The voluntary intake, digestibility, and retention time by sheep of leaf and stem fractions of five grasses

1973 ◽  
Vol 24 (6) ◽  
pp. 875 ◽  
Author(s):  
MA Laredo ◽  
DJ Minson
Keyword(s):  
Bulk Density ◽  
Retention Time ◽  
Dry Matter ◽  
Bacterial Degradation ◽  
Panicum Maximum ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Chloris Gayana ◽  
Voluntary Intake

Chloris gayana, Digitaria decumbens, Panicum maximum, Pennisetum clandestinum, and Setaria splendida were each cut at three stages of growth, dried, chaffed, and separated into "leaf" and "stem" fractions using a gravity separator. The mean purity of the leaf and stem fractions were 78 and 93%. Each fraction was fed to eight sheep to determine voluntary intake and dry matter digestibility. Mean voluntary intake of leaf was 46% higher than that of stem (57.7 v. 39.6 g/kg0.75), despite a slightly lower dry matter digestibility of the leaf fraction (52.6 v. 55.8%). The higher intake of the leaf fraction was associated (r =0.74, P< 0.01) with a shorter retention time of dry matter in the reticulo-rumen (mean 23.8 v. 31.8 hr), which appeared to be caused by the large surface of the leaf fraction initially available to bacterial degradation (mean 128 v. 41 sq cm/g). Ground leaf and stem samples showed no difference in rate of digestion in vitro since structural differences had been destroyed. The energy required to grind 1 g sample in a laboratory mill was less for leaf than stem (mean 234 v. 411 J/g) with a significant correlation between voluntary intake and grinding energy (r = –0.81). In the past a high voluntary intake has been attributed to a high bulk density, but in this study bulk density of the stem fraction was three times that of the leaf fraction and negatively correlated with voluntary intake (r = –0.70, P< 0,001). It was concluded that different plant fractions may be eaten in different quantities, despite similar dry matter digestibilities, and that in any study of the voluntary intake of roughages it is necessary to determine physical properties of the feed in addition to chemical composition.

Effect of fertilizer nitrogen on digestibility and voluntary intake of Chloris gayana, Digitaria decumbens and Pennisetum clandestinum

1973 ◽  
Vol 13 (61) ◽  
pp. 153 ◽  
Author(s):  
DJ Minson
Keyword(s):  
Dry Matter ◽  
Nitrogen Deficiency ◽  
Growing Season ◽  
Pennisetum Clandestinum ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Feeding Value ◽  
Chloris Gayana ◽  
Voluntary Intake ◽  
High Level

On five occasions during the growing season Chloris gayana, Digitaria decumbens and Pennisetum clandestinum were fertilized with urea at 125 or 500 kg ha-1 and cut after one month's regrowth. The minimum nitrogen level in herbage was 0.96 per cent and hence voluntary intake of these feeds was not limited by a nitrogen deficiency per se. Fertilizing at the high level increased dry matter yield (P < 0.01) and depressed the leaf percentage significantly in C. gayana. Each cut was fed to ten wethers to determine digestibility and voluntary intake. The higher rate of nitrogen fertilizer increased the overall mean dry matter digestibility 2.2 per cent, organic matter digestibility 1.3 per cent and voluntary intake of dry matter 2.3 gWkg0.75 (P > 0.05). Within the harvests significant increases and decreases in digestibility and voluntary intake were found. The direction and magnitude of these changes in feeding value were not correlated with differences in yield, leaf percentage or nitrogen content.

The digestibility and voluntary intake by sheep of six tropical grasses

1972 ◽  
Vol 12 (54) ◽  
pp. 21 ◽  
Author(s):  
DJ Minson
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Grass Species ◽  
Stages Of Growth ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Chloris Gayana ◽  
The Mean ◽  
Voluntary Intake ◽  
The Difference

The digestibility and voluntary intake of Chloris gayana, Digitaria decumbens, Panicimum maximum var tricboglume, Paspalm dilatatum, Pennisetm Clanhtinum, and Setaria splendih were measured with sheep in metabolism pens. All grasses were grown under the same conditions and cut at the same time. Each grass was cut after growing for 28, 70, and 98 days in the summer and then again (except for P. dilatatum) after 42, 70, and 105 days in the following autumn. Four successive 28-day regrowths of each grass (two cuts only for P. dilatatum) were also harvested during the summer. All 55 cuts were artificially dried and fed at the same time, each cut being fed to eight sheep. Differences in dry matter and organic matter digestibility between grass species were relatively small with a maximum mean difference of six digestibility units between S. splendida and P. clandestinzrm. For the 28-day regrowths S. splendida was 5.1 digestibility units higher but with the more mature regrowths the difference was 6.8 digestibility units. The mean voluntary intake of dry matter of S. splendida and P. clandestinum was 9 and 11 per cent lower than that of D. decmbens (P<0.01) with the largest differences in voluntary intake between grasses occurring at the mature stages of growth. Large differences were found between grass species in both the slope and intercept of regressions relating voluntary intake to dry matter digestibility.

