Rumination in sheep. IV. The investigation of some possible control mechanisms

1965 ◽  
Vol 16 (5) ◽  
pp. 837 ◽  
Author(s):  
GR Pearce
Keyword(s):  
Volatile Fatty Acids ◽  
Control Mechanisms ◽  
Apparent Effect ◽  
Ph Change ◽  
Once Daily ◽  
Ph Values ◽  
Rumen Ph ◽  
Per Se ◽  
Saliva Flow

Rumination of caged sheep was recorded under conditions of: (a) variable rumen pH, (b) rumen infusions of volatile fatty acids and urea, (c) variable saliva flow to the rumen, (d) mixing of the rumen contents in vivo, and (e) teasing with food. The circadian (24-hr) pattern of rumination after once daily feeding was similar to the pattern of rumen pH change, but no consistent effect of pH per se upon the initiation of rumination was found when rumen contents were replaced with buffered mixtures at pH values ranging from c. 5.10 to 6.95. Rumination, however, tended to be irregular at the lower pH levels. The addition of sodium carbonate to the rumen to prevent a fall in pH after feeding had no apparent effect upon the initiation of rumination. The infusion of volatile fatty acid or urea solutions into the rumen apparently did not affect rumination. Removal of part of the saliva by aspiration during eating, or adding previously aspirated saliva had no effect. The manual mixing of rumen contents by means of a large rumen fistula did not affect initiation of rumination. After teasing with food, one sheep did not recommence ruminating for several hours; another showed practically no reaction; and the remaining two intermediate responses. The initiation of rumination is discussed in relation to these and some other aspects.

scholarly journals Comparison of Two Sampling Techniques for Evaluating Ruminal Fermentation and Microbiota in the Planktonic Phase of Rumen Digesta in Dairy Cows

2020 ◽  
Vol 11 ◽  
Author(s):  
Camila Flavia de Assis Lage ◽  
Susanna Elizabeth Räisänen ◽  
Audino Melgar ◽  
Krum Nedelkov ◽  
Xianjiang Chen ◽  
...  
Keyword(s):  
Volatile Fatty Acids ◽  
Sampling Method ◽  
Bacterial Community Composition ◽  
Sampling Technique ◽  
Standard Diet ◽  
Ruminal Fermentation ◽  
Ph Change ◽  
Ruminal Fluid ◽  
Rumen Ph ◽  
Dissolved Hydrogen

The objective of this experiment was to compare ruminal fluid samples collected through rumen cannula (RC) or using an oral stomach tube (ST) for measurement of ruminal fermentation and microbiota variables. Six ruminally cannulated lactating Holstein cows fed a standard diet were used in the study. Rumen samples were collected at 0, 2, 4, 6, 8, and 12 h after the morning feeding on two consecutive days using both RC and ST techniques. Samples were filtered through two layers of cheesecloth and the filtered ruminal fluid was used for further analysis. Compared with RC, ST samples had 7% greater pH; however, the pattern in pH change after feeding was similar between sampling methods. Total volatile fatty acids (VFA), acetate and propionate concentrations in ruminal fluid were on average 23% lower for ST compared with RC. There were no differences between RC and ST in VFA molar proportions (except for isobutyrate), ammonia and dissolved hydrogen (dH2) concentrations, or total protozoa counts, and there were no interactions between sampling technique and time of sampling. Bacterial ASV richness was higher in ST compared with RC samples; however, no differences were observed for Shannon diversity. Based on Permanova analysis, bacterial community composition was influenced by sampling method and there was an interaction between sampling method and time of sampling. A core microbiota comprised of Prevotella, S24-7, unclassified Bacteroidales and unclassified Clostridiales, Butyrivibrio, unclassified Lachnospiraceae, unclassified Ruminococcaceae, Ruminococcus, and Sharpea was present in both ST and RC samples, although their relative abundance varied and was influenced by an interaction between sampling time and sampling method. Overall, our results suggest that ruminal fluid samples collected using ST (at 180 to 200 cm depth) are not representative of rumen pH, absolute values of VFA concentrations, or bacterial communities >2 h post-feeding when compared to samples of ruminal fluid collected using RC. However, ST can be a feasible sampling technique if the purpose is to study molar proportions of VFA, protozoa counts, dH2, and ammonia concentrations.

