Int.J.Curr.Microbiol.App.Sci (2014) 3(1): 684-706 ISSN: 2319-7706 Volume 3 Number 1 (2014) pp. 684-706 http://www.ijcmas.com Review Article Sheep and goat production: basic differences, impact on climate and molecular tools for rumen microbiome study A.R.Agrawal1, S. A. Karim2, Rajiv Kumar2, A.Sahoo2 and P. J. John1 1Department of Zoology, University of Rajasthan, Jaipur, Rajasthan, India 2Central Sheep and Wool Research Institute, Avikanagar, Tonk, Rajasthan, India *Corresponding author e-mail: A B S T R A C T Small ruminants are able to utilize the lingo-cellulosic materials and convert them to animal products of high nutritional value viz. meat, milk, wool/fur, hide and manure. However ruminants are also contributing towards green house gas emission. Like large ruminants, these fore gut fermenters also harbor a dense and diverse microbial population belonging to different group of flora and fauna. The mammalian system is K e y w o r d s devoid of enzymes cellulase to degrade structural carbohydrate while ruminants are able to degrade them by the enzymes elaborated by symbiotic microbes inhabiting in Sheep; the rumen. Importance of small ruminants in Indian economy lies in their smaller size, Goats; Rumen which is easy to graze and manage. Sheep and goat production is an integral microbiome; component of rural economy of India and serves as major source of economic Green House sustenance for weaker segments of the society in the hot semiarid and arid region. gas; Sheep and goats are closely related since both belong to subfamily Caprinae whereas Differences they are separate species. However, minor differences also exist in their anatomy, in sheep and physiology, grazing behavior, etc. Sheep as individuals and breeds are more sensitive Goatd; to environmental changes than other domestic animals but as a species they thrive Modern everywhere. The inherent characteristics of goats such as resistance to dehydration, Biotechnology wider choice of vegetation, and wide-ranging feeding habits with preference for browse tools. species, enable them to perform better than sheep in regions of scanty rainfall. Furthermore, goats appear to digest fiber more efficiently than sheep. Studies are required to delineate differences in microbial population between sheep and goat which might be helpful in enhancing productivity of the species reared under changing climatic conditions. Modern biotechnology based tools are widely applied to unravel complexities of microbial communities harboring rumen and their functions and interaction among different microbes. Introduction Herbivores, particularly ruminants, animals involved in production of food for constitute large share of the domestic human consumption. They are able to 684 Int.J.Curr.Microbiol.App.Sci (2014) 3(1): 684-706 utilize the lingo-cellulosic materials and employment to small holder farmers and convert them to animal products of high other weaker sections of society including nutritional value viz. meat, milk, wool/fur, women and landless laborers. Livestock is hide and manure. Moreover ruminants do the major source of cash income for not compete with human and monogastric subsistence of the livestock owners in livestock species for feed resources. They critical zones of the country. In today s are fore gut fermenters harboring a dense competitive economy driven environment, and diverse microbial population which the survival of small scale sustainable break down the lingo-cellulosic fibrous animal production has some inherent feeds. The mammalian system is devoid of constrains. Moreover with economic enzymes cellulase to degrade structural empowerment simultaneous greater carbohydrate while ruminants are able to demand is being placed on limited and degrade them by the enzymes elaborated finite natural resources resulting in chaotic by symbiotic microbes inhabiting in the situation. It is now essential to ensure that rumen medium. However rumen, also the farmers not only produce for their own called false stomach/fore-stomach, itself is needs but also to meet the expanding devoid of glandular tissues and as such do demand of the market. This is possible not secret any enzyme for digestion of only by application of appropriate ingested food. In rumen fermentation technological interventions besides hydrogen and CO2 are contributed by ensuring better access to credit and ciliate protozoa, bacteria and fungi while market. Unfortunately, there exist a wide methanogenic bacteria utilize the gap in demand and supply of nutrients for hydrogen to reduce CO2 to produce the Indian livestock which is the major methane. cause of concern in realizing optimal and sustained production. Therefore, in the Among the herbivores, the ruminants, present scenario, judicious utilization of particularly sheep, goat, cattle and feed resources from agriculture, Common buffaloes are dominant livestock species Property Resources (CPR) and forest for human consumption. Animal resource is of vital concern to meet the husbandry has made sizeable