THE EFFECT OF ORGANIC ACID SALTS ON GROWTH AND RUMEN VOLATILE FATTY ACIDS OF SHEEP FED PELLETED OR CHOPPED HIGH-ROUGHAGE RATIONS

1964 ◽  
Vol 44 (1) ◽  
pp. 58-67 ◽  
Author(s):  
J. W. G. Nicholson ◽  
H. M. Cunningham

Four experiments were conducted with sheep to compare the addition of sodium citrate and sodium propionate to pelleted and unpelleted rations and to determine the response to sodium citrate supplementation of different quality-hays. There were no significant differences in rate of gain or feed consumption of a ⅔ roughage −⅓ concentrate ration due to supplementation with sodium citrate or sodium propionate. Pelleting either the mixed ration or all-roughage rations increased feed consumption and rate of gain in all experiments. Pelleting the mixed ration decreased digestibility of dry matter, organic matter, and nitrogen in the one experiment in which this was determined. Pregnant and lactating ewes lost less body weight when fed a limited amount of long hay plus pelleted hay ad libitum than similar ewes fed a standard ration of long hay ad libitum plus 0.5 lb of concentrates per day. It was necessary to feed lambs 0.5 lb of rolled barley per day with long hay ad libitum to obtain gains equal to those of similar lambs fed pelleted hay ad libitum. The addition of sodium citrate significantly increased the rate of gain of lambs fed ad libitum a slightly moldy, weathered legume hay in the pelleted form together with 0.25 lb of long hay per head per day.The addition of sodium citrate to a mixed ration or to all-roughage rations did not usually alter the proportions of rumen volatile fatty acids. The addition of sodium propionate decreased the proportion of acetic acid while increasing that of propionic acid. In both experiments where this was determined, pelleting an all-roughage ration resulted in a decrease in the proportion of acetic acid and an increase in the longer chain volatile fatty acids in rumen fluid.

1963 ◽  
Vol 43 (1) ◽  
pp. 202-210
Author(s):  
C. M. Grieve ◽  
A. R. Robblee ◽  
L. W. McElroy

Concentrations and proportions of volatile fatty acids (VFA) were determined chromatographically in samples of rumen contents from 27 lambs and 5 mature wethers fed a control ration of alfalfa and barley or non-pelleted and pelleted test rations containing 45, 60 or 90 per cent of poor quality lowland hay in the case of lambs, and 60 or 90 per cent of test hay in the case of wethers.When the rations were fed in pelleted form, concentrations of VFA increased in rumen contents from lambs receiving 45 and 60, but not 90 per cent levels of lowland hay. In the case of the wethers, pelleting resulted in higher levels of the acids in rumen contents when either 60 or 90 per cent of test hay was fed. Pelleting had no effect on the proportions of VFA in the rumen fluid. Differences in concentration of VFA in rumen fluid were not of sufficient magnitude to account for more than a small fraction of the differences observed in feed consumption and rate and efficiency of gain of the fattening lambs fed the pelleted vs. non-pelleted rations.Concentrations of VFA were lower in rumen fluid from animals fed lowland hay than in that from animals fed the alfalfa-barley ration. As the level of lowland hay in the rations was increased the proportion of acetic acid increased, and the proportions of propionic and/or butyric acids decreased.


1971 ◽  
Vol 51 (3) ◽  
pp. 721-727 ◽  
Author(s):  
L. J. FISHER ◽  
J. D. ERFLE ◽  
F. D. SAUER

Glutamate, succinate, propylene glycol, or glycerol were added to a basic concentrate at 3.3% of air-dry feed. Each concentrate was fed both ad libitum and in restricted amounts to four cows in early lactation. Dietary intake, milk yield and composition, molar proportions of rumen volatile fatty acids and blood glucose, ketones and plasma free fatty acids were used as criteria of effect of these supplements. Propylene glycol in the diet resulted in a lower intake of concentrate compared with glycerol (11.44 versus 14.30 kg/day) and significantly decreased (P < 0.05) rumen butyrate and plasma beta-hydroxybutyrate. Glutamate supplementation prevented the fall in milk fat content which occurred when the other three supplemented concentrates were fed ad libitum, and this effect may have been related to the constancy in the ratio of acetate to propionate in the rumen fluid.