Effect of feeding lactose on rumen metabolism in-vitro and in-vivo

1998 ◽  
Vol 1998 ◽  
pp. 168-168 ◽  
Author(s):  
A. Hussain ◽  
E. L. Miller
Keyword(s):  
Volatile Fatty Acids ◽  
Gas Production ◽  
Adaptation Period ◽  
Rumen Ph ◽  
Rumen Metabolism ◽  
Lactose Fermentation ◽  
Better Regulation ◽  
Effect Of Feeding

Inclusion of lactose in dairy cow rations increases dry matter intake (DMI) and milk yield (Garnsworthy 1996). This may be due to the relatively slow rate of lactose fermentation ( Hussain and Miller, 1998) sustaining better regulation of rumen pH and also possible consequence for microbial protein synthesis (Chamberlain et al., 1993).This experiment was conducted to study the changes in rumen environment over the adaptation period and effect of these changes on the fermentation of lactose itself.Three Suffolk wethers (b.wt 56± 7.36 kg) maintained on hay and concentrate (600:400) were offered 50g lactose per day for 16 days. Rumen liquor collected on dayO (before offering lactose), 4, 8, 12 and 16 was used to measure gas production from sucrose and lactose ( Menke et al., 1979). On these days rumen samples were collected at 0, 1, 2, 4, 6 and 8 hrs after the morning feed. Rumen pH, ammonia N (NH3N) and volatile fatty acids (VFA) were measured. At 8 hrs time rumen samples were also taken for protozoa enumeration. Data obtained were analysed using ANOVA procedure of Genstat 5.

Investigating Eremophila glabra as a bioactive agent for preventing lactic acidosis in sheep

2010 ◽  
Vol 50 (6) ◽  
pp. 449 ◽  
Author(s):  
P. G. Hutton ◽  
Z. Durmic ◽  
P. E. Vercoe
Keyword(s):  
Lactic Acidosis ◽  
Volatile Fatty Acids ◽  
Native Plant ◽  
Rumen Ph ◽  
Freeze Dried ◽  
Australian Native Plant ◽  
And Control ◽  
Higher Doses

The Australian native plant Eremophila glabra was tested as a potential agent for preventing lactic acidosis in sheep after it was observed to be effective against acidosis in vitro. Ruminally fistulated wethers were infused via rumen cannula with single doses of kibbled wheat (14 g/kg bodyweight) and either virginiamycin (Eskalin500; AB, 80 mg/kg of wheat plus 100 g milled oaten hay/kg of wheat, n = 6), E. glabra (EG, 100 g freeze-dried and milled leaf material per kg of wheat, n = 10) or milled oaten hay (Control, 100 g milled oaten hay/kg of wheat, n = 16). Rumen samples were collected immediately before infusion and then 2, 4, 6, 8, 12, 16 and 24 h after the infusion. The samples were analysed for pH, D-lactate, volatile fatty acids (VFA) and osmolality. Rumen pH and D-lactate values indicative of acidosis were detected in the Control and EG groups. The pH nadir of the rumen was 12 h after the wheat infusion, at which time the values in the EG (pH = 4.87) and Control (pH = 5.09) groups were lower (P < 0.05) than in the AB group (pH = 5.63) and the D-lactate concentrations were higher (P < 0.05) in the EG and Control groups (24 mmol/L and 15 mmol/L, respectively) than in the AB group (0.9 mmol/L). At the same time, total VFA concentration was higher (P < 0.05) in the AB group (102 mmol/L) than in the Control (65 mmol/L) and the EG (14 mmol/L) groups. Rumen osmolality did not differ between groups. Virginiamycin was effective at preventing lactic acidosis. However, the inclusion of dried leaves from E. glabra at a similar level that was effective in vitro did not prevent lactic acidosis in vivo, and the reasons behind this remain unclear. The study demonstrates the difficulty in converting in vitro results to in vivo and highlights the need to test the plant at higher doses in vivo.

