scholarly journals Relationship of Portal-Drained Viscera and Liver Net Flux of Glucose, Lactate, Volatile Fatty Acids, and Nitrogen Metabolites to Milk Production in the Ewe

1999 ◽  
Vol 82 (3) ◽  
pp. 597-604 ◽  
Author(s):  
H.C. Freetly ◽  
C.L. Ferrell
Keyword(s):  
Fatty Acids ◽  
Milk Production ◽  
Volatile Fatty Acids ◽  
Net Flux ◽  
Relationship Of

Concentrate feeding and ruminal fermentation. 1. Influence of the frequency of feeding concentrates on rumen acid composition, feed intake and milk production.

1981 ◽  
Vol 29 (4) ◽  
pp. 239-248
Author(s):  
A. Malestein ◽  
A.T. van't Klooster ◽  
G.H.M. Counotte ◽  
R.A. Prins
Keyword(s):  
Fatty Acids ◽  
Lactic Acid ◽  
Milk Production ◽  
Milk Fat ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Molar Ratio ◽  
Ruminal Fermentation ◽  
Period 2 ◽  
Short Time

1. Four cows with rumen cannulae were given 12 kg concentrates daily in 2 equal portions at 0800 and 1530, in one portion of 12 kg at 0800 or in 4 portions of 3 kg each at 0800, 1100, 1400 and 1700 h. Every period lasted 2 weeks. In addition to the concentrates hay was provided at 0900 and 1630 h and was adjusted so that the daily remainder was at least 1 kg. In 1978 experiments were made with concentrates low in starch and sugars (LSS) (23%) and in 1979 with concentrates high in starch and sugars (HSS) (50%). In 1978 when total DM intake, milk production and milk fat content of each milking were estimated daily, the trend in pH and concentration of L-lactic acid in rumen fluid were estimated on the last day of the preliminary period (2 X 6 kg) and on the 1st, 7th and 14th days of the experimental periods (1 X 12 kg and 4 X 3 kg). In 1979 the same estimations were made, but D-lactic acid and volatile fatty acids were also estimated. Compared to 2 X 6 kg concentrates the changeover to daily 1 X 12 kg or 4 X 3 kg concentrates did not result in significant differences in DM intake nor in milk or milk fat production. Within types of concentrates there was hardly any difference in lowest rumen pH between frequencies of concentrate feeding. When HSS concentrates were given pH in rumen fluid tended to be lower than with the LSS concentrates. With 2 X 6 kg HSS concentrates, pH in rumen fluid was for a short time lower than 5.5. Lactic acid concentrations in the rumen fluid reached maximum within 1 h after concentrate feeding and L-lactic acid was 6.5, 5.0 and 2.0 mmol/litre, respectively, for 1 X 12, 2 X 6 and 4 X 3 kg LSS concentrates. For HSS concentrates the values were 4.5, 2.5 and 1.0 mmol/litre. When the HSS concentrates were given maximum concentration of D-lactic acid in rumen fluid were 2.5 to 3 times the L-lactic acid concentration. When lactic acid was not increased D- and L-lactic acid concentrations were similar. At 0800 h the molar ratio of volatile fatty acids (C2:C3:C4) as a percentage of total volatile fatty acids (VFA) in rumen fluid was 62:22:15 and changed gradually to 56:24:20 at 1900 h. Differences in VFA between frequencies of concentrate feeding were small. Total concentrations of VFA did not vary between treatments. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Effect of Inoculum Pretreatment on the Composition of Microbial Communities in Anaerobic Digesters Producing Volatile Fatty Acids

2020 ◽  
Vol 8 (4) ◽  
pp. 581 ◽  
Author(s):  
Lucia Blasco ◽  
Minna Kahala ◽  
Elina Tampio ◽  
Markku Vainio ◽  
Satu Ervasti ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Microbial Communities ◽  
Volatile Fatty Acids ◽  
Cost Effective ◽  
Added Value ◽  
Methane Formation ◽  
Anaerobic Digesters ◽  
Formation Pathway ◽  
Fuels And Chemicals ◽  
Relationship Of

Volatile fatty acids (VFAs) are intermediates in the methane formation pathway of anaerobic digestion and can be produced through the fermentation of organic wastes. VFAs have become an anticipated resource- and cost-effective way to replace fossil resources with higher added value and more versatile fuels and chemicals. However, there are still challenges in the production of targeted compounds from diverse and complex biomasses, such as urban biowastes. In this study, the aim was to modulate the microbial communities through inoculum treatment to enhance the production of green chemicals. Thermal and freeze-thaw treatments were applied to the anaerobic digester inoculum to inhibit the growth of methanogens and to enhance the performance of acidogenic and acetogenic bacteria. VFA fermentation after different inoculum treatments was studied in batch scale using urban biowaste as the substrate and the process performance was assessed with chemical and microbial analyses. Inoculum treatments, especially thermal treatment, were shown to increase VFA yields, which were also correlating with the dynamics of the microbial communities and retention times of the test. There was a strong correlation between VFA production and the relative abundances of the microbial orders Clostridiales (families Ruminococcaceae, Lachnospiraceae and Clostridiaceae), and Lactobacillales. A syntrophic relationship of these taxa with members of the Methanobacteriales order was also presumed.

