Whole wheat grain feeding of lambs. III. Rumen metabolic responses and animal physiological adjustment to mineral buffer supplements

1973 ◽  
Vol 24 (3) ◽  
pp. 425 ◽  
Author(s):  
ML Bigham ◽  
WR McManus ◽  
GB Edwards

An intensive 17-week study was made of nine rumen-cannulated crossbred lambs off pasture when given mineral buffer supplements as they were changed from lucerne chaff diets to diets of whole wheat grain plus 2 % of ground limestone. Diets were given ad libitum. Buffers were supplied during transition (period 11) and after transition (period III). The buffers were a 1/1/1/1 mixture of powdered disodium hydrogen phosphate, sodium bicarbonate, potassium bicarbonate, and calciuns hydrogen phosphate given as 2% of the grain offered (group B) and powdered alumirn~~m hydroxide (Al(OH)3) given as 1 % by weight of the grain ofiered (group C). The wheat gram diet was low in sodium (0 008%) and contained 1.50% nitrogen. Production responses to both mineral buffer treatments resulted. Soth buffer treatments increased the voluntary intake (P < 0.01) of wheat above that of the control animals. The rate of eating (g/hr) and pattern of eating did not differ significantly between groups, or between periods I (lucerne chaff) and 111 (post-transition). Groups B and C increased in liveweight to a greater extent than did control animals (P < 0 01) and had heavier carcasses (P <0.01). Results with the mineral mixture given to group B (above) confirm our earlier report. Ingestion of aluminium hydroxide was associated with abomasal ulceration. No significant differences were found between groups in any period for total volatile fatty acids in rumen liquor. Towards the end of period 111, animals given buffer had lower proportions of acetic and higher proportions of propionic acid than did control animals (P < 0.01). Hexanoic acid was detected in all rumen liquor samples obtained in period 111, sometimes in amounts equal to 17 % of total volatile fatty acids. Lactic acid was not detected in rumen liquor in period I, but was present in large amounts in all lambs during period 11, and in lesser but substantial amounts in all lambs during period III. Levels of lactic acid in the rumen liquor in animals receiving mineral buffer supplements fell at a faster rate during period I11 ?hall did levels in control animals. There was a significant decline in rumen pH values for all groups from period I to period III (P < 0.01). Significant rumen pH differences attributable to mineral buffer treatment were apparent (P < 0 05). Buffers were associated with a less acid rumen condition than found in control animals. Relative to control animals, animals given mineral buffers showed increases in rumen buffering capacity and salivary flow rates, and an increased buffering index of the total mixed saliva. Period effects were apparent. The saliva flow rates of control lambs fed on wheat were significantly increased compared with their flow rates on the roughage diet of lucerne chaff. In general, supplementation with aluminium hydroxide and with the mixed buffer respectively yielded similar patterns of response. It is concluded that responses were not primarily due to the sodium level of the diet per se, and that alterations in the animals' electrolyte and acid-base physiology induced by buffer treatment might be contributory factors. Various possible physiological mechanisms are discussed.

1977 ◽  
Vol 28 (6) ◽  
pp. 1075 ◽  
Author(s):  
GJ Lee

Changes in the composition of digesta along the gastrointestinal tract of scouring sheep fed on wheat grain ad libitum were studied relative to sheep fed on lucerne hay ad libitum. Wheat engorgement significantly (P < 0.005) depressed the pH of the digesta in the reticulorumen and the digestive tract distal to the jejunum. A mean total volatile fatty acids concentration of 10.3mM in the caecum of scouring sheep was significantly lower than the mean of 51.6mM in sheep fed on lucerne hay. Net absorption of water was negligible in the colon of scouring sheep as digesta were only 13.7–14.7% dry matter, whereas in sheep fed on lucerne, the dry matter of digesta increased from 14.7% in the caecum to 27.9% at the rectum.