Studies on the relationship of saliva to rumen function of sheep on low feed intakes

1962 ◽  
Vol 13 (5) ◽  
pp. 907 ◽  
Author(s):  
WR McManus
Keyword(s):  
Volatile Fatty Acid ◽  
Ph Values ◽  
In Vivo Experiments ◽  
Rumen Ph ◽  
Conscious Sheep ◽  
Mixed Saliva ◽  
Relationship Of ◽  
The Relationship ◽  
Standard Ration

Seven in vivo experiments are reported in which the effects of diverting alkaline mixed saliva from the actively fermenting contents of the rumen of anaesthetized and conscious sheep fed on a standard ration were studied for periods up to 6 hr. The absence of various quantities of saliva (225–1349 ml) was associated with profound alterations in the rumen environment: rumen liquor volatile fatty acid (V.F.A.) levels were consistently and substantially elevated, and rumen pH levels depressed. These changes in the rumen environment began about 40–60 min after saliva diversion commenced, and were sustained long after such values for the control animals had inflected towards fasting levels. Rumen movements were recorded in two experiments. Rumen movement was reduced, but not entirely suppressed, some 60 min after the minimal pH values obtained. It is suggested that this reduction in rumen movement was a consequence of depressed pH values. The rumen pH-rumen V.F.A. relationship was, in six such cases, altered but the strength of this relationship was not significantly changed. It was concluded that these effects on rumen pH-V.F.A. levels and relationship were due, directly or indirectly, to the changed buffering or osmotic regime, or both, of the saliva-depleted rumen liquor. Implications of these findings are discussed in the light of rumen physiology and the field use of oesophageally fistulated sheep.

scholarly journals The effect of phosphate and carbonate-bicarbonate supplements on the rumen buffering systems of sheep

1970 ◽  
Vol 24 (3) ◽  
pp. 653-660 ◽  
Author(s):  
Bijan Emmanuel ◽  
M. J. Lawlor ◽  
D. McAleese
Keyword(s):  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Control Diet ◽  
Cellulase Activity ◽  
Inorganic Phosphorus ◽  
Mineral Supplement ◽  
Mineral Supplements ◽  
Ph Values ◽  
Rumen Ph ◽  
Ph Range

1. Two wethers fitted with permanent rumen cannulas were used to study the effect of two mineral supplements, Na2HPO4 and a 1:1 mixture of Na2CO3 and NaHCO3, on the buffering system in the rumen of sheep given a pelleted roughage-concentrate diet.2. Measurements were made of rumen pH, buffering capacity value (β), total volatile fatty acids (VFA), CO2 and inorganic phosphorus concentrations as well as rumen cellulase activity.3. The addition of either mineral supplement to the diet significantly (P < 0.001) increased the rumen pH values during the critical post-feeding period, there was a difference of only 0.5 pH unit between the minimum and maximum pH values.4. Both mineral supplements significantly increased the concentrations of CO2 in the rumen fluid and rumen cellulase activity. They resulted in a general reduction in total VFA concentrations. It is suggested that this may possibly arise from increased absorption of VFA associated with increased CO2 tension in the rumen fluid.5. The Na2HPO4 supplement significantly ( P < 0.001) increased the β values in the pH range 6–8, whereas the bicarbonate supplement contributed to raising the β values in the pH range 5–6.6. The bicarbonate supplements raised cellulose digestibility from 39.7% for the control diet to 45.6% and the addition of Na2HPO4 further raised the digestibility to 51.1%. It would appear that low rumen pH impairs rumen cellulase activity and this could be offset by the addition of mineral supplements.

scholarly journals Niacin mitigates rumen epithelial damage in vivo by inhibiting rumen epithelial cell apoptosis on a high concentrate diet

