Biowastes encompass agricultural and forestry residues, municipal solid and liquid wastes, human food
wastes, and considerable quantities of manure excreted by ruminant animals [4]. Regarding animal manure, the
world’s livestock population is increasing especially in China and India; therefore, the manure-based methane
emissions are projected to increase by 16% by 2030 in almost all continents and contribute about 240 million
metric tons of carbon dioxide equivalents of methane emissions [4]. In the Arab countries, the livestock population
is estimated at 347 million, which accounts to approximately 7% of the world’s livestock population [5].
Furthermore, In the Arab Gulf States, waste generation predicted to increase from 22 million tons in 2010 to
29.07 million tons in 2017. Consequently, the Arab governments are urgently looking for innovative solutions to
the critical issues around sustainable waste management. In this context, utilizing and fermenting the almostfree-
to-take biowastes from small to large scale dairy cow farms is a win-win approach: it is economically attractive
through valorization of wastes and providing part of the daily energy needs and environmentally friendly
through reducing the harmful methane emissions and avoiding public health risks from the accumulation of
wastes nearby residential areas