1975 ◽  
Vol 26 (6) ◽  
pp. 1053 ◽  
Author(s):  
ML Bigham ◽  
WR McManus

Two slaughter trials were conducted with lambs to evaluate the effects on production and some rumen characteristics of the addition of low quality roughage (wheaten straw) and a high quality roughage (pelletized ground lucerne) to wheat grain diets. In the first trial one group of lambs was given a 1/1 mixture of whole wheat grain and chaffed wheaten straw and another chaffed lucerne hay ad libitum. Lucerne-fed lambs had significantly (P < 0.001) higher dry and organic matter intakes, grew faster and had higher levels of volatile fatty acids in their rumens than lambs offered the mixed ration, although there were no differences between rations in dry and organic matter digestibilities. The apparent nitrogen digestibility of the mixed ration was significantly (P < 0.001) lower than that of the lucerne ration. Of lambs offered the mixed ration, 46% had extensive lesions on the ventral wall of the rumen at slaughter, and these were associated with marked inappetence and loss in liveweight. In the second trial comparisons were made of diets consisting of lucerne (either alone or mixed with cracked wheat) and whole wheat grain + limestone. The effect of treating the lucerne with formaldehyde was also studied. There were no significant differences in carcass gain with the lucerne diets; parakeratosis developed in some animals on lucerne-wheat diets but did not affect productive performance. The animals offered whole wheat lost weight, two died of wheat poisoning, and several animals developed lesions on the rumen wall. _________________ *Part IV, Aust. J. Agric. Res., 26: 729 (1975).


2017 ◽  
Vol 86 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Leoš Pavlata ◽  
Ondřej Šťastník ◽  
Štěpánka Křivová ◽  
Hana Dočkalová ◽  
Lenka Sedláková ◽  
...  

The aim of the study was to determine the effect of different physical forms of starter feed on rumen fermentation indicators of calves after weaning and their weight gain. The experiment was performed with Czech Fleckvieh calves after weaning. The calves were fed ad libitum completely pelleted starter feed or texturized starter feed with chopped straw. The rumen fluid samples were collected after a month of feeding the starter feeds. The calves were weighed monthly. The pH, total acidity, total volatile fatty acids, acetate, propionate, butyrate, lactic acid, ammonia and the number of rumen ciliate protozoa were determined in the rumen fluid samples. The calves receiving the starter feed with straw showed significantly higher rumen pH (6.24 ± 0.51 vs. 5.58 ± 0.30), total volatile fatty acids (98.02 ± 20.46 vs. 61.40 ± 26.51 mmol/l), molar proportion of acetate (61.20 ± 4.87 vs. 50.53 ± 4.66%), and the acetate:propionate ratio (2.38 ± 0.53 vs. 1.34 ± 0.18) and lower molar proportion of propionate (26.55 ± 4.48 vs. 37.92 ± 3.58%) compared with the calves receiving pelleted starter feed. Average daily gain of the calves did not differ significantly. The feeding of starter feed with chopped straw compared with the pelleted starter feed led to better development of the rumen fermentation evaluated by rumen pH, by total volatile fatty acids production, and by the proportion and ratio of acetic and propionic acids. The feeding of starter feed with chopped straw reduced the occurrence of subacute ruminal acidosis in the weaned calves.


1994 ◽  
Vol 59 (2) ◽  
pp. 217-222 ◽  
Author(s):  
M. D. Carro ◽  
A. R. Mantecón ◽  
I. A. Wright ◽  
I. J. Gordon

AbstractEffects of time of supplementation on forage intake, nutrient apparent digestibility and rumen fermentation were studied with 12 mature castrated male sheep (wethers) offered grass hay from 16.30 h to 09.30 h and supplemented with a cereal-based concentrate given at either 09.30 or 16.00 h. Voluntary intake of hay organic matter (OM) was decreased by feeding the concentrate (P< 0·01). Offering concentrate at 09.30 h after hay was available, increased intake of hay and total OM compared with offering it at 16.00 h before hay was available (P< 0·05). Daily pattern of hay intake was not changed when concentrate was offered at 09.30 h compared with feeding hay alone, but concentrate given at 16.00 h resulted in a lower hay intake between 16.30 and 18.00 h. Sheep offered concentrate at 09.30 h had higher rumen ammonia levels than those offered concentrate at 16.00 h, but there were no differences in the apparent digestibility of the nutrients, rumen pH and molar proportions of the main volatile fatty acids. There were also no differences between groups in the blood plasma concentrations of 3-hydroxybutyrate (30HB), nonesterified fatty acids (NEFA) and glucose. It is concluded that feeding supplement after rather than before a period of intake of forage or a bout of grazing may offer a means of minimizing reduction of forage intake as a consequence of feeding concentrate.


