Percentage Crude Fibre Research Articles

Date of Cut vs. the Combination of Crude Fiber and Crude Protein as Estimators of Forage Quality

The relationship of the dates-of-cut of 22 alfalfa and grass hays grown in Delaware with their digestibilities by sheep were calculated to be represented by the regression equations: Ŷ=73.24−.24X±4.18 All hays Ŷ=75.4 7−.30X±3.36 Harvested prior to June 19 Ŷ=percent dry matter digestibility and X= number of days after April 15. The correlation coefficients were r=−.68 and r=−.74, respectively. Relationships were compared for forage quality estimations made by the date-of-cut equation for New York State: Ŷ=85.0−.48X X=number of days after April 10 (Reid et al., 1959) and estimations of TDN content by the equation: Y=percent TDN content, X1=percent digestible protein, and X2=percent crude fiber (Axlesson, 1952); percent digestible protein =0.946 times crude protein −3.52 (Holter and Reid, 1959). Both methods estimated dry matter digestibilities of the Delaware forages fairly well. The differences from the observed digestibility of dry matter with hays harvested within 70 days of April 10 averaged −.1±0.9 and −1.7±0.9 for the two methods, respectively. With the hays used in this study there was no advantage in accuracy of determination of one method over the other. Ease, speed and practicability of determination seem to favor the method of date-of-cut for evaluating quality of forages cut during 70 days after April 10. The knowledge of daily decrease of 0.3 percentage units in dry matter digestibility of first cutting hays will be of practical value in farm extension programs.

The relationship between the cell-wall constituents of roughages and the digestibility of the organic matter

There is a strong correlation between the digestibility of the organic matter and the percentage crude fibre, percentage lignin, and percentage cellulose plus lignin in the foodstuffs examined.There is evidence that the holocellulose and xylan in grasses are different from those in legumes in the extent to which they are digested. It is suggested that this is due mainly to the xylans or hemicellulose fraction in the forages, and may be a reflexion of a different molecular structure for the xylans in either group.Within each group of plants both the holocellulose and xylan percentages are strongly correlated to the percentage digestible organic matter.Excessive heating of hay led to a marked rise in the percentage lignin. This is probably due to the xylans becoming horny and insoluble, therefore being determined as lignin. This also offers an explanation for the decrease in digestibility of the organic matter.

The feed intake and performance of dairy cows fed on cut grass

SummaryIn the years 1959, 1960 and 1961 sections of the College herd of pedigree Guernsey cows were fed indoors on cut grass. The grass, cut twice each day, was fed in excess of appetite.The weight of grass dry matter consumed varied significantly in each year with the percentage of dry matter in the grass. In one year only did the dry-matter consumption vary significantly with the percentage of crude fibre in the grass.The weight of drinking water consumed varied significantly with the percentage of dry matter in the grass. The total water intake, i.e. drinking water plus uncombined water in the grass, remained almost constant at approximately 14 gal per cow per day.The use of a concentrate supplement in 1960 and 1961 produced small increases in yield which were not statistically significant. If, however, the differences recorded were real, then they would have been economic in one year and not in the other.The intake of starch equivalent, calculated from the chemical analyses of the grass, could not be reconciled with the performance of the cows.

SEASONAL PRODUCTIVITY AND CHEMICAL COMPOSITION OF MARSH REED GRASS (CALAMAGROSTIS CANADENSIS) (MICHX.) BEAUV. HARVESTED PERIODICALLY FROM FERTILIZED AND UNFERTILIZED NATIVE SOD

Yields of marsh reed grass from plots in a native wet-meadow cut two to seven times per summer were reduced in relation to yields of plots cut only once at the end of the season, by 15 to 20 per cent with two to four cuttings, by 35 to 45 per cent with five to six cuttings and about 70 per cent by seven cuttings. Fertilizer applications (200 lb./ac., 16-20-0), during the 2 final years of the 3-year study, increased dry matter from recipient plots cur less than five times in 1960, and from all fertilized plots during 1961. Percentage nitrogen declined progressively in forage of first cuttings from June to September but not in the bi-weekly re-growths. There was no appreciable difference in percentage nitrogen attributable to fertilizer but pounds of nitrogen per acre in forage from fertilized plots exceeded the controls, plots harvested for the first time near the end of June and again at the end of the season being greatest in this respect. Fertilizer increased percentage ether extract slightly, approximately doubled the percentage phosphorus, and had no effect on percentage crude fiber and calcium in the samples tested. Percentages of chemical constituents compared favorably with reported data for upland species.

