Investigation of feed value of alfalfa (Medicago sativa L.) harvested at different maturity stages as in situ and in vitro

The aim of this project is to determine yield (the green herbage yield, dry herbage yield, crude protein yield and crude oil yield) chemical and nutritional values (dry matter (DM), organic matter (OM), crude ash (ash), crude protein (CP), crude fat (EE), crude fiber (CF), Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), nitrogen-free extract (NFE), digestible dry matter (DDM), total digestible nutrients (TDN), dry matter intake (DMI), relative feed value (RFV), metabolized energy (ME), digestible energy (DE), net energy of lactation (NEL), macro and micro minerals, with the in-situ dry matter, organic matter and crude protein degradability values) of Alfalfa (Medicago sativa L.) in different stages of maturity (budding period, beginning of flowering period, full blooming period and seed setting period) both 'in situ' and 'in vitro' under Isparta ecological condition during 2012 vegetation.Twelve alfalfa parcels established according to Completely Randomized Parcels design. Alfalfa parcels were sampled based on the local vegetation periods which were budding period (5 cuts), beginning of flowering period (5 cuts), full flowering period (4 cuts) and seeding period (3 cuts). Alfalfa samples yields, nutrient content and in situ digestibility were determined.The highest forage yield were 9609.33 kg/da for the budding period. Forage yields were decreased 28% with maturation. The highest dry matter hay yield (1742.63 kg/da) were obtained from the beginning of flowering period. The highest crude protein (19.67%) were determined for the budding period. Crude protein levels were reduced 22% with maturation. The seeding period samples had 35.79% crude fiber, 53.84% NDF and 40.30% ADF content. Alfalfa samples DM content, CF, NDF, ADF contents were increased with maturity while the ash content, dry matter digestibility, percent of intake based on body weight, ME, DE and NEL values were decreased. The calculated NEL values from CF and ADF values were similar for the same samples, ME calculation from CF, ADF and NDF had 8-30% differences between them. The calculation of ME values of the margin of error is much higher than acceptable levels.Budding to seeding period samples RFV (132 to 100) were lowered 10 points for each vegetation period. In situ studies, DM, OM and CP increased degradability with increasing incubation times. The highest dry matter degradability were 76.67% for budding period and the lowest dry matter degradability were 59.84% for seeding period at 24 hours In Situ incubation time. The average value of DM digestibility (17%), OM digestibility (14%) and CP digestibility (13%) were decreased with maturity. Increasing maturation of herbage yield, alfalfa forage quality decreases. In terms of animal production having a large quantity of hay is important as much as with the high protein content but they have an inverse relationship between these two qualities.