scholarly journals The effect of pelleting on the voluntary intake and digestibility of leaf and stem fractions of three grasses

1975 ◽  
Vol 33 (2) ◽  
pp. 159-170 ◽  
Author(s):  
M. A. Laredo ◽  
D. J. Minson
Keyword(s):  
Chemical Composition ◽  
Retention Time ◽  
Mineral Supplement ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Acid Detergent Fibre ◽  
Chemical Factors ◽  
Chloris Gayana ◽  
Voluntary Intake ◽  
Lower Bulk Density

1. Leaf is eaten in greater quantities than stem of similar digestibility. To determine whether this difference is caused by physical or chemical factors, leaf and stem fractions from Digitaria decumbens, Chloris gayana and Setaria splendida were fed ad lib. to sheep in the chopped and pelleted forms. Pellets were made from leaf and stem which had been ground through a screen with 3 mm holes. All sheep received a protein and mineral supplement2. Voluntary intake of chopped leaf was 34% higher than that of the chopped stem fraction (40·3 and 30·0 g/kg body-weight0·75 respectively, P < 0·01) although dry matter digestibility ratios were similar (0·478 and 0·450 respectively, P > 0·05). The higher intake of leaf was associated with a larger surface area (13400 and 5200 mm2/g for chopped leaf and stem respectively), lower bulk density (60 and 180 kg/m3 respectively) and lower neutral-detergent fibre (706 and 724 g/kg respectively), acid-detergent fibre (383 and 413 g/kg respectively) and lignin (42 and 59 g/kg respectively) contents. Chopped leaf was retained in the reticulo-rumen for a shorter time than the stem fraction (19·9 and 26·4 h respectively)3. Grinding and pelleting increased the voluntary intake of the leaf fraction by 88% and the stem fraction by 60%. This increased voluntary intake caused by grinding and pelleting was not accompanied by any significant changes in the chemical composition of the diet. Grinding and pelleting reduced the time that the food was retained in the reticulo-rumen and this change appeared sufficient to account for the observed increases in voluntary intake4. It was concluded that the higher intake of the leaf fraction of grasses is caused by differences in retention time of food in the reticulo-rumen. These differences in retention time are caused by differences in physical properties and not chemical composition.

Studies of cattle and sheep eating leaf and stem fractions of grasses. 1. The voluntary intake, digestibility and retention time in the reticulo-rumen

1981 ◽  
Vol 32 (1) ◽  
pp. 99 ◽  
Author(s):  
DP Poppi ◽  
DJ Minson ◽  
JH Ternouth
Keyword(s):  
Organic Matter ◽  
Retention Time ◽  
Dry Matter ◽  
Digestive Efficiency ◽  
Mineral Supplement ◽  
Rhodes Grass ◽  
Digitaria Decumbens ◽  
Chloris Gayana ◽  
Voluntary Intake ◽  
Cattle And Sheep

Pangola grass (Digitaria decumbens) and Rhodes grass (Chloris gayana) were cut as 6 and 12 week regrowths, dried, chopped, and separated into leaf and stem fractions by using a gravity separator. Each of the eight diets was offered to four cattle and eight sheep fitted with a ruminal cannula to measure voluntary intake and digestibility of the dry matter (DM), organic matter (OM) and neutral detergent fibre (NDF). Possible deficiencies of protein and minerals were minimized in this study by feeding casein and a mineral supplement. The total DM, OM and NDF contents of the rumeno-reticulum (rumen) were measured by manually emptying the rumen and the values used to estimate retention times of DM, OM and NDF. Cattle consumed 35% more leaf than stem fraction. Sheep consumed 21 % more leaf. When the daily voluntary intake was expressed as g/kg0.9 the intake was similar for cattle and sheep. The higher intake of the leaf fraction was associated with the shorter time that it was retained in the rumen of both cattle and sheep. Leaf and stem fractions were digested to the same extent by cattle. There was also no difference in the digestibility of leaf and stem fed to sheep. The digestive efficiency of sheep was 0.033 lower than that of cattle for both DM and NDF. Cattle retained all diets for longer periods in the rumen than did sheep. This difference was associated with the higher digestive efficiency of the cattle. It was concluded that both cattle and sheep consumed more leaf than stem fractions of grasses, and that the higher intake of leaf was associated with the shorter time that it was retained in the rumen and not by differences in digestibility as such.

