Comparative Rumen-Dry Matter Degradability of Selected Parts of Different Local Napier (Pennisetum purpureum) Grass Cultivars in Sheep and Goats

Abstract

A degradability experimen t was conducted to evaluate the feeding value of four selected local Napier (Pennisetum purpureum) grass cultivars namely Madizini (L8), Kilakala (L11), Kigurunyembe (L12) and Mlimakola (L13). The four selected genotypes were among the local Napier accessions within the peri-urban and urban areas of Morogoro municipality. Dry Matter (DM) degradation characteristics were determined using nylon bags to incubate the four ground cultivars of the Napier into rumens of three fistulated Black Head Persian (BHP) rams as well as three cross-bred bucks.  Incubation was carried out for 12, 24, 48, 72, 96 and 120 hours. To determine the degradability trend, the data were fitted to the exponential model: Y = a+b(l  - e-ct). Potential degradability (a+b) ranged from 78.5 for Kilakala cultivar to 81.1 for Madizini and the degradation constant (c) ranged from 0.0481 for Madizini to 0.0687 fractions per hour for Kilakala. Effective degradability at 1% passage rate significantly (P<0.05) varied from 69.7 for Mlimakola to 71.2 for both Kilakala and Kigurunyembe· cultivars. DM degradation means for sheep and goats were not significantly (P>0.05) different. The results demonstrated a possible trend for the Kilakala and Kigurunyembe cultivars to be nutritionally superior to others