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

1966 ◽  
Vol 20 (3) ◽  
pp. 509-517 ◽  
Author(s):  
E. R. Ørskov ◽  
D. M. Allen

1. The effect, on the concentration of volatile fatty acids (VFA) in the rumen, of increasing the frequency of feeding from twice daily to four or six times daily was investigated in sheep given isocaloric rations containing VFA salts. In a second experiment isocaloric rations containing acetate and propionate were given to groups of lambs in two or six equal feeds daily. The efficiency with which the lambs utilized the VFA salts was measured as gain in live weight, empty body weight and carcass weight and was compared to that of lambs receiving only the basal ration. The composition of the carcasses was estimated from that of the loin. 2. Increasing the frequency of feeding from twice daily to four or six times daily significantly reduced the marked changes in rumen VFA composition associated with giving rations containing VFA salts twice daily. In lambs receiving acetate and propionate, final live weight, empty body weight and carcass weight were significantly greater than in lambs receiving only the basal ration (P < 0.001). The combustible energy from added VFA was apparently utilized more efficiently than the calculated metabolizable energy of the basal rations given above maintenance level, and there was no difference between the utilization of acetate and propionate. 3. There were no differences approaching significance between feeding twice daily and six times daily either between groups of lambs receiving only the basal diet or between those given the diets supplemented with VFA salts. Nor were there any interactions between VFA and frequency of feeding. 4. It is postulated that in ruminants the effect of frequency of feeding depends on the environment and level of feeding.

1970 ◽  
Vol 24 (3) ◽  
pp. 695-704 ◽  
Author(s):  
D. A. Poole ◽  
D. M. Allen

1. An experiment is reported in which groups of six lambs were fed two basal diets supplemented at three levels with a mixture of sodium and calcium acetates.2. The basal diets were given in amounts that provided equal intakes of digestible organic matter and crude protein. One contained 85 % of concentrates (Hc), the other 40% of concentrates (Lc). Rumen contents from a sheep receiving diet Hc contained a lower molar proportion of acetate and higher proportions of propionate and butyrate than when diet Lc was given.3. The calculated metabolizable energy of the basal Hc diet was utilized more efficiently than that of the basal Lc diet, for promoting empty body-weight and carcass-weight gains.4. On both basal diets, lambs receiving the diets supplemented with acetate made greater live-weight, empty body-weight and carcass-weight gains than lambs given unsupplemented diets. The responses of weight gain to increasing levels of acetate were linear.5. The responses to acetate were greater when it was given with the Hc diet than with the Lc diet. This effect was most marked for live-weight gain (P < 0.001), intermediate for empty body-weight gain (P < 0.05), but not significant for carcass-weight gain. This order of effects was in part due to a greater weight of alimentary tract tissue, and its contents, in lambs fed the Hc diet supplemented with acetate.6. It is concluded that under certain circumstances the energy of acetate may be utilized less efficiently than energy from propionate or butyrate.


1966 ◽  
Vol 20 (2) ◽  
pp. 307-315 ◽  
Author(s):  
E. R. Ørskov† ◽  
F. D. Hovell‡ ◽  
D. M. Allen

1. In two experiments with growing and fattening lambs sodium and calcium salts of volatile fatty acids (VFA) were added to a basal diet of hay and concentrate. In Expt I the lambs were approaching maturity, and the utilization of salts of acetic, propionic and butyric acids was studied. In Expt 2 the animals were younger; the experimental groups received acetate or propionate, and half of them were implanted with hexoestrol. The chemical composition of the carcass was assessed with the loin as a representative joint. The influence of the VFA salts on the digestibility of the basal ration was also investigated. 2. In both experiments the lambs receiving supplements of VFA salts grew faster, and their empty body weights and carcass weights were significantly greater than in lambs receiving the basal diet. 3. The energy derived from acetate and propionate was utilized more efficiently to promote carcass gains than the calculated metabolizable energy above maintenance of the basal ration. There were no differences in the utilization of energy from the different VFA, except in Expt I in which butyrate was utilized somewhat less efficiently than acetate and propionate. 4. Hexoes-trol implantation resulted in faster growth, and highly significantly greater empty body weights and carcass weights. There was no evidence of an interaction between the VFA and hexoestrol treatments. 5. There were no differences between the VFA treatments in the composition of the carcass gains as judged by the composition of the loins, except in Expt I in which lambs receiving acetate tended to be the fattest. The coefficient of variation in loin fat percentages was large in both experiments, but, in Expt I in which both ewe and wether lambs were used, the coefficient of variation among the wether lambs was four times that of the ewe lambs. 6. Additions of VFA salts to the diet resulted in a significant increase in the excretion of ash.


