scholarly journals The relationships between potassium intakes, transmural potential difference of the rumen epithelium and magnesium absorption in wethers

2004 ◽  
Vol 91 (2) ◽  
pp. 183-189 ◽  
Author(s):  
S. Jittakhot ◽  
J. Th. Schonewille ◽  
H. S. Wouterse ◽  
C. Yuangklang ◽  
A. C. Beynen
Keyword(s):  
Latin Square ◽  
Potential Difference ◽  
Serosal Side ◽  
Rumen Epithelium ◽  
K Concentration ◽  
Sheep Rumen

In vitro studies with isolated sheep rumen epithelium have shown that an increase in the lumen K concentration induces an increase in the transmural potential difference across the rumen epithelium (serosal side: positive), which is associated with a decrease in Mg transport. However, at lumen K concentrations >80 mmol/l, Mg transport across the epithelium became independent of the lumen K concentration. The present study was carried out to determine whether this observation also occurs in vivo. Four ruminally fistulated wethers were fed four rations supplemented with KHCO3 (15·7, 37·6, 59·4 or 77·4 g K/kg DM) in a 4×4 Latin square design. Increased K intakes significantly increased the rumen K concentration. For all data combined, Mg absorption expressed as % intake was negatively correlated with the rumen K concentration. However, apparent Mg absorption either expressed in absolute terms (g/d) or as % intake was not significantly affected when the dietary K concentration was increased from 59·4 to 77·4 g/kg DM. Rumen K concentration was inversely correlated with the transmural potential difference (blood side: positive) (Pearson's r −0·709; R2adj 0·468, P=0·002, n 16). It is concluded that in wethers apparent Mg absorption becomes independent of the dietary K concentration when the K concentration is >60 g/kg DM or equivalent to a postprandial rumen K concentration of about 125 mmol/l.

scholarly journals Rotavirus Infection Is Not Associated with Small Intestinal Fluid Secretion in the Adult Mouse

2006 ◽  
Vol 80 (22) ◽  
pp. 11355-11361 ◽  
Author(s):  
Shirin Kordasti ◽  
Claudia Istrate ◽  
Mahanez Banasaz ◽  
Martin Rottenberg ◽  
Henrik Sjövall ◽  
...  
Keyword(s):  
Fluid Secretion ◽  
Chloride Secretion ◽  
Potential Difference ◽  
Pathophysiological Mechanism ◽  
Rotavirus Infection ◽  
In Vivo Experiments ◽  
Adult Mice ◽  
Small Intestines

ABSTRACT In contrast to humans, adult but not infant small animals are resistant to rotavirus diarrhea. The pathophysiological mechanism behind this age-restricted diarrhea is currently unresolved, and this question was investigated by studying the secretory state of the small intestines of adult mice infected with rotavirus. Immunohistochemistry and histological examinations revealed that rotavirus (strain EDIM) infects all parts of the small intestines of adult mice, with significant numbers of infected cells in the ilea at 2 and 4 days postinfection. Furthermore, quantitative PCR revealed that 100-fold more viral RNA was produced in the ilea than in the jejuna or duodena of adult mice. In vitro perfusion experiments of the small intestine did not reveal any significant changes in net fluid secretion among mice infected for 3 days or 4 days or in those that were noninfected (37 ± 9 μl · h−1 · cm−1, 22 ± 13 μl · h−1 · cm−1, and 33 ± 6 μl · h−1 · cm−1, respectively) or in transmucosal potential difference (4.0 ± 0.3 mV versus 3.9 ± 0.4 mV), a marker for active chloride secretion, between control and rotavirus-infected mice. In vivo experiments also did not show any differences in potential difference between uninfected and infected small intestines. Furthermore, no significant differences in weight between infected and uninfected small intestines were found, nor were any differences in fecal output observed between infected and control mice. Altogether, these data suggest that rotavirus infection is not sufficient to stimulate chloride and water secretion from the small intestines of adult mice.

