Irrigation and manure application influence on in vitro digestibility of herbaceous legumes

Abstract

The study was conducted to investigate the effects of swine manure rates (0, 5, 10 tonha^-1) and irrigation frequencies (2 and 4 days interval) on in vitro fermentation characteristics of three herbaceous forage legumes (Lablab purpureus, Mucuna pruriens and Vigna unguiculata). The experiment was a factorial design with three replicates. The legumes were harvested 12 weeks after sowing. The results showed no significant (p > 0.05) difference in crude protein content for all the parameters determined while lowest neutral detergent fibre content was 450.00 g kg^-1 in legumes fertilized with 10tonha^-1 manure and the highest was 482.78 g kg^-1 in unfertilized legumes. Tannin contents ranged (p < 0.05) from 3.60 g kg^-1 in V. unguiculata to 6.60 g kg^-1 in M. pruriens. Application of 10 tonha^-1 manure caused (P<0.05) higher total anaerobic bacteria count (TABC) (1.65 x10⁶ cfu/ml), dry matter (63.98%) and crude protein (59.5 %) digestibility to be produced by the legumes compared to other manure rates. Lablab purpureus had highest TABC (1.13 x106 cfu/ml) while M. pruriens recorded highest DMD (62.22%) and CPD (58.00%). Legumes irrigated at 2 days intervals had higher TABC content (1.13 x10⁶ cfu/ml) while legumes irrigated at 4 days interval had higher DMD (57.91%) and CPD (52.50%). In conclusion, application of 10 tonha^-1 manure rate at 4 days irrigation frequency of the legumes will go a long way to improve the digestibility and availability of nutrients to ruminants.