Nutritive Value of Six Romanian Cultivars of Alfalfa as Hay and Semi-silage for Ruminants

Abstract

Six alfalfa cultivars developed at the Institute of Agricultural Research –NARDI Fundulea have been tested as hay and semi-silage to determine their nutritive values. The studied cultivars were Daniela, Madalina, Sandra, Catinca, Teodora and Cezara, harvested at 2nd cutting in early bloom phase. In order to apply a mathematical simulation model for energy and protein metabolism in ruminants (Burlacu, 2002) the following parameters were determined: chemical composition (by Weende analysis), gross energy (adiabatic calorimetry), and organic matter digestibility (in vitro method). For the hay samples the crude protein was between 20.2% (Sandra) and 21.4% (Madalina), the crude fibre was between 30.6% (Madalina) and 39.1% (Teodora). The crude protein in semi-silage samples was between 21.5% (Madalina) and 23.6% (Cezara) and the crude fibre was between 32.5% (Cezara) and 33.9% (Teodora). The net energy (FUmilk) has the highest value in Cezara hay (0.74) and in Madalina silage (0.70). PDIN values (g/kg DM) for hay ranged from 122 (Cezara) to 143 (Madalina), and for semi-silage from 131 (Teodora) to 142 (Cezara). PDIE values (g/kg DM) for hay ranged from 77 (Madalina) to 73 (Sandra); for semi-silage there were virtually no differences between the cultivars, four of them (Daniela Madalina, Catinca, Cezara) having the same value, i.e. 69. In conclusion, finding the nutritive value of these cultivars will allow selecting the ones for optimal ruminant diets.