Herbage Intake and Digestibility Considering Chlorophyll Content of Tropical Grass-legume Mixed Forages under Melia Azedarach Tree Shade

Abstract

Purpose: The impact of native multipurpose trees on herbage mass productivity was researched at low profile
in Nepal using physiological markers to the herbage intake and digestibility studies.
Methods: Under this context, the experiment was done with glycine (Neonantia weightii) and green leaf desmodium (Desmodium intortum) mixed with the Napier (Pennisetum purpureum) and blue panic (Panicum antidotale)
planted under three levels of shade of Melia trees by using the Split Plot Design (SPD). Each plot was replicated
three times, with one open. Standard agronomic practices were followed in the growth of the forages, whereas
three shade levels (heavy, medium, and low) were maintained by pruning the lowest branches of Melia tree and
also by measuring light intensity using a Lux meter. Additionally, 100 g of fresh leaf tissues were subjected
to a chlorophyll analysis. After regrowth, herbage mass was collected from a 1 m2 quadrant cutting over the
ground at 60 and 75 days in August and September, respectively. Lab analysis was done on the sampled forages
for proximate fractions, and a chlorophyll assay was performed on 100 g of fresh leaf tissues collected. Four
goats were used in the herbage digestibility experiment using the metabolic crates during the second year of
observation. Afterwards, the link between the digestibility attributes, herbage consumption, and relative dried
weight yield of the herbage mass was noted.
Results: Research results had shown that the forage combination only affected p < 0.05 the total chlorophyll
content, while the shade level p < 0.05 and forage mixture had significant effects p < 0.05 on the relative dried
weight yield. Later, it was found that the dry matter yield, dry matter intake, and digestibility of dry matter
(DM), crude protein (CP) and crude fiber (CF), respectively, have a significant positive correlation p < 0.05 with
the total chlorophyll concentration.
Conclusion: The study’s findings proved the Melia tree’s broad effect on under-storey forages and provided
the possibility of the establishment of an alternate model for forage development in Nepal’s southern plains to
have utilization by cultivating forages under tree shade, provided optimum shade is maintained by looping lower
branches of Melia tree.