scholarly journals The effect of drying and ensiling grass on its digestion in sheep

1971 ◽  
Vol 26 (2) ◽  
pp. 123-134 ◽  
Author(s):  
D. E. Beever ◽  
D. J. Thomson ◽  
E. Pfeffer ◽  
D. G. Armstrong
Keyword(s):  
Small Intestine ◽  
Digestive Tract ◽  
Terminal Ileum ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Proximal Duodenum ◽  
Fresh Frozen ◽  
Gross Energy ◽  
Water Soluble Carbohydrate

1. The effect of drying and ensiling ryegrass on the site of digestion of the energy andcarbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.2. The sheep were given fresh (frozen) grass, dried grass, wilted and unwilted silage pre-pared from herbage harvested from the same sward. The grass diets were offered twice dailyto each animal and paper impregnated with chromium sesquioxide was administered twicedaily into the rumen. Twenty-four hour collections of duodenal and ileal digesta, adjusted togive 100 yo recovery of Cr2O3, were analysed to determine the extent of digestion in the fore-stomachs, the small intestine and the caecum and colon.3. Total digestibility of the gross energy was similar for the fresh grass, dried grass andwilted silage diets (67·4,68·1 and67·5 %)but higher for the unwilted silage (72·0 %, P < 0·01).There was an increased flow of energy into the small intestine when the sheep were given driedgrass and unwilted silage. The proportion of the apparently digested energy lost within thesmall intestine was greater when the dried grass was given (302 yo) than when the fresh grasswas given (23·6 yo).4. Drying or ensiling of wilted material affected digestion neither in the entire alimentarytract nor in the different sections of the tract, of some carbohydrate fractions. About 97 yo ofthe digested water-soluble carbohydrate, over 90 yo of the digested cellulose and over 70 yo ofthe digested hemicellulose were digested before reaching the small intestine. The increasedamount of energy entering the duodenum of the sheep given the dried grass was notaccounted for by changes in the fate of these carbohydrate fractions in the digestive tract. Withunwilted silage, digestibilities of the cellulose and hemicellulose fractions were higher, andlower proportions of the digested carbohydrates were lost before the small intestine.

Quantitative digestion of fresh herbage by sheep:V. The digestion of four herbages and prediction of sites of digestion

1979 ◽  
Vol 92 (3) ◽  
pp. 605-616 ◽  
Author(s):  
M. J. Ulyatt ◽  
A. R. Egan
Keyword(s):  
Organic Matter ◽  
Small Intestine ◽  
Organic Acids ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Crude Protein ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Water Soluble Carbohydrate ◽  
Dietary Origin

SUMMARYThe extents and sites of digestion of organic matter (OM), and its constituent watersoluble carbohydrates, organic acids, pectin, cellulose, hemicellulose and crude protein have been studied in sheep prepared with re-entrant duodenal cannulas and fed four fresh herbage diets, Ruanui perennial ryegrass, Tama Westerwolds ryegrass, Pitau white clover and Fakir sainfoin, at each of two levels of intake.The water-soluble carbohydrate, organic acids and pectin of all diets were almost completely digested within the rumen. Some 10% of water soluble carbohydrate reached the duodenum on each diet, though this may not have been of dietary origin. Only on legume diets, where pectin concentration was higher, did measurable amounts of pectin reach the intestine, accounting for some 5% of the pectin.Hemicellulose and cellulose digestibilities differed between diets, being lowest for sainfoin, and next lowest for clover. Between 79 and 94% of digestible hemicellulose was digested in the stomach, but diet and intake had no significant effect on this partition. Of the digestible cellulose, 87–97% was digested in the stomach.Digestibility of N was lowest for sainfoin and highest for Tama ryegrass. There were no significant differences between herbage species or intake in the percentage of digested N digested in the stomach or intestines. The tannin contained in sainfoin had no effect on nitrogen digestion.Data from this and other studies reported in the literature were examined as a basis for establishing prediction equations whereby the partition of digestion of the major carbohydrate and nitrogenous constituents in stomach and intestines might be estimated from data obtainable from standard digestibility trials. Regressions were developed for predicting the amounts of OM, cellulose, and hemicellulose digested in the stomach. There are not yet enough suitable data available to predict the amount of nitrogen entering the small intestine.

