scholarly journals Lipid metabolism of liquid-associated and solid-adherent bacteria gin rumen contents of dairy cows offered lipid-supplemented diets

1990 ◽  
Vol 63 (3) ◽  
pp. 563-578 ◽  
Author(s):  
D. Bauchart ◽  
F. Legay- Carmier ◽  
M. Doreau ◽  
B. Gaillard
Keyword(s):  
Dairy Cows ◽  
Cell Envelope ◽  
Physical Adsorption ◽  
Latin Square ◽  
Basal Diet ◽  
Total Lipids ◽  
Associated Bacteria ◽  
Transmission Electron ◽  
Food Particles

The lipid distribution and fatty acid (FA) composition of total lipids, polar lipids and free fatty acids (FFA) were determined in liquid-associated bacteria (LAB) and solid-adherent bacteria (SAB) isolated from the rumen contents of seven dairy cows fitted with rumen fistulas. Two experiments, arranged according to a 4 x 4 and 3 x 3 Latin Square design, were performed using two basal diets consisting of one part hay and one part barley-based concentrate, and five lipid-supplemented diets consisting of the basal diet plus (g/kg dry matter): 53 or 94 rapeseed oil, 98 tallow, 87 soya-bean oil or 94 palmitostearin. For all diets used, total lipids were 1.7–2.2 times higher in SAB than in LAB (P < 005); this probably resulted from a preferential incorporation of dietary FA adsorbed onto food particles. Addition of oil or fat to the diets did not modify the polar lipid content but increased the FFA content of SAB and LAB by 150%. Lipid droplets were observed in the cytoplasm in SAB and LAB using transmission electron microscopy, which suggested that part of the additional FFA was really incorporated into the intracellular FFA rather than associated with the cell envelope by physical adsorption. Linoleic acid was specifically incorporated into the FFA of SAB, which emphasized the specific role of this bacterial compartment in the protection of this acid against rumen biohydrogenation.

scholarly journals Pseudomonas chlororaphis Produces Two Distinct R-Tailocins That Contribute to Bacterial Competition in Biofilms and on Roots

2017 ◽  
Vol 83 (15) ◽  
Author(s):  
Robert J. Dorosky ◽  
Jun Myoung Yu ◽  
Leland S. Pierson ◽  
Elizabeth A. Pierson
Keyword(s):  
Gene Cluster ◽  
Gene Clusters ◽  
Associated Bacteria ◽  
Content Type ◽  
Bacterial Competition ◽  
Transmission Electron ◽  
Lysis Cassette ◽  
First Time ◽  
Insight Into

ABSTRACT R-type tailocins are high-molecular-weight bacteriocins that resemble bacteriophage tails and are encoded within the genomes of many Pseudomonas species. In this study, analysis of the P. chlororaphis 30-84 R-tailocin gene cluster revealed that it contains the structural components to produce two R-tailocins of different ancestral origins. Two distinct R-tailocin populations differing in length were observed in UV-induced lysates of P. chlororaphis 30-84 via transmission electron microscopy. Mutants defective in the production of one or both R-tailocins demonstrated that the killing spectrum of each tailocin is limited to Pseudomonas species. The spectra of pseudomonads killed by the two R-tailocins differed, although a few Pseudomonas species were either killed by or insusceptible to both tailocins. Tailocin release was disrupted by deletion of the holin gene within the tailocin gene cluster, demonstrating that the lysis cassette is required for the release of both R-tailocins. The loss of functional tailocin production reduced the ability of P. chlororaphis 30-84 to compete with an R-tailocin-sensitive strain within biofilms and rhizosphere communities. Our study demonstrates that Pseudomonas species can produce more than one functional R-tailocin particle sharing the same lysis cassette but differing in their killing spectra. This study provides evidence for the role of R-tailocins as determinants of bacterial competition among plant-associated Pseudomonas in biofilms and the rhizosphere. IMPORTANCE Recent studies have identified R-tailocin gene clusters potentially encoding more than one R-tailocin within the genomes of plant-associated Pseudomonas but have not demonstrated that more than one particle is produced or the ecological significance of the production of multiple R-tailocins. This study demonstrates for the first time that Pseudomonas strains can produce two distinct R-tailocins with different killing spectra, both of which contribute to bacterial competition between rhizosphere-associated bacteria. These results provide new insight into the previously uncharacterized role of R-tailocin production by plant-associated Pseudomonas species in bacterial population dynamics within surface-attached biofilms and on roots.

