**2. Organic waste as a supplement in animal feed**

According to the United Nation findings in 2019, the world population was estimated to be 7.7 billion and was projected to be 9.7 billion in 2050 [2, 3]. In the recent times, hunger and food insecurity has become a global problem [2, 3]. Undernourishment or micronutrient deficiency was aggravated due to increasing population. Likewise, health challenges e.g. obesity may become an issue by 2025 [2, 3]. This is because human nutrition increases with increasing consumption of sugar, oils and fat compared to proteins [4]. Looking at the future, the demand for animal product such as meat may become unsustainable by 2050 [4]. In order to make provision for this, meat production is expected to double the amount of 455 million tons by 2050 [2, 3]. The production of poultry is increasing at alarming rate compared to livestock production [12]. The consumption of chicken meat and eggs has become a major source of proteins across the globe. Unfortunately, the food production may not be proportionate to human consumption due to finite natural resources [12, 13]. Urban development and industrial revolution has drastically influence the availability of land for food production. It was also estimated that

*Humic Substances*

Range Mean

manure is used for composting [6, 7]. Some farmers applied manure directly to the farm without pretreatment [6, 7]. Livestock manure contains toxic heavy metals that may affect plant growth and reduce the efficiency of agricultural land [7, 8]. Excessive application can impair nutrient elements and are often leached beneath the reach. These toxic heavy metals not only affect plants but also animals through grazing on fertilized pasture land via ingestion [6–8]. The presence of these heavy metals (**Table 1**) in the body tissue is detrimental to human health [6–8]. These attributes of livestock manure, however call for safety and security [6–8]. The use of modern technology is required to produce a compost that is more reliable and resilient at suppressing the global distribution of soil-borne pathogens that threaten food security [5–8]. According to research findings, effective control of Rhizoctoria can be prepared from lignocellulosic substrates such as tree bark, which colonize Trichoderma spp. [9]. Compost products based on poultry are hosted by *Rhizoctonia spp. solari* and *Escherichia. coli* [9]. Composting is a biological process through which microorganisms convert organic materials into useful end products, which may be used as soil conditioners and/or organic fertilizers [9, 10]. It is a thermophilic process that stimulates the action of microorganisms to digest organic waste under aerobic conditions to produce an end product that is stable and free of pathogens. Aerated compost teas (ACT) are products in which the compost-water extract is actively aerated during the fermentation process [8–10]. Non-aerated compost teas (NCT) are products in which the compost-water extract is not aerated or receives minimal aeration only at the initial mixing stage of the fermentation process [9, 10]. Compost performs the functions of fertility and carbon sequestration in thermophilic phases [9, 10]. This allows compost to mature and be cured. One of the biggest initiatives is to develop sustainable solutions to end hunger and achieve food security through small-scale farmers and sustainable food production systems [9–11]. Research

**Trace metal Content value Mean value**

Arsenic (As) 23–74 52 Boron (B) 108–240 174 Beryllium (Be) 9–39 18 Cadmium (Cd) 2.5 14.8 7.5 Cobalt (Co) 6–84 48 Chromium (Cr) 100–280 170 Copper (Cu) 280–1100 610 Mercury (Hg) 15–25 21 Manganese (Mn) 385–1600 800 Molybdenum (Mo) 20–35 25 Nickel (Ni) 90–180 140 Lead (Pb) 385–4100 1630 Selenium (Se) 3.5–6.9 4.8 Titanium (Ti) 2200 2200 Vanadium (V) 38–310 170 Zinc (Zn) 465–2250 1350

*Trace elements and heavy metal available in untreated livestock waste source: [7].*

**66**

**Table 1.**

1.3 billion tons of food are produced globally and are wasted during production, postharvest, and processing [12, 13]. A huge portion of organic waste include edible and inedible food. Organic waste generated at the latter part of food supply is comparatively higher than at the early stage of the chain. It was also projected that increasing demand for animal product may result in high demand for feed particularly the coarse grains such as maize and protein meal by 2025 [12–14]. The conventional poultry and swine diet depend on maize and soyabean as energy and proteins sources [12–14]. As well, these same, staple food is largely consumed in many part of the world particularly in the developing countries [13, 14]. As a result, a notable increase in the cost of staple food for animal feed drives the cost of production. However, the likely solution for this could be organic waste from cereal grains and plant proteins sources used in animal nutrition. However, production cost is reduced with introduction of food waste due to its low cost compared to conventional feeds [13–15]. Food organic waste from poultry, cattle, etc. is mixed with livestock feed. This reduces the amount of waste disposal in the community [13–15]. In other words, waste retains nutritive value, which may reduce the cost of feeding. However, the waste, the type and quantity of other foodstuffs, the way the excrement is treated and the species to which the treated excrement is fed is related to its efficiency [14, 15].
