Two trials were conducted for a period of 90 days each to evaluate the feeding value of different proportions of urea treated rice straw and gamba hay in the performance of growing and fattening Yankasa rams. In the first trial, twenty-four (24) growing Yankasa rams of mean initial body weight of 15.77±2.5 kg and aged 6 – 8 months were allotted to four dietary treatments with six (6) animals per treatment in a Completely Randomized Design. Urea treated rice straw and gamba hay proportions of 0:60, 20:40, 40:20 and 60:0 were used as roughage diets. A concentrate diet consisting of maize grain, cotton seed cake, rice milling waste, wheat bran, bone meal and salt was formulated to contain 15 % crude protein. The animals were fed roughage diets ad libitum while concentrate was fed at 1.5% of individual body weight. Data were collected on growth performance and blood profile. Data generated were subjected to analysis of variance and differences in means were compared using Duncan’s Multiple Range Test. The result of chemical analysis showed that treatment of rice straw with urea increased its crude protein content from 3.64 to 8.89 % and decreased the neutral detergent fibre content from 72.16 to 67.98 %. Total dry matter intake varied from 263.11 to 325.01 g/day with the highest value recorded in animals fed 60:0 UTRS:gamba hay diet. Results of crude protein and neutral detergent fibre intake followed similar pattern. The highest (P<0.05) average daily gain (79.81 g/day) was obtained in growing rams fed 60:0 UTRS:gamba hay diet while the lowest (P<0.05) value (44.44 g/day) was obtained in animals fed 0:60 UTRS:gamba hay diet. Growing rams placed on 60:0 UTRS:gamba hay diet had the lowest (P<0.05) feed conversion ratio value (7.77). Dry matter digestibility was significantly (P<0.05) affected by UTRS:gamba hay proportions. Animals fed 60:0 UTRS:gamba hay diet had a high dry matter digestibility (67.62%). The digestibility of other nutrients followed the same pattern. Animals fed 60:0 UTRS:gamba hay diet had significantly (P<0.05) higher nitrogen intake (16.12 g/day) and the lowest (P<0.05) in the diet containing 0:60 UTRS:gamba hay (12.06 g/day). Nitrogen balance significantly (P<0.05) differed across the dietary treatments. Animals fed diet containing 60:0 UTRS:gamba hay had high nitrogen retention (13.30 g/day) while those fed 0:60 UTRS:gamba hay diet had low nitrogen retention (7.78 g/day). With exception of serum creatinine, all the serum parameters measured were significantly (P<0.05) different. Animals on 60:0 UTRS:gamba hay diet had higher (P<0.05) value of serum glucose (61.02 mg/dl) while animals fed 0:60 UTRS:gamba hay diet had the lowest (P<0.05) value (49.55 mg/dl). Serum urea nitrogen and total protein followed similar pattern. In the second trial, twenty(20) intact Yankasa rams with mean initial body weight of 21.87±2 kg and aged 12 – 18 months were allotted to four dietary treatments with five (5) animals per treatment in a Completely Randomized Design. Urea treated rice straw and gamba hay proportions of 0:60, 20:40, 40:20 and 60:0 were used as roughage diets. A concentrate diet consisting of ingredients similar to those of the first trial was formulated to contain 13 % crude protein. The animals were fed roughage diet ad libitum while concentrate was fed at 2.0 % of their individual body weight. Data were collected on growth parameters, serum blood profile and rumen liquor metabolites. Data generated were subjected to analysis of variance and differences in means were compared using Duncan’s Multiple Range Test. The result of chemical analysis of the experimental diets was similar to that obtained in the growth trial. The result revealed that, there were significant (P<0.05) differences on all the growth parameters measured. Total dry matter intake was significantly (P<0.05) higher (1035.98 g/day) in animals fed diet containing 60:0 UTRS:gamba hay compared to those fed the rest of the diets. Similarly, animals fed 60:0 UTRS:gamba hay diet had high average daily gain (72.89 g/day) compared to animals on other diets. Lowest (P<0.05) value (38.00 g/day) was recorded in animals fed 0:60 UTRS:gamba hay diet. Rams fed 60:0 UTRS:gamba hay diet had the least (P<0.05) feed conversion ratio (14.21) indicating that animals on diet containing 60:0 UTRS:gamba hay were more efficient in converting feed to live weight gain than animals fed other diets. Digestibility of nutrients was significantly (P<0.05) different across the treatment groups. Total nitrogen intake and nitrogen retention were significantly higher (P<0.05) in animals fed diets containing 60:0 and 40:20 UTRS:gamba hay. No significant (P>0.05) difference was observed on rumen fluid pH while significant (P<0.05) differences were obtained on rumen ammonia nitrogen and Total volatile fatty acids (TVFA). Animals fed 60:0 UTRS:gamba hay diet had higher (P<0.05) rumen ammonia nitrogen and TVFA (27.80 mg/dl and 16.13 Mmol/l, respectively). Lowest (P<0.05) values (21.79 mg/dl and 12.98 Mmol/l, respectively) were obtained in rams fed 0:60 UTRS:gamba hay diet. Significant (P<0.05) differences were observed on all blood profile parameters measured except the serum creatinine. The serum glucose, urea nitrogen and total protein values ranged from 50.29 to 61.32 mg/dl, 5.73 to 8.64 mg/dl and 58.77 to 67.03 g/l, respectively. Values obtained for serum glucose, urea nitrogen, serum creatinine and total protein fell within the normal ranges of 50-100 mg/dl, 15-30 mg/dl, 1-2.7 mg/dl and 60-79 g/l, respectively for sheep. In terms of economic benefit, the results revealed that cost of feed consumed per kg body weight gain (497.76 ?/kg) was lower and better in fattening rams fed diet containing 60:0 urea treated rice straw:gamba hay proportions. The study recommends that urea treated rice straw and gamba hay proportions of 60:0 UTRS:gamba hay could be used to replace gamba hay as sole roughage diet for sheep feeding as sheep had higher weight gain in the treated straw based diets compared to gamba hay based diet. The study further recommends that small-holder farmers may adopt the treatment of rice straw with urea to improve its nutritive value and reduce the cost of feed per kg body weight gain.?

