Bromegrass Pastures Research Articles

Comparative Value of Afalfa Pasture, Bromegrass Pasture, or Alfalfa Hay for Lactating Dairy Cows

Thirty Holstein cows were distributed among three groups assigned at random to one of these roughage treatments: alfalfa pasture, bromegrass pasture, or alfalfa hay. Grain rations (12% protein for alfalfa or 16% for bromegrass) were fed at the rate of 1kg per 3.5kg milk. To prevent bloat, cows pastured on alfalfa received 20g poloxalene daily. From 0–8 weeks cows grazing alfalfa pasture produced significantly more milk, fat, and solids-not-fat (SNF) than those grazing bromegrass. The bromegrass pasture group produced significantly more milk, fat, and solids-not-fat than those fed alfalfa hay. Daily forage dry matter intakes per cow in kilograms were: alfalfa pasture, 25.3; bromegrass, 11.5; alfalfa hay, 17.3. Cows on alfalfa hay gained weight; those on alfalfa pasture maintained their weight; those on bromegrass lost weight, perhaps from low dry matter intake. Considering cost of roughages equal, milk income over grain costs was significantly more from pastures than from hay.

Volatile Compounds in Blood, Milk, and Urine of Cows Fed Silage-Grain, Bromegrass Pasture, and Hay-Grain Test Meals1,2

Two to four cows per treatment were fasted after test meals, their fluids were sampled for 28 to 54 hr, and analyzed by gas liquid chromatography. Methyl sulfide, acetone and butanone occurred and increased during the 1st hr after silage was fed and reached maximal concentrations at about 4.5 hr. Ethanol, however, reached an early maximum during the first hr and a secondary maximum at 4.5hr.The test meal of bromegrass pasture produced a small amount of methyl sulfide and an increase in acetone. They reached maxima at about 4.5hr.Acetone, butanone, and a small amount of methyl sulfide were the only components found consistently after test meals of alfalfa hay and grain, except that one of the four cows produced an unidentified material and did not produce butanone, except in urine.All animals fasted after the test meal developed high concentrations of acetone in body fluids at about 30hr.

Some Volatile Components in Milk, Blood, and Urine from Cows Fed Silage, Bromegrass, and Hay and Grain1,2

Summary Chromatographic analyses of volatile material in milk, blood, and urine of cows fed silage, bromegrass pasture, and a control ration of hay and grain were made. Off-flavors as determined by organoleptic analysis could not be related to any specific volatile materials determined from the analyses. Of the volatile constituents found in biological fluids, their concentrations were usually higher in urine than either milk or blood. Some chromatographic peaks from the analysis of some of the biological fluids were peculiar to certain feeds. Evidence for identification was presented for ethyl ether, ethanol, methyl sulfide, propanal, acetone, methanol, 2-butanone, 2-pentanone, and n-propanol. Identification was based upon agreement of retention time with known compounds and alteration of chromatographs by prior treatment of samples with various qualitative reagents. Of materials observed, only acetone and 2-butanone were conclusively identified.

Consumer and Taste Panel Evaluations of Some Methods for Controlling Feed Flavors in Milk1,2

summary Milk produced on experimental feeds was evaluated by a consumer panel and a trained taste panel. Off-flavored milk returned by consumers was used to measure its acceptability. An experienced taste panel evaluated both the experimental milk and the control milk on the same day deliveries were made to customers. Milk produced by cows fed sorghum silage, rye pasture, and bromegrass pasture was returned by consumers at rates of 1.1, 50.6, and 24.0% of the delivered quarts, respectively. Samples of these milks were scored 37.4, 33.3, and 34.2, respectively. These results were based on average values from six, four, and five trials on the silage, rye pasture, and bromegrass pasture, respectively. Vacuum treatment of milk produced on rye pasture resulted in 48.1% returns and a flavor score of 33.5; and on bromegrass pasture, 16.7% returns and a flavor score of 32.0. Removing cows from rye pasture 4 hr before milking resulted in 28.6% returns and a flavor score of 33.0; and from bromegrass pasture, 17.8% returns and a flavor score of 33.7. Correlation and regression coefficients between the log percentage of consumer returns and the panel flavor score were not significant at the 5% level for milk produced on rye pasture and bromegrass pasture.

Lamb Production as Affected by Forage Mixture and Grazing Management of Perennial Pastures

Early-weaned lambs were: (1) pastured on alfalfa-bromegrass pasture and rotationally grazed over either two or three paddocks; (2) pastured on fertilized bromegrass and rotationally grazed over three paddocks; or (3) self-fed grain and grazed over three alfalfa-bromegrass paddocks. Each treatment was replicated three times per year and the experiment was conducted over a 2-year period. Grain feeding significantly (P<0.01) increased average daily gain, carrying capacity and lamb production per acre over the other three treatments. Alfalfa-bromegrass rotationally grazed over three paddocks resulted in significantly (P<0.05) greater lamb production per acre than bromegrass 3X or alfalfa-bromegrass 2X. Daily gain was not significantly affected by plant species or number of rotational paddocks. Bromegrass pasture produced more forage during the second than the first year.

Comparison of the Digestible Dry Matter Harvest from Orchardgrass and Bromegrass Pastures by Grazing Cows ,

Summary A comparison of the yield of total dry matter and digestible dry matter from orchardgrass and bromegrass pasture plots was made during the pasture seasons of 1957 and 1958. Both grass species were seeded at the same time (August, 1955) and given identical subsequent management. The yields were determined by measuring the total harvests grazed by cows for each season. A combination of fecal chromogens and chromium sesquioxide indicators was employed. Determinations of yield were made at approximately 2-wk. intervals throughout the pasture seasons. The yield of dry matter from the bromegrass plots was 85.6 and 85.0% of that from the orchardgrass in 1957 and 1958, respectively. There was also a significant difference in digestibility favoring the orchardgrass. The stand of orchardgrass was maintained well throughout the trials, whereas only a poor stand of bromegrass survived.

Influence of Fertilizers on the Crude Protein Yields of Bromegrass Pasture in the Matanuska Valley

AbstractCrude protein yields of bromegrass pasture were markedly increased by nitrogen fertilizers. This conclusion is based on field trials in the Matanuska Valley of Alaska during 1949, 1950, and 1951. A split‐plot factorial design was used to compare five rates of nitrogen fertilization, spring versus summer nitrogen applications, and three levels of phosphate‐and‐potash applied in a fixed ratio.Each increment of nitrogen, including the highest level (128 pounds of nitrogen per acre) produced highly significant increases in protein yields. Greatest production amounted to 636 pounds of crude protein per acre as compared to unfertilized plots which produced only 100 pounds. Sixfold increases were obtained from heavy fertilization which is economically feasible under present conditions.Significant nitrogen × phosphate‐potash interactions were observed. Early season protein yields are usually increased by phosphate‐potash applications while later clippings are generally not benefitted.Stage of maturity when grazed also determines crude protein yields which are the greatest during the early flowering stage.