The cattle rumen has a diverse microbial ecosystem that is essential for the host to digest plant material. Extremes in body weight (BW) gain in mice and humans have been associated with different intestinal microbial populations. The objective of this study was to characterize the microbiome of the cattle rumen among steers differing in feed efficiency. Two contemporary groups of steers (n=148...

We conducted two experiments to determine the feeding value and effects on diet digestibilities, passage rates, and ruminal metabolism of wheat middlings (WM) fed as a replacement for either the concentrate or roughage components of finishing diets of steers. In Exp. 1, 120 medium-framed steers were blocked by weight and randomly allocated to one of six treatments of high-concentrate diets: con...

this study was conducted to determine nutritive value of common animal feed sources in east azerbaijan province including second cutting of alfalfa hay ( n=35) and wheat straw (n=26). chemical composition and mineral contents of alfalfa hay and wheat straw were determined according to standard methods. then the average chemical compositions of these samples were compared with those of the gilan...

Six hundred ten crossbred-yearling heifers (347 +/- 5 kg of initial BW) were obtained and used in a randomized complete-block design finishing study. Finishing diets were based on steam-flaked corn and ground alfalfa hay. The control (CONT) treatment contained no distillers grains with solubles (DGS), the second diet was formulated to contained 13% (DM basis) dried corn DGS derived from a tradi...

Two experiments were conducted to evaluate dry matter intake (DMI), milk yield, and milk composition from feeding rations that contained different sources of genetically modified whole cottonseed to Argentinean Holstein dairy cows. Twenty-four lactating multiparous Argentinean Holstein dairy cows were used in 2 experiments with a replicated 4 x 4 Latin square design, with cows averaging 565 kg ...

A culture system for digesting forages utilizing washed ruminal bacteria was examined. Cultures inoculated with washed bacterial suspensions had similar cellulolytic populations but lower methane production rates than did cultures inoculated with rumen fluid. Subsequent experiments utilized washed cell suspensions. Urea supplementation (8 mM) increased total bacterial and cellulolytic populatio...

Twenty-four Holstein cows were used to study the effect of dietary fat on milk production and metabolic traits. Whole cottonseed and tallow were used as fat sources and substituted into the control diet on an isocaloric basis. Chopped alfalfa hay and grain sorghum silage constituted the forage in all diets. Treatments were balanced for parity, body weight, and previous lactation milk production...

An experiment was performed with the objective of evaluating the performance of beef steers on diets consisting of increasing levels of corn milling by-products (BP) (50% wet corn gluten feed, 50%wet distillers grains; DM basis) and different alfalfa hay levels. 280 yearling steers (370 kg BW) were blocked (3 blocks) by weight, stratified within block and assigned to 35 pens (8 steers/pen). Pen...