A high concentrate diet was fed at 1.2, 1.5, 1.8 and 2.1% of body weight to four Angus steers (258 kg) equipped with cannulas in the proximal duodenum and distal ileum. As level of feed intake increased, flow of N, nonammonia N, microbial N and feed N to the small intestine increased linearly (P less than .05). Bypass of feed N increased from 44 to 71% of fed N. At the highest intake level, rum...

the aim followed in the present research was to study the effects of reduction in dietary crude protein on milk production and on blood components in lactating holstein dairy cows when in heat stress. a number of 63 holstein dairy cows (71 ± 16.5 dim) were chosen to be made use of in a randomized complete block design. the cows were randomly assigned to any one of the three experimental rations...

Cistus ladanifer L. (CL) is a perennial shrub abundant in dry woods and dry land of Mediterranean zone, with high level of tannins. Tannins bind to protein, preventing its degradation in the digestive compartments. This tannin/protein complex may be advantageous when partially protecting good-quality feed protein from excessive rumen protein degradation. The objective of this trial was to use a...

Dueto theactionofo-quinones formedviapolyphenoloxidase, conserved red clover (Trifolium pratense L.) contains abundant rumen undegradable protein (RUP), but inadequate rumen degradable protein (RDP) fordairy cattle. This studyexaminedhowforagemanagement influences RDP, RUP, crude protein (CP) and fiber fractions in red clover silage and dry matter (DM) yields during the first full production ye...

Elements of the metabolizable protein system in the United Kingdom were examined for their suitability as potential predictors of milk protein concentration. Models were based on data from 163 cows offered five forage mixtures for ad libitum intake plus concentrates at 3, 6, or 9 kg/d of dry matter. The models were then tested on a separate data set of 100 cows offered seven forage mixtures for...

Steers, equipped with simple rumen cannulas, were given diets of approximately equal parts of rolled barley and straw supplemented with urea. The diets provided sufficient estimated rumen degradable nitrogen (RDN; RDN:metabolizable energy values of 1:3) to maintain maximum microbial synthesis. In some experiments Na235SO4 was introduced into the rumen to label microbial protein. Rumen digesta s...

Two trials were conducted to evaluate the effect of rumen-degradable protein balance (OEB) deficit on voluntary intake (trial 1), microbial protein synthesis, and N metabolism (trial 2) in growing double-muscled Belgian Blue bulls. In trial 1, six bulls (339 +/- 26 kg of initial BW) were used in a replicated 3 x 3 Latin square and received a diet of 60% corn silage and 40% concentrate with ad l...

BACKGROUND The continuing growth of the ethanol industry has generated large amounts of various distillers grains co-products. These are characterized by a wide variation in chemical composition and ruminal degradability. Therefore, their precise formulation in the ruminant diet requires the systematic evaluation of their degradation profiles in the rumen. METHODS Three distillers grains plus...

A partially balanced changeover design experiment was undertaken to evaluate the effects of level of fish oil inclusion in the diet on rumen fermentation parameters and digestion with 10 beef cattle offered grass silage ad libitum as the basal forage supplemented with 5 kg concentrates headÿ1 dayÿ1. Concentrates were prepared to provide either 0 (T0), 150 (T150), 300 (T300) or 450 g (T450) fish...

Effects of supplementation with ruminal epithelial cells on fiber-degrading activity and cell growth of Ruminococcus albus (R. albus, strain 7) was tested using a basal substrate of rice straw and formulated concentrate. Cultures of R. albus alone and R. albus with rumen protozoa were grown at 39C for 48 h with an 8.4% crude protein (CP) substrate, 33% of the CP supplemented with either rumina...