Dynamics of seasonal variations and growth stages on forage quality and mimosine content management in Himalayan Subabul (Leucaena leucocephala)

Abstract

In the Himalayan region, climatic diversity arises from topographic, altitude, and seasonal variations. Green fodder scarcity during lean periods leads to economic losses for farmers and lower livestock productivity. To address this issue, the provision of quality feed is essential to unlock the full genetic potential of livestock. Fodder trees such as Leucaena have been identified as promising solution to alleviate feed shortages, especially during dry periods when other green fodder resources are depleted. Leucaena offers high-protein foliage, drought tolerance, and soil improvement, but contains mimosine, a harmful compound. To determine season driven changes in nutritional quality of Leucaena foliage was sampled at monthly intervals, grouped in four seasons, at different growth stages. Protein and total carbohydrate content in Leucaena foliage revealed significant variation across all seasons and was inversely related to leaf growth stage. Acid detergent lignin, Neutral detergent fiber and Acid detergent fiber content were lowest in tender leaves and highest in mature leaves, respectively. Total phenols showed no significant difference with tissue growth stage while simple phenol in summer season was lowest at tender growth stage. This study spanning two years aimed to identify the best harvesting period for nutritious Leucaena foliage led to conclusion that summer season and pre-mature leaf growth stages are the best combination for collection of Leucaena leaves with best balance among nutrients and antinutrients, for livestock feeding under mid-Himalayan conditions. However, the exploration for best treatment to reduce the mimosine content in Leucaena leaves revealed CaCl₂ (2 %) treatment as an efficient treatment on summer season collected tender and pre-mature leaves. Understanding these changes helps meet livestock nutritional needs in different seasons, contributing to sustainable livestock feeding practices in the Himalayas.