In sacco macromineral release from selected forages

Abstract

An in sacco technique was used to measure the release of Mg, Ca, Na, K from six forages - lucerne hay from the 1st and 2nd cut (LH1 and LH2), orchard grass hybrid Rela (GR) and hybrid Niva (GN), grass silage (GS), red clover silage treated with Feedtech (CSFT) and/or with Kofasil (CSKO). The forages differed in the content of macrominerals (Ca 15.82-3.66 g/kg DM; Mg 3.68-1.46 g/kg DM; Na 0.20-3.02 g/kg DM; K 21.57-34.79 g/kg DM), and large differences (P < 0.01) were also in the element release in the rumen between experimental forages. The lowest DM effective degradability was determined for grass forages (49.596-51.5%) and forages from legumes had higher degradability (62.996-67.1%). The extent of disappearance of macroelements was also higher from LH1, CSFT, CSKO than from G and GS. The release of individual elements in all incubation times is expressed very well by cubic polynomials. Maximum disappeared portions of individual minerals from forages are as follows: Ca 86.3% and Mg 93.2% from CSFT, Na 98.7% from GN and K < 98% from all feeds. Potassium solubility is rapid and is not affected by the incubation time.