The four dietary treatments were (i) control diet,
(ii) control diet supplementation with RPM at 60 g/
kg, (iii) control diet supplemented with PO at 20 g/kg
and (iv) control diet supplemented with RPM at 60 g/
kg and PO at 20 g/kg (RPO), of total DM intake. The
fallen rain tree pods were collected, chopped and sundried
for 2–3 days and ground to pass through a 1-
mm sieve. The control diet was formulated to be at
181 g/kg crude protein (CP) and 806 g/kg total digestible
nutrient (TDN), DM basis (Table 1). Cows were
fed the concentrate diets at a concentrate to milk yield
ratio of 1:2. Chopped 30 g/kg of urea-treated rice
straw was fed ad libitum. The ingredients and chemical
composition of diets are shown in the Table 1.