In situ ruminal degradation of organic matter of Trifolium pratense L.

Seven clover sampes (Trifolium pratense L.) were collected at three different miters I (n = 3), II (n = 3) and III (n = 1) during the growing season from 10th of May to 17th of August. The samples were analyzed for chemical composition, gross energy (BE) content, in vivo sheep digestibility of organic matter (KS OH) and gross energy (KS BE) and in situ rumen degradability of organic matter and neutral detergent fibre (NDF). The contents of ash, crude protein (NL), crude fibre (CF), NDF, acid detergent fibre (ADF), acid detergent lignin (ADL) and BE were significantly (P < 0,05) affected by the date of cutting time. The averaged values were for ash 119,2 g/kg of dry matter, NL 197,7 g/kg of dry matter, CF 214,1 g/kg of dry matter, NDF 400,7 g/kg of dry matter, ADF 296,2 g/kg of dry matter, ADL 73,8 g/kg of dry matter and BE 18,2 MJ/kg of dry matter. KS OH and KS BE generally decreased with higher dates of cutting time. On average KS OH and KS BE amounted 72,4 % and 70,2 %, respectively. The effective ruminal degradability of organic matter (EDOH) was in average 81,7 % for miter I, 79,7 % for miter II and 75,2 % for miter III. In situ organic matter degradability characteristics were in average 41,9 % for the immediately degradable (soluble) fraction (parameter a), 47,1 % for the potential degradable fraction (parameter b) and 0,105 h-1 for the fractional rate of degradation (parameter c). The effective ruminal degradability of NDF (EDNDF) also generally decreased (P < 0,05) with increasing date of cutting time with values of 63,0 % for miter I, 59,7 % for miter II and 51,6 % for miter III. Strong correlation (P < 0,05) was observed between the EDOH and EDNDF (r = 0,979)