CHAPTER ONE: INTRODUCTION

1.1       Background of the Study
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 of its high fibre content. Jung et al. (1993) reported that the potential of rice straw as energy source is limited because of the complex lignified cell wall structure, which shields the energy yielding nutrients from microbial degradation in the rumen. Most small ruminant farmers therefore, do not utilize the straw in feeding their animals but left it in the fields to rot or burned in situ, resulting in pollution of environment as well as causing soil erosion.
In recent time, there is concern on global warming due to burning of wastes. Akinfemi and Ogunwole (2012) reported that burning of rice straw increases particle matter into the atmosphere as well as increases atmospheric temperature by carbon dioxide emission, thus increasing global warming Such global concern necessitated alternative option of recycling of waste into beneficial products. Therefore, Feeding rice straw to livestock will not only serve as potential energy source for ruminants but will reduce its environmental impact.
Treatment of rice straw with urea for feeding of ruminants has been given more attention and has proved to be effective (Doyle et al., 1986; Schiere and Ibrahim, 1989; Chenost and Kayouli 1997). However, the technology has not been widely practiced by farmers in Nigeria probably due to inadequate awareness. The study will therefore determine the responses of growing and fattening Yankasa rams fed different proportions of urea treated rice straw and gamba hay.?

1.2 Aim and objectives of the study
The aim of the study was to improve the nutritive value of rice straw through treatment with urea for feeding small ruminants. Specific objectives were:
1. To determine the effect of feeding different proportions of urea treated rice straw and (Andropogon gayanus) gamba hay on feed intake and nutrient utilization by growing and fattening Yankasa rams.
2. To determine the effect of feeding different proportions of urea treated rice straw and gamba hay on blood serum metabolites of growing and fattening Yankasa rams.
3. To determine the effect of feeding different proportions of urea treated rice straw and gamba hay on rumen fluid metabolites of fattening Yankasa rams.
4. To determine the economic benefit of fattening Yankasa rams fed different proportions of urea treated rice straw and gamba hay.

1.3?Research Hypotheses
HA: Diet containing different proportions of urea treated rice straw and gamba hay have significant effect on blood serum metabolites of growing and fattening Yankasa rams.
HO: Diets containing different proportions of urea treated rice straw and gamba hay have no significant effect on rumen fluid metabolites of fattening Yankasa rams.
HA: Diet containing different proportions of urea treated rice straw and gamba hay have significant effect on rumen fluid metabolites of fattening Yankasa rams.
Ho: Diets containing different proportions of urea treated rice straw and gamba hay have no economic benefit on the fattening of Yankasa rams.
HA: Diets containing different proportions of urea treated rice straw and gamba hay have economic benefit on the fattening of Yankasa rams.?