2. Characteristics of animal manure

a critical role in the economic and social lives of the populace through its contribution to nutritious food supply, job creation, income generation and household earnings, asset saving, economic output and taxes, agricultural diversification, animal traction, soil fertility and transportation [1, 2]. Meeting the food needs of the growing world population which is estimated to be over 9 billion by 2050 is one of the greatest challenges facing animal agriculture the world over. Increasing food production is not as straightforward as simply increasing production capacity. There are constraints such as land and water use, environmental impact of animal agriculture and regulations which may limit the ability of producers to simply add enough animals to meet future demand for foods of animal origin. Therefore, animal agriculture must be carried out in a way that does not jeopardize the future use of natural resources while

Animals are raised primarily for food and non-food purposes such as companions, leather and even manure in some production systems [3]. By-products, which may constitute wastes if not managed appropriately, are generated in the process of producing, processing, transporting and marketing animals. Some potential wastes generated during animal production operations include waste or left-over feed, wastewater, hatchery wastes, abattoir wastes and manure. Manure from animal production often has external contributor such as beddings, urine, wash water, precipitation, spilled feed and spilled water [4]. Prior to the introduction of organic fertilizers, animal manure played the central role in enhancing soil fertility. In spite of the role of organic fertilizers in agricultural production, manure remains an important fertilizer resource especially in areas where organic fertilizers are not readily

The intensification of animal operations has led to the production of a considerable amount of manure concentrated in a particular location in excess of the need and may become a liability. The estimated total manure nitrogen production increased from 21.4 TgN/year in 1860 to 131.0 TgN/year in 2014 with an overall significant increasing trend during 1860–2014 (0.7 TgN/year, p < 0.01) [5]. Intensive animal production, therefore, can be significantly problematic with respect to waste storage and removal. Air and water pollution associated with animal manure has been at the centre of several regulatory discussions across the world. Animal manure contains a wide range of micro-organisms which could be a source of hazards to humans and animals. These micro-organisms can cause food contaminations and epidemics and therefore dangerous to public health. In fact, several foodborne illnesses around the world have been linked directly or indirectly to manure contamination. To therefore limit some of the challenges associated with animal manure handling, sustainable manure management practices and strategies are advocated. It is critical that manure management plans form an integral part of the animal production strategy. These include legislations and other legal instruments as well as other innovative practices that reduce the risks of exposure. Many manure management strategies and technologies are applicable to a wide range of production environment and scales. The adoption of sustainable manure management technologies holds a lot of direct and indirect benefits to the society. These include contributions to a clean environment, pollution reduction, job creation and the protection of biodiversity. This chapter gives an overview of

attempting to meet the food needs of man and animals.

sustainable animal manure management practices and strategies.

available or accessible to farmers.

120 Agricultural Waste and Residues

Manure contains many useful and recyclable components (Table 1). The physical and chemical characteristics of animal manure will impact its potential use particularly as a fertilizer and the ease with which it would be handled. Animal manure can be categorized based on their consistency or moisture content into liquid manure (up to 5% solids), slurry and semi-solid manure (between 5 and 25% solids) and solid manure (more than 25% solids) [6]. The general characteristics of manure generated from typical animal production operations are presented (Table 2). In view of high variability in consistency, physical structure and chemical composition of animal manure from one location to the other, preference should be given to locally derived manure characteristics.


Source: Adapted from [7].

Table 1. Beneficial uses of manure.



Table 2. Characteristics of manure of farm animals (per 1000 lb. animal unit per day).