Effects of intraruminal infusion of propionate on the concentrations of ammonia and insulin in peripheral blood of cows receiving an intraruminal infusion of urea

1995 ◽  
Vol 62 (4) ◽  
pp. 549-557 ◽  
Author(s):  
Jai-Jun Choung ◽  
David G. Chamberlain
Keyword(s):  
Lactic Acid ◽  
Dairy Cows ◽  
Propionic Acid ◽  
Peripheral Blood ◽  
Latin Square ◽  
Insulin Level ◽  
Basal Diet ◽  
Grass Silage ◽  
Lactating Dairy Cows ◽  
Urea Infusion

SUMMARYTo test the hypothesis that propionate can reduce hepatic capacity to detoxify ammonia, effects of the inclusion of propionate in intraruminal infusions of urea on the concentrations of ammonia, other metabolites and insulin in peripheral blood were investigated in two experiments with non-lactating dairy cows. Both experiments were of a 4 × 4 Latin square design with four animals, four treatments and four experimental periods of 7 d; feed was given in two equal meals each day, all intraruminal infusions were given for 1 h at the time of the morning feed, and propionic acid was partly neutralized with NaOH. In Expt 1, the treatments were a basal diet of pelleted lucerne and chopped hay alone or with the following infusions (g/d): urea 80, propionic acid 350, urea 80 plus propionic acid 350. The inclusion of propionate in the urea infusion markedly increased (P < 0·001) the concentration of ammonia in plasma compared with infusion of urea alone. Moreover, the inclusion of urea with the propionate infusion abolished (P < 0·01) the increase in blood insulin level seen with the infusion of propionate alone. In Expt 2, less severe treatments were imposed, the aim being to reproduce metabolic loads of propionate and ammonia that might be expected from a diet of high-protein grass silage rich in lactic acid. The treatments were a basal diet of grass silage alone or with the following infusions (g/d): NaCl 145, NaCl 145 plus urea 50, propionic acid 200, urea 50 plus propionic acid 200. Effects were less pronounced than in Expt 1 but, in the period immediately after infusion, similar effects were seen. It is concluded that propionate–ammonia interactions may have potentially important effects on milk production especially for diets with high proportions of grass silage containing high levels of protein and lactic acid.

scholarly journals Ruminal metabolism of flaxseed (Linum usitatissimum) lignans to the mammalian lignan enterolactone and its concentration in ruminal fluid, plasma, urine and milk of dairy cows

2009 ◽  
Vol 102 (7) ◽  
pp. 1015-1023 ◽  
Author(s):  
Nathalie Gagnon ◽  
Cristiano Côrtes ◽  
Daniele da Silva ◽  
Ricardo Kazama ◽  
Chaouki Benchaar ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Linum Usitatissimum ◽  
Biological Fluids ◽  
Latin Square ◽  
Gastrointestinal Microbiota ◽  
Flax Oil ◽  
Abomasal Infusion ◽  
Ruminal Microbiota