1968 ◽  
Vol 35 (3) ◽  
pp. 343-352 ◽  
Author(s):  
W. Steele ◽  
J. H. Moore

SummaryThe effects of the isocaloric replacement of part of the dietary concentrate mixture by cottonseed oil on the yield and composition of the milk fat and on the pattern of rumen fermentation was investigated in 2 feeding experiments with a total of 8 cows in mid-lactation. The concentrate mixtures were given with high- or low-roughage diets that supplied 9·1 or 1·8 kg of hay/day.In expt 1 the yield of milk fat was not altered by the addition of 10% cottonseed oil to the concentrate mixtures given either with the high- or with the low-levels of dietary roughage. On the low-roughage treatment, dietary cottonseed oil increased milk yield but reduced the fat content of the milk. The change from the high- to the low-roughage diets containing no cottonseed oil resulted in reductions in the yield and percentage of fat in the milk. In expt 2 the yields of milk and milk fat were similar irrespective of whether the concentrate mixture contained 5 or 10% cottonseed oil.In expt 1 the inclusion of 10% cottonseed oil in the concentrate mixture reduced the yields and percentages of the medium-chain fatty acids (12:0, 14:0 and 16:0) and increased the yields and percentages of the C18 fatty acids in the milk fat. In expt 2, when the concentrate mixture contained 5% cottonseed oil, the yields and percentages of all the fatty acids in the milk fat were similar to the values obtained when the concentrates contained 10% cottonseed oil. For any given concentrate mixture, the change from the high- to the low-roughage treatments in both expts 1 and 2 resulted in increases in the percentage of oleic acid in the milk fat. The highest concentration of trans-octadecenoic acid was observed in the milk fat of the cows when they were given the high-roughage diet with the concentrate mixture containing 10% cottonseed oil.In expt 2 the level of cottonseed oil in the concentrate mixture did not influence the pattern of rumen fermentation as measured by the concentrations of the various volatile fatty acids in the rumen liquor. However, the change from the high- to the low-roughage diets reduced the proportion of acetic and increased the proportions of propionic and n-valeric acids in the total volatile fatty acids in the rumen liquor.


1972 ◽  
Vol 27 (3) ◽  
pp. 553-560 ◽  
Author(s):  
J. L. Clapperton ◽  
J. W. Czerkawski

1. Propane-1:2-diol (loog/d) was infused through a cannula into the rumen of sheep receiving a ration of hay and dried grass. The concentration of volatile fatty acids, propanediol, lactic acid and of added polyethylene glycol, and the pH of the rumen contents were measured. The energy metabolism of the sheep was also determined.2. Most of the propanediol disappeared from the rumen within 4 h of its infusion. The infusion of propanediol resulted in a 10% decrease in the concentration of total volatile acids; the concentration of acetic acid decreased by about 30%, that of propionic acid increased by up to 60% and there was no change in the concentration of butyric acid.3. The methane production of the sheep decreased by about 9% after the infusion of propanediol and there were increases in the oxgyen consumption, carbon dioxide production and heat production of the animals; each of these increases was equivalent to about 40% of the theoretical value for the complete metabolism of 100 g propanediol.4. It is concluded that, when propanediol is introduced into the rumen, a proportion is metabolized in the rumen and a large proportion is absorbed directly. Our thanks are due to Dr J. H. Moore for helpful discussions, to Mr D. R. Paterson, Mr J. R. McDill and Mr C. E. Park for looking after the animals and to Miss K. M. Graham, Miss A. T. McKay and Mrs C. E. Ramage for performing the analyses.


1975 ◽  
Vol 26 (4) ◽  
pp. 729 ◽  
Author(s):  
ML Bigham ◽  
WR McManus

Two studies are reported in which young lambs were changed rapidly from roughage diets to whole wheat diets and subjected to various treatments aimed at facilitating adaptation to the wheat diet. In pen feeding studies, groups of three sheep with rumen cannulae were used to investigate the effects of the various treatments on wheat sickness. The treatments included intraruminal administration of sulphadimethoxine before and during wheat feeding; moistening; and restriction of grain intake. The studies indicated that except perhaps for restriction of intake, none of the methods used was successful in reducing the build-up of lactic acid and decline in rumen pH and therefore wheat sickness. Sulphadimethoxine did not have a major effect on volatile fatty acid or lactic acid production when wheat grain was consumed. In an antibiotic dose response trial, 59 lambs were changed from roughage to wheat grain diets, restricted amounts of wheat grain with sulphadimethoxine being offered at four levels (0, 45.4, 136.3 and 272.7 mg/kg liveweight). The drug proved to be toxic and the lamb mortality (5, 23, 39 and 62%) rose as the dose increased. Results are discussed in relation to metabolic and practical aspects of wheat grain feeding of lambs and the need for further work to seek practical means for regulating intake under group feeding conditions. *Part III, Aust. J. Agric. Res., 24: 425 (1973).


