Assessing the nutritive value of waterweeds to livestock production via <i>in vitro</i>

Abstract

The predominant increase in the price of feedstuffs and the consistent shift in climate have increased the cost of producing animal protein and an attendant increase in the search of available and valuable plant options in combating this problem. The study aimed to evaluate the nutritive value of ten identified water weeds (Polygonum lanigerum, Nymphaea lotus, Paspalum scrobiculatum, Ascroceras zizanioides, Ipomea aquatica, Panicum sulbabidum, Sacciolepis africana, Leersia hexandra, Heteranthera callifolia and Dicksonia antartica) via in vitro digestibility studies. The gas production was measured by incubating samples in buffered ruminal fluid from goats for 96hr. Cumulative gas production was recorded at 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 54, 57, 60, 66, 72, 84 and 96 hour of incubation periods and the organic matter digestibility (OMD), short chain fatty acid (SCFA) and metabolizable energy (ME) were also estimated. Results indicated that the total gas production varied significantly (P<0.05) at 24 and 48 hours incubation. Gas production ranged between 4.67 ml and 14.00 ml with least and highest obtained in Sacciolepis africana and Ipomea aquatic, respectively. The Metabolizable energy (MJ/KgDM) recorded in all weeds differed (P<0.05) in all hours of incubation. Paspalum scrobiculatum and Dicksonia antartica recorded the least value at 24 and 48 hours incubation while Nymphaea lotus and Dicksonia antartica had the least value at 72 and 96 hours incubation. Heteranthera callifolia had the highest organic matter digestibility (%) while the least short chain fatty acid (μmol) was observed in Dicksonia antartica at 24, 48 and 96 hours incubation. Based on the results of this study, these plants had the potentials of being fed to livestock especially during the dry season when forage feeds are generally scarce.

Keywords: Waterweeds, ruminal fluid, Metabolizable energy, organic matter digestibility
and short chain fatty acids.