Secoisolariciresinol diglucoside is the main flax (Linum usitatissimum) lignan that is converted to the mammalian lignans enterodiol (ED) and enterolactone (EL) by gastrointestinal microbiota. The objectives of the present study were to investigate the role of ruminal microbiota and the effects of flax oil onin vivometabolism of flax lignans and concentration of EL in biological fluids. Four rumen-cannulated dairy cows were used in a 4 × 4 Latin square design. There were four periods of 21 d each and four treatments utilising flax hulls (1800 g/d) and oil (400 g/d) supplements. The treatments were: (1) oil and hulls administered in the rumen and abomasal infusion of water; (2) oil and hulls administered in the abomasum; (3) oil infused in the abomasum and hulls placed in the rumen; (4) oil placed in the rumen and hulls administered in the abomasum. Samples were collected during the last week of each period and subjected to chemical analysis. The site of supplementation of oil and hulls had no effect on ruminal EL concentration. Supplementing flax oil in the rumen and the abomasum led to similar EL concentrations in urine, plasma and milk. Concentrations of EL were higher in the urine, plasma and milk of cows supplemented with hulls in the rumen than in those placed with hulls in the abomasum. The present study demonstrated that ruminal microbiota play an important role in the metabolism of flax lignans.

Digestion, milk production and milk fatty acid profile of dairy cows fed flax hulls and infused with flax oil in the abomasum

2011 ◽  
Vol 78 (3) ◽  
pp. 293-300 ◽  
Author(s):  
Cristiano Côrtes ◽  
Ricardo Kazama ◽  
Daniele da Silva-Kazama ◽  
Chaouki Benchaar ◽  
Lucia M Zeoula ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Fat ◽  
Nutritive Value ◽  
Latin Square ◽  
Basal Diet ◽  
Milk Composition ◽  
Flax Oil ◽  
Abomasal Infusion ◽  
Protein Milk

Flax hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids (FA) but there is little information on digestion of flax hull based diets and nutritive value of flax hull for dairy production. Flax oil is rich in α-linolenic acid (LNA) and rumen bypass of flax oil contributes to increase n-3 FA proportions in milk. Therefore, the main objective of the experiment was to determine the effects of abomasal infusion of increasing amounts of flax oil on apparent digestibility, dry matter (DM) intake, milk production, milk composition, and milk FA profile with emphasis on the proportion of LNA when cows were supplemented or not with another source of LNA such as flax hull. Six multiparous Holstein cows averaging 650±36 kg body weight and 95±20 d in milk were assigned to a 6×6 Latin square design (21-d experimental periods) with a 2×3 factorial arrangement of treatments. Treatments were: 1) control, neither flax hull nor flax oil (CON), 2) diet containing (DM basis) 15·9% flaxseed hull (FHU); 3) CON with abomasal infusion of 250 g/d flax oil; 4) CON with abomasal infusion of 500 g/d flax oil; 5) FHU with abomasal infusion of 250 g/d flax oil; 6) FHU with abomasal infusion of 500 g/d flax oil. Infusion of flax oil in the abomasum resulted in a more pronounce decrease in DM intake for cows fed the CON diets than for those fed the FHU diets. Abomasal infusion of flax oil had little effect on digestibility and FHU supplementation increased digestibility of DM and crude protein. Milk yield was not changed by abomasal infusion of flax oil where it was decreased with FHU supplementation. Cows fed FHU had higher proportions of 18:0, cis9-18:1, trans dienes, trans monoenes and total trans in milk fat than those fed CON. Proportion of LNA was similar in milk fat of cows infused with 250 and 500 g/d flax oil in the abomasum. Independently of the basal diet, abomasal infusion of flax oil resulted in the lowest n-6:n-3 FA ratio in milk fat, suggesting that the most important factor for modification of milk FA profile was the amount of n-3 FA bypassing the rumen and not the amount of flax hull fed to dairy cows. Moreover, these data suggest that there is no advantage to supply more than 250 g/d of flax oil in the abomasum to increase the proportion of LNA in milk fat.

