Determination of chemical composition, nutrients digestibility and degradability of irrigated and rainfed sainfoin treated by urea in sheep

Sainfoin is a perennial forage plant belonging to the legume family, cultivated in both rainfed farming and irrigated area for grazing and hay production for the feeding of livestock. The present experiment was conducted to determine chemical composition, total phenolic compounds and tannin, nutrients degradability and digestibility of two type sainfoin, cultivar rainfed and irrigated conditions sainfoin forage, in sheep.
There was six treatments, consisted of untreated irrigated sainfoin (UNIS), untreated rainfed sainfoin (UNDS), irrigated sainfoin by water (ISTW), rainfed sainfoin treated by water (DSTW), irrigated sainfoin treated by urea (ISTU) and rainfed sainfoin treated by urea (DSTU). Data of chemical composition, total phenolic compounds, total and condensed tannin and degradability were analyzed based on completely randomized design and digestibility were analyzed with using a latin square (change over) design. as well data of pH and N-NH3 with repeated measurements on time.
Among treatment, the highest crude protein content (14.25%) was related to irrigated sainfoin treated by urea (ISTU). The highest concentration of total phenolic compounds, total tannin and condensed tannin was for rainfed sainfoin (5.58, 5.36 and 3.35%, respectively). Therefore, Treatment by water or urea in irrigated sainfoin compared to non-treated irrigated sainfoin, and rainfed sainfoin treated by water or urea, was the highest percent of the reduction in phenolic compounds, total tannin and condensed tannin. Treatment by water or urea resulted to increased of DM digestibility. The water treatment increased effective degradability (ED) of DM in irrigated sainfoin compared with other treatments. The ISTW treatment had higher degradability of neutral detergent fiber (NDF) than other treatments. Treatment by water and urea lead to increasing the ED of sainfoin nutrients.
Generally, the results showed that using water or urea for the treatment of sainfoin was a suitable method for decreasing or elimination of tannin undesirable effects.