Goats, earliest domesticated animals on land, evolved from wild goats and their relatives which were first appearing in the Central Asia. Goats include in the group of small ruminants which are used for various purposes, e.g. milk, meat, wool, hair, charm, ceremonial and sacrificial animals all over the world. In addition to these, goat-keeping plays important role in the growth of national economy. Goats provide income and support to the farmers and help in their poverty reduction. Besides all the mentioned utilities of goats throughout the globe, goats are facing the problems of infections caused by different harmful microorganisms including parasites.
Parasites render the goats less productive and beneficial to mankind. Among parasites, gastrointestinal (GI) parasites are those which are living in the digestive tracts of the goats and are responsible for extensive production losses by lowering the milk and meat. Generally, GI parasites are controlled through the use of chemicals commonly called as anthelmintics. However, over the counter availability of anthelmintics, low quality brands having less than the optimum drug concentration and inappropriate methods of drug administration lead to the development of resistance in GI parasites which makes the condition substandard. There are some other strategies which have been practiced across the globe, including: rotational grazing, use of herbal Dewormers, copper oxide wire particles, and biological control through nematode trapping fungi. All of the enlisted strategies used to control the gastrointestinal parasites have some limitations. Therefore, there is a need to explore or ascertain sustainable control measures which are valuable and practical having minimal limitations. This includes selective breeding of goats which have shown resistance to GI parasites. Actually, this is not a novel method, as it was started from New Zealand, Africa and Australia in sheep, now commonly practiced in goats. To date, these breeds of goat have been proven completely, partially or intermediately resistant to GI parasites: Creole goat kids, Black Iraqi goats, Local Ardi goats, imported Syrian, Barbari, Jamunapari goats, West African Dwarf goats, Crossbred cashmere goats, Galla and Small East African goats, canned, Bhuj and Anglo-Nubian, a Thai native.
The probable mechanisms which render goats resistant and resilient are related to goats specific characters which are: age, sex, breed, nutrition, immunity, production of specific antibody and immunoglobulins, blood cell, cytokines, some proteins and the most important is a genetic basis (gene) of specific goat breeds. The resistant goat breeds immune system responds earlier to infection. Moreover, better gene expression and antibody production by resistant goats against the GI parasite. Now, it is considered that it is one of the practically approved methodologies to control GI parasites of goats across the world. Furthermore, this is beneficial for both goat breeders and goat keepers at commercial and domestic levels. The benefits of breeding resistant goats to GI parasites are: (a) low pasture contamination (b) reduced chances of reinfection (c) no cost of treatment (D) production of genetically resistant offspring, reduced chances of drug residues in milk and meat, and improvement of health and production.
Pakistan has been endowed with 37 indigenous goat breeds and ranked third goat producing country in the world with an estimated population of 60 million heads. The most common breeds of goats in Pakistan are Beetal, Dera Din Pannah, Kamori, Nachi and Teddy. Consequently, it is the utmost need of the hour to evaluate these indigenous breeds of goats for their natural response to GI parasite through standard parasitological protocols, as GI parasites are common problems of goats throughout the country. This would be a positive step towards developing methods to control GI parasite at national levels. Further, we would be able to ascertain the natural response of indigenous goat breeds against GI parasites. The first step has been taken by the Department of Parasitology, University of Agriculture, Faisalabad, towards in vitro and in vivo susceptibility of various indigenous breeds against experimental and natural helminth infections in goats. The results of the study will support us to ascertain the specific response of each breed to natural and challenged infections. Consequently, supportive in drawing conclusions that which of the goat breed is resistant or resilient to GI parasites. In this way, we would be able to establish guidelines for farmers and recommending them to start breeding resistant goats breed in the country. In future the study can be extended to other indigenous goat breeds to their susceptibility to worm infections. The benefits of breeding resistant goats would be a positive step towards minimizing the economic losses caused by GI parasites in goats. The authors, of this leaflet are associated with the Department of Parasitology, Faculty of Veterinary Science, University of Agriculture Faisalabad.
The writers are associated with the Department of Parasitology, University of Agriculture, Faisalabad, Pakistan. They can be reached at <asimshamimuajk@gmail.com>