EVALUATION OF IMPROVED NAPIER GRASS (PENNISETUM PURPUREUM (L.) CULTIVARS UNDER FARMERS CONDITIONS IN WEST HARARGHE ZONE, OROMIA REGION, ETHIOPIA

Abstract

This study was conducted to evaluate the forage production, chemical composition, in vitro dry matter digestibility and rumen degradability potentials of improved Napier grass cultivars as well as their preference as livestock feed under farmer’s conditions in West Hararghe Zone of Oromia region, Ethiopia. Four improved Napier grass cultivars (ILRI cultivar number: 16801, 16800, 16798, and 16840) and local check were planted in a Randomized Complete Block Design (RCBD) with six replications. The dry matter (DM) yield, plant height, leaf length and leaf-stem ratio were measured at harvest. Chemical composition, in vitro DM (IVDMD) digestibility and in sacco rumen DM degradability (DMD) were also analyzed. Farmers preference of the Napier grass cultivars as livestock feed was collected through visual and hand evaluation of the multiple ranking criteria of the cultivars based on phenological nature. Five Napier grass cultivars were incubated using the nylon bag technique in the rumen of three steers for 6, 12, 24, 48, 72 and 96 hours. The results shows that, ILRI cultivar no. 16800 was higher (P<0.01) in the leaf to stem ratio than other Napier grass cultivars tested under farmers conditions. Similarly, ILRI cultivar 16800 was higher in DM yield (P<0.05; 16.6 t/ha) than ILRI cultivar 16798 (11.65 t/ha), but similar with other cultivars. There were no significant (P>0.05) differences in crude protein, DM%, neutral detergent fiber, hemicellulose, cellulose and ME content among the tested Napier grass cultivars. However, there were significant (P<0.05) differences in ash, organic matter, acid detergent fiber, lignin, and IVDMD values among the cultivars. According to the farmer's and developmental agent (DA) preferences, ILRI cultivar No. 16800 scored highest (4.56) followed by ILRI cultivar No. 16840 (4.00) and ILRI cultivar No. 16801(3.89). The lowest score was given to ILRI cultivar No. 16798 (3.11) followed by local check (3.67). The results indicated that all Napier grass cultivars was ranked beyond good performance score (>3), as an indicator for livestock feed. In sacco degradability of DM of Napier grass for many of the incubation hours including 48 hours which was relatively higher for local and ILRI#*16801 cultivars. The DM in sacco degradability characteristics were affected by cultivars. From this study, it is concluded that Napier grass cultivars No. 16800, 16840 and 16801 were found promising in terms of agronomic traits, DM yield and nutritive valves than others during main rainy season (July to September) that needs further evaluation during dry season to demonstrated and popularized as an alternative feed resources under smallholder conditions in the study areas and other places of east and West Hararghe zones of Oromia region with similar climatic and edaphic conditions.