1982 ◽  
Vol 54 (2) ◽  
pp. 127-135
Author(s):  
Liisa Syrjälä-Qvist

The criteria used in comparing the utilization of grass silage by reindeer and sheep were rumen pH, ammonia, volatile fatty acids (VFA) and microbes. Rumen samples were taken before feeding, and 2 ½ and 5 ½ hours after the beginning of feeding. Rumen fermentation was lower in the reindeer than in the sheep and differed less between the three sampling times. In the reindeer/the pH of the rumen fluid averaged 6.94 and in the sheep 6.61. The average amounts of NH3—N were 17.0 and 24.2 mg/100 ml rumen fluid and those of total VFA 8.46 and 10.90 mmoles/100ml rumen fluid, respectively. The proportion of acetic acid in the VFA in the reindeer was 75.3 molar % and in the sheep 66.0 molar %, the corresponding values for propionic acid being 18.5 and 22.0 molar % and for butytic acid 4.2 and 8.8 molar %. The number of rumen ciliates in the reindeer averaged 87/mm3 rumen contents and in the sheep 314/ mm3. The numbers of bacteria were 16.0 X 106/mm3, respectively. The proportion of the total microbe mass in the reindeer rumen contents was 1.8 % and in the sheep 2.4 %. The proportions of bacteria in this mass were 87 % and 70 %, respectively. The differences between the reindeer and sheep in the rumen fermentation results and in the numbers of rumen microbiota were nearly all statistically significant (P


1971 ◽  
Vol 22 (1) ◽  
pp. 139 ◽  
Author(s):  
RH Weston ◽  
JP Hogan

Subterranean and berseem clovers, harvested at early and late stages of maturity, were dried and offered to sheep ad libitum, or at about 90 % of ad libitum intake. Feed consumption and the times spent in ruminating and eating were measured when the forages were offered ad libitum and several aspects of digestion were studied at the restricted level of feeding. The effects of maturity on (i) forage chemical composition, (ii) nutrient digestibility, (iii) parameters relating to the movement of digesta through the stomach, (iv) ruminal volatile fatty acid production, (v) the molar proportions of individual amino acids in abomasal digesta and peripheral blood plasma, (vi) nitrogen balance, and (vii) the time and energy expenditure in ruminating and eating, were generally the same with these clovers as has been observed previously with grasses. Substantial amounts of nutrients were derived from forages harvested in the immature state, the consumption of which provided about 1200 g organic matter per day. It was calculated that under conditions of ad libitum feeding about 500 g of volatile fatty acids was produced in the rumen and 160-230 g of crude protein was digested in the intestines per day. High mean values for nitrogen balance were obtained with immature subterranean clover but the variation between sheep was large. The levels of amino acids in blood plasma were also exceptionally high with this diet. The data obtained on the digestion of immature clover forages were compared with those obtained previously with immature grass forages. The patterns of digestion were generally very similar for both types of forages and any differences observed could usually be ascribed to the higher feed intake with the clovers. The forages had similar capacities to furnish volatile fatty acids in the rumen and digested crude protein in the intestines. The calculated energy expenditure in eating and ruminating, however, was slightly lower for the clovers. The data were interpreted to indicate that if immature clovers are superior to immature grasses in promoting animal production, the superiority cannot be attributed to an inherent capacity of clovers to provide the animal with a more favourable balance of nutrients.