The voluntary intake and digestibility of diets containing different proportions of legume and mature Pangola grass (Digitaria decumbens)

1967 ◽  
Vol 7 (29) ◽  
pp. 546 ◽  
Author(s):  
DJ Minson ◽  
R Milford
Keyword(s):  
White Clover ◽  
Crude Protein ◽  
Dry Matter ◽  
Protein Deficiency ◽  
Direct Proportion ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Direct Replacement ◽  
Voluntary Intake

Three experiments were conducted with sheep fed ad lib. Digitaria decumbens Stent. (Pangola grass) containing 4.4 per cent crude protein (C.P.) (experiment I), and 3.7 per cent C.P. (experiments 2, 3) and supplemented with 0, 100, 200, 400 g/day lucerne (experiments 1 and 2) and white clover (experiment 3). Both legumes were also fed ad lib. with no grass. 546 The voluntary intake of the grass in experiment 1 decreased at all levels of legume feeding. In experiment 2 the voluntary intake of the grass was increased from 607 to 844 when 200 g of legume was fed, and in experiment 3 from 653 to 843 when 100 g of legume was fed, When the voluntary intake of the grass was not limited by a crude protein deficiency, the legume had a direct replacement effect causing a depression in the voluntary intake of the Pangola grass. The dry matter digestibility increased in direct proportion to the legume percentage of the ration.

Influence of water stress on parameters associated with herbage quality of Panicum maximum var. trichoglume

1975 ◽  
Vol 26 (1) ◽  
pp. 127 ◽  
Author(s):  
JR Wilson ◽  
TT Ng
Keyword(s):  
Cell Wall ◽  
Water Stress ◽  
Dry Matter ◽  
Stem Elongation ◽  
Physiological Age ◽  
Wall Material ◽  
Panicum Maximum ◽  
Dry Matter Digestibility ◽  
Influence Of Water

Plants of Panicum maximum var. trichoglume grown in soil in pots under a controlled environment were subjected to water stress and the effect on forage quality was assessed. Stress was applied as a series of drying and re-wetting cycles, and harvests of total laminae, stem, root, and also specific laminae, were taken 5, 10, 17, 27 and 57 days after the commencement of stress treatment. When compared with control plants of similar chronological age, the dry matter digestibility (estimated by an in vitro technique) of the stressed plants was lower in leaves 4, 6 and 8, similar in total green laminae and in leaves 10 and 12, and higher in stem and dead laminae. The cell wall content of various tissues of the stressed plants was lower than that of the controls. Water stress delayed stem elongation and flowering. It is postulated that stress also delayed the normal ontogenetical changes of the leaves. If comparison was made on a physiological age basis then stress markedly lowered the dry matter digestibility but had little effect on the cell wall content. The broader implication of delayed ontogeny is briefly discussed. The decrease in dry matter digestibility in stressed plants was not associated with changes in the proportions of cellulose, hemicellulose or lignin, but reflected a decline in digestibility of cell wall material.

Effect of partial delignification on the in vitro digestibility of cell wall polysaccharides in Digitaria decumbens (pangola grass)

1978 ◽  
Vol 29 (6) ◽  
pp. 1157 ◽  
Author(s):  
CW Ford
Keyword(s):  
Dry Matter ◽  
Lignin Content ◽  
In Vitro Digestibility ◽  
Sodium Chlorite ◽  
Cell Wall Polysaccharides ◽  
Dry Matter Digestibility ◽  
Digitaria Decumbens ◽  
Total Digestion ◽  
Two Stages

Leaf and stem fractions of Digitaria decumbens (pangola grass) cut at two stages of regrowth (47 and 89 days), were extracted with ether, ethanol and water (100°C) before being partially delignified with sodium chlorite in acetic acid. Delignification reduced the lignin concentrations by 52 and 72% in the 47-day-old leaf and stem, and by 69 and 87% in the 87-day-old leaf and stem. In vitro dry matter digestibility was correspondingly increased, by 17–20% (47-day material) and 28–31% (89-day material). Hemicelluloses were digested to a greater degree than cellulose in the delignified material. The reverse was found in the material prior to delignification. In the hemicelluloses arabinose was always digested to a greater extent than xylose. Polysaccharides from delignified 89-day regrowth leaf and stem tissue were still digested to a lesser extent than those from the 47-day regrowth. Maximum digestibilities estimated for zero lignin content were 96.6, 88.1 and 82.8% for young leaf, young stem-told leaf, and old stem respectively. Thus, while lignin has been shown to be the major factor limiting total digestion of the plant material, other minor factors could not be excluded, particularly in the older tissues.

