scholarly journals The effect of changes in the amount of energy infused as volatile fatty acids on the nitrogen retention and creatinine excretion of lambs wholly nourished by intragastric infusion

1983 ◽  
Vol 50 (2) ◽  
pp. 331-343 ◽  
Author(s):  
F. D. DeB. Hovell ◽  
E. R. Ørskov ◽  
N. A. MacLeod ◽  
I. McDonald

1. The nitrogen balance and creatinine excretion of wether lambs of 30–48 kg, wholly nourished by the intragastric infusion of nutrients, were measured in two experiments. Four lambs were used in each experiment. In Expt 1 a constant amount of casein was infused into the abomasum (640 mg N/kg body-weight (W)0·75 per d) and the amount of volatile fatty acids (VFA) infused into the rumen ranged from 0 to 670 kJ/kg W0·75 per d as six increments. Expt 2 was of similar design but two levels of casein were infused (530 and 1060 mg N/kg W0·75 per d) and, with each level of casein, VFA infused ranged from 0 to 700 kJ/kg W0·75 per d as seven increments.2. Daily creatinine excretion was not constant, but varied between 2-d means with standard deviations of between 7·1 and 16·5% (average 13·1%) of the over-all means. There was an apparent correlation between creatinine excretion and the amount of energy infused in six out of eight lambs. There was no effect of the amount of casein infused.3. In both experiments N balance was negative only when the amount of energy infused was substantially below published values for energy maintenance. In Expt 1, N equilibrium was calculated to be achieved at a gross (VFA plus protein) energy infusion level of 162 (SE 29) kJ/kg W0·75 per d. In Expt 2 it was observed that, at a given level of energy infusion, N retention was greater when the amount of energy had been increased from the previous level, than when it had been decreased.4. It is concluded that the animal appears to allocate available amino acids to protein synthesis, rather than to oxidation, even when in negative energy balance. It is also concluded that the enhanced N retention observed when the amount of energy infused had been increased represented compensation after a period of energy restriction.

1979 ◽  
Vol 41 (3) ◽  
pp. 541-551 ◽  
Author(s):  
E. R. ØRskov ◽  
D. A. Grubb ◽  
J. S. Smith ◽  
A. J. F. Webster ◽  
W. Corrigall

1. Two experiments were conducted with lambs sustained entirely by intragastric infusion of volatile fatty acids (VFA), protein, minerals and vitamins.2. In the first experiment to determine the effects of VFA on nitrogen retention four mixtures of VFA (B, C, D and E) were used containing acetic, propionic and butyric acid in the following molar proportions respectively: 45,45 and 10; 55,35 and 10; 65,25 and 10; 75, 15 and 10.The level of infusion was 836 kJ/live weight0.75 per d and the design was a 4 × 4 Latin square with 14 d periods. There were no significant differences in the N balance between the different mixtures of VFA though mixture B tended to give the highest N retention.3. Thirty-two lambs were used in the second experiment for measurements of heat production in closed- circuit respiration chambers. Six mixtures of VFA were used. These included mixtures B-E from Expt I and in addition two mixtures (A and F) containing acetic, propionic and butyric acid in the following molar proportions respectively: 35, 55 and 10; 85, 5 and 10. The heat production was measured both at 450 and 900 kJ/W0.75 per d, except for mixture F, where it was not possible to achieve a rate of infusion in excess of 675 kJ/W0.75 per d.4. The energy required for maintenance was determined to be 0.45±0.02 MJ/kg live weight0.75 per d regardless of the mixture used.5. The efficiency of utilization for fattening (kf) values for the six mixtures were 0.78, 0.64, 057, 0.61, 0.61 and 0.59 for mixtures A, B, C, D, E and F respectively. Only mixture A was significantly better utilized than the other mixtures. This mixture also gave the most efficient N utilization.6. It is concluded from this evidence that differences in k, for diets normally given to ruminants cannot be attributed to differences in utilization of volatile fatty acids.


