Protein degradability in prairies for rotational grazing in the coast of Cantabria andits prediction

Depart. of farming tech. at I.E.S. "La Granja, 39792 Heras, Cantabria (Spain)

FAO/CIHEAM European 1998. Lowland Grassland of Europe. Utilisation and development

During the years 1994 and 1995 we have sudied the ruminal degradability of crude protein in prairies of Lolium peremne (cv. Tove) and Trifolium repens (cv. Grassland Huia), used for rotational grazing with milk cows from march to november. The results showed a high effective degradability (73.67%), the protein solubility (43.7%), a rate of time degradability of 0.125 and a potential degradability of 88.12%. The highest degrading peaks took place in autumn and the lowest in summer. The content of neuter detergent fibre is the variable in closer relationship with effective degradability of protein (Depb)=126.8 – 1.07 NDF. The relationship degrading nitrogen in rumen per MJ of metabolizing energy (NDR/MJ of ME) is higher in autumn (2.26 g), minimum in summer (1.96 g) and intermediate in spring (2.03 g); its prediction is closely influenced by the content of crude protein in pasture.