scholarly journals Digestion of concentrate and of hay diets in the stomach and intestines of ruminants

1968 ◽  
Vol 22 (2) ◽  
pp. 281-290 ◽  
Author(s):  
J. H. Topps ◽  
R. N. B. Kay ◽  
E. D. Goodall ◽  
F. G. Whitelaw ◽  
R. S. Reid

1. Two young steers, aged approximately 6 months and each fitted with a rumen and an abomasal cannula, were used to measure the flow of digesta to the abomasum over periods of 24 h. A diet of concentrates, at two levels, and a diet of hay cubes were given to the steers. Paper impregnated with chromium sesquioxide was inserted into the rumen twice daily.2. The amount of digesta passing to the abomasum and the output of faeces were measured and the values were adjusted to give 100% recovery of chromium sesquioxide. Measurements were also made of concentrations of plasma glucose, of volatile fatty acids (VFA) in both the rumen and abomasal fluid, and of rumen fluid volume and outflow.3. About 60–80% of the digestible dry matter and of the digestible energy of both diets disappeared from the forestomach (reticulo-rumen and omasum). The amounts of starch flowing through the abomasum differed little between diets and ranged from 29 to 77 g daily.4. The volume of rumen fluid did not differ consistently between diets, but the outflow of fluid from the rumen was considerably higher when hay was given.5. Diet had little influence on plasma glucose but affected the concentrations and molar proportions of VFA in the rumen fluid, and to a lesser extent in the abomasal fluid.

1968 ◽  
Vol 22 (2) ◽  
pp. 261-280 ◽  
Author(s):  
J. H. Topps ◽  
R. N. B. Kay ◽  
E. D. Goodall

1. The flow of digesta to the abomasum and through the duodenum and terminal ileum was measured over 24 h periods in sheep. Pelleted diets of concentrates, principally composed of barley, and of poor-quality hay were given. The seven Scottish Blackface ewes studied were all fitted with rumen cannulas, and in addition two had simple abomasal cannulas, one a re-entrant abomasal cannula, two re-entrant duodenal cannulas, and two re-entrant ileal cannulas.2. Paper impregnated with chromium sesquioxide was given twice daily by rumen fistula. The amounts of dry matter, starch, cellulose, total nitrogen and energy passing through the abomasum, duodenum and ileum and the amounts excreted in the faeces were measured. The flows of digesta were adjusted to give 100% recovery of chromium sesquioxide and the extent of digestion in various parts of the alimentary tract was calculated using these adjusted values. Concentrations of glucose in the blood and of volatile fatty acids (VFA) in the rumen were also measured.3. For the concentrate diet, 69% of the digestible dry matter disappeared in the stomach (reticulo-rumen, omasum and abomasum), 17% in the smail intestine and 14% in the large intestine. Values for disappearance of digestible energy were 72% in the stomach, 23% in the small intestine and 5% in the large intestine. Of the 298 g starch fed daily only 6–35 g passed through the abomasum or duodenum and only 1–4 g reached the terminal ileum. The cellulose in the diet was poorly digested.4. For the hay diet, 67% of the digestible dry matter disappeared in the stomach, 22% in the small intestine and 11% in the large intestine. Values for disappearance of digestible energy were 81% in the stomach, 7% in the small intestine and 12% in the large intestine. Of the 33 g of starch consumed daily, from 5 to 13 g passed through the abomasum or duodenum. The cellulose in the hay was 59% digestible and virtually all this digestion took place in the stomach.5. The concentration of VFA and the proportion of propionate in the rumen fluid, 2·5 h after feeding, were considerably greater on the concentrate diet than on the hay diet, but diet had little influence on the concentration of blood glucose.6. The importance of the small amount of starch passing to the sheep's small intestine is discussed.