1973 ◽  
Vol 13 (63) ◽  
pp. 341
Author(s):  
JP Langlands

The digestibility of wheat and formaldehyde (HCHO) treated wheat and the metabolites formed during their digestion were examined in three experiments. The wheat ranged in nitrogen content from 2.4 to 2.6 g N/100 g organic matter. HCHO treatment had little effect on organic matter digestibility or on the proportions of individual volatile fatty acids (VFA) in the rumen although total VFA concentration and the proportion of organic matter digested in the stomach declined. The effect of HCHO treatment on apparent nitrogen digestibility varied between experiments although N retention and the quantity of nitrogen digested in the intestines were generally increased. The addition of urea to HCHO treated diets had no effect on digestibility, the quantity of N digested in the intestine, the concentration of total VFA or on the proportions of individual acids. Abomasal infusion of L-lysine hydrochloride and DL-methionine induced a small but not significant increase in nitrogen retention.


1992 ◽  
Vol 68 (1) ◽  
pp. 293-303 ◽  
Author(s):  
T. KÖhler ◽  
R. Mosenthin ◽  
M. W. A. Verstegen ◽  
J. Huisman ◽  
L. A. Den Hartog ◽  
...  

The effects of post-valve T-caecum (PVTC) cannulation and end-to-side ileo-rectal anastomosis (IRA) on growth performance, nitrogen retention and intestinal fermentation were measured in growing pigs by comparison with a control group of intact animals. There were no differences between PVTC-pigs and intact pigs in growth performance and N balance. In IRA-animals reduced growth (P < 0.01), less efficient feed conversion (P < 0.01) and decreased N retention (P < 0.001) were found. Indices of fermentation measured in deal digesta of PVTC- and IRA-pigs were considerably different. In IRA-animals the concentration of volatile fatty acids (VFA) was about 112–162 mmol/l, higher (P < 0.001) than in digesta of PVTC-pigs (20–31 mmol/l). The molar proportions of acetate and propionate depended (P < 0.01 and P < 0.001 respectively) on the digesta-collection technique. Concentrations and ratios of VFA measured in PVTC-pigs were similar to reported values. Diaminopimelic acid (DAPA) concentration and N:DAPA ratios measured in digesta were significantly (P < 0.05 and P < 0.001 respectively) different between treatments. All digesta variables measured showed increased microbial activity in digesta of IRA-pigs; thus, an influence on digestibility measurement can be assumed.


1980 ◽  
Vol 94 (1) ◽  
pp. 219-227 ◽  
Author(s):  
C. G. Wernli ◽  
R. J. Wilkins

SummaryGrass silage (21.0 % D.M.) was given ad libitum to sheep together with supplements of rolled barley, dried-grass pellets or dried-grass wafers at 12 and 25 g organic matter (OM)/kg0·75.Intake of silage was greater with supplement at 12 g/kg0·75 but total intake of OM and digestible organic matter (DOM) increased with increasing supplement. Intake of OM was higher with the pellet supplement than with other supplements. Intake of DOM, however, did not differ between the pellet and barley treatments, but was lower with wafers.Concentrations of ammonia and total volatile fatty acids and the molar proportions of butyric and higher volatile fatty acids were higher when silage was supplemented with barley than with dried grass. Mean rumen retention times of silage and of supplement were highest in the barley-supplemented treatments. Dried-grass wafers were retained longer than dried-grass pellets. Supplement treatments did not differ significantly for eating and ruminating times, rumen fluid volume and pH, digestion rate in the rumen and nitrogen retention.At the low supplement rate silage consumption may have been controlled by factors associated directly with the silage, whereas at the high rate intake was limited either by physical factors or by the potential energy demand of the animals.