Relation between chemical composition and nutritive value of Uganda grasses.

IN the various regression equations which have been published the relation between the percentage of crude fibre and the digestibility of organic matter was used1–3. Walker and Hepburn3 used the percentages of crude fibre and crude protein to calculate the digestibility of crude protein, while Watson and Ferguson4calculated protein equivalent by using crude protein only. Glover, Duthie and French5 also used percentage crude protein only, although this was later modified by Glover and French6 for cases where there was an abnormal ratio of crude fibre to crude protein by proposing an equation using both crude fibre and crude protein. Watson and Ferguson4 used the percentages of crude fibre and crude protein in their equation for the calculation of starch equivalent, while Mitchell7 and Hallsworth2 used crude fibre only.

CHEMICAL COMPOSITIONS OF NATIVE FORAGE PLANTS IN BRITISH COLUMBIA IN RELATION TO GRAZING PRACTICES

The percentages of crude protein and phosphorus decreased markedly and that of crude fibre increased in all classes of common forage in the southern interior of British Columbia from spring to fall on both grassland and forest ranges. No consistent trend was observed in percentage of total ash or calcium except that calcium increased markedly in weathered forbs both in the grasslands and in the forest. The grasses had a higher percentage of crude fibre than forbs or current shrub growth. The percentages of crude protein, crude fibre and phosphorus in a sedge meadow at a high elevation were all rather low during the grazing period; those of crude protein and phosphorus dropped sharply in mid-September. The chemical analyses indicated that the nutritive level of the range forage is generally satisfactory for livestock production although some winter supplementation, especially of phosphorus, may be necessary under certain conditions.

The effect of stage of maturity on the yield and chemical composition of oats for haymaking

1. Ayr Line Potato oats was studied in the later stages of development for 3 years under upland conditions in Kincardineshire, Scotland. Some major changes in yield and chemical composition of the crop and certain effects of haymaking have been demonstrated.2. In each year, between the ‘milky’ stage and full ripeness of the grain, the growth curve falls into the distinct phases of growth, maturity and senescence when dry-matter loss occurs. The position of the peak yield in terms of stage of maturity varies from year to year.3. Percentage crude protein is low throughout, falling to a minimum after the early ‘milky’ stage and rising again to a maximum at the last cut. Yield of crude protein is highest at the last cut in one year and at the penultimate cut in two years.4. Percentage crude fibre tends to decrease with increasing maturity, while crude fibre yield is low at both extremes of the experimental period.5. More detailed chemical analyses at different stages of maturity show total ash content to be low. The content of calcium is especially poor.6. Separation of the whole of the aerial part of the plant into leaf, stem and inflorescence shows that chemical constituents are being actively re-distributed throughout the plant during the experimental period; with the exception of crude fibre and calcium all constituents estimated tend to be concentrated in the grain with advancing maturity.7. In one year, dry-matter losses during curing range from 22 to 7% at the first and last cuts respectively, while corresponding figures for crude protein are 18 and 10%.8. In the absence of digestibility data and feeding trials under Scottish conditions, the tentative conclusion is drawn that in the higher rainfall areas of the north and west where the crop is most likely to be used, cutting between the late ‘milky’ and late cheesy' stages should give optimum results.9. Attention is drawn to the need for caution in the general application of the results.