1957 ◽  
Vol 8 (6) ◽  
pp. 691 ◽  
Author(s):  
RL Reid ◽  
JP Hogan ◽  
PK Briggs

Detailed data are presented on changes in the proportions of acetic, propionic, and butyric acids in the rumen after feeding on various diets. Pre-feeding proportions were constant on each diet but varied from a mixture of 72-76 per cent. acetic, 14-16 per cent. propionic, and 10-12 per cent. butyric acid on all-roughage diets to one of 63-65 per cent. acetic, 18-20 per cent. propionic, and 16-18 per cent. butyric acid on a diet containing 70 per cent. wheat grain. On all diets the proportion of propionic acid increased after feeding and reached a peak which coincided with the maximum level of total volatile fatty acids. The response of butyric acid was variable, low levels being recorded on a diet of lucerne chaff and on one containing a high proportion of cracked maize. The proportion of acetic acid always declined after feeding. These responses were modified in experiments on rations containing high proportions of wheaten starch, in which rumen pH fell below 5.0 as a result of lactic acid accumulation. When animals were first fed on such diets, a decline in rumen pH below 5.0-5.5 after feeding was always associated with a pronounced decline in the proportions of propionic and butyric acids, to levels as low as 8 and 5 per cent. respectively. Continued feeding of such diets did not affect the response of butyric acid, but there was evidence of a change in propionic acid production in response to low pH conditions, both in respect to short-term change during experiments in which low rumen pH levels were maintained for considerable periods and to long-term change when such diets were fed intermittently over considerable periods. The implications of these findings are discussed with respect to the effects of pH on individual volatile fatty acid production in the rumen, and on the qualitative nature of the microbial population and on their metabolic patterns.


1974 ◽  
Vol 25 (2) ◽  
pp. 349 ◽  
Author(s):  
RH Weston

The voluntary feed consumption (VFC) and body weight gain of lambs initially 12 weeks old and weighing 22 kg were measured when diets based on whole wheat grain and varying in straw content were offered. The basal diet comprised, on an organic matter (OM) basis, about 82 parts whole wheat grain and 18 parts protein concentrate; ground wheaten straw was added to provide diets with 2%, 7% or 13% straw. Daily VFC, expressed in relation to body weight in kg0.75 (BW0.75), increased from 85.6 with 2% straw through 90.4 with 7% straw to 94.2 with 13% straw. The corresponding OM digesti bilities were calculated to range from 84.8 to 77.6%. However, the intake of digestible OM and the rate of body weight gain were not affected by the straw content of the diet, the respective mean values for all lambs being 73g/day BW0.75 and 293 g/day. Lambs initially 25 weeks old and weighing 38 kg were offered a diet (2% straw) based on wheat in which the wheat was presented either as whole grains or in ground and pelleted form. With the whole grain diet the daily rates of OM intake, digestible OM intake and body weight gain were 75.6 g/ BW0.75, 64.7 and 254 g respectively; the corresponding values with the ground grain diet were about 20% lower. Studies involving the slaughter of animals showed that a large proportion of the wheat grain consumed reached the rumen in the form of whole grains and these contributed significantly to the dry matter of the ruminal digesta. The rate of ruminal digestion of whole wheat grains was slow (37% in 96 hr) when the sheep were given a diet based on wheat. By contrast, when a roughage diet was consumed the rate was high (81% in 96 hr). Fractured grain was rapidly digested in the rumen (67% in 20 hr). The mean residence time of water-soluble marker in the rumen and the rate of digesta flow from the rumen were greater in fistulated sheep given a whole grain diet than with a ground grain diet. The diets also differed with respect to the concentration of potassium in rumen liquor, the rumen potassium pool size and the rate of flow of sodium and volatile fatty acids to the omasum. It was concluded that the roughage requirement of the ruminant lamb fed on concentrate diets based on whole wheat did not exceed the equivalent of 2 g ground straw per 100 g diet. The possibility of a higher roughage requirement with ground wheat diets is suggested. ___________________ *Part VII, Aust. J. Agric. Res., 24: 387 (1973).


1970 ◽  
Vol 12 (3) ◽  
pp. 503-512 ◽  
Author(s):  
P. Jackson ◽  
J. A. F. Rook

SUMMARYThe effect of introducing a solution of fatty acids (consisting mainly of ammonium acetate) into the drinking water of Jersey and Friesian cows on the yield and composition of milk was investigated. In short-term experiments there were small increases in milk yield and in the yield of fat in Jersey cows receiving either a high-roughage or a high-concentrate diet and in Friesian cows receiving a high-concentrate diet. Friesian cows receiving a high-roughage diet gave no response. In a long-term experiment extending over 16 weeks of lactation with Jersey cows receiving a high-concentrate diet, there was no immediate effect on milk yield but a greater persistency and overall the yield of fat was increased by 5·9%.Inclusion of ammonia salts in the drinking water caused increases in the ammonia contents of rumen liquor and of blood but there was little effect on rumen pH or the volatile fatty acids of rumen liquor.


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