In- situ degradability and in vitro gas production of rhodes (chloris gayan) and butterfly (clitoria ternatea) as affected by stage of growth, phosphorous fertilization and intercropping

Nutritive value and fermentation characteristics of Chloris gayana as sole crop, Clitoria ternatea as sole crop and a mixture of both Chloris gayana and Clitoria ternatea with the effect of stage of growth and phosphorous fertilization was determined using two different techniques: (i) the in vitro gas production and (ii) the in situ nylon bag degradability technique. Samples of 45 and 60 days from sowing were used. The phosphorous fertilization was applied at a rate of 0, 50, 75 and 100 kg P2O5 / ha. Samples were incubated in situ and in vitro for 4, 8, 16, 24, 48, 72 and 96 h. In situ and in vitro DM degradation kinetics were described using the equation y = a + b (1 - e ct). For all forages, readily degradable fraction (a) and effective degradability at all out flow rates were higher than the late stage of growth. However, slowly degradable fraction (b) and degradation rate (c) were higher in the late stage of growth. The potential degradability (PD) is similar in both time of cutting. Phosphorous fertilization had no significant effect on in situ parameters. The gas produced was found to be higher in the early stage of growth than late stage of growth. For gas production paremeters, late stage of growth for Rhodes grass in the pure stand and in the mixture had higher value than the early stage of growth. But for clitoria early stage of growth had a higher value than late stage of growth. Also, Phosphorous fertilization had no significant effect on in situ parameters.