Extracts of herbs and spices as feed additives mitigate ruminal methane production and improve fermentation characteristics in West African Dwarf sheep.

The study aims to evaluate the effect of aqueous and methanolic extracts of three herbs, namely, neem (Azadirachta indica), drumstick (Moringa oleifera) and scent (Ocimum gratissimum), and three spices garlic (Allium sativum), ginger (Zingiber officinale) and onion leaflets (Allium cepa) on ruminal methane production and fermentation characteristics. The feed samples (200 mg substrates plus extracts of the selected herbs and spices) were incubated with rumen liquor taken from three mature West African dwarf ewes at 3, 6, 9, 12, 15, 18, 21 and 24 h. The results show that extracts of the selected herbs and spices increased the gas produced, from the insoluble fraction, degradability rate, volume of gas produced at time and time of most rapid change in gas produced. The organic matter digestibility (OMD), metabolizable energy (ME) and short-chain fatty acid (SCFA) contents of aqueous extracts of the selected herbs and spices (1 ml/200 mg substrates samples) were between 32.82 and 71.34 g/100 g OM, 4.10 and 10.25 MJ/kg DM and 0.28 and 1.31 µmol, respectively. Furthermore, the OMD, ME and SCFA contents of methanolic extracts of the selected herbs and spices (1 ml/200 mg substrates samples) were between 32.82 and 99.50 g/100 g OM, 4.10 and 14.37 MJ/kg DM and 0.28 and 2.07 µmol, respectively. Methane produced from the methanolic extracts of the herbs and spices highly differed (P < 0.05). This study suggests that extracts of the selected herbs and spices have the potential to affect rumen fermentation and also to reduce the methane production in sheep.

Growth-promoting effect of water-washed neem (Azadirachta indica A. Juss) fruit inclusion in West African dwarf rams.

In a study to determine the growth-promoting effect of water-washed neem (Azadirachta indica A. Juss) fruit (WN) in West African Dwarf (WAD) rams, a total mixed ration was formulated with 0 (WN0), 2.5 (WN2.5), 5.0 (WN5), 7.5 (WN7.5), and 10.0 (WN10) % of WN inclusion. Twenty-five yearling rams (12.3 ± 2.0 kg) were assigned to one of the five dietary groups with five animals per group in a completely randomized design. Each group received the diet for 90 days inclusive of the initial 28 days used for anticoccidial efficacy trial. After the growth trial, three rams from each group were used for digestibility and nitrogen metabolism trial. Anticoccidial efficacy linearly increased (P = 0.002) with increased inclusion of WN and duration of feeding (P = 0.003). Feed intake (P = 0.018) and weight gain (P = 0.009) quadratically increased with WN5 inclusion compared to WN10. Optimal inclusion level of WN for daily weight gain was 5.1% (R2 = 0.30). Digestibility of crude protein was linearly and quadratically increased (P = 0.032; P = 0.031, respectively) with up to WN7.5 inclusion. Nitrogen retention was similar among the treatments. Incorporation of water-washed neem fruit in the diets of West African dwarf rams improved nutrient utilization and animal health by increasing anticoccidial efficacy, feed intake, and weight gain. This is an indication that water-washed neem fruit could be used as growth promoter in sheep production.

Prediction of biogas and pressure from rumen fermentation using plant extracts to enhance biodigestibility and mitigate biogases.

Improving digestibility, fermentation characteristics, and reducing greenhouse biogases to protect the environment without the use of synthetic materials is an important goal of modern-day farming and nutritionist. Plant extracts are capable of solving these. This is due to the digestive enzymes and the bioactive components capable of performing antimicrobial functions inherent in these plants. This study was aimed to investigate the effect of standard maize substrate treated with selected herbs and spices extracts on ruminal environmental biogas production and pressure during fermentation via biogas production technique. Herbs (Azadirachta indica leaves (T1), Moringa oleifera leaves (T2), Ocimum gratissimum leaves (T3) and spices (Allium sativum bulb (T4), Zingiber officinale rhizome (T5)) were harvested, air dried, and milled using standard procedures. Methanolic extracts of the herbs and spices were prepared and used as additives at different concentrations (50, 100, and 150 µL) to the maize substrate for in vitro biogas production. Data were analyzed using regression analysis. There were significant (P < 0.05) differences across all the treatments on the volume and pressure of biogas. The pressure and volume of biogas when compared with the levels tested showed differences (P < 0.05) across all the treatments for the prediction of volume from pressure of biogas. The pressure and volume of gas produced in vitro increased (P < 0.05) and biogases decreased (P < 0.05) by the substrate treated with herbs and spices but for the drum stick leaves which was similar for the levels of concentration tested. This means that the level tested had a pronounced mitigation effect on pressure of biogas and volume of biogas produced. It was concluded that the herb and spice extracts have the potential to improve rumen fermentation and reduce the production of biogases in ruminant diet.