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 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. 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.

scholarly journals Mathematical modelling of digesta passage rate, mean retention time and in vivo apparent digestibility of two different lengths of hay and big-bale grass silage in ponies

2003 ◽  
Vol 90 (1) ◽  
pp. 109-118 ◽  
Author(s):  
M. J. S. Moore-Colyer ◽  
H. J. Morrow ◽  
A. C. Longland
Keyword(s):  
Retention Time ◽  
Live Weight ◽  
Apparent Digestibility ◽  
Passage Rate ◽  
Faecal Excretion ◽  
Mean Retention Time ◽  
Grass Silage ◽  
Chloride Hexahydrate ◽  
Grass Hay

Welsh-cross pony geldings (about 300kg live weight) were used in a 4×4 Latin square experiment to determine the rate of passage and apparent digestibility of unchopped big-bale grass silage (BBL), chopped big-bale grass silage (BBS), unchopped grass hay (HL) and chopped grass hay (HS) offered at approximately 15g/kg live weight per d. On day 1 of collection weeks, ponies were fed 85g ytterbium chloride hexahydrate-marked feed 1·5h after the morning meal. Total faecal collections commenced 8h later and continued for 168h. Apparent digestibilities of feed DM, organic matter (OM), crude protein (CP, N×6·25), acid-detergent fibre (ADF) and neutral-detergent fibre (NDF) were also determined. Faecal excretion data were subjected to the models of Pond et al. (1988) and digesta mean retention time (MRT) calculated from these models and using the algebraic method of Thielmans et al. (1978). Silage had significantly (P<0·05) higher digestibilities of DM, OM, CP, ADF and NDF than hay; however, chop length had no effect. All the models of Pond et al. (1988) accurately described (R2>0·8) the pattern of faecal marker excretion. MRT of BBL (29·0h)>BBS(27h)>HS and HL (26h). Compartmental analysis using the G3 model of Pond et al. (1988) showed BBL and HS diets had longer MRT in the time-dependent compartment, whereas BBS and HL had longer MRT in the time-independent compartment. Results from this experiment indicate that BBL and BBS are readily accepted and digested by ponies. While Yb is a successful external marker for determining total tract MRT and for modelling faecal excretion curves in horses, the results did not allow any definite conclusions to be drawn on digesta MRT within the different compartments of the equid gut.

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 effect of incubation sequence on in situ degradation of concentrate feed components in the caecum of ponies

1996 ◽  
Vol 1996 ◽  
pp. 97-97
Author(s):  
J J Hyslop ◽  
G J Stefansdottir ◽  
D Cuddeford
Keyword(s):  
Sample Size ◽  
Passage Rate ◽  
Mineral Supplement ◽  
Grass Hay ◽  
In Situ Degradation ◽  
Ad Libitum ◽  
Digesta Passage ◽  
Fixed Times ◽  
Cattle And Sheep

Previous work as shown that incubation sequence has no effect on the degradation profile of feeds in the rumen of cattle and sheep. However, compared to the rumen the equine caecum is small, digesta passage rate through it is fast and total digesta volumes can vary widely. Consequently, this experiment examines the effect of bag incubation sequence on degradation co-efficients in situ in the equine caecum.Four caecally fistulated Welsh cross pony geldings (approx LW 250 kg) were offered ad libitum grass hay (DM: 938, CP: 70; NDF: 728) plus 30 g/h/d of a horse mineral supplement. Duplicate incubation bags (monofilament polyester, 6.5 x 20 cm, 41 um pores, 16 mg/cm2 sample size) containing a commercial horse concentrate (DM: 918, CP:151, NDF: 403) were incubated in the caecum for fixed times according to both a forward (0,3,5,16,8,24,48) or reverse (48,24,8,16,5,3,0) incubation sequence.

Estimating digestibility and faecal output in lambs using internal and external markers

1988 ◽  
Vol 111 (1) ◽  
pp. 19-25 ◽  
Author(s):  
L. J. Krysl ◽  
M. L. Galyean ◽  
R. E. Estell ◽  
B. F. Sowell
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Average Weight ◽  
Adaptation Period ◽  
Passage Rate ◽  
Faecal Output ◽  
Dry Matter Digestibility ◽  
Sorghum Grain ◽  
Internal Markers