Factors affecting the outflow of protein supplements from the rumen. 2. The composition and particle size of the basal diet

1984 ◽  
Vol 39 (2) ◽  
pp. 201-206 ◽  
Author(s):  
M. E. Elimam ◽  
E. R. Ørskov
Keyword(s):  
Particle Size ◽  
Dairy Cows ◽  
Fish Meal ◽  
Latin Square ◽  
Basal Diet ◽  
Protein Supplements ◽  
Factors Affecting ◽  
Treated Fish ◽  
The Difference ◽  
Effect Of The Composition

ABSTRACTTwo experiments were conducted to investigate the effect of the composition and particle size of the basal diet on the outflow of chromium-treated fish meal from the rumen of lactating British Friesian dairy cows, using Cr-concentrations in faeces. A 4 × 4 Latin square design was used and the cows were fed at twice the estimated energy requirements for maintenance in two equal meals.Fractional outflow rates per h were, 0·079, 0·088, 0·086 and 0·064 for the 1·00 hay: 0·00 concentrate, 0·75 hay: 0·25 concentrate, 0·50 hay: 0·50 concentrate and 0·25 hay: 0·75 concentrate respectively. The difference between 0·75 and 0·50 concentrate was significant (P < 0·05).Grinding of long dried grass through 40 or 20 mm screens had no significant effect on the outflow of Cr-treated fish meal from the rumen, however fine grinding (5 mm) and pelleting significantly reduced the outflow from rumen (P < 0·05). Fractional outflow rates per h were 0·080, 0·086, 0·088 and 0·047 for the long, 40, 20 mm and the 5 mm and pelleted diets respectively.

scholarly journals  Effects of a rumen-protected form of methionine and a methionine analogue on the lactation performance of dairy cows

2012 ◽  
Vol 57 (No. 9) ◽  
pp. 410-419 ◽  
Author(s):  
J. Čermáková ◽  
V. Kudrna ◽  
J. Illek ◽  
K. Blažková ◽  
J. Haman
Keyword(s):  
Dairy Cows ◽  
Dry Matter ◽  
Milk Protein ◽  
Control Diet ◽  
Latin Square ◽  
Basal Diet ◽  
Dry Matter Intake ◽  
Isopropyl Ester ◽  
Lactation Performance ◽  
Beta Casein

The objective the present study was to determine the influence of a supplemental methionine analogue, the isopropyl ester of 2-hydroxy-4-(methylthio)-butanoic acid, commercially available as MetaSmart<sup>TM</sup>, on lactation performance, particularly milk protein production. The effects of this preparation were compared with those of a rumen-protected form of methionine, marketed as Smartamine<sup>TM</sup> M. Experiments were conducted according to a 3 &times; 3 Latin square design and included 30 high-yielding dairy cows (22&nbsp;Holstein and 8 Czech Fleckvieh) randomly allocated to three balanced groups. Cows were fed a basal diet based on maize silage, lucerne silage, lucerne hay, fresh brewer&rsquo;s grains, and a concentrate mixture in the form of a total mixed ration ad libitum. The diet M was supplemented with MetaSmart<sup>TM</sup> (42.5 g/day) and diet S was supplemented with Smartamine<sup>TM</sup> M (19 g/day), while control diet C contained solvent-extracted soybean meal, which was added to achieve required levels of dietary protein. Each period lasted four weeks in total, including three preliminary weeks and one experimental week during which samples of milk and tail vein blood were taken. Supplementation of MetaSmart<sup>TM</sup> decreased dry matter intake of cows (18.96&nbsp;kg) in contrast to the diet containing Smartamine<sup>TM</sup> M, for which dry matter intake was the highest (20.48 kg; P&nbsp;&lt; 0.001). Despite decreased dry matter intake, the highest average milk yields were recorded for cows supplemented with MetaSmart<sup>TM </sup>(31.34 kg), which produced by approximately 1.14&nbsp;kg (P &lt; 0.001) and 0.78&nbsp;kg (P &lt; 0.01) more milk than cows fed diets C and S, respectively. As expressed by greater ratios milk/DMI, FCM/DMI, and ECM/DMI, the feed efficiency was improved in cows supplemented with MetaSmart<sup>TM</sup>.Both MetaSmart<sup>TM </sup>and Smartamine<sup>TM</sup> M dietary supplementation increased milk yield, milk protein concentrations, and yields and increased the prevalence of &beta;-casein fraction in milk protein. &nbsp;

