The voluntary intake, digestibility and retention time by cattle and sheep of stem and leaf fractions of a tropical legume (Lablab purpureus)

1981 ◽  
Vol 32 (2) ◽  
pp. 389 ◽  
Author(s):  
RE Hendricksen ◽  
DP Poppi ◽  
DJ Minson
Keyword(s):  
Rate Constant ◽  
Retention Time ◽  
Volatile Fatty Acids ◽  
Lablab Purpureus ◽  
Passage Rate ◽  
Tropical Forage ◽  
Large Particles ◽  
Voluntary Intake ◽  
A Minor ◽  
Cattle And Sheep

Hay made from the tropical forage legume Lablab purpureus was chopped and separated into leaf and stem fractions by using a gravity separator. Each diet was fed to four cattle and six sheep fitted with rumen fistulae to measure the digestibilities of the dry matter (DM), organic matter (OM) and neutral detergent fibre (NDF), and the retention times of DM, OM and NDF in the rumeno-reticulum (rumen) and the rumen volume. Mean voluntary intake of the DM in the leaf fraction was 79 % higher by cattle and 61 % higher by sheep than the stem fraction, and this appeared to be associated with the shorter time it was retained in the rumen. Both leaf and stem DM were digested to a similar extent by cattle. Sheep digested the leaf fraction to the same extent as cattle. However, the DM digestibility of the stem eaten by sheep was 0,061 lower than that of the leaf fraction (P < 0.05). Cattle retained the DM, OM and NDF in all diets for longer periods in the rumen than did sheep. This difference led to a 48% higher voluntary intake (g(kg body d-1) by sheep. The proportion of large particles that disappeared within the rumen was lower (P < 0.01) for cattle (0.968) than for sheep (0.994). The large particles of the leaf and stem fraction were retained for the same mean time by sheep (5.7 and 5.6 h), which was shorter (P < 0.01) than the corresponding times for cattle (13.8 and 21.6 h). The rate of disappearance of large particles in the rumen appeared to be only a minor factor causing the longer retention time of stem fractions in the rumen. The concentrations of volatile fatty acids and ammonia in the rumen were higher for leaf than stem fractions with no differences between cattle and sheep. The proportion of acetic acid for cattle (0.75) was higher (P < 0.05) than that for sheep (0.69) while the corresponding propionic acid proportions were lower (P < 0.01) in cattle (0.14) compared with sheep (0.19). These differences were associated with a higher passage rate constant for water flowing from the rumen and a higher digestion rate constant in sheep. It was concluded that both cattle and sheep ate more of the leaf than the stem fraction of the legume Lablab purpureus and that the higher intake of leaf was associated with the shorter time that it was retained in the rumen and was not due to differences in digestibility. Cattle had a smaller relative voluntary intake of legume than sheep, a difference that was associated with the longer time that digesta was retained in the rumen.

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.

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.

scholarly journals Resistance of leaf and stem fractions of tropical forage to chewing and passage in cattle

1990 ◽  
Vol 63 (1) ◽  
pp. 105-119 ◽  
Author(s):  
M. N. Mcleod ◽  
P. M. Kennedy ◽  
D. J. Minson
Keyword(s):  
Panicum Maximum ◽  
Lablab Purpureus ◽  
Small Particles ◽  
Tropical Forage ◽  
Large Particles ◽  
The Mean ◽  
Voluntary Intake ◽  
Tropical Forages ◽  
Wet Sieving

The voluntary intake (VI) of separated leaf and stem fractions of a grass and legume (Panicum maximum and Lablab purpureus respectively) was determined using Hereford steers fistulated at the rumen and oesophagus. VI of leaf fractions was higher than that of the stem fraction (8·23 ν. 3·67 kg/d, P < 0·001) while that for the legume diets was higher than for the grass diets (6·65 ν. 5·22 kg/d, P < 0·05). The total number of eating chews per day was higher on the leaf than stem fraction (1·6 × 104 ν. 9·8 × 103, P < 0·05). The mean number of rumination chews (2·4 × 104) was similar (P > 0·05) for all four diets. The mean resistance of large particles (LP, i.e. retained on a 1·18 mm sieve during wet sieving) to breakdown (chews per g LP breakdown) during eating was lower for leaf than stem fractions (8–4 ν 23·7) and lower for the grass than legume diets (10–5 ν 21·6). The mean resistance to breakdown of LP by rumination (chews per g LP breakdown) was lower in leaf than in stem fractions (8·2 ν. 13·2, P < 0·01) and higher in grass than in legume (12·5 ν 9·0, P < 0·05). The resistance of LP to breakdown during rumination was higher than during eating for the grass diets, but was lower for the legume. Fractional passage rates (FPR) of small particles (i.e. passing through a 1·18 mm sieve during wet sieving) from the reticulo-rumen were negatively related to dimensions of particles, with greater ease of outflow for legume than for grass particles of the same length or diameter. When corrected for content of cellulase-indigestible fibre, FPR of small particles of leaf was greater than for small stem particles. It was concluded that VI of tropical forages was associated with the resistance of LP to breakdown by chewing during both eating and rumination and that the patterns of escape of small particles from the reticulo-rumen were only partially explicable in terms of particle dimensions, and that other properties of the particles may be of importance.