The Utilization of Urea Nitrogen by Young Dairy Calves1

Thirty-six, 2-day-old male and female calves (18 Jerseys and 18 Holsteins) were raised to 86 days of age on a limited milk-hay-starter system to study the value of urea as a source of nitrogen for young dairy calves. Three experimental starters were used: Starter 1 (low protein) 6.7% protein; starter 2 (urea supplement) 15.1% protein equivalent; and starter 3 (conventional-protein supplement) 15.2% protein. Urea supplied 54.2% of the nitrogen in starter 2. All groups of calves grew at comparable rates for the first 6 weeks during which time whole milk was being fed. When whole milk feeding was discontinued, the urea-supplemented and conventional-protein groups grew at a significantly faster rate than the low-protein group. These two groups consumed significantly more feed and had significantly higher feed efficiency values than the low-protein group. Differences between the conventional protein group and the urea-supplemented group in average daily gain, starter consumption or pounds of feed required per pound of gain, were not significant. Calves on the low-protein ration digested a significantly smaller percentage of protein and crude fiber and retained less nitrogen than either of the other two groups. Calves on the urea ration digested a lower percentage of crude fiber than those on the conventional protein ration. The results show that a portion of the nitrogen requirements of the young calf can be supplied in the form of urea. Cud inoculation of calves had no value as measured by growth, feed consumption, apparent digestibility or nitrogen retention.

The Apparent Digestibility of the Crude Protein of the Pig Ration as a Function of Its Crude Protein and Crude Fiber Content

Increasing the protein percentage or decreasing the crude fiber percentage of the ration tends to increase the apparent digestibility of protein by pigs. The partial regression coefficients of protein percentage and of crude fiber percentage on apparent protein digestibility are approximately equal. Consequently, if in a practical pig ration the level of protein is three times as large as the crude fiber level, a change of 1 unit in ration crude fiber has 3 times the weight of a 1 unit change in ration protein on the apparent digestibility of protein.

The effect of ground water-level upon productivity and composition of fenland grass

1. Studies were made of the effects of varying ground water-levels upon the productivity and composition of Italian Ryegrass grown on a calcareous light peat in the Fenland area. Six cuts were taken throughout the season at 3 to 4-weekly intervals.2. High ground water-level (approximately 15in. below ground surface) had a very deleterious effect on the total yield of fresh grass and of dry matter. Yields were little more than half of those obtained at medium and low water-levels (24 and 38 in. below ground surface, respectively).3. High water-level apparently interfered with nitrogen metabolism in the soil, and considerably lower percentages of crude protein were found in the grass growing on the high water-level plots than at the other levels. On the other hand, the percentage of crude fibre remained fairly constant for all levels of ground water.4. High water-level also had a depressing effect on the percentage of potassium, magnesium and chlorine in the grass. It had no obvious effect upon the calcium and phosphorus levels in the plants. The silica content of the grass rose steadily as the season advanced, this being most marked on the high water-level plots.5. Physical examination of typical plants showed the effect of the various ground water-levels upon the development of the root systems, with consequent effect upon the chemical composition of the grass.6. The composition of hay and aftermath showed similar changes to those reported for the green herbage.7. The findings are discussed in relation to grassdrying policies in Fenland areas.

Digestibility trials with poultry: The digestibility of dura, carobs and hide-fleshings

Digestibility trials with poultry were carried out with dura, carobs and hide-fleshings.1. Dura equals the feeding value of corn and exceeds that of wheat, barley and oats. The high feeding value of dura is due to the large amount of easily digestible starch, and to the very small percentage of crude fibre.2. Carobs. The main nutrient factor in carobs is represented by the totally digestible sugars contained in the N-free extract. Protein and crude fibre are not digested to any appreciable extent. The feeding value of carobs was compared with that of grain foodstuffs.3. Hide-fleshings are a by-product of the tanneries. They contain 66·25 % of protein, which is digested by poultry like meat-meal protein (89·9 %).The authors wish to thank Mrs Gnessia Rabinovicz for her untiring assistance in the execution of these experiments.

Dehydrated Pea Vines and Starfish Meal in Poultry Feeds

The two entirely unrelated products mentioned in the title were investigated as possible substitutes for alfalfa meal and fish meal, respectively. The dehydrated pea vines, a cannery by-product, were furnished by Charles G. Summers, Jr., Inc., New Freedom, Pennsylvania, and contained 102 p.p.m. of carotene and 23.26 percent crude fiber as compared with 138 p.p.m. of carotene and 20.36 percent fiber in the alfalfa meal used in this experiment.2 The starfish meal was furnished by the Bingham Oceanographic Laboratory of Yale University through the courtesy of Dr. Daniel Merriman. This material has been described in an interim report of the Bingham Laboratory (April, 1943). Typical analyses show 34 percent protein, 16.9 percent calcium, and 0.43 percent phosphorus. In this experiment it was compared with a commercial fish meal (chiefly menhaden) as to its ability to supplement a mash containing no animal protein.Mash 16 has the following composition: ground yellow .

