000K utf8 1100 $c2023 1500 eng 2050 urn:nbn:de:gbv:8:3-2023-00077-0 2051 10.3390/ani13020224 3000 Okon, Paul 3010 Bachmann, Martin 3010 Greef, Jörg Michael 3010 Rodehutscord, Markus 3010 Rupp, Christiane 3010 Susenbeth, Andreas 3010 Titze, Natascha 3010 Wensch-Dorendorf, Monika 3010 Zeyner, Annette 4000 Feed Clusters According to In Situ and In Vitro Ruminal Crude Protein Degradation [Okon, Paul] 4209 Effective degradation (ED) of crude protein (CP) was estimated in vitro at 0.02, 0.05 and 0.08 h-1 assumed ruminal passage rates for a total of 40 feedstuffs, for which in situ ED was available and used as reference degradation values. For this, the Streptomyces griseus protease test was used. The differences between in vitro CP degradation and the in situ CP degradation values were lowest in legume grains and highest in cereal by-products and barley. The differences between in situ and in vitro ED were expressed using a degradation quotient (degQ), where degQ = (EDin vitro - EDin situ)/EDin situ. Among the tested feedstuffs, eight specific clusters were identified according to degQ for the assumed passage rates. The feedstuffs clustered in an unspecific way, i.e., feedstuffs of different nutrient composition, origin or treatment did not necessarily group together. Formaldehyde-treated rapeseed meal, soybean meal, wheat, a treated lupin, sunflower meal and barley could not be assigned to any of the clusters. Groupwise degradation (range of degQ for assumed passage rates are given in brackets) was detected in grass silages (-0.17, -0.11), cereal by-products together with sugar beet pulp (-0.47, -0.35) and partly in legume grains (-0.14, 0.14). The clustering probably based on different specific nutrient composition and matrix effects that influence the solubility of feed protein and limit the performance of the protease. The matrix can be affected by treatment (chemically, thermally or mechanically), changing the chemical and physical structure of the protein within the plant. The S. griseus protease test had reliable sensitivity to reflect differences between native feedstuffs and treatments (thermally or chemically) that were found in situ. 4950 https://doi.org/10.3390/ani13020224$xR$3Volltext$534 4950 https://nbn-resolving.org/urn:nbn:de:gbv:8:3-2023-00077-0$xR$3Volltext$534 4961 https://macau.uni-kiel.de/receive/macau_mods_00003397 5051 333.7 5051 590 5550 Concentrates 5550 Grass Silages 5550 In situ 5550 In vitro 5550 Ruminal Crude Protein Degradation 5550 Streptomyces griseus Protease