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.

Effect of hydraulic retention time on pretreatment of blended municipal sludge

2011 ◽  
Vol 64 (4) ◽  
pp. 967-973
Author(s):  
S. Koyunluoglu-Aynur ◽  
R. Riffat ◽  
S. Murthy
Keyword(s):  
Retention Time ◽  
Volatile Fatty Acids ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Methane Yield ◽  
Municipal Sludge ◽  
Volatile Solids ◽  
Significant Difference ◽  
Autothermal Thermophilic Aerobic Digestion ◽  
Pretreatment Processes

The objective of the present work was to evaluate the effect of hydraulic retention time (HRT) on hydrolysis and acidogenesis for the pretreatment processes: acid phase digestion (APD) and autothermal thermophilic aerobic digestion (ATAD) using blended municipal sludge. The effect of the different pretreatment steps on mesophilic anaerobic digestion (MAD) was evaluated in terms of methane yield, keeping the operating conditions of the MAD the same for all systems. Best operating conditions for both APD and ATAD were observed for 2.5 d HRT with high total volatile fatty acids (tVFA), and the highest methane yield observed for MAD. No significant difference was observed between the two processes in terms of overall volatile solids (VS) reduction with same total HRT. The autothermal process produced heat of 14,300 J/g VS removed from hydrolytic and acetogenic reactions without compromising overall methane yields when the HRT was 2.5 d or lower and the total O2 used was 0.10 m3 O2/g VS added or lower. However, the process needs the input of oxygen and engineering analysis should balance these differences when considering the relative merits of the two pretreatment processes. This is the first study of its kind directly comparing these two viable pretreatment processes with the same sludge.

Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses

1990 ◽  
Vol 50 (3) ◽  
pp. 425-438 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Relationship Of ◽  
The Relationship ◽  
Linear Regressions

ABSTRACTData on individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI) and live weight of steers and data on silage composition including toluene dry matter (TDM), pH, total nitrogen (N), ammonia nitrogen (NH3-N), volatile fatty acids (VFAs), digestible organic matter in the dry matter (DOMD) and neutral-detergent fibre (NDF) obtained from experiments conducted at three sites were used to obtain simple and multiple linear regressions of SDMI on other variables.Live weight accounted for a high proportion of the variation in intake but this effect could generally be removed by scaling intake by live weight raised to the power of 0·75 (M0·75). CDMI was the most important factor affecting scaled intake in mixed diets. TDM, NH,-N and VFAs all had important effects on SDMI. The relationship of SDMI with TDM was curvilinear suggesting that there is little to be gained in intake terms from wilting to TDM above 250 g/kg. The effect of NH3-N appeared to be related more to its correlation with VFAs than with any other nitrogenous constituent while the VFAs appeared to have a direct effect on SDMI. The effects of N and pH on SDMI were generally small. DOMD and NDF had relatively little effect on SDMI. Significant differences in intercepts between sites were found for most relationships although common slopes were often found.

scholarly journals Volatile Fatty Acids and Biomethane Recovery from Thickened Waste Activated Sludge: Hydrothermal Pretreatment’s Retention Time Impact

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1580
Author(s):  
Farokh laqa Kakar ◽  
Ahmed El Sayed ◽  
Neha Purohit ◽  
Elsayed Elbeshbishy
Keyword(s):  
Fatty Acids ◽  
Activated Sludge ◽  
Retention Time ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Hydrothermal Pretreatment ◽  
Waste Activated Sludge ◽  
Optimum Conditions ◽  
Pretreatment Temperature ◽  
Biomethane Production

The main objective of this study was to evaluate the hydrothermal pretreatment’s retention time influence on the volatile fatty acids and biomethane production from thickened waste activated sludge under mesophilic conditions. Six different retention times of 10, 20, 30, 40, 50, and 60 min were investigated while the hydrothermal pretreatment temperature was kept at 170 °C. The results showed that the chemical oxygen demand (COD) solubilization increased by increasing the hydrothermal pretreatment retention time up to 30 min and stabilized afterwards. The highest COD solubilization of 48% was observed for the sample pretreated at 170 °C for 30 min. Similarly, the sample pretreated at 170 °C for 30 min demonstrated the highest volatile fatty acids yield of 14.5 g COD/Lsubstrate added and a methane yield of 225 mL CH4/g TCODadded compared to 4.3 g COD/Lsubstrate added and 163 mL CH4/g TCODadded for the raw sample, respectively. The outcome of this study revealed that the optimum conditions for solubilization are not necessarily associated with the best fermentation and/or digestion performance.

