FARMING PRACTICES AND CHEMICAL BASES FOR A PROPOSED QUALITY STANDARD OF VETCH-CEREAL HAYS

Forage hay from vetch species or mixed stands with small-grain cereals has the potential to meet the forage deficit and integrate crop and l ivestock production in Mediterranean cereal-based systems. On-farm bal e samples were collected during two growing seasons (1990-91 and 1992- 93) from collaborative farmers (n = 56 and 38, respectively) in the Ca stile-La Mancha region (8 x 10(6) ha) in the south-central plateau of the Iberian peninsula. The aims of the research were to assess the ran ge of variation of botanical and chemical composition and how these di fferences in nutrient components can be related to forage ideotypes. T he great diversity in composition reflected the lack of standardizatio n in cropping and haymaking practices and concealed differences betwee n growing seasons. Mean data of the aggregate hay sample and intended use of hays (multipurpose-small ruminant feeding) suggested the follow ing forage quality ideotype: CP > 130; NDF < 475; ADF < 300; ADIN < 2 and ADI-ash < 20 g kg(-1) DM. The proposed quality standard was accomp lished by 33 and 26% of hay samples in the two growing seasons, respec tively. In those hays in which vetch (Vicia sativa L.) contributed mor e than 500 g kg(-1) to the dry biomass, the chemical criteria were acc omplished by 68 and 54% of samples in the two growing seasons, Vetch c ontribution to hay was better related with CP than with most fibre fra ctions and constituents except the hemicelluloses.