سعید دوازده امامی - Natural Resources Research Department, Isfahan Agricultural and Natural Resources Research Center, Agricultural Research Education and Extension Organization (AREEO), P. O. Box: ۸۱۷۸۵-۱۹۹, Isfahan, Iran.
محمد علی علیزاده - Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran.
حسین زینلی - Agricultural Research Education and Extension Organization (AREEO), Tehran, Iran.
صادق جلالی - Natural Resources Research Department, Isfahan Agricultural and Natural Resources Research Center, Agricultural Research Education and Extension Organization (AREEO), P. O. Box: ۸۱۷۸۵-۱۹۹, Isfahan, Iran.

Sainfoin (Onobrychis vicifolia Scop.) is one of the most important forage legumes cultivated as high quality forage. Fifty three species have been identified in this genus in Iran. A field experiment was conducted using randomized complete block design to compare yield and forage quality of ۲۰ populations of sainfoin in Isfahan Agricultural and Natural Resources Center, Iran during ۲۰۱۳ – ۲۰۱۴. Populations were evaluated at three cutting dates (۲۹ April, ۲۰ July and ۲۶ October, ۲۰۱۴). Dry matter yield and forage quality indices such as crude protein (CP), water-soluble carbohydrates (WSC), neutral detergent fiber (NDF), acid detergent fiber (ADF), dry matter digestibility (DMD), and ash content were determined. Results showed that populations were different in the majority of traits. Means of interaction effects indicated that the maximum and minimum dry matter yield were ۵۶۱۲.۷ kg ha-۱ at the third cutting and ۱۱۸.۵ kg ha-۱ at the first cutting in ۸۱۹۹ and ۹۲۶۳, respectively. According to the results of quality analysis in the majority of populations, maximum DMD, CP and WSC were obtained at the third cutting and maximum ADF and NDF were obtained at the first cutting. In terms of forage yield some populations, such as ۸۱۹۹, ۳۸۰۰, Oshnavieh, ۹۱۴۷, ۸۷۹۹ and Isfahan camposit were superior to other populations. High digestibility populations (۲۷۵۹, ۱۹۴۰۲, PLC, ۱۲۵۴۲, ۳۰۰۱ and Oshnavieh) and high protein populations (۸۱۹۹, ۱۵۳۵۳, ۲۷۵۹, ۳۰۶۲, ۱۵۳۶۴ and ۱۹۴۰۲) had the best forage quality among populations. Regarding quantitative and qualitative characteristics of forage, these populations could be considered as desired parents for developing synthetic varieties.

crude protein, dry matter digestibility, Onobrychis vicifolia Scop, water-soluble carbohydrates, Yield