Comparative Effect of Organic Fertilizer Treatments on the Herbage Production and Nutritive Value of Congo Grass (Brachiaria Ruziziensis) Hay

This study evaluated the effect of organic fertilizer treatments on the nutritional value of Brachiaria ruziziensis hay. Congo grass was cultivated in the field and treated with fertilizers: T1 (no fertilizer), T2 (Natsoil), T3 (Wonder fertilizer), and T4 (poultry manure) in a randomized complete block design with four replications. The fresh herbage and dry matter yields were determined. The grass was harvested at bloom stage, packed and air-dried as hay and stored for chemical analysis, volatile fatty acid content and In Vitro Dry Matter Digestibility (IVDMD). The fertilizer treatments had significantly higher (p<0.05) values for fresh herbage yields compared to the control treatment: T3 (18.38 tons/ha), T4 (16.66 tons/ha), T2 (14.05 tons/ha), and control (10.25 tons/ha). Also, the dry matter yield obtained for T3 (6.90 tons/ha), T4 (6.19 tons/ha), T2 (5.23 tons/ha) were significantly higher than that for the control (3.85 tons/ha). The results showed that crude protein, ether extract and carbohydrate fraction were significantly higher (p<0.05) in T3 (Wonder fertilizer) than in other fertilizer treatments. Furthermore, for metabolizable energy, the T3 (4.36%), T4 (4.28%) and T2 (4.16%) fertilizers were significantly higher (p<0.05) than control (3.80%), while the cellulose content was significantly the highest (p<0.05) in T2 (21.75%) followed by T1 (21.65%), T3 (21.19%) and T4 (21.02%). The fertilizers T3, T4, and T2 had significantly higher (p<0.05) propionate, butyrate and lactate contents than T1 (control). The total volatile acid was significantly the highest (p<0.05) in T3 (152.50 mmol/100ml), followed by T4 (145.00 mmol/100ml), T2 (142.80 mmol/100ml) and the lowest in control (123.40 mmol/100ml). T3 had the highest (p<0.05) gas produced at 9, 12, 21 and 24, as well as NH3-H gas and IVDMD, higher than other fertilizer treatments. Conspicuously, the Organic Matter Digestibility (OMD) was significantly higher (p<0.05) in T3 (60.87%), T4 (60.06%) and T2 (60.11%) than in control T1 (56.06%). It was concluded that Congo grass treated with Natsoil, Wonder and poultry litter fertilizers had increased crude protein, metabolizable energy, volatile fatty acid as well as IVDMD. However, the wonder fertilizer treatment was outstanding.