The effects of feeding grass silage and molassed sugarbeet pulp either separately or as an ensiled mixture to twin-bearing ewes

1998 ◽  
Vol 130 (2) ◽  
pp. 217-227 ◽  
Author(s):  
J. V. O'DOHERTY ◽  
P. NOWAKOWSKI ◽  
T. F. CROSBY
Keyword(s):  
Crude Protein ◽  
Body Condition Score ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Condition Score ◽  
Acid Detergent Fibre ◽  
Gross Energy ◽  
Farm Scale ◽  
Soyabean Meal ◽  
Water Soluble Carbohydrate

First-harvest, precision-chopped Lolium perenne grass with a dry matter (DM) content of 132·0 g/kg and water-soluble carbohydrate (WSC) and crude protein (CP) contents of 24 g/kg and 106 g/kg DM, respectively, was ensiled in farm scale silos following the addition of formic acid (FA) (2·5 l/t) or molassed sugarbeet pulp (MSBP) (50 kg/t). Mature twin-bearing ewes (n=56) were allocated to one of seven treatments and offered either FA-treated silage or MSBP silage ad libitum. The trial commenced on day 91 of pregnancy, when the ewes were offered FA-treated silage (T1), FA-treated silage+soyabean meal (T2), MSBP silage (T3), MSBP silage+soyabean meal (T4), FA-treated silage+MSBP (T5), FA-treated silage+MSBP+soyabean meal (T6) or FA-treated silage+a barley-based supplement (150 g CP per kg DM) (T7, control). Soyabean meal supplementation was only offered in the last 3 weeks of pregnancy, with the objective of achieving a total CP intake of 220 g/ewe per day. Compared with the FA-treated silage, the MSBP silage had a higher nitrogen content (P<0·01) and a lower neutral detergent fibre (NDF) content, but the two silages did not differ in DM, acid detergent fibre (ADF) or gross energy contents. Silage DM intakes (SDMI) were higher on the MSBP silage-based diets (T3, T4) than for any other treatment (P<0·05). The addition of soyabean meal significantly increased SDMI in T2 in the last week of pregnancy (P<0·05), but there was no response in SDMI to soyabean meal supplementation in any of the other treatments. Ewe liveweight changes (kg) of −0·4, 4·1, 7·8, 10·2, 7·1, 9·6 and 10·8 (S.E.±1·2), body condition score changes of −0·96, −0·59, −0·42, −0·33, −0·37, +0·01 and −0·27 (S.E.±0·1) and total lamb birth weights (kg) of 8·0, 8·7, 9·2, 9·9, 8·6, 8·0 and 10·4 (S.E.±0·5) were recorded for ewes in T1 to T7 respectively.

scholarly journals Studies on intestinal digestion in the sheep

1969 ◽  
Vol 23 (2) ◽  
pp. 377-387 ◽  
Author(s):  
J. C. Macrae ◽  
D. G. Armstrong
Keyword(s):  
Small Intestine ◽  
Large Intestine ◽  
Terminal Ileum ◽  
Dry Matter ◽  
Alimentary Tract ◽  
Crude Fibre ◽  
Proximal Duodenum ◽  
Glucose Polymer ◽  
Gross Energy ◽  
Almost All