SummaryTwenty fine-wool, ruminally cannulated lambs (average weight 45–9 kg) were used in a completely random design to evaluate the ability of three internal markers to predict dry matter digestibility and two external markers to estimate faecal output. Lambs were allotted randomly to one of four diets: 100% prairie hay (PH), 100% lucerne hay (LH), 50% prairie hay:50% sorghum grain (PS) and 50% lucerne hay: 50% sorghum grain (LS). The trial consisted of a 14-day adaptation period followed by a 7-day total faecal collection period. Feed and faecal samples were subjected to 96 h ruminal fluid and 48 h acid-pepsin digestions, followed by extraction with acid detergent (IVADF) or neutral detergent (IVNDF) solution. Dry matter digestibility (DMD) calculated from feed:faeces ratios of IVADF, IVNDF and acid detergent lignin (ADL) was compared with in vivoapparent digestibility. Ytterbium-labelled forage (YLF) and dysprosium-labelled faeces (DLF) were pulse-dosed via ruminal cannulae, and faecal Yb and Dy excretion curves were fitted to a one-compartment, agedependent model for estimation of faecal output, paniculate passage rate (PPR) and mean gastrointestinal retention time. In vivoDMD in lambs fed PH was greater (P <005) than DMD calculated from IVNDF, IVADF and ADL. In lambs fed LH and LS, in vivoDMD did not differ (P >005) from marker estimates. In vivoDMD for lambs fed PS did not differ from IVNDF or IVADF estimates but was greater than (P <005) the ADL estimate. No differences (P> 005) were observed in recovery among the three internal markers for any of the diets. Faecal output for lambs fed PH did not differ {P >005) from marker estimates but was overestimated by 15 to 20% by YLF and DLF. Faecal output for lambs fed LH was similar to the estimate from YLF, but less than (P <0–05) the estimate with DLF. For lambs fed PS, faecal output did not differ from marker estimates, but YLF and DLF values were 16% lower and 17% higher, respectively. No significant differences were observed in actual and estimated faecal output for lambs fed the LS diet. Estimates of PPR with DLF were numerically greater than YLF estimates for all diets except LS. Correspondingly, mean gastrointestinal retention time was less (P <005) for DLF compared with YLF for all diets except LS.

The effect of incubation sequence on in situ degradation of concentrate feed components in the caecum of ponies

1996 ◽  
Vol 1996 ◽  
pp. 97-97
Author(s):  
J J Hyslop ◽  
G J Stefansdottir ◽  
D Cuddeford
Keyword(s):  
Sample Size ◽  
Passage Rate ◽  
Mineral Supplement ◽  
Grass Hay ◽  
In Situ Degradation ◽  
Ad Libitum ◽  
Digesta Passage ◽  
Fixed Times ◽  
Cattle And Sheep

Previous work as shown that incubation sequence has no effect on the degradation profile of feeds in the rumen of cattle and sheep. However, compared to the rumen the equine caecum is small, digesta passage rate through it is fast and total digesta volumes can vary widely. Consequently, this experiment examines the effect of bag incubation sequence on degradation co-efficients in situ in the equine caecum.Four caecally fistulated Welsh cross pony geldings (approx LW 250 kg) were offered ad libitum grass hay (DM: 938, CP: 70; NDF: 728) plus 30 g/h/d of a horse mineral supplement. Duplicate incubation bags (monofilament polyester, 6.5 x 20 cm, 41 um pores, 16 mg/cm2 sample size) containing a commercial horse concentrate (DM: 918, CP:151, NDF: 403) were incubated in the caecum for fixed times according to both a forward (0,3,5,16,8,24,48) or reverse (48,24,8,16,5,3,0) incubation sequence.

scholarly journals Nanocrystal-Loaded Micelles for the Enhanced In Vivo Circulation of Docetaxel

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4481
Author(s):  
Meng Cheng ◽  
Qiaoming Liu ◽  
Tiantian Gan ◽  
Yuanying Fang ◽  
Pengfei Yue ◽  
...  
Keyword(s):  
Thin Film ◽  
Retention Time ◽  
Blood Circulation ◽  
Crystalline State ◽  
Circulation System ◽  
Particle Sizes ◽  
High Pressure Homogenization ◽  
Rapid Dissolution ◽  
Efficient Route

