scholarly journals Efficiency of utilization of volatile fatty acids for maintenance and energy retention by sheep

1979 ◽  
Vol 41 (3) ◽  
pp. 541-551 ◽  
Author(s):  
E. R. ØRskov ◽  
D. A. Grubb ◽  
J. S. Smith ◽  
A. J. F. Webster ◽  
W. Corrigall
Keyword(s):  
Fatty Acids ◽  
Butyric Acid ◽  
Heat Production ◽  
Volatile Fatty Acids ◽  
Latin Square ◽  
Nitrogen Retention ◽  
Live Weight ◽  
N Retention ◽  
N Utilization ◽  
Energy Retention

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.

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
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Nitrogen Retention ◽  
Negative Energy ◽  
Energy Restriction ◽  
Creatinine Excretion ◽  
N Retention ◽  
Protein Energy ◽  
Apparent Correlation ◽  
Energy Maintenance

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.

Experiments on the nutrition of the dairy heifer. XI. Further observations on the effect of energy intake on protein utilization

1978 ◽  
Vol 91 (2) ◽  
pp. 399-413 ◽  
Author(s):  
W. H. Broster ◽  
T. Smith ◽  
J. W. Siviter ◽  
E. Schuller ◽  
Valerie J. Broster
Keyword(s):  
Weight Gain ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Live Weight ◽  
Regression Equations ◽  
N Retention ◽  
Live Weight Gain ◽  
N Utilization ◽  
Digestible Organic Matter ◽  
Dry Food

SUMMARYFive experiments were made to observe the effect on nitrogen (N) utilization by young cattle of supplements of sucrose, glucose monohydrate (dextrose), and maize starch when added to basal diets of concentrates and straw. The supplements provided about 12% of the total intake of air-dry food. Twenty-four yearling Friesian heifers were used in each of two randomized block experiments to measure live-weight gain, and 6, 10 and 10 yearling Friesian steers in three changeover design experiments to measure N retention.Rates of live-weight gain and N retention were increased by all the supplements amongst which no order of superiority in benefit conferred could be established. The improvement in N retention was associated with a marked reduction in urinary N and a small increase in faecal N with supplemented rations.The proportions of volatile fatty acids (VFA) in rumen fluid were not affected by starch supplementation. Both sugars, but glucose more than sucrose, decreased the ratio of acetic to propionic acid, measured 2 h after feeding.Statistically significant multiple linear regression equations were observed between N retained and intakes of N and digestible organic matter (DOM), both as absolute amounts with live weight as a further independent variate, and as intakes/unit metabolic body size. N2and DOM × N as additional variates did not benefit the fit of the equations over the range of intakes studied.

Wheat as a survival ration for sheep. 1. The digestion of wheat and formaldehyde treated wheat

1973 ◽  
Vol 13 (63) ◽  
pp. 341
Author(s):  
JP Langlands
Keyword(s):  
Fatty Acids ◽  
Organic Matter ◽  
Nitrogen Content ◽  
Volatile Fatty Acids ◽  
Nitrogen Retention ◽  
N Retention ◽  
Abomasal Infusion ◽  
Organic Matter Digestibility

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.

scholarly journals Effect of ileo-rectal anastomosis and post-valve T-caecum cannulation on growing pigs

1992 ◽  
Vol 68 (1) ◽  
pp. 293-303 ◽  
Author(s):  
T. KÖhler ◽  
R. Mosenthin ◽  
M. W. A. Verstegen ◽  
J. Huisman ◽  
L. A. Den Hartog ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Growth Performance ◽  
Volatile Fatty Acids ◽  
Nitrogen Retention ◽  
Growing Pigs ◽  
Diaminopimelic Acid ◽  
Control Group ◽  
Feed Conversion ◽  
Rectal Anastomosis ◽  
N Retention

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.

Ground and pelleted straw and hay for fattening Israeli-Friesian male calves

1972 ◽  
Vol 15 (2) ◽  
pp. 157-165 ◽  
Author(s):  
D. Levy ◽  
S. Amir ◽  
Z. Holzer ◽  
H. Neumark
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Conversion Ratio ◽  
Crude Fibre ◽  
Significant Difference ◽  
Ground Wheat ◽  
Energy Conversion Ratio

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.