1987 ◽  
Vol 67 (4) ◽  
pp. 1083-1091 ◽  
Author(s):  
L. R. NDLOVU ◽  
J. G. BUCHANAN-SMITH

Nine lambs fitted with rumen cannulae were used in two 5 × 5 Latin squares to measure the effect of alfalfa hay, C4- and C5-branched- and straight-chain volatile fatty acids (C4/C5 VFAs), cell wall from alfalfa hay (ALFCW) and a soybean protein preparation on intake and rumen digestion of a basal corncob diet with urea included at 30 g kg−1. Relative to the control, alfalfa hay decreased (P < 0.05) intake of the basal diet but increased (P < 0.05) total dry matter intake. ALFCW and soybean protein did not affect intake of the basal diet and total dry matter (P > 0.05). C4/C5 VFAs increased intake of basal diet by sheep in one square (P < 0.05) but had no effect (P > 0.05) on intake with sheep in the other square. Alfalfa hay, ALFCW and soybean protein increased (P < 0.05) total VFA concentration in rumen fluid while only alfalfa hay and C4/C5 VFAs consistently increased isobutyrate, isovalerate and valerate levels in rumen fluid (P < 0.05). In comparison with the control diet, soybean protein elevated (P < 0.05) mean rumen ammonia-N levels whereas C4/C5 VFAs depressed them; however, values exceeded 17 mg dL−1 rumen fluid on all treatments. Most measures of digestion kinetics of fiber from corncobs were unaffected by supplementation (P > 0.05). Alfalfa hay and ALFCW increased (P < 0.05) rate of passage of digesta from the reticulo-rumen. It was concluded that alfalfa hay has a reduced role in improving intake of corncob diets when there is also sufficient NPN in the diet. Key words: Roughage (poor quality), volatile fatty acids, rumen ammonia levels, chromium-mordanted cell walls


1982 ◽  
Vol 99 (1) ◽  
pp. 215-224 ◽  
Author(s):  
J. C. Mathers ◽  
E. L. Miller

SUMMARYTwo experiments were carried out with adult sheep to investigate the effects of chloral hydrate (CH) on rumen metabolism and on the sites and extent of digestion.Experiment 1 confirmed that CH is a very potent methane inhibitor; doses of 1 or 4 g/day reduced methane production to 4% of that observed in the absence of the drug. In both experiments, CH administration altered the proportions of volatile fatty acids in rumen fluid. The main changes were an increase in propionic acid and a decrease in acetic acid with smaller increases in the proportion of isovaleric, valeric and caproic acids. Stoichiometric calculations indicated that only 21% of the hydrogen saved by prevention of methanogenesis was diverted to the synthesis of additional propionic and butyric acids and the fate of the remaining hydrogen was not determined unequivocally.CH had little effect on the extent of biohydrogenation in the rumen of the long-chain fatty acids in dried grass.The apparent digestibility of ether extract was reduced (P< 0·05) by CH but those of other proximate constituents and energy were little affected. There were no s gnificant effects of CH on the extent of digestion of dry matter, organic matter, non-ammonia nitrogen or ash between the mouth and abomasum, abomasum and terminal ileum or ileum and anus.


1972 ◽  
Vol 14 (2) ◽  
pp. 209-217 ◽  
Author(s):  
D. J. Farrell ◽  
K. A. Johnson

SUMMARY1. Six pigs, four with caecal cannulae, were given diets containing 8% or 26% cellulose. Cannulation did not affect the digestibility of dry matter or cellulose.2. Digestibility of cellulose, though variable, was higher for the 8%-cellulose diet.3. Pigs on the 26%-cellulose diet had larger amounts of digesta in the caecum, and lower caecal retention times, than pigs on the 8%-cellulose diet.4. Measurements of production rates of volatile fatty acids in the caecum indicated that only 2·7% and 1·9% of the apparent digestible energy of the 26%- and 8%-cellulose diets respectively came from the acids, and it was concluded that the caecum played only a small role in the breakdown of feed substances.


1981 ◽  
Vol 32 (2) ◽  
pp. 231-233 ◽  
Author(s):  
B. Laksesvela

ABSTRACTWhole, moist barley treated with ammonia (A), whole, untreated barley (WU) and ground barley (G) were fed with hay and a little high protein, mixed concentrate. Digestibilities of dry matter, organic matter and crude fibre, assessed with young adult female sheep, were highest in diet A and lowest in diet G. The digestibilities of dry matter and crude fibre were also higher in diet WU than in diet G. Digestibility coefficients for dry matter and organic matter in barley, calculated by difference, appeared higher in A and in WU than in G. Young female sheep fed on the above diets from the age of 7 to 11 months ate more hay and gained more weight on A than on G; again diet WU was intermediate. Differences also occurred between the three groups as regards volatile fatty acids in the rumen fluid. Sheep on A or WU had a higher pH in the rumen fluid than those on G. Finally, sheep on A gave birth to more offspring than those on WU or G. All these differences were significant.