Effects of intravenous infusion of amino acids and glucose on the yield and concentration of milk protein in dairy cows

2001 ◽  
Vol 68 (1) ◽  
pp. 27-34 ◽  
Author(s):  
CHANG-HYUN KIM ◽  
TAE-GYU KIM ◽  
JAI-JUN CHOUNG ◽  
DAVID G. CHAMBERLAIN
Keyword(s):  
Amino Acids ◽  
Dairy Cows ◽  
Intravenous Infusion ◽  
Protein Concentration ◽  
Milk Protein ◽  
Latin Square ◽  
Basal Diet ◽  
Feather Meal ◽  
Grass Silage ◽  
Amino Acid Mixtures

To test the hypothesis that the availability of glucose or its precursors can influence the response of milk protein concentration to the intravenous infusion of amino acids, five cows were used in a 5 × 5 Latin square design with period lengths of 7 d. The five treatments were the basal diet of grass silage ad lib. plus 5 kg/d of a cereal-based supplement containing feather meal (Basal); Basal plus 4 g/d histidine, 8 g/d methionine and 26 g/d lysine (4H); Basal plus 8 g/d histidine, 8 g/d methionine and 26 g/d lysine (8H); and these two amino acid mixtures together with 600 g/d of glucose (4HG and 8HG respectively). Earlier experiments with this basal diet had shown that histidine was first-limiting for secretion of milk protein, followed by methionine and lysine. The yield of milk protein was increased progressively with the amount of histidine infused. The efficiency of transfer of histidine into milk protein was 0·42 for the 4H and 4HG and 0·35 for the 8H and 8HG treatments, and the concentration of milk protein was increased over Basal by all infusion treatments. However, milk protein concentrations were higher, and lactose concentrations in the milk were lower, in the absence of added glucose. Concentrations of insulin in blood plasma were not affected by treatment. It is concluded that, with the treatments without added glucose, a shortage of glucose prevented an increase in lactose secretion, and hence limited the increase in milk yield, leading to an increased concentration of protein in the milk.

Dye removal from textile industrial effluents by adsorption on exfoliated graphite nanoplatelets: kinetic and equilibrium studies

2016 ◽  
Vol 73 (9) ◽  
pp. 2189-2198 ◽  
Author(s):  
Marilda N. Carvallho ◽  
Karolyne S. da Silva ◽  
Deivson C. S. Sales ◽  
Eleonora M. P. L. Freire ◽  
Maurício A. M. Sobrinho ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Industrial Effluents ◽  
Theoretical Models ◽  
Adsorptive Capacity ◽  
Graphite Nanoplatelets ◽  
Equilibrium Studies ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Transmission Electron

The concept of physical adsorption was applied for the removal of direct and reactive blue textile dyes from industrial effluents. Commercial graphite nanoplatelets were used as substrate, and the quality of the material was characterized by atomic force and transmission electron microscopies. Dye/graphite nanoplatelets water solutions were prepared varying their pH and initial dye concentration. Exceptionally high values (beyond 100 mg/L) for adsorptive capacity of graphite nanoplatelets could be achieved without complicated chemical modifications, and equilibrium and kinetic experiments were performed. Our findings were compared with the state of the art, and compared with theoretical models. Agreement between them was satisfactory, and allowed us to propose novel considerations describing the interactions of the dyes and the graphene planar structure. The work highlights the important role of these interactions, which can govern the mobility of the dye molecules and the amount of layers that can be stacked on the graphite nanoplatelets surface.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

1991 ◽  
Vol 49 ◽  
pp. 580-581
Author(s):  
L. Tang ◽  
G. Thomas ◽  
M. R. Khan ◽  
S. L. Duan
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Magnetic Recording ◽  
Magnetic Thin Films ◽  
Magnetic Films ◽  
Substrate Bias ◽  
Epitaxial Relationship ◽  
Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

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