Past positive experiences can increase herbivores' motivation to eat low-quality foods. However, this is not always translated into a higher preference for low-quality foods in choice tests among foods of higher nutritional quality. Foraging behavior is also affected by properties of the feeding context because the quality and abundance of foods in nature change in time and space. We hypothesiz...

The aim of this study was to evaluate the effect of fat supplementation for enhancing milk conjugated linoleic acid (CLA) in early lactation without affecting ruminal fermentation. 24 Holstein dairy cows were assigned to a completely randomized design employing a 2 × 4 factorial arrangement. Factors were particle size (15 and 25 mm) and two different sources of alfalfa supplemented with and wit...

Two hundred ninety-nine crossbred yearling steers (363 +/- 15 kg initial BW) were fed for an average of 114 d in a finishing study comparing 7 diets in which steam-flaked corn was used as the principal energy source. Forty-nine pens were used in this study with 7 BW blocks, 7 pens per treatment, and 5 to 7 steers per pen. A control diet with no distillers grains with solubles (DGS) was compared...

The objectives of this study were to expand the database and determine the intestinal digestibility of rumen undegradable protein (dRUP) of common dairy feeds and to determine the effects of feeding 37.9% wet corn gluten feed on these estimates. Two ruminally and duodenally fistulated steers were assigned randomly to a crossover design with 4-wk periods. The mobile bag technique was used to det...

Alfalfa (Medicago sativa L.) persistence and forage and cow-calf production were evaluated on pastures containing smooth bromegrass with or without grazing-tolerant or hay-type alfalfa cultivars rotationally stocked in either a season-long or complementary system. In 1997, six 2.02-ha pastures were seeded with smooth bromegrass, a mixture of a grazing-tolerant alfalfa (Amerigraze variety) and s...

Anecdotal evidence suggests that cattle fed alfalfa hay during the winter are inclined to graze locoweed on spring range. Two studies were conducted to compare the influence of feeding alfalfa hay vs grass hay during the winter on subsequent consumption of white locoweed (Oxytropis sericea Nutt. ex T&G) in the spring. Eight cows were daily fed alfalfa hay (15.2% CP in 1998, % CP in 2000) and 8 ...

I arrived at UC Davis in October 1979, back in the Stone Ages. I can still remember my first UC Davis Dairy Cattle Day presentation (1980) in 194 Chemistry. I presented data from my Ph.D. research on forage quality at Penn State. In my research project the main forage was corn silage along with about three pounds of long alfalfa hay per cow daily. After my talk, a dairy producer came up to intr...

Two in vitro experiments were performed to identify promising exogenous fibrolytic enzyme products (EFE) and optimum dose rates (DR) for improving the degradation of alfalfa hay and corn silage. The relationship between enzymatic activity and fermentation responses was examined to identify optimum formulations. In experiment 1, 5 EFE containing mainly endoglucanase and xylanase activities, with...

The aim of this paper was to study of the effect of fenugreek seed (Trigonella foenum-graecum) and asparagus root (Asparagus officinalis) on in vitro digestibility and kinetics of gas production of alfalfa hay. Fenugreek seed (FS) and asparagus root (AR) were added at different levels (0, 5, 10, 15 and 20% of DM). Total phenolic components of alfalfa hay (AH), fenugreek seed (FS) and asparagus ...