A COMPARATIVE STUDY OF LOW AND HIGH QUALITY FORAGES FOR CHEMICAL COMPOSITION AND IN VITRO DEGRADABILITY

Four low quality forages (LQF) alongside three high quality forages (HQF) were analysed for their chemical components and in vitro degradability (IVD) to establish their complementary properties in ruminant diets. The HQF involved dried ryegrass; rapeseed plant and ryegrass silage and LQF involved rice straw, wheat straw, ryegrass hay and sugarcane bagasse. The HQF had significantly more CP, EE, soluble sugar, total phenolic, tannin, saponin and mineral contents than LQF (P<0.05). The variations for oxalate contents were not significant (P>0.05) between two groups. Among minerals Ca, P, S, Mg, K, Cu and Co were significantly higher but Mn was lower in HQF than LQF (P<0.05). The LQF contained large amount of saturated fatty acids, especially palmitic acid (C16:0) and HQF contained large amount of poly-unsaturated fatty acids especially alpha-linolenic acid (C18:3). About 61% of fatty acids in ryegrass were represented by alpha-linolenic acid. Due to higher nutrient and lower fibre contents, the IVD and IVOMD were higher in HQF than LQF (P<0.001). Among the minerals, PHOS was found to be more effective to increase the IVD of forages. It appeared that the selected forages can offer complementary properties for their use to formulate forage based balanced diets to optimize the degradability and utilization of LQF in ruminants.