Kinetics of exsheathment of infective ovine and bovine strongylid larvae in vivo and in vitro

Parasitology ◽  
2002 ◽  
Vol 125 (1) ◽  
pp. 65-70 ◽  
Author(s):  
H. HERTZBERG ◽  
U. HUWYLER ◽  
L. KOHLER ◽  
St REHBEIN ◽  
M. WANNER
Keyword(s):  
Haemonchus Contortus ◽  
Buffer System ◽  
Bicarbonate Concentration ◽  
Infective Larvae ◽  
Nylon Mesh ◽  
Mesh Bags ◽  
Sheep Rumen ◽  
Kinetics Of

The aim of the study was to investigate the longitudinal changes of exsheathment of ovine and bovine 3rd-stage strongylid larvae in an artificial rumen (RUSITEC) and to compare the results with in vivo data obtained from rumen-fistulated sheep. Infective larvae were incubated in nylon mesh bags in the sheep rumen or the RUSITEC apparatus for periods of 1, 6 and 12 h, respectively. The 12 h exsheathment rates in the rumen and the RUSITEC apparatus (in parentheses) were as follows: Haemonchus contortus: 100% (100%), Ostertagia circumcincta: 100% (76%), O. leptospicularis: 100% (100%), O. ostertagi: 53% (59%), Trichostrongylus axei: 100% (100%), T. colubriformis: 37% (36%), Cooperia curticei: 94% (76%), C. oncophora: 95% (89%), Nematodirus filicollis: 0% (N.D.), N. spathiger: 11% (15%), N. battus: 7% (5%), Oesophagostomum venulosum: 17% (9%), Chabertia ovina: 7% (2%), Dictyocaulus filaria: 1% (N.D.). Larvae of Nematodirus spp. and T. colubriformis showed a quick rise of the exsheathment rate 2 h after transfer into the abomasum. These results confirm that exsheathment generally occurs in the part of the gastrointestinal tract immediately anterior to the habitat of the adult parasite. The overall similar course of exsheathment in both systems indicates that the essential stimuli for exsheathment were generated and maintained under in vitro conditions of the artificial rumen. In both systems, the bicarbonate concentration and the pH reflected a similar status of the H2CO3/HCO buffer system, which is known to provide the essential stimuli for larval exsheathment of the abomasal species. These results give evidence that the RUSITEC system represents a valid system for studying the kinetics of exsheathment of strongylid nematodes under in vitro conditions. For 7 of the species investigated the obtained results represent the first data on larval exsheathment in vivo and in vitro.

In situ and in vitro techniques for estimating degradation parameters and digestibility of diets based on maize or sorghum

2020 ◽  
Vol 158 (1-2) ◽  
pp. 150-158 ◽  
Author(s):  
B. C. Silva ◽  
M. V. C. Pacheco ◽  
L. A. Godoi ◽  
F. A. S. Silva ◽  
D. Zanetti ◽  
...  
Keyword(s):  
Dry Matter ◽  
Latin Square ◽  
In Vitro Techniques ◽  
Sorghum Grains ◽  
Sorghum Silage ◽  
The Individual ◽  
Individual Grains

AbstractAn experiment was conducted to evaluate: (1) the effects of ensiling maize or sorghum grains after reconstitution on readily soluble fraction (a), potentially degradable fraction in the rumen (b) and rate constant for degradation of b (c) of dry matter (DM), organic matter (OM) and starch (STA); and (2) an appropriate incubation time for in situ or in vitro procedures to estimate in vivo digestibility. Four rumen-cannulated Nellore bulls (body weight = 262 ± 19.6 kg) distributed in a 4 × 4 Latin square were used. Diets were based on dry ground maize (DGM); or dry ground sorghum (DGS); or reconstituted ground maize silage; or reconstituted ground sorghum silage. In vitro and in situ incubations of the individual grains and diets were simultaneously performed with in vivo digestibility. In general, reconstituted grains and diets based on reconstituted grains presented greater (P < 0.05) fraction a and lower (P < 0.05) fraction b of DM, OM and STA compared to dry grains and diets based on dry grain. However, the magnitude of response of the reconstitution and ensiling process on DM and OM degradability parameter was greater for maize than that for sorghum. Moreover, no differences (P > 0.05) were observed between DGM- and DGS-based diets for c estimates. The results suggest that the reconstitution process promotes grains protein matrix breakdown increasing STA availability. The incubation times required for in vivo digestibility estimations of DM, OM and STA are 24 h for in situ and 36 h for in vitro procedures.