1995 ◽  
Vol 35 (8) ◽  
pp. 1063
Author(s):  
CC Hoang ◽  
BJ Hosking ◽  
JHG Holmes

Steam-rolled lupins were studied as a cheaper alternative to complex and expensive commercial calf rations for rearing dairy calves. Four diets were fed to 4 groups of 6-8 calves: diet 1, 100% commercial pelletted calf ration (CR), 0% steam-flaked lupins (SFL); diet 2, 67% CR, 33% SFL; diet 3, 33% CR, 67% SFL; and diet 4, 100% SFL. A multimineral salt block and fresh water were available. Calves received milk-replacer (MR) in week 1, MR plus experimental diets in weeks 2-5, then experimental diets plus a small amount of straw in weeks 6-10. Calves grazed fresh pasture in weeks 11-15. Blood and rurnen contents were sampled in weeks 2 (blood only) 4,6 (diets 1-4), 8 and 10 (diets 1-3). In weeks 2-5, calves fed diet 4 ate less than calves fed diets 1, 2 and 3 (SFL 0.38 v. 0.50 kg dry matter (DM)/day, MR 0.47 v. 0.49 kg DM/day; P<0.05), grew less rapidly (0.58 v. 0.66 kg/day, not significant) and lost appetite in weeks 5-7. Feeding diet 4 was abandoned and CR, barley and hay were fed in weeks 8-10. In weeks 6-10, calves ate 2.49 kg DM/day of diets 1, 2 and 3 and grew 0.99 kg/day. Growth rates did not differ, at 0.59 kg/day in weeks 11-15; thus calves fed diet 4 seem to have sustained no permanent injury. Plasma glucose was higher in calves fed diet 4 in week 6 (P<0.05) but otherwise did not differ between diets or ages. Ruminal volatile fatty acids differed between diets only in week 6, when diet 4 resulted in a lower concentration than diets 1, 2 and 3 (95 v. 118 mmol/L), with 54.6 v. 49.9% acetic, 31.0 v. 34.1% propionic, and 8.0 v. 10.7% butyric acids. Plasma acetate increased steadily from 0.23 mmol/L at week 2 to 0.58 mmol/L at week 10 (P<0.05), with no difference between diets. We conclude that SFL can be a satisfactory component of the diet of young calves at up to 67% of the ration, producing calves with sufficiently developed ruminal digestion to permit unsupplemented grazing after 10 weeks of feeding.


Animals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 304 ◽  
Author(s):  
Yiguang Zhao ◽  
Fuguang Xue ◽  
Dengke Hua ◽  
Yue Wang ◽  
Xiaohua Pan ◽  
...  

As the co-enzyme of pyruvate formate-lyase under ruminal anaerobic condition, thiamine plays a critical role in carbohydrate metabolism in dairy cows. The objective of this study was to investigate the impacts of thiamine supplementation on ruminal carbohydrate-active enzymes. Twelve Holstein dairy cows were randomly assigned into three dietary treatments: control diet (CON; 20% starch, dry matter (DM) basis), high-concentrate diet (HC; 33.2% starch, DM basis) and a high-concentrate diet supplemented with 180 mg thiamine/kg DM (HCT; 33.2% starch, DM basis). Dry matter intake and milk production were recorded for 21 days. Rumen fluid samples were collected, and ruminal pH and volatile fatty acids (VFAs) were measured. The metagenome sequencing technique was used to detect the genes in ruminal microorganisms and identify putative carbohydrate-active enzymes. The total abundances of carbohydrate-active enzymes and fiber-degrading enzymes were both reduced by HC with no effect on starch-degrading enzymes compared with CON. However, the fiber-degrading enzymes and starch-degrading enzymes were both increased after thiamine supplementation. These results indicated that 180 mg thiamine /kg DM might effectively improve rumen carbohydrate metabolism through increasing the abundance of ruminal carbohydrate-active enzymes and consequently balanced the rumen volatile fatty acids and rumen pH, providing a practical strategy in preventing subacute ruminal acidosis in cows offered HC.


