DETERMINE THE PREVALENCE OF GASTROINTESTINAL HELMINTH AMONG SLAUGHTERED CATTLE IN BENIN CITY ABATTOIRS.
1.1 General Background to the Study
Cattle constitute an important source of animal protein to many Nigerians. A lot of socio-economic importance is therefore attached to ownership of these animals that, in some cases, may be the only realizable wealth of a rural household (Omeke, 1988).
The world’s total numbers of cattle were 861.9 and 1078.2 million, respectively, i.e. there is about one goat to approximately 1.25 specimen 1 of cattle (FAOSTAT, 2008). In Nigeria, the total numbers of cattle were 53.8 and 33.9 million, respectively (FAOSTAT, 2008). This constitutes 6.2% and 3.1% of the world total population of cattle respectively (FAOSTAT, 2008).
Cattle harbour a variety of gastrointestinal tract (GIT) parasites, many of which are shared by many species.Among these parasites, helminths such as nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes) are the most important as they affect the growth as well as the production of the animals. Gastrointestinal nematodes of the Trichostrongylidae family are perhaps the most important parasites of cattle world-wide, causing significant morbidity and loss of production (Bagley, 1997; Pawel et al., 2004).
Gastrointestinal nematodes of cattle are roundworms parasitizing the abomasum, small intestine and large intestine. Infection usually occurs primarily through contaminated feed and water, enhanced by poor hygiene (Gatongi, 1996).
Intestinal helminthosis has for many years been recognized as a major problem in livestock rearing (Barger, 1997). Most specimen 2 of cattle infected have been shown to be asymptomatic or produce only mild symptoms, as a result of which infections are often overlooked till serious complication or chronic clinical signs occur (Rausch and Jentoft, 2002).
Gastrointestinal nematodes could be harmful to the infected animals and cause economic loss due to mortalities and reduced weight gain (Menkir et al., 2007; Vlassoff et al., 2001). Gastrointestinal nematodes also cause hypoproteinemia, impaired digestive efficiency and pathogenic complications such as anaemia, diarrhoea, oedema and recumbency which will lead to lowered productivity, retarded growth rate and even death of lambs (Holmes, 1986; Sykes, 1994; Forse, 1999; AlShaibani et al., 2009). The loss through reduced productivity is related to reduction of food intake, stunted growth, reduced work capacity, cost of treatment and control of helminthosis (Pedreira et al., 2006; Odoie et al., 2007; Chaudhary et al., 2007).
The severity of infections depends on the genera of helminth parasites involved, animal species, the number of infective stages on pasture, an alteration in host susceptibility, the introduction of susceptible stock into an infected environment, the introduction of infections into an environment, ineffective parasite removal from the host animals due to poor drug administration techniques, and local environmental conditions such as humidity, temperature, rainfall, vegetation and management practices (Fakae, 1990a; Hansen and Perry, 1994; Sykes, 1994; Nwosu et al., 1996 a,b; Urquhart et al., 1996).
Several studies carried out on gastrointestinal helminthosis of cattle in many African countries showed that the prevalence of the infections varies from place to place. Studies on seasonal incidence of GI helminthosis are carried out to find the time in which infection with infective larvae begins, rises to a peak and decline so that the treatment can be timed to prevent severe infection as well as reduce contamination of pastures with eggs and larvae. Comprehensive studies are required to know the level of GIT helminths in cattle in Benin, Northern Nigeria and factors contributing to their prevalence.
1.2 Statement of Research Problems
Gastrointestinal trichostrongyles of which Haemonchus contortus ranks highest in importance globally (Perry et al., 2002; Tariq et al., 2010) are recognized as a major constraint to both small and large-scale small ruminant production in developing countries, leading to significant economic losses (Martinez-Gonzalez et al., 1998). These nematodes (Haemonchus, Trichostrongylus and Cooperia) cause impaired digestion and also affect the absorption of minerals particularly calcium and phosphorus (Speedy, 1992).