scholarly journals Resistance of Erythrocytes of Hibernating Mammals to Loss of Potassium during Hibernation and during Cold Storage

1971 ◽  
Vol 58 (6) ◽  
pp. 620-633 ◽  
Author(s):  
S. L. Kimzey ◽  
J. S. Willis
Keyword(s):  
Ground Squirrel ◽  
Normal Values ◽  
Ground Squirrels ◽  
Storage Medium ◽  
Cold Adapted ◽  
Maximum Period ◽  
K Concentration

In two species of hibernators, hamsters and ground squirrels, erythrocytes were collected by heart puncture and the K content of the cells of hibernating individuals was compared with that of awake individuals. The K concentration of hamsters did not decline significantly during each bout of hibernation (maximum period of 5 days) but in long-term bouts in ground squirrels (i.e. more than 5 days) the K concentration of cells dropped significantly. When ground squirrels were allowed to rewarm the K content of cells rose toward normal values within a few hours. Erythrocytes of both hamsters and ground squirrels lose K more slowly than those of guinea pigs (nonhibernators) when stored in vitro for up to 10 days at 5°C. In ground squirrels the rate of loss of K during storage is the same as in vivo during hibernation, and stored cells taken from hibernating ground squirrels also lose K at the same rate. The rate of loss of K from guinea pig cells corresponded with that predicted from passive diffusion unopposed by transport. The actual rate of loss of K from ground squirrel cells was slower than such a predicted rate but corresponded with it when glucose was omitted from the storage medium or ouabain was added to it. Despite the slight loss of K that may occur in hibernation, therefore, the cells of hibernators are more cold adapted than those of a nonhibernating mammal, and this adaptation depends in part upon active transport.

The effects of anAspergillus oryzaeextract containing alpha-amylase activity on ruminal fermentation and milk production in lactating Holstein cows

2005 ◽  
Vol 81 (3) ◽  
pp. 365-374 ◽  
Author(s):  
J. M. Tricarico ◽  
J. D. Johnston ◽  
K. A. Dawson ◽  
K. C. Hanson ◽  
K. R. McLeod ◽  
...  
Keyword(s):  
Milk Production ◽  
Amylase Activity ◽  
Latin Square ◽  
Alpha Amylase ◽  
Holstein Cows ◽  
Ruminal Fermentation ◽  
Nutrient Metabolism ◽  
Lactating Cows

AbstractThe effects of anAspergillus oryzaeextract containing alpha-amylase activity (Amaize™, Alltech Inc., Nicholasville, KY) were examinedin vivoandin vitro. A lactating cow study employed 20 intact and four ruminally fistulated Holstein cows in a replicated 4 × 4 Latin-square design to examine the effects of four concentrations of dietary Amaize™ extract on milk production and composition, ruminal fermentation and serum metabolite concentrations. The treatment diets contained 0, 240, 480 or 720 alpha-amylase dextrinizing units (DU) per kg of total mixed ration (TMR) (dry-matter basis). The supplemental alpha-amylase increased the yields of milk (P= 0·02), fat (P= 0·02) and protein (P= 0·06) quadratically. The maximum milk yield was obtained when 240 DU per kg of TMR were offered. Ruminalin situstarch disappearance was not affected by alpha-amylase supplementation in lactating cows or ruminally cannulated steers. Supplemental alpha-amylase extract reduced the molar proportion of propionate in the rumen of steers (P= 0·08) and lactating cows (P= 0·04), and in rumen-simulating cultures (P= 0·04). The supplement also increased the molar proportions of acetate (P= 0·06) and butyrate (P= 0·05), and the serum beta-hydroxybutyrate (P= 0·01) and non-esterified fatty acid (P= 0·03) concentrations in lactating cows. The improvements in milk production appear to be a consequence of the effects of alpha-amylase on ruminal fermentation and the potential changes in nutrient metabolism that result from them. We conclude that supplemental alpha-amylase may be given to modify ruminal fermentation and improve milk and component yield in lactating Holstein cattle.

