In vitro and Ruminal Characteristics of the Three Selected Nigerian Herbs: Phyllanthus amarus, Ocimum gratissimum and Lactuca taraxacifolia as Feed Additives in Ruminant Production

This study evaluated the effects of selected herbal feed additives on in vitro fermentation and ruminal characteristics of West African Dwarf (WAD) goats. Twenty goats (4 per treatment) were assigned to five dietary treatments in a 12-week completely randomised design: basal diet only (T1, control), diet + Ocimum gratissimum leaf meal (T2), diet + Phyllanthus amarus leaf meal (T3), diet + Lactuca taraxacifolia leaf meal (T4), and diet + a mixture of the three herbs (T5). Phytochemical screening confirmed the presence of saponins, tannins, and alkaloids in the herbs. The additives, incorporated at 3 g/kg feed, were offered at 5% of body weight. Feed samples were incubated for 24 h, with gas volume measured every 3 h, and methane subsequently estimated. Gas data were used to derive metabolizable energy (ME), organic matter digestibility (OMD), and short-chain fatty acid (SCFA) concentrations. At the end of the feeding trial, the rumen liquor was analysed for its fermentation characteristics and microbial populations. The herbs were rich in crude protein (CP) and moderate in carbohydrate content. The mixture diet (T5) contained the highest CP, while T2 had the greatest crude fibre. In vitro fermentation showed increasing gas production with incubation time, with T1 and T4 yielding the highest gas volumes. Methane production was lower in T3 and T5 compared with other treatments. Similarly, T1 and T4 recorded the highest ME, OMD, and SCFA values. However, T3 and T5 markedly improved ruminal fermentation and beneficially modified microbial populations. In conclusion, P. amarus (T3) and the combined herbal treatment (T5) demonstrated potential as natural feed additives for mitigating methane emissions and enhancing rumen ecology, thereby improving ruminant productivity.