1. In seven experiments sheep were given diets ranging from all-hay to all-barley, and also a diet comprising one part hay to two parts flaked maize. Each sheep was equipped with a cannula into the rumen and a re-entrant cannula in the proximal duodenum; six of the ten also had a re-entrant cannula in the terminal ileum. Paper impregnated with chromic oxide (Cr2O3) was given twice daily by rumen fistula.2. Amounts of α-linked glucose polymer entering and leaving the small intestine and excreted in the faeces were measured. Some values for a fraction designated non-glucose reducing polymer for cellulose and for gross energy were also obtained. The amounts passing the proximal duodenum and the terminal ileum were adjusted to give 100% recovery of Cr2O3 and the values were used to measure the extent of digestion in various parts of the alimentary tract.3. When rolled or whole barley was given alone or was the major feed constituent the amount of α-linked glucose polymer entering the small intestine was 6.0±0.76% of that ingested (range 2.6–8.1%). The value was significantly lower than that found for the diet of hay and flaked maize (10.4±1.3%, range 8.0–13.6 %).The α-linked glucose polymer which entered the small intestine was almost completely digested there.4. The digestibility of the non-glucose reducing polymer, which included much of the hemicelluloses present, ranged from 51 to 73% and almost all the digestible fraction (93–97%) was digested before the small intestine when hay or predominantly hay diets were given. On high-cereal diets only 71–85% of the digested fraction disappeared before the small intestine and appreciable amounts were digested in the large intestine.5. On the all-hay diet 91% of the digestible cellulose and 67% of the digestible energy were lost before the small intestine, 0 and 21% in the small intestine and 9 and 12% in the large intestine.6. Mean digestibility coefficients determined in sheep fed solely on either whole or rolled barley were: for dry matter 88.1 and 87.9%, for nitrogen 83.5 and 82.1%, for crude fibre 53.7 and 56.6% and for gross energy 87.7 and 88.0%.

scholarly journals The effect of forage species and stage of harvest on the processes of digestion occurring in the rumen of cattle

1986 ◽  
Vol 56 (2) ◽  
pp. 439-454 ◽  
Author(s):  
D. E. Beever ◽  
M. S. Dhanoa ◽  
H. R. Losada ◽  
R. T. Evans ◽  
S. B. Cammell ◽  
...  
Keyword(s):  
Small Intestine ◽  
White Clover ◽  
Live Weight ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Late Season ◽  
Forage Species ◽  
Water Soluble Carbohydrate ◽  
Microbial N

1. Pure swards of perennial ryegrass (Lolium perenne L. cv. Melle) or white clover (Trifolium repens L. cv. Blanca) were harvested daily as either primary growth (May-June) or mid- (July) and late- (August-September) season 4-week regrowths and offered to Friesian steers at two levels of feed allowance (18 and 24 g dry matter (DM)/kg live weight), to examine the effect of forage species and stage of harvest on nutrient digestion and supply.2. The early- and mid-season grasses had low nitrogen (23 g/kg DM) and high water-soluble carbohydrate (169 g/kg) contents whilst the late-season grass had a higher N content (28 g/kg). All clover diets had high N (average 45 g/kg) and low water-soluble carbohydrate (89 g/kg) contents, and DM digestibility on all diets ranged from 0.77 to 0.83 (mean of two feeding levels).3. Mean total rumen volatile fatty acid concentrations were significantly (P < 0.001) higher on the clover diets, whilst on the grass diets molar proportions of propionate showed a slight but not significant decline with advancing season and tended to be higher than those on the clover diets. Mean rumen ammonia concentrations were significantly (P < 0.001) lower on the early- and mid-season grasses (59 mg NH3-N/1) than the late-season grass (242 mg/l) and early-season clover (283 mg/l) which were all significantly (P < 0.01) lower than the mid-and late-season clovers (372 and 590 mg/l) respectively.4. Rates of organic matter (OM) and N digestion in the rumen were estimated using established nylon-bag techniques and found to be high on all diets, but significant effects due to forage species (clover > grass; P < 0.001) were detected, whilst overall potential degradability in the rumen exceeded 0.89 for both OM and N on all diets.5. Significantly (P < 0.001) more OM entered the small intestine of calves fed on white clover (10.2 g/kg live weight) than those fed on ryegrass (8.33 g/kg) and similar effects due to level of feeding (g/kg; low 7.9, high 10.6; P < 0.05) and stage of harvest (g/kg; early 8.3 v. mid 10.0, late 9.50; P < 0.05) were also detected. Non-NH3-N (NAN) flow (g/kg) to the small intestine was increased by forage species (grass 0.56, clover 0.69; P < 0.05) and stage of harvest (early 0.59 v. mid 0.65, late 0.64; P > 0.05) whilst NAN flow/N intake ranged from 0.96 to 1.65 g/g (mean 1.25) on the grass diets and from 0.64 to 0.84 g/g (mean 0.75) on the clovers (P < 0001).6. Microbial N flow to the small intestine averaged 0.72 of duodenal NAN (grass 0.76, clover 0.69). Efficiency of microbial N synthesis was high on all diets, (g/kg OM truly digested in the rumen; grass 33.5, clover 36.3), as was the estimated extent of in vivo feed N degradation (g/g N intake; grass 0.75, clover 0.79).7. A model is described to simulate the progress curves of the ratio, degraded N:degraded OM in the rumen for the six diets, using indices obtained in the present study. The results are ratified with the in vivo observations of N utilization in the rumen for the grass and clover diets.8. It is concluded that both forage species and stage of harvest can significantly influence the processes of rumen digestion and nutrient supply, but with the fresh forages examined in the present study, it would appear that the processes of digestion in the rumen greatly outweighed the passage of potentially digestible nutrients from the rumen.