The relationship of circulating glucose, ketones, and F.F.A. to milk production in Awassi ewes

1967 ◽  
Vol 69 (3) ◽  
pp. 349-354 ◽  
Author(s):  
J. H. Adler ◽  
E. Lotan
Keyword(s):  
Fatty Acids ◽  
Adipose Tissue ◽  
Blood Glucose ◽  
Free Fatty Acids ◽  
Milk Production ◽  
Ketone Group ◽  
Relationship Of ◽  
The Relationship ◽  
Low Serum ◽  
Clinical Cases

The relationship between milk production, blood glucose, blood ketones and free fatty acids (F.F.A.) were studied in lactating Awassi ewes. Increased milk production in ewes was associated with diminished blood glucose and increased serum F.F.A. Clinical cases of ketosis were not observed.The ewes studied here could be divided into two metabolic populations depending on their blood ketone levels. Those with blood ketone levels of 11 mg % or more, did not show a significant increase in serum F.F.A. or a decrease in blood glucose values with increased milk production. The group of ewes with less than 11 mg % blood ketones showed a significant decrease in blood glucose and a significant increase in serum F.F.A. as milk production increased. Ketonemia of the high ketone group of ewes, was associated with relatively low serum F.F.A. levels. It is suggested that these ketones not originate from depot fat via serum F.F.A. These ketones and/or their precursors, acetic and butyric acids probably participate in caloric homeostasis and are associated with a glucose sparing serum F.F.A. suppressing mechanism.The suggestion that ketones derived from rumen (R.D.K.) should be distinguished from those derived from adipose tissue (A.D.K.) is discussed.

The composition of rumen fluid from cows fed biuret and urea

1968 ◽  
Vol 35 (2) ◽  
pp. 203-212 ◽  
Author(s):  
R. Waite ◽  
Agnes G. Wilson
Keyword(s):  
Fatty Acids ◽  
Chemical Composition ◽  
Milk Production ◽  
Volatile Fatty Acids ◽  
Rumen Fluid ◽  
Total Volatile ◽  
Urea Treatment ◽  
Lactating Cows ◽  
Total Fatty Acids ◽  
Dietary Treatments

SummaryThe effect on the chemical composition of rumen fluid of replacing oilcake nitrogen by either biuret or urea N in the concentrate part of the ration for cows has been investigated. The biuret treatment produced the highest concentrations of NPN and the lowest concentrations of ammonia N in the fluid, whereas the urea treatment gave rise to higher concentrations of NPN than did the oilcake treatment and the highest ammonia N concentrations of the 3 diets. It is unlikely, however, that the differences in either peak or mean ammonia concentrations between the biuret and urea diets, if they occurred in lactating cows receiving these diets, would be sufficient to affect milk production. The concentration of ammonia N in the rumen liquor of cows on the biuret diet increased progressively up to the 5th to 8th week of feeding this diet. The different dietary treatments did not result in any marked differences in the concentrations of total volatile fatty acids in the rumen fluids or in the proportions of acetic, propionic and butyric acids in the total fatty acids.

Portal drained-viscera heat production and net flux of volatile fatty acids in Iberian pigs fed acorn

2019 ◽  
Vol 59 (8) ◽  
pp. 1470 ◽  
Author(s):  
M. Lachica ◽  
L. González-Valero ◽  
J. M. Rodríguez-López ◽  
L. Lara ◽  
I. Fernández-Fígares
Keyword(s):  
Fatty Acids ◽  
Heat Production ◽  
Volatile Fatty Acids ◽  
Sampling Period ◽  
Potential Contribution ◽  
Net Flux ◽  
Proportional Contribution ◽  
Metabolisable Energy ◽  
Evergreen Oak ◽  
Over Time

The aim of the present study was to determine the portal-drained viscera (PDV) heat production (HP) and net PDV flux of volatile fatty acids (VFA: acetic, propionic and butyric acids) in Iberian pigs (34-kg bodyweight) fed with acorn from evergreen oak, and to ascertain whether there is an effect of acorn feeding over time. In addition, potential contribution of both parameters to the energy budget of the animal was calculated. The following two sampling periods were conducted with six gilts: after 1 day (I) and after 1 week (II) of acorn feeding. Postprandial PDV HP was 29% greater (P < 0.01) in Sampling period II than in Sampling period I, but net PDV flux of VFA was only slightly greater (5%, P > 0.1). Potential proportional contribution of VFA to the whole HP was almost identical in both sampling periods (0.057, on average), representing 0.109 (on average) of the metabolisable energy requirements for maintenance. Pigs adapted for 1 week to an acorn diet had increased PDV HP without an increase in the net PDV flux of VFA, indicating that, apparently, nutrients other than VFA were responsible for the increased PDV HP.

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