1973 ◽  
Vol 29 (3) ◽  
pp. 347-355 ◽  
Author(s):  
B. Eskelandt ◽  
W. H. Pfander ◽  
R. L. Preston

1. Glucose, and acetic, propionic and butyric acids, the major energy sources available to ruminants, have been comparatively evaluated as energy sources for growth in lambs. The energy sources were administered intravenously at 2·092 and 2·510 MJ metabolizable energy per 24 h for periods of 9–12 d. Nitrogen was given in excess of requirement so that growth rate was limited by energy, as indicated by the increased N retention after intravenous administration of energy.2. The N-balance results from the trials showed that propionic acid promoted a significantly (P < 0·01) higher N retention than acetic acid. In some of the experiments there were no significant differences between propionic and butyric acids, and in others, no significant differences between acetic and butyric acids. Compared with isoenergetic glucose infusion, all volatile fatty acids were less efficiently utilized than glucose. The mean values for N balance (g/d) were 2·31 during control infusion, 6·53, 5·71, 5·48 and 4·59 during glucose, propionate, butyrate and acetate infusions, respectively.3. All energy sources reduced the faecal N excretion significantly. The greatest reduction was observed during butyrate treatment. The mean values for faecal N excretion (g/d) were 4·24 for control, 4·00 for acetate, 3·89 for propionate, 3·83 for glucose, and 3·76 for butyrate infusion. The reduced faecal N excretion after butyrate infusion partly accounts for the increased N retention with that treatment.


1991 ◽  
Vol 66 (1) ◽  
pp. 83-93 ◽  
Author(s):  
J. B. Schutte ◽  
J. de Jong ◽  
R. Polziehn ◽  
M. W. A. Verstegen

Hemicellulose consists primarily of pentose sugars, joined together in a polysaccharide chain with d-xylose as the most abundant component. Ileal digestibility and urinary excretion of d-xylose and associated effects of this pentose sugar on ileal and faecal digestibility of dry matter (DM), organic matter (OM), gross energy (GE) and nitrogen were studied in pigs. Castrated pigs were prepared with a post-valvular T-caecum cannula to measure ileal digestibility. Faecal digestibility was measured in non-cannulated pigs. d-xylose was given at dietary inclusion levels of 100 and 200 g/kg, and the control sugar, d-glucose, at a rate of 200 g/kg diet. Ileal digestibility of d-xylose as well as that of d-glucose was found to be close to 100%. The presence of d-xylose in the diet decreased ileal digesta pH and increased ileal flow of volatile fatty acids, suggesting the occurrence of microbial degradation of d-xylose in the pig small intestine. In pigs fed on the 100 g d-xylose/kg diet, 44.5% of the d-xylose intake appeared in the urine. This percentage increased significantly to 52.6 when pigs were fed on the 200 g d-xylose/kg diet. Ileal and faecal digestibility of DM, OM, GE and N, as well as N retention, decreased significantly in pigs fed on the 200 g d-xylose/kg diet.


1983 ◽  
Vol 100 (1) ◽  
pp. 63-74 ◽  
Author(s):  
A. G. Kaiser ◽  
D. F. Osbourn ◽  
P. England

SUMMARYThree silages were prepared from a second cut of perennial ryegrass, using additives of 2 l formic acid/t fresh crop together with formaldehyde at either 0, 47 or 100 g/kg crude protein (CP) in the crop. The silages were offered to appetite either alone, or with supplements of maize starch or maize starch + urea, to 18 British Friesian steer calves, half of which were rumen-cannulated. The maize starch and urea supplements were provided at 184·4 and 18·9 g/kg total dietary dry matter (D.M.) respectively.The low contents of volatile fatty acids and ammonia N in each silage indicated that they were well preserved. Formaldehyde treatment reduced protein degradation in the silages and reduced total acid content. There was a small increase in butyric acid content at the low application of formaldehyde, and the content of 2,3·butanediol increased with formaldehyde application.Formaldehyde treatment depressed intake, although the decline at the high level of application was less when calves were given the starch + urea supplement. Supplementation with starch reduced silage D.M. intake, although total D.M. intake was unaffected, and increased digestible organic matter (OM) intake. The addition of urea to the supplement further increased total D.M., digestible OM and digestible energy intakes. The apparent digestibilities of D.M., OM, N, cellulose and energy were depressed by formaldehyde treatment. Starch supplementation increased the apparent digestibility of D.M. and OM but depressed that of N and cellulose. The deleterious effect on cellulose digestibility was most evident at the high application of formaldehyde. Starch + urea supplementation further increased the digestibility of D.M. and OM, and increased N digestibility. Both supplements increased energy digestibility.N retention was improved by formaldehyde treatment, particularly when the starchfurea supplement was provided. Supplementation with starch did not improve the utilization of dietary N, but reduced N retention on the formaldehyde-treated silages.Within the rumen, ammonia-N concentration declined with increasing application of formaldehyde, and was increased by starch + urea supplementation. There was a tendency for the molar proportion of acetate to increase, and that of propionate and butyrate to decrease with increasing application of formaldehyde. Starch supplementation resulted in a small increase in the molar proportion of butyrate.The apparent rate of digestion of silage in nylon bags in the rumen was reduced by the high application of formaldehyde. On this silage diet, rate of digestion was further depressed by supplementation with starch, but improved by supplementation with starch + urea. The apparent rate of digestion was also depressed when a reference silage (the control) was incubated in the rumens of calves on the high formaldehyde silage, indicating that the adverse effect of formaldehyde was partly due to an effect on the rumen environment. However, it is also possible that formaldehyde reacted with cell wall components, inhibiting fibre digestion.It was concluded that formaldehyde treatment, but not starch supplementation.