2021 ◽  
Author(s):  
Zhen Gao ◽  
Yanjiao Li ◽  
Chao Xu ◽  
Dan Luo ◽  
Qinghua Qiu ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Antioxidant Capacity ◽  
Inflammatory Cytokines ◽  
Cell Apoptosis ◽  
Volatile Fatty Acids ◽  
Epithelial Damage ◽  
Rumen Epithelium ◽  
Rumen Ph ◽  
Epithelial Cell Apoptosis

Abstract To investigate the effects of niacin on rumen fermentation, rumen epithelial antioxidant activity, and rumen epithelial cell apoptosis on high concentrate (HC) diets, nine male Hu sheep were randomly divided into: low concentrate diet (LC; concentrate : forage (C:F) = 20:80, high concentrate diet (HC; C:F = 80:20), and HCN diet (HC diet + niacin at 800 mg/kg diet air-dry matter). Compared with the LC group, the HC group had a lower rumen pH, increased volatile fatty acids and lactic acid in the rumen, reduced activity of antioxidant enzymes and total antioxidant capacity, and increased malondialdehyde content in the rumen epithelium (P < 0.05). Rumen epithelial papilla morphology was decreased, and apoptosis-related indicators and serum inflammatory cytokines were increased in the HC group over the LC group (P < 0.05). Compared with the HC diet, the HCN diet increased rumen pH, rumen epithelium antioxidant capacity, and rumen epithelial papilla morphology, decreased rumen lactate content, serum inflammatory cytokines, and apoptosis-related indicators (P < 0.05). Therefore, adding 800 mg/kg niacin helped protect against rumen epithelial damage by avoiding drastic changes in the rumen environment and improved rumen epithelial antioxidant capacity to inhibit rumen epithelial cell apoptosis in sheep on a HC diet.

Intercellular pH of Peach and Apricot Mesocarp

1988 ◽  
Vol 15 (4) ◽  
pp. 505 ◽  
Author(s):  
TD Ugalde ◽  
PH Jerie ◽  
DJ Chalmers
Keyword(s):  
Growth Rate ◽  
Prunus Persica ◽  
Prunus Armeniaca ◽  
Ph Change ◽  
Ph Values ◽  
Rate Of Growth ◽  
Prunus Armeniaca L

Intercellular pH of developing peach (Prunus persica (L.) Batsch) and apricot (Prunus armeniaca L.) mesocarp was estimated from the pH of small volumes of water in contact with washed cut surfaces. In both fruits, the pH changed from neutral to acidic as the rate of growth changed from slow and declining to rapid. In peaches, the changes in intercellular pH and growth rate occurred gradually over a 4-week period, while in apricots these changes were more rapid. Studies on the mechanism of the pH change showed the measured pH values to be a reasonable and adequate estimate of intercellular pH in vivo. We propose that intercellular acidity influences mesocarp development in at least two ways. It allows high rates of assimilate utilisation by inducing activity in existing intercellular invertase, and it predisposes the tissue to ripening.

Net alkali requirement of foods of different acidogenicities in a continuous culture system

1998 ◽  
Vol 22 ◽  
pp. 154-156
Author(s):  
D. Wadhwa ◽  
R. J. Dewhurst ◽  
M. S. Dhanoal ◽  
L. P. Borgida
Keyword(s):  
Volatile Fatty Acids ◽  
Animal Health ◽  
Eating Rate ◽  
Blood Ph ◽  
Continuous Culture System ◽  
Fermentable Carbohydrates ◽  
And Performance ◽  
Saliva Flow

