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.

Studies of cattle and sheep eating leaf and stem fractions of grasses. 3. The retention time in the rumen of large feed particles

1981 ◽  
Vol 32 (1) ◽  
pp. 123 ◽  
Author(s):  
DP Poppi ◽  
DJ Minson ◽  
JH Ternouth
Keyword(s):  
Particle Size ◽  
Retention Time ◽  
Dry Matter ◽  
Simulation Studies ◽  
Small Particles ◽  
Dry Matter Distribution ◽  
Rhodes Grass ◽  
Large Particles ◽  
Voluntary Intake ◽  
Cattle And Sheep

Pangola grass (Digitavia decumbens) and Rhodes grass (Chlovis gayana) cut as 6 and 12 week regrowths were separated into leaf and stem fractions and fed ad libitum to four cattle and eight sheep fitted with ruminal fistulae to determine the importance of particle size in controlling the retention time of feed in the rumeno-reticulum (rumen). Particle size was determined by using a wet sieving technique, and based on the cumulative dry matter distribution on the sieves of faeces from cattle and sheep; all particles >1.18 mm were described as large particles. The proportion of large particles was measured in the chopped diet offered, the masticated diet, the ruminal contents and the faeces. Chopped leaf and stem fractions contained 0.85 and 0.86 g/g large particles respectively. Mastication by cattle reduced the proportion of large particles in leaf and stem to 0.58 and 0.76 (P < 0.01), and mastication by sheep to 0.56 and 0.67 (P < 0.01). The proportion of large particles in the rumen of sheep was 0.236 and 0.249 for leaf and stem respectively (P > 0.05) and in cattle 0.272 and 0.345 (P < 0.05). The faeces contained relatively few large feed particles (< 0.045 for cattle and <0.018 for sheep). Cattle eating leaf and stem produced faeces containing 0.027 and 0.040 (g/g) large particles (P <0.05), compared with only 0,008 and 0.013 (P < 0.05) in sheep. Most of the large particles entering the rumen in the masticated feed disappeared in the rumen by breakdown to smaller particles or by digestion. In cattle the proportions that disappeared were 0.978 and 0.976 (P > 0.05) for leaf and stem, and in sheep 0.993 and 0.991 (P > 0.05). Large particles in leaf and stem were retained in the rumen of the sheep for 11.0 and 11.7 h (P > 0.05). Cattle retained large particles in all diets for a longer time (P < 0.01); 16.1 h for leaf and 20,2 h for stem (P > 0.05). Differences in retention time of large particles in the rumen did not appear to be the only factor controlling the retention of dry matter in the rumen and voluntary intake. A model was developed to describe the flow of large and small particles through the rumen. Intake simulation studies indicated that the most important factor influencing dry matter retention time in the rumen was the retention time of small particles (> 1.18 mm). Changes in the rate of breakdown of large particles had a small effect on dry matter retention time.

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.

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.

scholarly journals The voluntary intake and digestibility, in sheep, of chopped and pelleted Digitaria decumbens (pangola grass) following a late application of fertilizer nitrogen

1967 ◽  
Vol 21 (3) ◽  
pp. 587-597 ◽  
Author(s):  
D. J. Minson
Keyword(s):  
Organic Matter ◽  
Protein Content ◽  
Retention Time ◽  
Crude Protein ◽  
Dry Matter ◽  
Nitrogen Retention ◽  
Fertilizer Nitrogen ◽  
Food Digestibility ◽  
Voluntary Intake ◽  
Chopped Grass

1. Experiments were conducted with wether sheep in 1964 and 1965 fed pelleted or chopped mature Digitaria decubemes Stent (pangola grass) bay containing different crude protein contents. The voluntary intake of food, digestibility of dry matter and nitrogen, nitrogen retention and apparent time of retention of feed organic matter in the reticulo-rumen were measured. The different crude protein contents of the grass were obtained by applications of urea to the sward 14 and 28 days before cutting for hay in 1964 and 1965 respectively. This treatment increased the crude protein content of the dry matter from 4.9% to 8.7% in 1964 and from 3.7% to 7.2% in 1965. The size of the particles of the ground hay before pelleting is given.2. The mean voluntary intake of chopped fertilized grass was 10% and 54% greater than that of the unfertilized; the voluntary intake of pellets made from fertilized grass was 35% and 75% greater than of those made from the unfertilized grass in 1964 and 1965 respectively.3. The voluntary intake of pellets of unfertilized grass was 7% and 14% greater than that 30% greater than that of chopped fertilized grass in 1964 and 1965 respectively.4. The digestibility of the pellets was less than that of the chopped grass.5. The apparent digestibility of the feed nitrogen was increased by the fertilizer nitrogen, but grinding and pelleting had no consistent effect. Sheep eating chopped or pelleted fertilized hay were in positive nitrogen balance.6. The apparent retention time of organic matter in the reticulo-rumen was longer when the sheep were eating chopped hay than when they were eating pellets. In 1964 the apparent retention time of organic matter in the reticulo-rumen was shorter for chopped and pelleted unfertilized grass than for chopped and pelleted fertilized grass, but in 1965 the order was reversed.7. The relationship between voluntary intake, apparent retention time of organic matter in the rumen and the protein content of the food is discussed.

