ESTABLISHMENT OF AN AZOLLA (Azolla pinnata) POND AND USE OF AZOLLA AS A FEED INGREDIENT IN CALF DIETS

Abstract

There is significant potential to enhance livestock productivity by providing balanced diets formulated from locally available feed resources, such as Azolla pinnata. This study aimed to achieve two objectives: (1) to introduce effective management practices for an azolla pond, and (2) to evaluate the impacts of azolla on the growth performance of young cattle. A pond (3 m x 1 m x 0.3 m) was constructed with a 20cm water level for azolla cultivation. The pond was fertilized with 14 g of triple super phosphate, 3kg of cow dung, and 25kg of topsoil, followed by the introduction of 1kg of azolla. For the second objective, a feeding trial was conducted with nine young cows aged 3 to 24 months, randomly assigned to three treatments in a complete block design at the faculty farm in the Faculty of Agriculture at the Rajarata University of Sri Lanka. Treatment 1 (T1) served as the control, provided with the farm diet; 99.5% Megathyrsus maximus and 0.5% concentrates. Treatment 2 included 69.9% Megathyrsus maximus, 0.4% concentrates, and 35.7% azolla, while Treatment 3 consist of 32.4% Gliricidia sepium, 42.6% Megathyrsus maximus, 0.2% concentrates, 23.8% azolla, and 1.0% mineral mixture. Daily feed intake and weekly growth rates of the calves were recorded. Related to the first objective; the first harvest of azolla was collected after one week of establishment, followed by subsequent harvests of 1 kg on alternate days. Azolla must be harvested regularly to prevent overgrowth, otherwise, the growth of new plants and the pond's ecosystem are potentially disrupted. As expected, the mean feed intake (5.0±0.06kg calf-1 ) was significantly higher in T3 compared to T1 (4.7±0.06 kg calf-1 ) and T2 (4.6±0.06 kg calf-1 ). Cattle in T3 exhibited a significantly higher mean body weight (120.8±5.23 kg) compared to T2 (111.7±5.23 kg) and T1 (106.1±5.23 kg). Moreover, incorporating azolla into grass mixtures (T1 and T2) or providing young cattle with a balanced diet (T3) can effectively promote healthier growth and development.