Nitrogen losses in ruminant manure management and use of cattle manure vermicast to improve forage quality

Ruminants have low efficiency of nitrogenutilisation; unutilised nitrogen is being excreted in thefaeces and urine. The most effective way to minimisenitrogen losses in ruminant production is through efficientfeeding strategy. Ruminant manure is an inevitable consequenceof its production. All these have adverse environmentaleffects. Composting and vermicomposting havebeen suggested as efficient tools for recycling manure,these bring a stabilised and sanitised end product foragriculture. Composting process is an accelerated aerobicdegradation of fresh organic matter by microorganism tomature compost. Nevertheless, it may bring some environmentalproblems by releasing gases which includeammonia, methane and nitrous oxide, reduce the agronomicvalue of the manure and increase the cost of compostingthrough turning of the compost to ensure aeration.To overcome the cost of composting and produce highquality products, vermicomposting is being recommended.Vermicomposting involves the bio-oxidation and stabilisationof organic material by the joint action of earthwormand microorganism. Moreover, the combination of compostingand vermicomposting has been considered as a wayof achieving stabilised substrates. Ensiled cattle manuretreated with straws has been used to improve nutritionalquality of ruminant feed and the result was encouraging.Vermicast, an end product of vermicomposting has highernutrients content compared with manure or compostedmanure. Therefore vermicomposting of ruminant manurewith rice/wheat straws might have the potential of beingused as feed supplement to small ruminant. The likelybenefit will be an increase in feed intake, increase inmicrobial protein supply, increase in fibre digestibility andpossibly an increase in weight gain. The aim of this reviewis to discuss nitrogen losses in ruminant production andmanure management and to provide an insight on thepossibility of using vermicast as feed supplement toruminants and as probiotic for treating fibrous feed.