Rumen metabolism and nitrogen flow to the small intestine in steers offeredLolium perennecontaining different levels of water-soluble carbohydrate

2002 ◽  
Vol 74 (3) ◽  
pp. 587-596 ◽  
Author(s):  
M. R. F. Lee ◽  
L. J. Harris ◽  
J. M. Moorby ◽  
M. O. Humphreys ◽  
M. K. Theodorou ◽  
...  
Keyword(s):  
Small Intestine ◽  
Dry Matter ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Total N ◽  
Dry Matter Digestibility ◽  
Rumen Metabolism ◽  
And Control ◽  
Water Soluble Carbohydrate

AbstractEight Hereford ✕ Friesian steers were used to investigate the effect of feeding Lolium perenne (L) forage containing elevated levels of water-soluble carbohydrate (WSC) on rumen metabolism and nitrogen (N) absorption from the small intestine. The steers were offered ad libitum access to one of two varieties with matched heading dates (Ba11353, high WSC, HS; AberElan, intermediate WSC, control) cut at different times of the day to accentuate WSC differentials, zero-grazed for 21 days. This was followed by a 14-day period where the animals were on grass silage to provide a covariate intake. Although the total N concentration was similar for the two grasses, all other measured values were significantly different. The dry matter (DM) concentration of HS was greater than that of the control (202 v. 167 g DM per kg; P 0·01). WSC and in-vitro dry matter digestibility (IVDMD) were 243 and 161 g/kg DM, and 0·61 and 0·56 for HS and control, respectively. In contrast, acid- and neutral-detergent fibre were 251 and 296 g/kg DM and 480 and 563 g/kg DM for HS compared with control, respectively. DM intake was increased (9·3 v. 6·7 kg/day; P 0·001) for HS animals and this contributed significantly towards higher flows of non-ammonia N to the duodenum as well as increased absorption of amino acids from the small intestine. This DM intake response was partly due to the elevation in DM concentration of HS. However fresh weight intake was increased proportionately by ca. 0·15 (P 0·05) in animals on HS compared with control. Rumen ammonia levels were lower (14·0 and 26·4 mg N per l; P 0·001) and concentrations of rumen propionate higher (P 0·01) and acetate lower (P 0·01; increasing the glucogenic: lipogenic volatile fatty acid ratio) in animals on HS compared with control. However, the efficiency of microbial protein synthesis (15·9 and 17·8 g microbial nitrogen per kg organic matter apparently digested) and flow of N to the duodenum per unit N intake (0·84 and 0·93) for HS and control, respectively, were similar across both diets.

scholarly journals Studies on the flow of zinc, cobalt, copper and manganese along the digestive tract of sheep given fresh perennial ryegrass, or white or red clover

1975 ◽  
Vol 34 (1) ◽  
pp. 73-82 ◽  
Author(s):  
N. D. Grace
Keyword(s):  
Small Intestine ◽  
Digestive Tract ◽  
Large Intestine ◽  
Perennial Ryegrass ◽  
Terminal Ileum ◽  
Dry Matter ◽  
Red Clover ◽  
Chromic Oxide ◽  
Proximal Duodenum ◽  
Cobalt Copper