1970 ◽  
Vol 50 (1) ◽  
pp. 147-155
Author(s):  
J. D. MILLIGAN ◽  
C. M. GRIEVE

Three experiments were conducted with Holstein-Friesian calves to study the effects of diets and early weaning on body growth and development of rumen function. In the first experiment, calves fed restricted levels of milk replacer and a simple calf meal grew as fast to 120 days of age as calves fed high levels of milk replacer or a complex calf meal. When calves were fed a high-energy milk replacer and weaned at 3 weeks of age, feed consumption and growth rate to 120 days of age was comparable with that of calves fed a low-energy milk replacer and weaned at 4 weeks of age. There were no differences in digestibility of the simple and complex calf meals. Apparent coefficients of digestibility of dry matter, nitrogen and gross energy increased slightly between the 5th and 9th weeks; nitrogen retention increased from 14.9 to 29.9%. Concentrations of total volatile fatty acids (VFA) averaged 10.3 and 10.0 mmoles/100 ml rumen fluid at 5 and 9 weeks, respectively, and there were no significant changes in proportions of VFA.In the second experiment, there was no difference in feed consumption or growth rate when calves were fed the simple and complex calf meals in pelleted form.In the third experiment, concentrations of total VFA increased from 2.3 to 12.6 mmoles/100 ml rumen fluid between 6 and 37 days of age. The proportion of acetate decreased from 71.6% at 6 days to 42.9% at 37 days, while molar proportions of propionate and butyrate increased from 19.7 and 4.5% to 37.5 and 12.0%, respectively, for the same period of time. Rumen pH declined as the concentration of volatile fatty acids increased. Blood glucose levels increased from 6 to 55 days of age.


1972 ◽  
Vol 15 (2) ◽  
pp. 157-165 ◽  
Author(s):  
D. Levy ◽  
S. Amir ◽  
Z. Holzer ◽  
H. Neumark

SUMMARYThe performance of Israeli-Friesian male calves on six rations, including two levels (15% and 30%) of ground wheat straw and oatvetch hay in pelleted mixtures, and the same two levels of ground straw in non-pelleted mixtures, was examined.Daily live-weight and carcass gain were higher on the lower level of both roughages. The differences in performance on hay and straw were insignificant. Feed intake was higher on the 15% level of both roughages when pelleted but the energy conversion ratio was higher on pelleted rations of both levels of straw.The dressing percentage was higher for animals on pelleted rations. There was no significant difference in percentage fat trim, percentage bone or percentage saleable meat in the carcasses. There was 20% more kidney, pelvic and cod fat on the lower level of roughage.The digestibility of organic matter was higher on rations with the lower level of roughage, and on the pelleted rations compared with the non-pelleted at equal level of roughage. This was not the case for the digestibility of crude fibre. Nitrogen retention was significantly higher on the lower levels of straw and on the pelleted rations of a similar level, and was higher on hay rations than on straw rations. Ration differences in the molar proportions of volatile fatty acids in the rumen liquor were detected.Pelleting appeared to improve the nutritive value of straw.


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