caused by Haemonchus (H.)contortus, is among the top 10 most importantconditions having an impact on sheep and goatproduction (Githiori et al., 2004). 

Conventionally, trichostrongylids has been tackledwith use of synthetic chemicals but owning todevelopment of anthelmintic resistance against majorgroups of anthelmintics viz., benzimidazole,levamisole and avermectins (Jabbar et al., 2006),people are looking for alternatives to syntheticchemicals like vaccination coupled with improvedmanagement and ethnomedicinal practices.Ethnomedicine is an integral part of traditionalmedical practices in many countries of the developingworld. A large proportion of the population uses thisform of treatment for primary health care and for thetreatment of ailments in their livestock (Waller et al.,2001). The plants are known to provide a rich sourceof botanical anthelmintic, antibacterial andinsecticides (Satyavati et al., 1976). A number ofmedicinal plants have been used to treat parasiticinfections in man and animals (Nadkarni, 1954; Said,1969; Akhtar et al., 2000).

Development of herbal products depended upon localbotanical flora with the result that different remediestended to develop in different parts of the world.Recent surveys in the developing countries haveidentified many plants that have the potential to beused as anthelmintics (Jabbar et al., 2006). However,majority of the evidences reported in ethnoveterinarysources are in the form of observations, rather thanfrom controlled studies (Hammond et al., 1997). Thereare many plants which have been validatedscientifically for their anthelmintic properties based ontheir traditional uses (Hammond et al., 1997; Iqbal etal., 2001; Iqbal et al., 2003; Iqbal et al., 2004; Iqbal etal., 2005; Iqbal et al., 2006; Githiori et al., 2006). 

The present study was planned to evaluate theanthelmintic activity of some locally availableindigenous plants against Trichostrongylid in sheepin District Zhob, Balochistan.