Maintaining blood pH within a narrow range is the first priority of an animal compared with the other body functions (Erdman et al., 1982). Under normal forage feeding conditions, maintenance of rumen, blood and cellular pH within safe ranges poses no problem for the animal. However, the inclusion of high levels of readily fermentable carbohydrates is often necessary to meet the energy requirements of high producing ruminants. Unfortunately, these foods can result in low rumen pHs which can have adverse effects on animal health and performance. When saliva flow is inadequate to counteract excessive ruminal acidity, the use of buffers may be justified. The in vivo studies reviewed by Muller and Kilmer (1979) have shown that the responses to the addition of buffers to dairy cow rations has been variable and inconclusive.Part of the reason for this uncertainty is because buffer requirements cannot be accurately predicted from the chemical composition of foods, since measurements such as buffering capacity (BC) take no account of changes during fermentation such as the production of volatile fatty acids (VFA), ammonia and the disappearance of the fibre which confers BC. An in vitro approach was adopted for this work since it is difficult to conduct in vivo experiments in this area, owing to the health risks to cows as well as difficulties in distinguishing diet effects because of the strategies employed by cows to overcome excess acidity (e.g. eating rate, salivation, rumination).

Effect of feeding lactose on rumen metabolism in-vitro and in-vivo

1998 ◽  
Vol 1998 ◽  
pp. 168-168
Author(s):  
A. Hussain ◽  
E. L. Miller
Keyword(s):  
Volatile Fatty Acids ◽  
Gas Production ◽  
Adaptation Period ◽  
Rumen Ph ◽  
Rumen Metabolism ◽  
Lactose Fermentation ◽  
Better Regulation ◽  
Effect Of Feeding

Inclusion of lactose in dairy cow rations increases dry matter intake (DMI) and milk yield (Garnsworthy 1996). This may be due to the relatively slow rate of lactose fermentation ( Hussain and Miller, 1998) sustaining better regulation of rumen pH and also possible consequence for microbial protein synthesis (Chamberlain et al., 1993).This experiment was conducted to study the changes in rumen environment over the adaptation period and effect of these changes on the fermentation of lactose itself.Three Suffolk wethers (b.wt 56± 7.36 kg) maintained on hay and concentrate (600:400) were offered 50g lactose per day for 16 days. Rumen liquor collected on dayO (before offering lactose), 4, 8, 12 and 16 was used to measure gas production from sucrose and lactose ( Menke et al., 1979). On these days rumen samples were collected at 0, 1, 2, 4, 6 and 8 hrs after the morning feed. Rumen pH, ammonia N (NH3 N) and volatile fatty acids (VFA) were measured. At 8 hrs time rumen samples were also taken for protozoa enumeration. Data obtained were analysed using ANOVA procedure of Genstat 5.

scholarly journals The rumen buffering system of sheep fed pelleted roughage–concentrate rations

1969 ◽  
Vol 23 (4) ◽  
pp. 805-811 ◽  
Author(s):  
Bijan Emmanuel ◽  
M. J. Lawlor ◽  
D. M. Mcaleese
Keyword(s):  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Inorganic Phosphorus ◽  
Barley Straw ◽  
Total Volatile ◽  
Inorganic P ◽  
Ph Buffering ◽  
Ph Values ◽  
Rumen Ph ◽  
Inverse Pattern

1. Three wethers fitted with permanent rumen cannulas were given a pelleted roughage–concentrate ration containing 45% ground barley straw as roughage. The animals were given 1 kg of the diet at 08.00 h and 500 g at 17.00 h.2. The measurements made to determine the buffering components of the rumen fluid were: rumen pH, buffering capacity value (β), total volatile fatty acids (VFA), CO2 and inorganic phosphorus concentrations. β was expressed as the quantity of titrant (m-equiv./l.) required to bring about 2 unit changes in rumen fluid pH. The pH ranges in which the β values were measured were 4–6, 5–7 and 6–8. All measurements were made at hourly intervals over a 9 h period commencing 1 h before feeding.3. Rumen pH values were high before feeding, decreased to a minimum 2 h after feeding and then increased to approximately the original values. The concentrations of total VFA followed an inverse pattern. There was diurnal variation in the concentrations of CO2 but inorganic P levels varied very little throughout the day.4. Significant correlations were obtained between VFA, inorganic P and CO2 levels and the β values. It would appear that the bicarbonate and phosphate buffers were not effective in regulating the rumen pH when sheep were given a roughage–concentrate ration.

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