Chemical composition and nutrient digestibility of three varieties of elephant grass (Pennisetum purpureum ) by Sokoto Gudali heifers

Abstract

Pennisetum purpureum is often rejected by grazing cattle during the rainy season but readily acceptable during the dry season when forage is scarce. However, a significant limitation of elephant grass as fodder for ruminants is its low nutritive value which depreciates as the plant matures. Thus, this study was carried out to evaluate the chemical composition and digestibility of three varieties of Pennisetum purpureum by Sokoto Gudali heifers. The varieties (Landrace purple, S-King and S.13) were harvested at 8 weeks regrowth for the experiments. Nine Sokoto Gudali heifers of about 14 months of age and average weight of 178.05 kg were used for digestibility study and they were randomly assigned to the three experimental diets (L. purple, S-King and S.13) using completely randomised design. Results of chemical analysis of the grasses showed that L. purple had the highest CP content of 11.2% while S.13 and S-King had 7.7 and 7.4% respectively. Dry matter (DM) content was significantly (P<0.05) lowest in S-King with a value of 17.9%, higher in L. purple having a value of 22.5% and highest in S.13 with a value of 26.3%. There was no significant (P>0.05) difference in neutral detergent fibre and acid detergent fibre of the three grasses. Results showed apparent digestibility values for S-King as 56.52, 50.06, 50.57 and 47.55% for DM, CP, EE and ash, respectively; S.13 had apparent digestibility values for same parameters as 68.89, 65.66, 51.18 and 58.82 respectively, while L. purple had apparent digestibility values of 69.77, 74.9, 71.45 and 61.4% for DM, CP, EE and ash respectively which were significantly (P<0.05) higher than those of the other two varieties. Digestibility of crude fibre (CF) and nitrogen free extract (NFE) were highest in S.13 but not significantly different (P>0.05) from L. purple and lowest in S-King. Apparent digestibility of nutrients differed significantly (P<0.05) across all parameters considered with S-King having the lowest digestibility values for all parameters. It is concluded that L. purple had the highest CP value and its nutrient contents were better digested than the other two varieties, thus recommended for production intensification.