PERFORMANCE OF GROWING AND FATTENING YANKASA RAMS FED DIFFERENT PROPORTIONS OF UREA TREATED RICE STRAW AND GAMBA HAY

CHAPTER ONE
INTRODUCTION

Sheep are important part of the global agricultural economy and they play a major role in many local economies (Weaver, 2005). Njidda and Kibon (2004) stated that sheep are multipurpose animals, but they are primarily kept for the production of meat (mutton), and they account for about 11% of the total meat supply in Nigeria. The authors further stated that the inclusion of animals slaughtered in the rural areas outside the slaughter
houses would have made this figure higher. Afolayan (1996) reported that Yankasa sheep is very popular among sheep farmers, most especially in northern Nigeria. Their high productivity in terms of growth performance and prolificacy are paramount to the farmer (Akpa et al., 2006). Inadequate and poor quality of feed, especially during the long dry
season is one of the major factors militating against livestock production in Nigeria. The seasonality of feed supply in northern Nigeria has affected animal production adversely (FDLPCS, 1992).

According to Rumirez-Orduna et al. (2005), due to high cost, most smallholder livestock farmers cannot afford to supplement the diet of their animals with expensive feed ingredients. Production of livestock and their productivity are far below the population’s requirement for animal protein. This under-production and low productivity are attributed
mainly to inadequate year-round availability of feed and water, coupled with poor management (Abbey et al., 2001). In the Savannah zone of Nigeria the basal diets of most ruminants in the dry season is based on crop residues and dry standing grasses, and most of these feed resources are imbalanced in nutritional value and vary from year to year (Zemmelink, 1999). 
The natural rangeland serves as the major sources of forages for ruminants in Nigeria. Rangeland forages, however, decline in both quality and quantity during the dry season, resulting in low productivity of animals. Gamba (Andropogon gayanus) is a tropical grass which is widely distributed throughout the savanna ecology of Nigeria and forms the bulk
of feed available to ruminants grazing on rangelands (Fitzhugh, 1978). Gamba grass is usually established as permanent pasture in most commercial ranches or smallholder farms. It can be cut as fresh feed or conserved as hay. The crude protein content of gamba grass is moderate in young growth (7 – 10%) but declines rapidly with maturity (2 – 5%)
(Leeuw, 1979; Agishi, 1985). Alli-Balogun (2010) reported CP, NDF and ADF contents of gamba hay as 3.76, 76.4 and 56.2%, respectively.

Rice straw, like other cereal crop residues is a potential source of energy for ruminants. However, its potential as an energy source is limited because it is high in dietary fibre (>50%) and low in crude protein (2 – 7%) and mineral contents (0.02 – 0.16%) (Sundstol and Owen, 1984; Jung et al., 1993). One way in which, the low nutritive value of rice straws could be improved, is through treatment with urea. In feeding trial strategies for
improving milk production by Ehoche (2002), urea treatment of crop residues is acknowledged to improve nutritional value of crop residues and other fibrous by-products and reduce feed cost and wastages with practical application at the smallholder level in developing countries. The author further stated that in the tropics, cereal crop residues such as maize, sorghum, millet stover and rice straw were produced in large quantities and could be used as ruminant livestock feeds. Akande (2001) reported that in Nigeria, rice is cultivated in virtually all agro-ecological zones and the residue (straw) can be obtained or purchased at relatively cheap or free of charge from all rice farms. According to FAO (2012), Nigeria is the second largest producer of rice in Africa after Egypt and the largest in West Africa. FAO (2013) reported that Nigeria production of paddy rice was estimated at 4,700,000 tonnes. This gives rise to increase in rice straw output in the country which could be harnessed for ruminant livestock feeding. It was also reported by Parnich (1983) that, information on the utilization of rice straw in the diets of sheep is scanty. The use of rice straws could help improve ruminant livestock production, if its nutritive value is enhanced.