CHAPTER ONE 

INTRODUCTION-------1 

1.1 Objective - ------3 

CHAPTER TWO 

LITERATURE REVIEW------4 

2.1History of in vitro Gas production----4 

2.2Factors affecting Gas production ----6 

2.2.1Effect of Venting Gas during the Incubation---6 

2.2.2Effect of Changes in atmospheric pressure ---6 

2.2.3Effect of agitation of medium---- 7 

2.2.4Effect of sample size and preparation ---8 

2.2.5Effect of inoculums------- 8 

2.2.6Effect of inoculums concentration and sampling time -9 

2.2.7Effect of inoculums preparation ---10 

2.2.8Use of blanks -------10 

2.2.9 Effect of medium composition-----11 

2.2.10Effect of apparatus------12 

2.3 Methanogenesis-------13 

2.4Maize straw -------13 

2.5Cassava peel supplement -----14 

CHAPTER THREE 

MATERIALS AND METHODS ---- -13 

3.1The Experimental Site -----15 

3.2Source of Feed Ingredients-----15 

3.3Experimental Diets ------16 

3.4Management of Experimental Animals---16 

3.5Feeding procedure------ 17 

3.5.1Composition of Supplement ---- - 18 

3.6Filling of bags into incubation bags ----18 

3.6.1Collection of Rumen liquor-----18 

3.6.2Preparation of inoculum-----19 

3.6.3 Methane gas production -----21 

3.7Chemical analysis ------21 

3.7.1Moisture content determination ----22 

3.7.2Ash Determination ------22 

3.7.3Crude Protein Determination ----22 

3.8Cell wall determination----243.8.1 Neutral detergent fibre determination ----24 

3.8.2 Acid detergent fibre determination ----- 25 

3.9 Statistical analysis------25 

CHAPTER FOUR 

RESULTS--------26 

4.1 Chemical composition of Maize straw and cassava peels supplement 26 

4.2 In vitro gas characteristics of maize straw and cassava peels 

Supplement with or without oil drench--- 26 

4.3 Post in vitro gas fermentation of maize straw and cassava peels- 29 

CHAPTER FIVE 

DISCUSSION -------31 

5.1 Chemical Composition of maize straw and cassava peels-31 

5.2 In vitro gas production at different hours of incubation for maize 

straw and cassava peels -----31 

5.3 Post in vitro gas fermentation of maize straw and cassava peels 

Supplement-------32 

CHAPTER SIX 

CONCLUSION-------34 

REFERENCES-------35 



LIST OF TABLES 

PAGE 

Table 1: Composition of cassava peels supplement---18 

Table 2: Chemical composition of Maize straw and cassava peels 

Supplement -------26 

Table 3: In vitro gas characteristics of maize straw and cassava 

peels supplement------28 

Table 4: Post in vitro gas fermentation of maize straw and cassava peels supplement-------29 

LIST OF PLATES 

Plate1: Collection of rumen liquor -----19 

Plate 2: Preparation of inoculums-----20 

Plate 3: Reading of methane production ----21 

Plate 4: Weighing of chemical sample ----24 



CHAPTER ONE 

INTRODUCTION 

The in vitro gas production technique has been frequently used to assess biological values of feeds based on their pattern of accumulated gas when incubated with rumen fluid under anaerobic conditions. The technique was initially proposed by Menke et al., (1979) to assess digestibility and metabolizable energy (ME) content f feeds commonly fed to ruminants. Empirical equations using gas production and chemical components of the feeds were used to predict ME (Menke and Steingass, 1988). Furthermore, it has been reported that the feedstuffs in vitro is time consuming, laborious, expensive, requires large quantities of feed and is unsuitable for large scale feed evaluation. 

Methodology used to measure in vitro gas production is reviewed to determine impacts of sources of variation on resultant gas production profiles (GPP). Current methods include measurement of gas production at constant pressure (e.g., use of gas tight syringes), a system that is inexpensive, but may be less sensitive than others thereby affecting its suitability in some situations. Automated systems that measure gas production at constant volume allow pressure to accumulate in the bottle, which is recorded at different times to produce a GPP, and may result in sufficiently high pressure, that solubility of evolved gases in the medium is affected, thereby resulting in a recorded volume of gas that is lower than that predicted from stoichiometric calculations. Several other methods measure gas production at constant pressure and volume with either pressure transducers or sensors, and these may be manual, semi-automated or fully automated in operation. In these systems, gas is released as pressure increases, and vented gas is recorded. Agitating the medium does not consistently produce more gas with automated systems, and little or no effect of agitation was observed with manual systems. 

The annual world production of cereal straws and stovers is approximately 2 000 million tons, however, the energy contained in this vast bulk of material is on the whole poorly utilized and its nitrogen incompletely returned to the soil (Reddy et al.,2003). With the rising prices of both energy and nitrogen fertilizer, interest is developing in more efficient ways of utilizing straws, presently used mainly as livestock feed and as compost material (small amounts are used for the manufacture of paper and fibreboards). In the tropical and subtropical areas of the world almost all straw is fed to livestock, the resulting dung being widely used as fuel. With straw feeding, energy utilization is relatively efficient, except for the residual energy in the indigestible matter which is wasted, but the introduction of dung fermentation in place of dung burning increases the proportion of straw nitrogen which is returned to the soil, thus improving the overall efficiency. In developing countries like Nigeria where there is abundance of agricultural wastes, the use of in vitro becomes relevant. The in vitro method of feed evaluation is less expensive and less time consuming when compared with in vivo methods (Akinfemi et al., 2010). The in vitro gas production system helps to better quantity the nutrient utilization and its accuracy in describing digestibility in animal has been validated numerous experiments (Rymer et al.,1999). Although, gases produced during rumen fermentation are colossal waste products and of no nutritive value to the ruminant, but gas production test are used routinely in feed research as gas volumes are related to both the extent and rate of substrate degradation. 

1.1 Research Objective 

The objective of this paper is to investigate the effect of in vitro gas production using maize straw with cassava peels supplements as feeds for ruminants. This will help to show; 

The degradation of maize straw with cassava peels supplement in terms of digestibility. 

The effect of oil drench in defaunation of ruminants. 

Effect of oil on methane gas production