NITRIFICATION UNDER AND AFTER ALFALFA, BROME, TIMOTHY, AND WESTERN RYE GRASS: III. COMPOSITION OF HAY CROP RESIDUES

Proximate analyses of roots (to plow depth) and stubble in one-, three-, and five-year-old sods, considered in relation to sequence effects as judged by the nitrogen absorption of the first two wheat crops after each age of sod, indicated the nitrogen content of the hay crop residues to be the dominant influence. Alfalfa was much superior to the grasses, a result apparently of the higher quantity of nitrogen returned to the soil and of the narrower C:N ratio in its residues. Timothy led the grasses, contributing the highest quantity of nitrogen in residues with the lowest percentage of crude fibre and the narrowest ratio of crude fibre to nitrogen-free extract. Brome contributed more residual nitrogen than western rye, but was slightly inferior in sequence effects.

Nutritive value of pasture: IV. The influence of the intensity of grazing on the yield, composition and nutritive value of pasture herbage (Part II)

The object of this series of investigations is to secure detailed information concerning the composition, digestibility and nutritive value of pasture grass in its different stages of growth. The results which were obtained in these respects by cutting the herbage of the experimental pasture plot at weekly and at fortnightly intervals have been described in previous communications. During the season of the present experiment, the trials have been carried a stage further by the adoption of a system of cutting at 3-weekly intervals. The main findings of the 1928 investigation are recorded below:(1) Chemical composition of 3-weekly pasture cuts: The adoption of a more lenient system of cutting at 3-weekly intervals led to a slight lowering of the percentage of crude protein in the grass and a slight raising of the percentages of crude fibre and N-free extractives. On the other hand, no corresponding effect was noted in respect of the ether extract, SiO2-free ash, lime and phosphate, the percentages of these constituents being very similar in the weekly and 3-weekly pasture samples obtained in 1928. The falling off of the percentage of crude protein in the 1928 3-weekly-mown herbage, as compared with the weekly and fortnightly-mown herbage of 1925 and 1927 respectively, was not wholly the consequence of the more lenient system of cutting, but was also due in part to the protein-depressing influence of the droughty periods which were experienced in the 1928 season.

Nutritive value of pasture. III. The influence of the intensity of grazing on the composition and nutritive value of pasture herbage (Part I)

The present investigation was undertaken with the object of ascertaining the effect of cutting at fortnightly instead of weekly intervals on the yield of pastures, and on the composition, digestibility and nutritive value of the herbage.The main trial was carried out on the 1925 light-land pasture. The plot was divided into 14 sub-plots, and one sub-plot was mown per day. The whole plot, therefore, was cut over once per fortnight during the season. The results in respect of yield, composition and nutritive value were compared with corresponding results obtained on the same pasture plot under a system of weekly cuts during 1925.A second trial was carried out on sub-plots 2 and 3 of the 1926 heavy-land pasture, one sub-plot being cut weekly and the other fort-nightly. The work in this case was restricted to securing comparative data in respect of yield and composition of herbage.The results from both trials lead to the conclusion that the differences in chemical composition, both organic and inorganic, between pasture grass cut at weekly and fortnightly intervals are inconsiderable. The dry matter of the fortnightly-cut grass is extremely rich in crude protein and contains, in comparison with grass cut at the hay stage of maturity, a low percentage of crude fibre. Moreover, these characteristics are retained, by systematic cutting at fortnightly intervals, over the entire season.The results of the digestion trials justify the conclusion that the dry matter of the pasture herbage grown under a system of fortnightly cutting is a protein concentrate equal in digestibility and nutritive value to that obtained by weekly cutting. There is no significant running off in respect of composition and feeding value during the second week of growth. At the end of a fortnight the herbage still consists of the same immature, non-lignified. tissue as it was at the end of a week's growth.