The relationship between apparent retention time in the rumen, voluntary intake, and apparent digestibility of legume and grass diets in sheep

1973 ◽  
Vol 24 (6) ◽  
pp. 889 ◽  
Author(s):  
RF Thornton ◽  
DJ Minson
Keyword(s):  
Organic Matter ◽  
Retention Time ◽  
Daily Intake ◽  
Organic Matter Content ◽  
Matter Content ◽  
Apparent Digestibility ◽  
Jaw Movements ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
The Relationship

Eight grasses and six legumes were fed ad libitum at hourly intervals to wethers fitted with large rumen fistulas to determine voluntary intake, apparent digestibility, and the apparent retention time of organic matter in the rumen, as well as the quantity of rumen digesta and the organic matter content of the rumen digesta. The voluntary intake of legumes was 28% higher than that of equally digestible grasses. This difference was caused by a shorter retention time (17%) and a higher amount of organic matter (14%) in the rumen digesta from legume diets than from grass diets. The weight of wet digesta in the rumen of sheep fed on legumes was 7% lower than from those fed on grass. Neither the quantity of digesta nor the quantity of organic matter in the rumen was related to the voluntary intake, digestibility, or retention time of organic matter in the rumen. Number of jaw movements each day and rate of cotton thread digestion were not related to the retention time of the diets either. Daily intake of digestible organic matter (DOMI, g/day) was closely correlated with retention time (RTOM, hr) for the feeds in this study (r = –0.93) and the same relation applied to both temperate and tropical feeds, viz. DOMI = 1276–50.7 RTOM (r=0.96) Differences in voluntary intake between grasses and legumes were attributed to differences in retention time and the density to which the food was packed in the rumen.

The effect of sucrose on the utilization of straw plus urea diets by sheep

1965 ◽  
Vol 16 (2) ◽  
pp. 159 ◽  
Author(s):  
GJ Faichney
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Body Weight Gain ◽  
Ammonia Nitrogen ◽  
Nitrogen Excretion ◽  
Limiting Factor ◽  
Crude Fibre ◽  
Passage Rate ◽  
Available Energy ◽  
Rumen Nitrogen

An experiment was carried out on sheep to investigate the effect of supplementary energy, in the form of sucrose, on the intake and utilization of a diet of oat straw supplemented with urea. The sucrose supplement had no significant effect on the dry matter intake, although there was a tendency for the intake of straw to decline with an increase in the sucrose supplement. There was no significant effect on the digestibility of dry matter or crude fibre, but the digestibility of crude fibre tended to decrease when the sucrose supplements were fed. This may explain an increase in faecal nitrogen excretion, which was reflected in a significant (P < 0.05) decrease in the apparent digestibility of nitrogen on the diets supplemented with sucrose. There were no significant differences between the diets in rate of passage, rate of cellulose digestion in the rumen, nitrogen balance, body weight gain, rumen pH, or concentrations of volatile fatty acids and ammonia nitrogen in the rumen. It was concluded that the lack of a supplement of readily available energy was not a limiting factor in the sheep's utilization of the diets used.

scholarly journals Effect of Hydrothermal Pretreatment on Volatile Fatty Acids Production from Source-Separated Organics

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 576 ◽  
Author(s):  
Farokh laqa Kakar ◽  
Ehssan Hosseini Koupaie ◽  
Hisham Hafez ◽  
Elsayed Elbeshbishy
Keyword(s):  
Fatty Acids ◽  
Chemical Oxygen Demand ◽  
Retention Time ◽  
Volatile Fatty Acids ◽  
Oxygen Demand ◽  
Hydrothermal Pretreatment ◽  
Soluble Substance ◽  
Pretreatment Temperature

The current study investigates the effect of hydrothermal pretreatment (HTP) on acidification of source-separated organics (SSO) in terms of volatile fatty acids (VFAs) production and solubilization. Temperature and retention time for HTP of SSO ranged from 150 to 240 °C and 5 to 30 min, respectively. The soluble substance after hydrothermal pretreatment initially increased, reaching its peak at 210 °C and then declined gradually. The highest overall chemical oxygen demand (COD) solubilization of 63% was observed at “210 °C-20 min” compared to 17% for raw SSO. The highest VFAs yield of 1536 mg VFAs/g VSS added was observed at “210 °C-20 min” compared to 768 mg VFAs/g VSS for raw SSO. Intensification of hydrothermal pretreatment temperature beyond 210 °C resulted in the mineralization of the organics and adversely affected the process.

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