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.

Studies of cattle and sheep eating leaf and stem fractions of grasses. 2. Factors controlling the retention of feed in the reticulo-rumen

1981 ◽  
Vol 32 (1) ◽  
pp. 109 ◽  
Author(s):  
DP Poppi ◽  
DJ Minson ◽  
JH Ternouth
Keyword(s):  
Rate Constant ◽  
Retention Time ◽  
Water Volume ◽  
Passage Rate ◽  
Mineral Supplement ◽  
Rhodes Grass ◽  
Digestion Rate ◽  
Chopped Grass ◽  
Cattle And Sheep

Pangola grass (Digitauia decumbens) and Rhodes grass (Chlouis gayana) cut as 6 and 12 week regrowths were separated into leaf and stem fractions and fed ad libitum to four cattle and eight sheep fitted with ruminal cannulae. Cattle and sheep ate more of the leaf than of the stem fraction, and this was associated with the shorter time that neutral detergent fibre (NDF) was retained in the rumeno-reticulum (rumen). To study this difference, measurements were made of the retention time of lignin, passage rate of undigested NDF and water from the rumen, ruminal water volume, potential digestibility of NDF and rate of digestion of NDF by means of the nylon bag technique and in vivo techniques. Possible deficiencies of protein and minerals were minimized from this study by feeding casein and a mineral supplement. Lignin was used to measure the time that indigestible feed fractions remained in the rumen. The retention time of the NDF was closely correlated with the time lignin was retained in the rumen (r = 0.93, P < 0.01). This indicated that the longer retention time and lower intake found with the stem fraction was associated with the slower rate of passage of NDF through the reticulo-omasal orifice. The longer retention time of NDF by cattle compared with sheep could also be explained in this way. The passage rate constant for water leaving the rumen was slightly higher for cattle and sheep fed on leaf fractions and lower for cattle compared to sheep on all diets. The flow of water from the rumen through the reticulo-omasal orifice was 25 and 22% (P < 0.05) more for cattle and sheep respectively when they consumed leaf compared to when they consumed stem. The concentration of NDF in water passing through the reticulo-omasal orifice was similar for leaf and stem fractions (26 and 27 gl-1. There was a higher frequency of ventral ruminal sac contractions in sheep fed on leaf compared with those eating stem. The potential digestibility of the NDF was higher for leaf than stem fractions (0.658 v. 0.600, P < 0.05). Rates of digestion of leaf and stem samples in nylon bags suspended in the rumen of cattle were similar. Samples that had been masticated had a higher digestion rate constant than chopped grass (0.0216 v. 0.0159, P < 0.05). Digestion rate constants calculated from a rumen model showed large differences both between leaf and stem (0.0488 c. 0.0305, P < 0.05) and between cattle and sheep (0.0307 v. 0.0486, P < 0.05). It was suggested that the higher digestion rate constant calculated from a rumen model compared with the nylon bag method was due to additional mastication during rumination. It was concluded that the higher voluntary intake and shorter retention time in the rumen of the leaf than of the stem fraction of grasses was associated with an apparent higher rate of digestion of NDF in vivo, the higher rate of passage of the NDF from the rumen and the higher potential digestibility of the leaf. Sheep were found to retain NDF in the rumen for a shorter time than cattle, and this difference also was associated with a higher rate of digestion of the NDF and more rapid rate of passage of the NDF.

