scholarly journals Volatile fatty acids and lactic acid in the rumen of dairy cows receiving a variety of diets

1957 ◽  
Vol 11 (3) ◽  
pp. 288-298 ◽  
Author(s):  
D. A. Balch ◽  
S. J. Rowland
1990 ◽  
Vol 73 (8) ◽  
pp. 2168-2178 ◽  
Author(s):  
D.E. Otterby ◽  
D.G. Johnson ◽  
R. Towns ◽  
R.M. Cook ◽  
R.A. Erdman ◽  
...  

1929 ◽  
Vol 19 (4) ◽  
pp. 649-655 ◽  
Author(s):  
V. Subrahmanyan

Methods for extraction, concentration and determination of minute quantities of soluble carbohydrates, lactic acid and volatile fatty acids have been described. Different factors affecting the accuracy of the determinations have been studied and corrections, where necessary, have been suggested.


2011 ◽  
Vol 79 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Qendrim Zebeli ◽  
Sarah J Terrill ◽  
Alberto Mazzolari ◽  
Suzanna M Dunn ◽  
Wen Z Yang ◽  
...  

This study evaluated the effects of intraruminal administration ofMegasphaera elsdeniion ruminal fermentation patterns, the profile of plasma metabolites, and milk yield and composition of mid-lactation dairy cows. Eight primiparous, ruminally cannulated Holstein cows were arranged in a paired 2×2 crossover design. Cows were randomly assigned to one of two treatments: 1) intraruminal inoculation of 35 ml suspension per day ofM. elsdeniiATCC 25940 (MEGA), containing 108cfu/ml of bacteria, dissolved in 35 ml of saline (0·15m), or 2) carrier alone (35 ml saline; CTR). Both postprandial and preprandial rumen volatile fatty acids (VFA) and plasma metabolite measurements were analysed. Postprandial VFA patterns were affected the most, with butyrate (P<0·01) and valerate (P<0·01) proportions increasing, and acetate (P<0·01), isobutyrate (P=0·05) and isovalerate (P<0·01) decreasing in MEGA cows. Preprandial data measured at various days showed that MEGA dosage tended to increase the molar proportion of propionate (P=0·09) and lower the acetate to propionate ratio (P=0·07) in the rumen fluid. There was no effect of treatment on rumen pH and on the concentration of lactate in the rumen as well as on selected preprandial plasma metabolites. Postprandial plasma concentrations of cholesterol tended to increase (P=0·07) in MEGA cows compared with CTR. Concentrations of non-esterified fatty acids (NEFA) in the plasma were lower in MEGA cows after the morning feeding (P<0·01). Sampling hour also affected plasma NEFA in this study. Plasma β-hydroxybutyrate (BHBA) were not affected by the treatment (P>0·05); however, after the morning feeding BHBA concentration was increased in both groups of cows. Dry matter intake and milk yield and composition were not affected by treatment. In conclusion, results indicate thatM. elsdeniihas the potential to modulate the rumen fermentation profile in mid-lactation Holstein cows, but these effects were only slightly reflected in changes in plasma metabolites and milk composition.


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.


1992 ◽  
Vol 68 (1) ◽  
pp. 195-207 ◽  
Author(s):  
J. B. Schutte ◽  
J. de Jong ◽  
E. J. van Weerden ◽  
S. Tamminga

The pentose sugar l-arabinose is one of the most abundant components released by complete hydrolysis of non-starch polysaccharides of feed ingredients of vegetable origin. Two studies were conducted to investigate the apparent ileal digestibility and urinary excretion of l-arabinose at dietary inclusion levels of 50 and 100 g/kg, and 25, 50, 75 and 100 g/kg respectively, in pigs. As a reference, d-glucose was included in the studies. Water intake, ileal flow of volatile fatty acids and ileal and faecal digestibilities of dietary nutrients in pigs fed on the different diets were also examined. Castrated pigs were prepared with a post-valvular T-caecum cannula to measure ileal digestibility. Faecal digestibility was measured in non-cannulated pigs. Apparent ileal digestibility of l-arabinose was found to be approximately 70%. The presence of l-arabinose in the diet increased ileal flow of volatile fatty acids and lactic acid, suggesting the occurrence of microbial degradation of l-arabinose in the pig small intestine. l-arabinose was partly excreted in the urine. The extent of this urinary excretion as a percentage of intake increased linearly (P < 0.01) as the dietary level increased. In pigs fed on the 25 g l-arabinose/kg diet, 10.9% of the l-arabinose consumed appeared in the urine. This level was increased to 14.7% when pigs were fed on a diet containing 100 g l-arabinose/kg diet. Faecal digestibility and retention of nitrogen decreased significantly in pigs fed on the l-arabinose diets.


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