1966 ◽  
Vol 20 (3) ◽  
pp. 519-532 ◽  
Author(s):  
E. R. Ørskov ◽  
D. M. Allen

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.


1966 ◽  
Vol 20 (2) ◽  
pp. 295-305 ◽  
Author(s):  
E. R. Ørskov ◽  
D. M. Allen

1. An experiment was conducted in which sodium and calcium salts of acetic, propionic and butyric acids were given to groups of eight lambs as additions to basal diets of hay and concentrate. Two control groups were included, one group which received only the basal ration and one high-level control group which received sufficient additional concentrate to achieve growth rates greater than those of the groups receiving volatile fatty acid (VFA) salts. 2. With rumen-fistulated sheep, the effect on the rumen VFA composition and the pH of the rumen liquor, of diets supplemented with VFA salts given twice daily, was also investigated and compared with the effect of the basal diet alone. 3. The lambs receiving the VFA salts grew faster and achieved significantly greater empty body and carcass weights than those receiving only the basal rations; the high-level control group had significantly greater empty body and carcass weights than groups receiving salts of VFA. 4. There were no differences approaching significance in the efficiency of the three VFA in promoting gains in live weight, empty body weight and carcass weight. There appeared to be equal efficiency of utilization of the gross energy of the VFA and of the calculatedmetabolizable energy of the concentrates. 5. The effect of twice-daily feeding on the rumen VFA composition was that the concentration of the supple- mentary acid was greatest shortly after feeding, and about 5–6 h after feeding the effect was difficult to detect. There were no differences in the pH of the rumen liquor between animals given diets containing VFA salts and those given the basal ration.


1969 ◽  
Vol 23 (3) ◽  
pp. 443-453 ◽  
Author(s):  
E. R. Ørskov ◽  
W. P. Flatt ◽  
P. W. Moe ◽  
A. W. Munson ◽  
R. W. Hemken ◽  
...  

1. In an experiment of 3 x 3 latin square design, four lactating Holstein cows were given a basal ration designed to induce low percentages of milk fat. The treatments were (I) basal ration, a pelleted mixture of lucerne hay (20%) and concentrates (80%), with 40 l. of water infused intraruminally, (2) basal ration with acetic acid substituted for 15.4% of the metabolizable energy (ME) and (3) propionic acid substituted for 15.4% of the ME. In the last 3 weeks of the 6-week experimental period respiration trials were carried out in an open-circuit indirect calorimeter. The levels of feeding offered in the three periods were 325, 275 and 225 kcal ME/kg body-weight 0.75 in periods 1, 2 and 3 respectively.2. No differences were detected in the utilization of the energy of acetic and propionic acids, but there were differences in the partition of energy into milk or body tissues; with acetic acid infusion more energy was secreted as milk and with propionic acid infusion more was deposited in body tissue.3. There was an increase in milk fat percentage with acetic acid infusion, but not complete recovery to normal. The milk fat percentages were 1.96, 2.58 and 1.92 for treatments 1, 2 and 3 respectively. Acetic acid infusion caused increases in the C12, C14 and C16 fatty acids of milk fat and decreased the proportion of C18:1 fatty acids.4. It is suggested that the low percentages of milk fat found when cows are given concen- trates could result from a decreased extent of fermentation in the rumen, allowing a greater proportion of the starch consumed to be absorbed as glucose in the small intestine.


Parasitology ◽  
2011 ◽  
Vol 139 (1) ◽  
pp. 110-119 ◽  
Author(s):  
G. DAŞ ◽  
H. ABEL ◽  
J. HUMBURG ◽  
A. SCHWARZ ◽  
S. RAUTENSCHLEIN ◽  
...  

SUMMARYThis study examined whetherAscaridia galliinfection can be controlled by dietary non-starch polysaccharides (NSP) in chickens. One-day-old chicks were fed either a basal diet (CON) or CON plus insoluble NSP (I-NSP), or CON plus soluble NSP (S-NSP) for 11 weeks. Three weeks later, birds from half of each feeding group were inoculated with 250 embryonated eggs ofA. galli, and slaughtered 8 weeks post-infection to determine worm counts. Both NSP diets, particularly S-NSP, increased prevalence of infection (P<0·05) and worm burden (roughly +50%) of the birds (P<0·001).A. galliinfection caused a less efficient (P=0·013) feed utilization for body weight gain (BWG) resulting in lower body weights (P<0·001) irrespective of type of diet consumed. NSP-fed birds, particularly those on I-NSP, consumed more (+8%) feed per unit BWG and showed retarded (P<0·001) BW development compared to CON-fed birds. Intracaecal pH was lowered by S-NSP (P<0·05). Both NSP diets increased the volatile fatty acids pool size in caeca (P<0·001) with S-NSP exerting a greater effect (+46%) than I-NSP (+24%). It is concluded that both NSPs supplemented diets alter gastrointestinal environment in favour of the nematode establishment, and thus have no potential for controllingA. galliinfection in chickens.


