Flavonoid’s are one of diet component of domestic livestock in wild life, but, there is not enough information in area of importance that. In the first step, flavonoid’s components (FC) isolated from propolis by ethanol extraction. The extract analyzed for total flavonoid and phenolic components, in the second experiment. In third experiment, In vitro trial was performed to investigate the importance of flavonoid’s in the diet of ruminants. The In vitro incubations by using batch rumen culture procedures were conducted to study the effects of different levels of FC (140, 70, 35 and 17 ?g/ml) and alfalfa ethanol extract (AE) (44000 ?g/ml) on ruminal fermentation. Rumen fluid collected from two sheep fed diets contained (DM basis); 1) 100% alfalfa, 2) 50% alfalfa + 50% concentrate and 3) 20% alfalfa + 80% concentrate. Presence of FC in the incubation reduced (P 0.005) dry matter disappearance (IVDMD), NDF disappearance (IVNDFD), ADF disappearance (IVADFD), gas production, ammonia-N, and protozoa population in diets 1 and 2 in comparison with controls, but increased (P 0.005) IVDMD in diet 3 as AE as. Manner of ruminal fermentation is effect by flavonoid’s presence in diet. More research is essential to show importance of this component in ruminant food. In fourth experiment, Using 3 diet 1) 100% alfalfa, 2) 50% alfalfa+ 50% concentrate and 3) 20% alfalfa + 80% concentrate and a mixed culture of ruminal microorganisms, have been studied the in vitro effects of flavonoid components addition (140, 70, 35 and 17 ?g/ml) in compare with monensin (2.5 ?g/ml) on ruminal fermentation parameters. IVDMD, IVNDFD and IVADFD of ration 1 and 2, were decreased significantly (P 0.05) with all levels of FC and monensin in compared to control, but FC and monensin increased IVDMD in ration 3. Ammonia-N concentration and numbers of protozoa were decreased in a dose dependent manner of FC as monensin as. In the fifth experiment, in a completely randomized design 20 Holstein calves (7±2 d) in four groups received 7.3×10 -5 , 7.3×10 -6 , 3.6×10 -3 and 0 g/Kg BW of FC. The results showed that using FC affected (P 0.05) the weaning age and weight and also forage consumption after weaning, but without any effect on growth parameters. Serum IgG was not affected by FC. At 6 wk, control group had a higher concentration of IgM than did treatment calves (P 0.05). More research is essential to evaluate this component in calf’s nutrition.