Experiments on rumen retention time, fermentation rate and dry-matter digestibility in zebu and european-type cattle on a grass hay ration

1960 ◽  
Vol 54 (3) ◽  
pp. 417-420 ◽  
Author(s):  
G. D. Phillips ◽  
R. E. Hungate ◽  
A. MacGregor ◽  
D. P. Hungate
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Rumen Fermentation ◽  
The Other ◽  
Fermentation Products ◽  
Fermentation Rate ◽  
Dry Matter Digestibility ◽  
Two Factors ◽  
High Level

1. Experiments are described in which retention time of digesta in the reticulo-rumen, fermentation rates of rumen contents, and dry-matter digestibilities were studied simultaneously in four grade European and three zebu steers.2. Fermentation rates and rumen retentions were significantly negatively correlated.3. Correlations between digestibility and the other two factors were not significant at a high level.4. The multiple regressions calculated for retention time and fermentation rate were significant at the 5% level and that for digestibility approached this level.5. While only fermentation rates show significant differences for the two types of cattle, the results suggest that grades and zebus differ also in the rate of passage of digesta through the rumen.6. The loss in weight of substrate per unit of fermentation products was measured inin vitroexperiments.7. Using certain assumptions, estimates are made of the extent to which the measured fermentation rates could account for the loss in weight of dry matter during digestion, and are compared with the loss actually found.

Pattern of intake of three roughage diets by non-pregnant, non-lactating Scottish Blackface ewes over a long period and the effects of previous nutritional history on current intake

1978 ◽  
Vol 26 (2) ◽  
pp. 203-215 ◽  
Author(s):  
Janet Z. Foot ◽  
A. J. F. Russel
Keyword(s):  
Food Intake ◽  
Dry Matter ◽  
Tritiated Water ◽  
Live Weight ◽  
Dry Matter Digestibility ◽  
Negative Effect ◽  
Voluntary Intake ◽  
Positive Effect ◽  
Water Space

ABSTRACTThe voluntary intake of two hays and one dried grass by 48 mature non-pregnant Blackface ewes was measured for 33 weeks. The apparent dry-matter digestibility coefficients of the diets in vitro were 59, 61 and 77% respectively for the hays and the dried grass. At the end of the first phase of the experiment each group of 16 ewes was split into two subgroups of five animals, each of which was subsequently given one of the other diets, and one subgroup of six animals which remained on the same diet. Food intake was measured for a further 8 weeks. Body fat was estimated at intervals from tritiated water space.The amount of variation in voluntary food intake that could be attributed to variation in live weight and fatness of the animals and in apparent dry-matter digestibility and cell wall constituents of the diet was calculated for various periods.The range of live weight and fatness increased during the experiment. Initially, and after the change in diets, variation in apparent dry-matter digestibility had an important positive effect on intake, but at the end of the 33-week phase its influence was negligible or, when fat weight was not considered, negative. The negative effect of fat weight on intake increased during the experiment.Within individual diets during short periods of time (1 to 5 weeks) the highest proportions of the variation in intake that could be attributed to variation in live weight and fatness of the ewes were 50, 94 and 65% respectively for the hays and the dried grass. Taking all three diets together all the variables considered could explain 75% of the variation for a few weeks at a time, but for longer periods seasonal influences, and other factors not included among the independent variables, probably operated.

The effect of supplementary and fertilizer sulphur on voluntary intake, digestibility, retention time in the rumen, and site of digestion of pangola grass in sheep

1974 ◽  
Vol 82 (3) ◽  
pp. 419-422 ◽  
Author(s):  
M. C. Rees ◽  
D. J. Minson ◽  
F. W. Smith
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Nutritive Value ◽  
Sulphur Content ◽  
Sulphur Deficiency ◽  
Dry Matter Digestibility ◽  
Sulphur Fertilizer ◽  
Voluntary Intake ◽  
The Difference

SUMMARYPangola grass grown with and without sulphur fertilizer was cut as a 7-week regrowth to measure voluntary intake and digestibility by sheep. To determine the extent of a simple sulphur deficiency half the sheep on each feed were supplemented with 0·6 gsulphur daily. Retention time of feed in the reticulo-rumen and proportion of feed digested anterior to the duodenum was also determined.Sulphur fertilizer increased the sulphur content of the pasture from 0·09 to 0·15%, voluntary intake of dry matter from 44·4 to 64·1 g/kg W0·75/day and dry-matter digestibility from 55·2 to 60·2%. Sulphur fertilizer reduced the retention time in the reticulo-rumen by 16% and increased the extent of dry-matter digestion before the duodenum from 13 to 34%.Feeding a sulphur supplement increased dry-matter digestibility of the low sulphur feed to that found with sulphur fertilized pangola grass but only accounted for 63% of the difference in voluntary intake.It was concluded that fertilizer sulphur leads to large increases in both voluntary intake and digestibility of sulphur deficient grass and that the improvement in nutritive value may be more than can be achieved by feeding a sulphur supplement.

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