contribution ever-increasing demand of animal derived to human being in the past century. protein. Animal products provide one-sixth of human food energy and more than one- Importance of small ruminants in Indian third of the protein on global basis economy lies in their smaller size, which (Bradford, 1999). Livestock production in is easy to graze and manage. Sheep and India is an integral part of traditional goat production is an integral component mixed farming (crop-livestock) and play of rural economy of India and serves as important role in the agrarian economy. major source of economic sustenance for The importance of livestock increases with weaker segments of the society in the hot aridity of the environment since traditional semiarid and arid region. The species is crop production is a gamble in the region traditionally reared by small and marginal due to unfavorable agro-climatic farmers and land less laborers under condition. The livestock contribute milk, extensive range management on CPR with meat, fiber, manure, fuel, farm power and top feed supplementation during lean rural transport and thus have major role in season. As per last Census (2007), India rural economy by providing income and was host to 71.5 and 140.5 million (m) 685 Int.J.Curr.Microbiol.App.Sci (2014) 3(1): 684-706 sheep and goats which increased to 74.0 has revealed that sheep are most important and 154.0 m , respectively by 2010 (FAO, domestic animals, harboring huge genetic 2010). As per literature (Karim, 2008; diversity (40 descript breeds in India) and Karim and Sankhyan, 2009) the slaughter substantial prospects for continued rate of sheep and goats is 32% and 36 % breeding (Acharya, 1982) to further boost hence a total of 23.68 and 55.44 m heads meat and wool production for rising are slaughtered annually. Considering population. Human have molded sheep to average carcass weight of 10 kg the total suit diverse environments and to enhance meat production by sheep and goats comes the specialized production of meat, wool to 237 and 554 m kg respectively and milk. Earlier studies have identified (Gadekar et al, 2011). particular regions of the sheep genome that appear to have changed rapidly in Hoofed mammals like sheep and goats response to selection for genes controlling belong to the highly successful order traits such as coat color, coat cover, body Artiodactyls, family Bovidae with wide size, reproduction and especially, the lack geographical distribution. The main of horns: one of the earliest goals of difference between ruminants and selective breeding (Kijas et al, 2012). monogastric animal is that ruminant have Sheep (Ovis aries) are range fed ruminant four parts in stomach i.e. rumen, and like all ruminants are even-toed reticulum, abomasum and omassum. Food ungulate. Domestic sheep are relatively mixed with saliva in rumen and reticulum smaller sized ruminants and depending on and separated in two layers solid and breed, sheep exhibit a wide range of liquid. Then solid part of food regurgitated heights and weights usually with a and mixes with saliva to break down in crimped hair called wool or hairy. Their small particles. Fiber particles of food rate of growth, mature weight and break in hexose monomers and further fecundity are heritable traits that are often degraded by rumen microbes into volatile used in selection for breeding. Ewes fatty acids like acetic acid, propionic acid, worldwide weigh between 45 and 100 kg butyric acid etc. Polymers of amino acids and rams between 45 and 160 kg whereas and non structural carbohydrates are in India the average weight of sheep is fermented to propionates. Then digested around 30-35 kg with coat cover ranging part of food moves towards stomach and from hairy to wooly with fiber diameter of from stomach it moves towards small 20- 55 µ (Melinda et al, 2004). intestine where the digestion is effected by the enzymes elaborate by the system Sheep and goats are closely related since followed by absorption of nutrients. both belong to subfamily Caprinae whereas they are separate species. Visual Sheep rearing is one of the oldest differences between sheep and goats professions closely associated with human include the beard and divided upper lip of civilization wherein the domestication of goats. Sheep tails also hang down, even animals was carried out during neolithic when short or docked, while the short tails times along with the cultivation of cereals. of goats are held upwards. Sheep breeds First sheep and goat, followed by cattle are also often naturally polled (either in and pig, and finally draft animals such as both sexes or just in the female), while horse and asses were domesticated. Sheep naturally polled goats are rare (though ancestry status over the past 11,000 years many are polled artificially). Sheep are 686 Int.J.Curr.Microbiol.App.Sci (2014) 3(1): 684-706 primarily herbivorous mammals: most There is not dominant role of lignin, lipid, breeds are close grazers on surface vitamins and minerals to produce energy.