1976 ◽  
Vol 27 (5) ◽  
pp. 691 ◽  
Author(s):  
JP Langlands ◽  
J Sanson

The digestibility and nitrogen content of the diet and of the green fraction of the diet, and concentrations of individual volatile fatty acids in the rumen were measured in sheep and cattle grazing together on five Phalaris tuberosa pastures varying in forage availability. The sheep and cattle were aged 5 and 6 months respectively. Measurements were made at monthly intervals for 5 consecutive months during which animals were rotated between pastures. Measurements of forage availability, structure and composition were subjected to a principal components analysis from which orthogonal variables describing pasture composition were calculated. These were related to the nutritive value of the diet and the composition of rumen fluid by regression analysis. Diets selected by sheep were of higher digestibility and nitrogen content than those selected by cattle, because they contained more green material and the green material selected by the sheep was of higher digestibility and nitrogen content. The nutritive value of the diet of sheep varied with the availability of green forage, and that of cattle with both the availability of green and the bulk of forage on offer. Cattle were the more sensitive to changes in the quantity of green material available, and differences between sheep and cattle in the nutritive value of diets were reduced as the quantity of green material and the bulk of forage increased. The rumen liquor of cattle contained proportionately more acetic acid, and the proportions of other volatile fatty acids were less than in sheep. These differences were generally associated with differences in selective grazing.


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.


2003 ◽  
Vol 47 (12) ◽  
pp. 191-198 ◽  
Author(s):  
S. Barnes ◽  
R. Dalhoff ◽  
J. Keller ◽  
P. Wilderer ◽  
L. Kendall

The accumulation of volatile fatty acids such as acetic acid can cause reactor pH problems and the inhibition of microorganisms utilised in anaerobic digestion processes. A cross-flow membrane process using Teflon and ion-exchange membranes was investigated as a means of separating acetic acid from pure acetic acid solution and rumen fluid. Acetic acid transfer across the Teflon membrane was dependent on the free acid concentration (CH3COOH) in the acid solution. Concurrent transfer of water was minimal due to the hydrophobic nature of the membrane. The strong base anionic exchange membrane facilitated the separation of acetic acid from both pure solutions and rumen fluid with flux again being dependent on the free acid gradient across the membrane. Flux rates were lower than other studies of diffusion dialysis, however, this may be partly attributed to improper preparation of the membrane. The currently achieved rates of transfer using these membranes are very low and are therefore not yet suitable for full-scale use in anaerobic digestion. Additional research is needed to achieve higher trans-membrane transport rates at reasonable costs.


1973 ◽  
Vol 16 (2) ◽  
pp. 195-203 ◽  
Author(s):  
Hi Shin Kang ◽  
Jane Leibholz

SUMMARYAn experiment was conducted with 50 male Friesian calves between 5 and 11 weeks of age. Milled wheat straw (0·95 cm screen) was included in a pelleted all-concentrate diet at concentrations of 0, 15, 30 or 45 %. The nitrogen content of the diets was maintained by the addition of urea. The diets were given alone or with a chaffed lucerne hay or wheat straw supplement ad libitum. All diets contained 2 % sodium bicarbonate.The feed intake and weight gains of the calves were increased significantly by the inclusion of 15 % milled wheat straw, but were reduced by 30 or 45 % straw. The supplements of chaffed wheat straw or lucerne hay ad libitum did not influence the performance of the calves. The inclusion of wheat straw in the diets reduced their dry-matter digestibility but the digestibility of acid detergent fibre was maximal with 27 % straw. The digestibility of nitrogen was significantly increased by 15% straw but reduced by further increases in straw.The inclusion of wheat straw in the diets did not influence the pH of the rumen contents or the concentration of total volatile fatty acids in the rumen. Increasing the level of straw in the diet caused a significant linear increase in the proportion of acetic acid and decreases in butyric, propionic and valeric acids.


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.


1970 ◽  
Vol 21 (2) ◽  
pp. 297 ◽  
Author(s):  
ID Hume

When sheep were fed on a virtually protein-free purified diet adequately supplied with nonprotein nitrogen, 71 g microbial protein was produced in the rumen daily. The addition of a mixture of higher volatile fatty acids (VFA) increased protein production to 81 g daily (P < 0.05). The VFA supplement also increased the molar proportions of these acids in the rumen fluid and the flow of total nitrogen from the rumen. There were no differences in nitrogen balance associated with the supplement. There were significant variations between sheep and between periods in both protein production and the molar proportion of acetic acid in the rumen fluid. A negative correlation was found between acetic acid proportions and protein production (r = -0.62, P < 0.025). The mean yield of protein from the ruminal fermentation was 13.0 g/100 g organic matter digested in the rumen. The addition of the higher VFA did not result in any appreciable increase in the efficiency of protein production from the energy available.


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