Tropentag, September 10 - 12, 2025, Bonn "Reconciling land system changes with planetary health"

Effect of feeding azolla on performance and blood parameters of ruminant livestock: a systematic review

¹University of Kassel / Ministry of agriculture, fisheries and water resources (Oman), Animal Husbandry in the Tropics and Subtropics, Oman
²University of Kassel / University of Goettingen, Animal Husbandry in the Tropics and Subtropics, Germany
³University of Kassel / University of Goettingen, Animal Husbandry in the Tropics and Subtropics, Germany

Abstract

Sustainable feeding strategies are essential in arid and semi-arid regions facing feed scarcity. Azolla is a rapidly proliferating, protein-rich aquatic fern that offers a potential alternative to costly concentrates in ruminant livestock diets used in such environments. The present study systematically reviewed published literature to establish the effects of Azolla inclusion in (sub-)tropical ruminant diets on growth performance and hematological parameters.
Twelve peer-reviewed in vivo studies were identified via a comprehensive online literature search. A study was included based on publication date (2000–2023) and language (English, German, Arabic), geo-climatic zone ((Sub-)Tropics), species (sheep [n=5], goats [n=5], cattle [n=1], buffalo [n=1]), and study clarity.
Across the studies, Azolla was used either fresh or dried at inclusion rates of 50–500 g/kg feed dry matter (DM). Feeding 60-100 g/kg DM Azolla to sheep increased feed intake (FI) by up to 0.1% and daily weight gain (DWG) by 11.4-18.0 g compared to zero inclusion. Also, FI and DWG in goats increased by up to 1.4% and between 14.7–24.5 g/day, respectively, for Azolla inclusion of 150-200 g/kg DM. The only studies for cattle and buffaloes reported increased DWG and FI at 50 and 250 g/kg DM Azolla inclusion, respectively. However, inclusion above 100 g/kg DM in sheep and 200 g/kg DM in goats led to reduced performance.
Across the six studies that reported hematological outcomes, blood albumin, and total protein levels increased across species with increasing dietary Azolla inclusion (50-250 g/kg DM). By contrast, creatinine concentration and serum urea levels were reduced across species with increasing dietary Azolla inclusion (50-200 g/kg DM), indicating better nitrogen utilisation and digestibility.
It can be concluded that Azolla inclusion positively affects DWG and FI when fed at up to 100 and 250 g/kg DM to sheep and goats, respectively, thereby also improving key blood parameters and overall nitrogen utilisation. However, the current evidence remains limited for large ruminants and further studies are needed to determine optimal inclusion levels that balance animal performance and cost-effectiveness.

Keywords: Azolla, growth performance, hematological parameters, ruminant nutrition

Contact Address: Christian Bateki Adjogo, University of Kassel / University of Goettingen, Animal Husbandry in the Tropics and Subtropics, Steinstr. 19, 37213 Witzenhausen, Germany, e-mail: christian.batekiuni-kassel.de