Effect of Azolla Supplementation on Milk Yield and Feed Cost in Lactating Murrah Buffaloes

Abstract

Azolla, a floating fern that hosts a nitrogen-fixing cyanobacterium, is widely recommended as a home-grown protein supplement for dairy animals, and it is often said to raise milk yield and lower feed cost. This narrative review asks whether those claims are plausible for lactating Murrah buffaloes and how much weight the evidence can carry. It draws on published work on the biology, composition and safety of Azolla, on protein and fibre nutrition in ruminants, and on the design and statistics of feeding trials, and it reports no new data. Azolla is best viewed as a source of rumen-degradable nitrogen and minerals whose composition varies with species and growing conditions, so a response in milk is most likely where the basal ration is short of nitrogen and least likely where it is not. Claims of lower cost depend on whether pond construction, water, nutrients, daily labour, failed batches and testing are counted, and on whether cost is expressed per litre of milk. Common weaknesses of trials, notably few animals, short duration, the animal treated as the replicate when animals share a pen, and an undescribed basal ration, limit how far reported effects can be generalised. The review concludes that a positive but modest effect is plausible, that its size in buffaloes is not established, and it lists what a decisive trial and cost account would contain.