1976 ◽  
Vol 56 (2) ◽  
pp. 227-232 ◽  
Author(s):  
S. O. THORLACIUS

Manure from a commercial feedlot was dehydrated at an alfalfa dehydration plant. The manure contained, on a dry matter (DM) basis, 14.8% crude protein, 14% ash, 0.83% calcium, 0.69% phosphorus, 30.5% crude fiber, and 2.6% fat. About 45% of the DM in the manure was wheat straw bedding. Each of three pelleted rations: 50% hay 50% barley (HB); 50% manure 50% barley (MB); and 100% manure (M) was fed ad libitum to eight individually penned yearling wethers in a 38-day feeding trial. In addition to the manure pellets, lambs on ration M were fed 200 g/day alfalfa hay until intake of pellets exceeded 600 g/day, and 200 g/day barley during the first 28 days on test. A digestibility trial, five wethers per treatment, was conducted after the 38-day feeding trial. Mean daily DM intake during the feeding trial was 2,054, 1,714, 1,165 (pellets only) g and mean daily gain was 272, 148 and −57 g for rations HB, MB, and M, respectively. The corresponding values were 2,632, 2,277, and 2,050 g for DM intake during the final 10 days of the feeding trial, 62.7, 51.7, and 26.7% for DM digestibility, and 70.9, 62.6, and 42.2 for nitrogen digestibility. Molar percent volatile fatty acids in rumen fluid of lambs on ration M were similar to those normally observed for high roughage rations. Molar percent acetic in rumen fluid of lambs on ration HB was greater (P < 0.05) and percent valeric lower (P < 0.05) than on ration MB. It was concluded that sheep will consume rations containing large amounts of dehydrated manure, but low digestibility of manure severely limits its value as a ration ingredient.


1988 ◽  
Vol 111 (1) ◽  
pp. 147-153 ◽  
Author(s):  
A. Brosh ◽  
I. Choshniak ◽  
A. Tadmor ◽  
A. Shkolnik

SummaryIn Bedouin goats maintained outdoors during the summer, fed lucerne hay and watered once daily, drinking was followed by a 35% increase in rumen fluid volume, with a concomitant drop in osmolality from 300 to 150 m-osmol/kg. When water was provided to these goats only once every 4 days, a three-fold increase in the rumen fluid volume was recorded and osmolality dropped from 360 to 80 m-osmol/kg.Feeding, which was depressed during the hot hours of the day, resumed in the afternoon and was followed by an expansion of rumen fluid volume. This expansion occurred irrespective of drinking and was sustained throughout the night. On the 1st day of water denial it amounted to 40% of the noontime rumen fluid volume and was less pronounced during the rest of the water deprivation period. An evening increase in the concentrations of volatile fatty acids, along with a compatible increase in the osmolality and a drop in the pH, also followed the afternoon resumption of feeding.In goats maintained on wheat straw, drinking as well as feeding time affected the physico-chemical conditions in the rumen to a lesser degree than in goats maintained on lucerne hay.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1247
Author(s):  
Xin Wu ◽  
Shuai Huang ◽  
Jinfeng Huang ◽  
Peng Peng ◽  
Yanan Liu ◽  
...  

The rumen contains abundant microorganisms that aid in the digestion of lignocellulosic feed and are associated with host phenotype traits. Cows with extremely high milk protein and fat percentages (HPF; n = 3) and low milk protein and fat percentages (LPF; n = 3) were selected from 4000 lactating Holstein cows under the same nutritional and management conditions. We found that the total concentration of volatile fatty acids, acetate, butyrate, and propionate in the rumen fluid was significantly higher in the HPF group than in the LPF group. Moreover, we identified 38 most abundant species displaying differential richness between the two groups, in which Prevotella accounted for 68.8% of the species, with the highest abundance in the HPF group. Functional annotation based on the Kyoto Encyclopedia of Gene and Genome (KEGG), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG), and Carbohydrate-Active enzymes (CAZy) databases showed that the significantly more abundant species in the HPF group are enriched in carbohydrate, amino acid, pyruvate, insulin, and lipid metabolism and transportation. Furthermore, Spearman’s rank correlation analysis revealed that specific microbial taxa (mainly the Prevotella species and Neocallimastix californiae) are positively correlated with total volatile fatty acids (VFA). Collectively, we found that the HPF group was enriched with several Prevotella species related to the total VFA, acetate, and amino acid synthesis. Thereby, these fulfilled the host’s needs for energy, fat, and rumen microbial protein, which can be used for increased biosynthesis of milk fat and milk protein. Our findings provide novel information for elucidation of the regulatory mechanism of the rumen in the formation of milk composition.


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