Ruminal volatile fatty acids and ammonia in cattle grazing dry tropical pastures

1976 ◽  
Vol 86 (2) ◽  
pp. 367-372 ◽  
Author(s):  
M. J. Playne ◽  
P. M. Kennedy
Keyword(s):  
Fatty Acids ◽  
Butyric Acid ◽  
Rainy Season ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Cattle Grazing ◽  
Dry Season ◽  
Wet Season ◽  
Tropical Pastures ◽  
Grazing Cattle

SummaryTotal VFA concentrations, individual VFA proportions and ammonia concentrations in the rumen of cattle grazing tropical pastures for 7 months during the dry season were compared with concentrations of these metabolites in cattle grazing in the wet season and in cattle given two pasture hays in pens.Neither total VFA nor ammonia concentrations were altered by periods of new pasture growth within the dry season although responses in live weight occurred. Further evidence that concentrations of total VFA were insensitive to differences in feed quality was shown in the pen experiment.VFA concentrations were 53% higher in the rainy season than in the dry season and ammonia concentrations doubled from 62 mg/1 in the dry to 128 mg/1 in the wet season. Ruminal ammonia was related to ingested bolus N concentration (r= 0·58,P< 0.001) during the dry season.Individual VFA proportions did not vary greatly. The highest acetic (79·1%) and lowest butyric acid (5.10%) proportions occurred in the same sample. Iso-valeric and valeric acid proportions were related positively to ruminal ammonia (P< 0·001).In grazing cattle, concentrations of VFA and ammonia in their rumen taken at hourly intervals between 07.00 and 18.00 h did not vary greatly with time. Samples taken before 10.00 h had higher VFA and ammonia levels.

scholarly journals Effect of level of input of different proportions of volatile fatty acids on energy utilization in growing ruminants

1993 ◽  
Vol 70 (3) ◽  
pp. 679-687 ◽  
Author(s):  
E. R. Ørskov ◽  
N. A. Macleod
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Propionic Acid ◽  
Heat Production ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Energy Utilization ◽  
Rumen Content ◽  
Vitamin Supplement ◽  
Urine Metabolites

Four steers were maintained wholly by intragastric infusion of volatile fatty acids (VFA) and protein, together with a mineral–vitamin supplement. The infusion was given at three levels of energy, namely 450, 675 and 900 kJ/g live weight0·75, calculated to supply energy at 1·0,1·5 or 2·0 times that required for maintenance. The VFA provided 0·837 and the protein 0·163 of the energy infused. The molar proportions of individual VFA were varied so that the infusate contained 0·36–0·91 of acetic acid, 0·56–0·01 of propionic acid and a constant 0·08 of butyric acid. Heat production was measured in respiration chambers. Urine was analysed for N, urea, β-hydroxybutyrate and VFA. Blood plasma was analysed for β-hydroxybutyrate, free fatty acids, insulin and glucose. As the proportion of acetic acid was increased, and propionic acid reduced, there was no change in blood or urine metabolites or in heat production until acetic acid exceeded a proportion of about 0·75. At higher proportions β-hydroxybutyrate increased in plasma and urine, blood glucose and insulin tended to fall and urinary N excretion rose. At a proportion of acetic acid of > 0·80, acetate appeared in the urine and at > 0·86 heat production declined. The effect of level of infusion on the molar proportion at which plasma and urine metabolites changed was less clear. There was a tendency for the increase in β-hydroxybutyrate to occur at a slightly lower proportion of acetic acid at the highest level of infusion. It is concluded that differences in heat production that are observed between diets are probably not caused by differences in rumen VFA proportions. The reaction to a highly elevated proportion of acetic acid is to excrete β-hydroxybutyrate and acetate in the urine and so decrease rather than increase heat production. Regardless of level of infusion a metabolic crisis occurred when the proportion of acetic acid was above the levels found in the rumen content of normally-fed animals.

Prediction of the energy requirements for growth in beef cattle. 2. Hereford × British Friesian steers given dried grass or barley

1976 ◽  
Vol 23 (3) ◽  
pp. 329-340 ◽  
Author(s):  
A. J. F. Webster ◽  
J. S. Smith ◽  
R. M. Crabtree ◽  
G. S. Mollison
Keyword(s):  
Weight Gain ◽  
Heat Production ◽  
Nitrogen Balance ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Castrate Male ◽  
Body Weights ◽  
Energy Retention ◽  
Barley Protein

SUMMARY1. Hereford × British Friesian castrate male cattle, growing from about 80 to 500 kg, were given equal amounts of metabolizable energy (ME) from dried grass pellets or from a pelleted diet of barley and a protein supplement. Two animals on each diet were fed close to appetite (High) and two at a level mid-way between maintenance and appetite (Medium). The rations for all animals were reduced to approximately maintenance for 4 weeks on three occasions equally spaced throughout the experiment. Measurements of energy and nitrogen balance were made for each animal at intervals of 6 to 8 weeks. Total body-water content was estimated from D20 dilution at intervals of 110 kg live weight.2. Values for the metabolizability of the gross energy of the dried grass and barley/protein diets were 0·55 and 0·67.3. Metabolic heat production during growth was closely related to body weight to the power 0·75. Predicted basal metabolism was 395 kJ/kg 0·75 per 24 hr.4. Estimates of the net efficiency of utilization of ME for growth were unaffected by small variations in the exponent of W used to describe the effect of body size on heat production. Both diets were utilized above maintenance with a net efficiency close to 0·62.5. Nitrogen balance trials seriously overestimated nitrogen retention. Gains in fat-free body mass estimated from D2O dilution were combined with calorimetric measurements of energy retention to predict the relationship between energy retention and weight gain. The agreement between observed and predicted live-weight gain was good at the lower body weights and on the lower ration. For fatter animals eating the high ration at higher body weights, live-weight gains were less than predicted.

