Third-cutting alfalfa with 37% DM was ensiled untreated or treated with either 2.8 g of formic acid/100 g of DM or .31 g of formaldehyde/100 g of DM and fed to lactating dairy cows in two experiments. Silage treated with formic acid had the lowest pH and concentrations of NPN, NH3, and total free AA. Both treatments decreased rumen in vitro protein degradability but did not affect in vitro rume...

Th is experiment compared linear relationships among end-products of rumen fermentation measured at the time (t1⁄2) at which a feed produces half of its asymptotic gas production) or at 48 h. Meadow hay and corn grain were incubated for t1⁄2 (16 and 9 h, respectively) or for 48 h into glass bottles. Each bottle (310 ml) was fi lled with feed sample (0.5 g) and 75 ml of buff ered rumen fl uid, a...

Alfalfa was harvested as second-cutting regrowth herbage, ensiled either at low DM (direct-cut) or high DM (wilted), untreated or treated with .82 or .66% anhydrous NH3 (percentage of DM), respectively, and offered to four Holstein heifers. Silages low in DM had more gross energy and more NDF in DM than silages high in DM. Ammonia treatment increased total, soluble, rumen-insoluble, and NH3 N f...

Two adult Texel sheep fitted with permanent rumen fistulae were defaunated for 12 weeks in a preliminary experiment. They were then reinoculated with Isotricha sp for 11 weeks, and finally with a mixed fauna (Entodinium, Epidinium, Eudiplodinium and Isotricha) for 10 weeks. They were fed a diet composed of dehydrated lucerne (700 g/d), pelleted barley grain (300 g/d), grass hay (100 g/d) and wh...

From the results of a large series of calorimetric studies with artificially dried grasses (Armstrong, 1964), it was found that the value of a dried grass as an energy source for sheep could be predicted from considerations of its species and its chemical composition (Armstrong, Blaxter & Waite, 1964). The question arises whether the nutritive value of fresh grass can be inferred from that of d...

1. Sheep were given 800 g low-protein roughage/d at 2 h intervals and infused intraruminally with 0,500, 750, 1000, 1250, 1500 or 2000 mmol sodium chloride/d in 436 ml water. The digestibility of various food fractions and rumen ammonia, volatile fatty acids (VFA) and liquid turnover rate were measured, along with renal haemodynamics and the renal excretory patterns of nitrogen and electrolytes...

Four multiparous, ruminally fistulated Angus x Hereford cows (average BW = 568 kg) were bred to the same bull and used to monitor periparturient changes in DMI, ruminal capacity, and digestion and fermentation characteristics. Cows were individually fed alfalfa hay (16.0% CP, 51.3% NDF) at 130% of the average DMI of the previous 5-d period. Ruminal capacity and DM fill were measured once every ...

HOUPT, T. RICHARD, AND KATHERINE A. HOUPT. Transfer of urea nitro,gen across the rumen wall. Am. J. Physiol. 2 1 /t(6) : 1296-1303. 1968.-Net movement of urea N across the wall of Pavlov-type rumen pouches was measured in three goats and one sheep as urea concentration difference between pouch and blood was varied. When urease activity of the rumen epitheliurn was depressed by vigorous rinsing ...

Eight Angus heifer calves (234 kg) were assigned to either a high (HP; 126 g N/d) or low (LP; 66.5 g N/d) protein intake. Calves received 4.8 kg DM/d consisting of 30% cottonseed hulls and 70% corn-soybean meal in equal portions at 4-h intervals. Single doses of 14C- and 15N-urea and 15N-ammonium sulfate were injected into the blood urea-N (BUN) and ruminal NH3-N (RAN) pools, respectively, to m...

This study was performed to determine the effects of different levels of chromium methionine (Cr-Met)supplementation on growth performance, meat oxidative stability and ruminal metabolites in male kids. Thirty-two male Mahabadi goat kids, with an average initial body weight (BW) of 22 ± 2 kg at 4 months of age, were allocated in a completely randomized design with four treatments: control witho...