Prolonging in vivo circulation has proved to be an efficient route for enhancing the therapeutic effect of rapidly metabolized drugs. In this study, we aimed to construct a nanocrystal-loaded micelles delivery system to enhance the blood circulation of docetaxel (DOC). We employed high-pressure homogenization to prepare docetaxel nanocrystals (DOC(Nc)), and then produced docetaxel nanocrystal-loaded micelles (DOC(Nc)@mPEG-PLA) by a thin-film hydration method. The particle sizes of optimized DOC(Nc), docetaxel micelles (DOC@mPEG-PLA), and DOC(Nc)@mPEG-PLA were 168.4, 36.3, and 72.5 nm, respectively. The crystallinity of docetaxel was decreased after transforming it into nanocrystals, and the crystalline state of docetaxel in micelles was amorphous. The constructed DOC(Nc)@mPEG-PLA showed good stability as its particle size showed no significant change in 7 days. Despite their rapid dissolution, docetaxel nanocrystals exhibited higher bioavailability. The micelles prolonged the retention time of docetaxel in the circulation system of rats, and DOC(Nc)@mPEG-PLA exhibited the highest retention time and bioavailability. These results reveal that constructing nanocrystal-loaded micelles may be a promising way to enhance the in vivo circulation and bioavailability of rapidly metabolized drugs such as docetaxel.

scholarly journals DIGESTIBLE ENERGY IN FORAGE BYIN VIVOANDIN VITROASSAYS

1970 ◽  
Vol 50 (3) ◽  
pp. 557-562 ◽  
Author(s):  
J. E. TROELSEN
Keyword(s):  
Energy Analysis ◽  
Energy Content ◽  
In Vitro Assay ◽  
Pure Species ◽  
Vitro Assay ◽  
Digestible Energy ◽  
The Relationship ◽  
Cattle And Sheep

Forage of six pure species was harvested for hay at several maturity stages during four years. The digestible energy content of 102 different lots of hay was determined by feeding to four groups of sheep during the same period, and by in vitro digestions and energy analysis of the undigested residues. The relationship between digestible energy content assayed by the two methods was highly significant (r = 0.85) and did not differ between years and species. Exclusion from regression of the hays containing less than 2 or more than 3 digestible kcal/g revealed that the in vitro assay could reproduce the in vivo digestible energy value with a standard deviation of 0.31 in over 70% of the hays. This represented the maturity and quality range of forage commonly fed to cattle and sheep. The in vitro assay therefore appeared promising for commercial quality determinations.

scholarly journals Praziquantel in a Clay Nanoformulation Shows More Bioavailability and Higher Efficacy against Murine Schistosoma mansoni Infection

2015 ◽  
Vol 59 (6) ◽  
pp. 3501-3508 ◽  
Author(s):  
Gina S. El-Feky ◽  
Wael S. Mohamed ◽  
Hanaa E. Nasr ◽  
Naglaa M. El-Lakkany ◽  
Sayed H. Seif el-Din ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Rate Constant ◽  
Elimination Rate ◽  
New Drugs ◽  
Egg Load ◽  
Potential Cost ◽  
Time Curve ◽  
Content Type ◽  
Mmt Clay

ABSTRACTConsideration of existing compounds always simplifies and shortens the long and difficult process of discovering new drugs specifically for diseases of developing countries, an approach that may add to the significant potential cost savings. This study focused on improving the biological characteristics of the already-existing antischistosomal praziquantel (PZQ) by incorporating it into montmorillonite (MMT) clay as a delivery carrier to overcome its known bioavailability drawbacks. The oral bioavailability of a PZQ-MMT clay nanoformulation and itsin vivoefficacy againstSchistosoma mansoniwere investigated. The PZQ-MMT clay nanoformulation provided a preparation with a controlled release rate, a decrease in crystallinity, and an appreciable reduction in particle size. Uninfected and infected mice treated with PZQ-MMT clay showed 3.61- and 1.96-fold and 2.16- and 1.94-fold increases, respectively, in area under the concentration-time curve from 0 to 8 h (AUC0–8) and maximum concentration of drug in serum (Cmax), with a decrease in elimination rate constant (kel) by 2.84- and 1.35-fold and increases in the absorption rate constant (ka) and half-life (t1/2e) by 2.11- and 1.51-fold and 2.86- and 1.34-fold, respectively, versus the corresponding conventional PZQ-treated groups. This improved bioavailability has been expressed in higher efficacy of the drug, where the dose necessary to kill 50% of the worms was reduced by >3-fold (PZQ 50% effective dose [ED50] was 20.25 mg/kg of body weight for PZQ-MMT clay compared to 74.07 mg/kg for conventional PZQ), with significant reduction in total tissue egg load and increase in total immature, mature, and dead eggs in most of the drug-treated groups. This formulation showed better bioavailability, enhanced antischistosomal efficacy, and a safer profile despite the longer period of residence in the systemic circulation. Although the conventional drug's toxicity was not examined, animal mortality rates were not different between groups receiving the test PZQ-clay nanoformulation and conventional PZQ.

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