scholarly journals Utilization of salts of volatile fatty acids by growing sheep

1966 ◽  
Vol 20 (3) ◽  
pp. 519-532 ◽  
Author(s):  
E. R. Ørskov ◽  
D. M. Allen
Keyword(s):  
Fatty Acids ◽  
Body Weight ◽  
Acetic Acid ◽  
Volatile Fatty Acids ◽  
Body Weight Gain ◽  
Nitrogen Retention ◽  
Live Weight ◽  
Metabolizable Energy ◽  
Different Types ◽  
Digestible Organic Matter

1. Two experiments are reported in which sodium and calcium salts of volatile fatty acids (VFA) were given to lambs as additions to two basal dietsof hay andconcentrate. The two diets induced distinctly different types of rumen fermentation. A low-concentrate diet gave higher acetic and lower butyric acid proportions in the rumen contents than a high-concentrate diet. The two diets were given to lambs to provide equal intake of digestible organic matter. In one change-over experiment with twelve sheep the nitrogen retention was determined, and in a second experiment involving sixty-four lambs the efficiency of the VFA salt to promote body-weight gain was estimated. 2. The estimated metabolizable energy (ME) from the high-concentrate diet was utilized significantly more efficiently than that from the low-concentrate diet to promote positive nitrogen retention and to increase empty body-weight and carcass weight. These differences in final live weight were not significant owing to the greater content of the alimentary tract of lambs given the low-concentrate diet. 3. On both diets the lambs receiving the additions of VFA salts grew faster and produced significantly greater empty body and carcass weights than the lambs receiving only the basal diets. 4. For promoting carcass gain the energy derived from the VFA salts appeared to be utilized more efficiently than the calculated ME above maintenance of the two basal diets. 5. There were no significant differences between the efficiency of utilization of the energy from acetate, propionate and butyrate to promote carcass gains. There was, however, a tendency for the response to acetate to be greater on the high-concentrate diet than on the low-concentrate diet. 6. With a low level of feeding but with positive N balance, addition of acetate resulted in a greater N retention than that of propionate with both diets. 7. It is concluded that if the reported low utilization of the ME of diets high in roughage is related to the proportion of acetic acid in the rumen contents, then the implied losses of energy may be associated with the formation of acetic acid rather than its utilization.

scholarly journals Effect of incremental amounts of fish oil in the diet on ruminal lipid metabolism in growing steers

2010 ◽  
Vol 104 (1) ◽  
pp. 56-66 ◽  
Author(s):  
K. J. Shingfield ◽  
M. R. F. Lee ◽  
D. J. Humphries ◽  
N. D. Scollan ◽  
V. Toivonen ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Fish Oil ◽  
Latin Square ◽  
Live Weight ◽  
Dependent Manner ◽  
Growing Cattle ◽  
Potential Benefits ◽  
Ruminal Biohydrogenation ◽  
Long Chain

Based on the potential benefits to human health, there is interest in developing sustainable nutritional strategies to enhance the concentration of long-chainn-3 fatty acids in ruminant-derived foods. Four Aberdeen Angus steers fitted with rumen and duodenal cannulae were used in a 4 × 4 Latin square experiment with 21 d experimental periods to examine the potential of fish oil (FO) in the diet to enhance the supply of 20 : 5n-3 and 22 : 6n-3 available for absorption in growing cattle. Treatments consisted of total mixed rations based on maize silage fed at a rate of 85 g DM/kg live weight0·75/d containing 0, 8, 16 and 24 g FO/kg diet DM. Supplements of FO reduced linearly (P < 0·01) DM intake and shifted (P < 0·01) rumen fermentation towards propionate at the expense of acetate and butyrate. FO in the diet enhanced linearly (P < 0·05) the flow oftrans-16 : 1,trans-18 : 1,trans-18 : 2, 20 : 5n-3 and 22 : 6n-3, and decreased linearly (P < 0·05) 18 : 0 and 18 : 3n-3 at the duodenum. Increases in the flow oftrans-18 : 1 were isomer dependent and were determined primarily by higher amounts oftrans-11 reaching the duodenum. In conclusion, FO alters ruminal lipid metabolism of growing cattle in a dose-dependent manner consistent with an inhibition of ruminal biohydrogenation, and enhances the amount of long-chainn-3 fatty acids at the duodenum, but the increases are marginal due to extensive biohydrogenation in the rumen.

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