degradation of dry matter (dm) and nitrogen (n) in fresh or frozen-thawed alfalfa and ryegrass was studied by using in situ technique. the forages were labeled with 15n during growth in a glasshouse, harvested at similar growth phase, and fresh (f) or frozen-thawed (ft) samples were incubated in the rumen of 3 sheep. there was no difference (p>0.05) between forage type (s) for the immediately s...

the chemical and fermentative parameters of three fresh forages and silages of sorghum including sweet, pegah and speedfeed varieties were compared with corn using in vitro method, also degradability coefficients of forages and silages were determined by in situ method. forages were planted in the same condition and harvested in soft dough stage, then ensilaged in four replicates for each time ...

current ruminant feeding systems depend on knowledge of the composition of feeds and the rate and extent of degradation of feed organic matter (om) and crude protein (cp) in the rumen. the effect of storage and preparation of samples on in vitro gas production and fermentation characteristics of two common forage species, namely alfalfa and ryegrass werestudied. samples were prepared as fresh (...

A method has been developed to prepare fresh forages for in sacco and in vitro incubation by freezing and mincing to achieve a particle size distribution of dry matter (DM) similar to in vivo conditions. The method is described and data presented to indicate losses of nitrogen (N) during in sacco digestion and net yield of ammonia from proteolysis in vitro for 22 fresh and conserved forages. Gr...

The nutritional image of bovine milk fat has suffered for years because of the association of saturated fatty acids and coronary heart disease. Thus the alteration of fatty acid composition has been a long-term strategy. Forages, even though containing a relatively low level of lipids, are the cheapest and often the major source of beneficial unsaturated fatty acids in ruminant diets. Recent pr...

The established calculation of ruminal extent of degradation using the polyester bag method overestimates extent. The wash fraction, at least in part, is subject to losses from the rumen due to passage. Four formulae are proposed to minimize this risk of overestimation. Four options are considered: 1) passage losses for particulate matter escaping from the bag at zero time are according to the ...

Two methods of feed preference trials were compared to evaluate the acceptability of 5 fresh foliages: Leucaena leucocephala, Moringa oleifera, Portulaca oleracea, Guazuma ulmifolia, and Brosimum alicastrum that was included as control. The evaluation included chemical analyses and forage intake by rabbits. The first method was a cafeteria trial; 12 California growing rabbits aged 8 wk, allocat...

In order to study the extent to which rumen soluble nitrogen can contribute to the intestinal flow, a study was carried out to simultaneously assess the dynamics of protein disappearance from dacron bags placed in the rumen and the amount of various N products in the rumen fluid (total nitrogen (tN), ammonia nitrogen (NH3-N), non-ammonia nitrogen (NAN)). The measurements were carried out on 4 s...