1. Sheep fitted with a rumen fistula and either a re-entrant cannula at the proximal duodenum or a re-entrant cannula at the terminal ileum were given twice daily 480–520 g dry matter as fresh perennial ryegrass, or white or red clover. Flows of digesta were corrected to 100% recovery of chromic oxide.2. The quantities (g/24 h) of zinc and cobalt leaving the stomach were significantly greater than those in the food. No significant change was found in the quantities of copper and manganese. Significantly smaller quantities of Co (all three diets) and Zn (all diets except red clover) left the small intestine than those which entered this region. No significant differences in the quantities of Cu and Mn entering and leaving the small intestine were found. Significantly smaller quantities of Zn, Co, Cu and Mn were excreted in the faeces than entered the large intestine.3. From the flow results it was determined that there was a significant net secretion of Zn and Co in the stomach, and a significant net absorption of Zn (except with the red-clover diet) and Co from the small intestine, and of Zn, Co, Cu and Mn from the large intestine.

Comparison by direct animal calorimetry of the net energy values of an early and a late season growth of herbage

1966 ◽  
Vol 8 (1) ◽  
pp. 13-27 ◽  
Author(s):  
J. L. Corbett ◽  
J. P. Langlands ◽  
I. McDonald ◽  
J. D. Pullar
Keyword(s):  
Freeze Drying ◽  
Volatile Fatty Acids ◽  
Water Soluble ◽  
Soluble Carbohydrate ◽  
Net Energy ◽  
Botanical Composition ◽  
Gross Energy ◽  
Metabolisable Energy ◽  
The Difference ◽  
Water Soluble Carbohydrate

1. Herbage was harvested from a single pasture in early June and late August of the same year and was preserved by freeze-drying. The June herbage contained more water-soluble carbohydrate than that cut in August but in other respects, including chemical and botanical composition and the apparent digestibility of organic matter and nitrogen, differences between the herbages were small.2. The June herbage was given to a mature ewe during eight periods each of about 4 weeks' duration, and the August herbage was given during nine periods. The level of feeding varied between periods from about 0·35 to 1·5 times the maintenance level; in addition the fasting metabolism of the sheep was determined on three occasions. Gross energy intakes and the losses of energy in faeces, urine, methane and as heat were measured in each period.3. The metabolisable energy of the June herbage was utilised more efficiently than that of the August herbage for fattening, and probably for maintenance also. It is suggested that this result stemmed from the difference in soluble carbohydrate content which was lower in the August material. The cellulose of that herbage was digested to a significantly greater extent, a larger proportion of the gross energy was lost as methane, and the ruminai volatile fatty acids, included a significantly lower proportion of propionic acid.

Characterisation of the WSC fraction of six species of temperate pasture grass

2004 ◽  
Vol 32 ◽  
pp. 247-248
Author(s):  
J. C. Ince ◽  
A. C. Longland ◽  
A. J. Cairns ◽  
M. Moore–Colyer
Keyword(s):  
Perennial Ryegrass ◽  
Water Soluble ◽  
Italian Ryegrass ◽  
Soluble Carbohydrate ◽  
Meadow Fescue ◽  
Pasture Grass ◽  
Pasture Grasses ◽  
Optimal Health ◽  
Water Soluble Carbohydrate ◽  
Field Plots

The carbohydrate (CHO) fraction of pasture grasses is a major source of energy for many domestic herbivores. However, the amounts, and types, of the water–soluble carbohydrate (WSC) fraction (i.e. glucose, fructose, sucrose, and polymers of sucrose and fructose, the fructans) present in such grasses, varies with species and environmental conditions. As the WSC constitute a highly digestible, energy yielding fraction of grasses, it is important to be able to measure their levels in a sward so that the diets of pastured animals may be designed to elicit optimal health and productivity. The aim of this study was to characterise the WSC profile of six UK pasture grasses, and to develop a technique for extracting the fructan portion of the WSC.Six species of UK pasture grasses [Cocksfoot (C), Timothy (T), Meadow Fescue (M), Italian Ryegrass (IR), Perennial Ryegrass (PR) and Hybrid Ryegrass (HR)] were grown in experimental field plots at IGER.

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