EVALUATION OF PENNISETUM PURPUREUM AND ORANGE-FLESHED SWEET POTATO VINE MIXED SILAGE AS DRY SEASON FEED FOR RUMINANTS

Authors

  • R. M. Akinbode Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.
  • S. O. Afuape Sweet Potato Program, National Root Crop research Institute, Umudike, Abia State, Nigeria
  • O. A. Isa Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.
  • C. F. I. Onwuka Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, Ogun State, Nigeria.

Keywords:

Potato vines, Pennisetum purpureum, Silage, Nutritive values, Ruminants

Abstract

Preservation of low quality grass with crop residue (orange-fleshed sweet potato vine) improved the feed value for ruminants during period of forage scarcity. This study evaluated the nutritive value of Pennisetum purpureum and orange-fleshed sweet potato mixed silage as potential feed resource for ruminants. Pennisetum purpureum (Pp) and Orange-fleshed sweet potato vines (OFSPV) were ensiled using experimental silo bottles at different proportions as follows: 100% Pp (P100O0), 75%Pp +25%OFSPV (P75O25), 50%Pp +50%OFSPV (P50O50), 25% Pp+75% OFSPV (P25O75)  and 100%OFSPV (P0O100). Molasses and lactic acid bacteria inoculants (5% and 1.0 X 107 CFU/1000g fresh weight respectively) were added to all treatments as additives and were kept for 14 and 28 days at room temperature in the laboratory. At 14 and 28 days of ensiling, silages were analyzed for chemical composition, microbial population and fermentative parameters. The dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) (35.14%, 41.55% and 27.40%) were highest in silage ensiled for 14 days while those ensiled for 28 days recorded the highest crude protein (CP) (13.45%). Increased in days of ensiling from 14 to 28 days resulted in higher dry matter intake (DMI), digestible dry matter (DDM) and relative feed value (RFV) of the silage. The ratios of Pp to OFSPV influenced (P < 0.05) all the chemical composition parameters considered except ether extract. The CP, ash, DMI, DDM and RFV increased as the level of OFPV increased in the silage mixture. Silage containing 100% OFSPV had the highest values for all these. However, silage containing 100% Pp recorded highest DM, NDF and ADF contents. The pH, lactic acid bacteria, coliforms, total bacteria and yeast counts were significantly (P < 0.05) affected by the ensiling periods while temperature and concentration of lactic, acetic, propionic and butyric acid were similar (P > 0.05). Silage of 28 days had the least (P < 0.05) pH value of 4.23 compared to 14 days silage (4.52). Lactic acid bacteria, total anaerobic bacteria and yeast counts were higher in silage ensiled for 28 days while silage of 14 days contained higher coliform bacteria counts. The pH, temperature and butyric acid concentration were more in silage containing 100% Pp (4.81, 28.28°C and 0.03% respectively). Lactic acid concentration and lactic acid bacteria counts increased with increase in OFSPV level. Inclusion of orange-fleshed sweet potato vine in Pennisetum purpureum silage of 28 days improved the fermentative, nutritive and feeding values of the silage.

Published

2020-06-30