The digestibility and intake of six varieties of Rhodes grass (Chloris gayana)

1968 ◽  
Vol 8 (33) ◽  
pp. 413 ◽  
Author(s):  
R Milford ◽  
DJ Minson
Keyword(s):  
Dry Matter ◽  
Dry Matter Intake ◽  
Maximum Difference ◽  
Rhodes Grass ◽  
Dry Matter Digestibility ◽  
Feeding Value ◽  
Chloris Gayana ◽  
Voluntary Intake

The dry matter digestibility and voluntary intake of six varieties of Rhodes grass cut on eight occasions were measured with sheep in metabolism cages. The maximum difference between varieties in digestibility percentage was 2.6 (P<0.01) for monthly regrowths and 1.1 (P<0.05) for older regrowths. The corresponding maximum differences for voluntary dry matter intake (g/W0.75/day) were 2.2 (P<0.05) and 3.5 (P<0.01). The differences in feeding value were therefore small and it was concluded that the chances are not good of selecting Rhodes grass varieties that have a superior feeding value.

scholarly journals Fertilizer calcium as a factor affecting the voluntary intake, digestibility and retention time of pangola grass (Digitaria decumbens) by sheep

1976 ◽  
Vol 36 (2) ◽  
pp. 179-187 ◽  
Author(s):  
M. C. Rees ◽  
D. J. Minson
Keyword(s):  
Body Weight ◽  
Retention Time ◽  
Dry Matter ◽  
Structural Composition ◽  
Digitaria Decumbens ◽  
Ca Deficiency ◽  
Three Stages ◽  
Dietary Components ◽  
Voluntary Intake ◽  
And Control

1. Pangola grass (Digitaria decumbens) grown with and without calcium fertilizer was cut at three stages of regrowth to measure voluntary intake of dry matter (DM) and digestibility of various components of the dried-grass diet by sheep kept in metabolism crates. To determine the extent of a simple Ca deficiency half the sheep on each diet were supplemented with 1·4g Ca/d. Retention times of the various dietary components in the reticulo-rumen were also determined.2. Feeding a Ca supplement had no effect on voluntary intake or digestibility.3. Ca fertilizer increased the Ca content of the grass from 2·2 to 3·8 g/kg DM and DM digestibility from 0·455 to 0·476 (P < 0·01) due to an increase in the digestibility of the hemicellulose.4. Voluntary intake was increased from 38·8 to 43·2 g/kg body-weight0·75 per d by Ca fertilizer due to an 18% reduction in the period of time the DM was retained in the reticulo-rumen.5. Regressions relating voluntary intake to DM digestibility for the Ca-fertilized and control grass were significantly different (P < 0·01). When compared at the same DM digestibility the voluntary intake of the Ca-fertilized grass was 2·6 g/kg body-weight0·75 per d higher than that of the control.6. It was concluded that Ca fertilizer increased both DM digestibility and voluntary intake as a result of changes in the structural composition of the grass and not by a simple increase in the Ca content of the diet.

Effect of leucaena supplementation level, and provision of urea, on utilisation by sheep of Rhodes grass hay

2001 ◽  
Vol 41 (2) ◽  
pp. 155 ◽  
Author(s):  
I. W. Karda ◽  
G. McL. Dryden
Keyword(s):  
Organic Matter ◽  
Rumen Fluid ◽  
Latin Square ◽  
Rhodes Grass ◽  
Microbial Nitrogen ◽  
Grass Hay ◽  
Digestible Organic Matter ◽  
Ruminal Degradation ◽  
Chloris Gayana ◽  
Dietary Treatments

Tarramba leucaena (Leucaena leucocephala cv. Tarramba) foliage had per kilogram dry matter, 169 g protein and 29.8 g condensed tannins. Its value as a supplement, given either with or without urea, to sheep given a low-quality Callide Rhodes grass (Chloris gayana cv. Callide) hay was studied. Six rumen fistulated sheep (mean s.d. liveweight, 34 1.4 kg) were used to compare 6 dietary treatments in an incomplete latin square design. Rhodes grass hay was given ad libitum either alone, or with urea 7 g/day (U), or with leucaena 150 g/day (L150), or leucaena with urea (L150U), or leucaena 300 g/day (L300), or leucaena with urea (L300U). Digestible organic matter intake was increased significantly by leucaena supplementation although digestibility of the whole diet did not alter. Rumen fluid ammonia-N was not altered by leucaena supplementation, but was increased by urea. This suggests that Tarramba foliage protein has some resistance to ruminal degradation. Liquid and solids passage rates were not affected by the treatments. Microbial nitrogen supply to the intestine (g/day), and the efficiency of microbial nitrogen synthesis (g/kg organic matter apparently digested in the rumen), were increased by leucaena supplementation (P<0.01). Microbial protein synthesis was the only response in which 300 g/day air-dry Tarramba foliage gave improved results over 150 g/day.

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