In sacco macromineral release from selected forages

Abstract

Solubilization and release of mineral elements from feedstuffs are important processes for their utilisation by animals (Khorasani and Armstrong, 1990). According to Playne et al. (1978), the elements not released from feedstuffs in nylon bags after 48 h incubation in the rumen are probably unavailable for absorption to the animal. The location of mineral elements in the forage structure may influence their release (Van Eys and Reid, 1987;Emanuele and Staples, 1990;Gralak et al., 1997;Islam et al., 2001). High proportions (> 60%) of K and Mg were released during short incubation in the rumen. Ca had the lowest disappearance. Flachowsky et al. (1994) reported that Ca release was dependent on the type of feedstuff and incubation time. Disappearance of elements from the bags in the rumen depends on mineral content and fibre content of incubated feeds (Flachowsky and Grün, 1992).The objective of the present study was to compare the release of selected macrominerals from different types of forages in times of their incubation in the rumen by an in sacco method. MATERIAL AND METHODS In sacco methodTo study the release of mineral macroelements we used the following forages: lucerne hay from the 1 st cut (LH1) and 2 nd cut (LH2), two hybrids of orchard grass (Rela hybrid GR and Niva hybrid GN), red clover silage treated with the chemical Kofasil (CSKO) and biological conserving agent Feedtech (CSFT) and grass silage (GS). A meadow sward composed of 80% grass (with a dominant portion of Dactylis glomerata, and Festuca pratensis, Poa pratensis, etc.), 15% herbs (Taraxacum officinale) and 5% clover (Trifolium repens) was used for ensiling.An in sacco method was used to study the release of mineral elements from forages. Incubation of forages was done in the rumen of 3 young bulls (average live weight 350 kg) with large rumen cannulas (inner diameter 10 cm). The animals were fed a ration consisting of lucerne hay, maize silage, cereal meal and mineral and vitamin feed additive. Access to water was ad libitum. , 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 (49.5%-51.5%) and forages from legumes had higher degradability (62.9%-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.

In situ and in vitro estimation of mineral release from common feedstuffs fed to cattle

“…High variability in mineral content between feedstuffs, and different solubilities between minerals have been described (Čerešňáková et al 2007). In the current study, high variability was observed for effective release among minerals and effective release in each mineral between feeds.…”

Ruminal degradability of dry matter and neutral detergent fibre of grasses

“…This method is used for measuring of degradation parameters of a whole spectrum of nutrients and feeds (Čerešňáková et al, 2007;Homolka et al, 2007Homolka et al, , 2008. However, the in sacco method requires rumen-cannulated animals, and is time consuming and expensive.…”