2000 ◽  
Vol 70 (1) ◽  
pp. 51-61 ◽  
Author(s):  
L. O. W. McClintont ◽  
A. F. Carson

AbstractThis study investigated the efficiency of growth and the carcass characteristics of 24 Greyface (Border Leicester × Scottish Blackface), 24 Texel (12 purebred and 12 Texel × Texel-Greyface) and 24 Rouge (12 purebred and 12 Rouge × Rouge-Greyface) lambs finished on the same level of feeding. The efficiency of live-weight gain (kg/MJ) was higher in Greyface compared with Texel lambs (P< 0·01). The efficiency of empty body-weight gain (kg/MJ) was higher in Greyface (P< 0·01) and Rouge (P< 0·05) compared with Texel lambs. The efficiency of carcass gains (kg/MJ) tended to be higher in Greyface and Rouge compared with Texel lambs (P= 0·07). The efficiency of non-carcass component gains (kg/MJ) was also higher in Greyface compared with Texel lambs (P0·05). Carcass water, protein, lipid and ash gains did not vary significantly between the genotypes, however carcass energy gain tended to be higher in Greyface and Rouge compared with Texel lambs (P= 0·08). The relative proportions of water, protein, lipid and ash in carcass gains did not vary significantly between the genotypes. At the end of the experiment carcass water content was higher in Texel compared with Greyface lambs (P< 0·05) and carcass ash content was lower in Texel compared with Greyface (P< 0·01) and Rouge (P< 0·05) lambs. The concentration of saturated fatty acids was higher in Greyface compared with Rouge lambs (P< 0·001) and higher in Rouge compared with Texel lambs (P< 0·05). Monounsaturated fatty acid concentrations were higher in Rouge compared with Greyface lambs (P< 0·05) and higher in Texel compared with Rouge lambs (P< 0·001). Polyunsaturated fatty acid concentrations were higher in Rouge and Texel compared with Greyface lambs (P< 0·01). The ratio of n-6:n-3 fatty acids was lower in Rouge compared with Greyface lambs (P< 0·05).The efficiency of empty body gain was higher in male compared with female lambs (P< 0·05). Carcass water (P< 0·01) and protein (P< 0·05) gains were higher in male lambs. At the end of the experiment male carcasses contained a higher content of water (P< 0·05), protein (P< 0·01) and ash (P= 0·07), and a lower lipid (P< 0·05) and energy (P< 0·001) content. Carcass lipids from male lambs contained a higher concentration of polyunsaturated fatty acids (P< 0·001) and tended to contain a lower concentration of saturated fatty acids (P = 0·06).


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


2020 ◽  
Vol 65 (No. 4) ◽  
pp. 135-144
Author(s):  
Afaf Abdelrahman Elshareef ◽  
Julian Arroyave-Jaramillo ◽  
Lucas Miguel Zavala-Escalante ◽  
Angel Trinidad Piñeiro-Vázquez ◽  
Carlos Fernando Aguilar-Pérez ◽  
...  

The aim of the present study was to assess enteric methane (CH<sub>4</sub>) emissions by crossbred heifers fed a basal ration of low-quality tropical grass supplemented with different nitrogen sources. Four crossbred heifers (Bos taurus × Bos indicus) with an average live weight (LW) of 355 ± 6.01 kg were used in a 4 × 4 crossover Latin square design with four periods of fifteen days each. Basal ration was chopped low-quality tropical grass Pennisetum purpureum fed to cover ~70% of metabolizable energy requirements for maintenance of heifers and it was supplemented with either poultry litter (control ration, T1), urea (T2), canola meal (T3) or soybean meal (T4). Enteric CH<sub>4</sub> emissions of heifers were measured in open-circuit respiration chambers for 23 hours. Dry matter (DM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) intakes decreased when feeding urea (1.6% of ration) as a source of nitrogen (7.64, 3.78, and 1.83 kg/d, respectively). Rations including urea (T2) or canola meal (T3) given to heifers fed a basal ration of low-quality Pennisetum purpureum grass significantly reduced acetic acid concentration and increased propionic acid concentration in the rumen and decreased the loss of gross energy as methane (P = 0.004). Incorporation of urea or canola meal in the ration of cattle fed low-quality tropical grass can decrease methane emissions and improve rumen fermentation patterns.


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.


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