Halothane-sensitivity gene and muscle contractile properties in malignant hyperthermia

1989 ◽  
Vol 257 (4) ◽  
pp. C781-C786 ◽  
Author(s):  
E. M. Gallant ◽  
J. R. Mickelson ◽  
B. D. Roggow ◽  
S. K. Donaldson ◽  
C. F. Louis ◽  
...  
Keyword(s):  
Malignant Hyperthermia ◽  
Convincing Evidence ◽  
Heterozygous Condition ◽  
Muscle Contractile Properties ◽  
Partial Pressure Of Co2 ◽  
K Concentration ◽  
Muscle Contractile ◽  
Sensitivity Gene

Malignant hyperthermia (MH) results from the presence of the halothane-sensitivity gene and is characterized by abnormalities in muscle function. Populations of genetically defined pigs were used to determine the in vivo and in vitro expression of this gene in both the homozygous and the heterozygous condition. On exposure to halothane, isolated muscle bundles from the homozygous halothane-sensitive pigs exhibited decreased tetanus tension and increased tetanus half-relaxation time and contracture and were clearly distinguished from homozygous normal muscles. The heterozygous and homozygous normal muscles were similar in contractile responses except for the occurrence of halothane-induced contractures in the heterozygotes. The heterozygous halothane-negative pigs did not exhibit the characteristic signs of an MH episode in response to halothane succinylcholine, although some metabolic responses were significantly altered (e.g., increased venous partial pressure of CO2 and arterial and venous K+ concentration). Thus the heterozygous pigs were not MH susceptible but did represent a phenotype distinct from the homozygous normal pigs both in vitro and in vivo. These data provide the first convincing evidence for the expression of the halothane-sensitivity gene in heterozygotes.

scholarly journals Effects of the inclusion of glycerin in diets containing 30 or 70% roughage on feed disappearance and digestibility

2018 ◽  
Vol 39 (4) ◽  
pp. 1717
Author(s):  
Antonio Carlos Homem Junior ◽  
Jane Maria Bertocco Ezequiel ◽  
Leonardo Fernandes Cremasco ◽  
Marco Túlio Costa Almeida ◽  
Josimari Regina Paschoaloto ◽  
...  
Keyword(s):  
Latin Square ◽  
Nutrient Digestibility ◽  
Neutral Detergent Fibre ◽  
Nellore Cattle

The objective of this study was to evaluate in vitro nutrient disappearance and in vivo nutrient digestibility of cattle diets containing 70 or 30% roughage, with and without glycerin supplementation. Four Nellore cattle were used in the study based on a 4 × 4 Latin Square design in a 2 × 2 factorial arrangement. Inclusion of glycerin and roughage proportion did not affect the nutrient disappearance of each ingredient (P > 0.05). Regardless of the inclusion of glycerin, a reduction in the proportion of roughage led to an increase (P < 0.05) in DMDis (64 vs. 72%), NDFDis (41 vs. 54%), and ADFDis (31 vs. 44%) of the total rations. Inclusion of glycerin resulted in an increase (P < 0.05) in DMD (70 vs. 62%) and a reduction (P < 0.05) in CPD (32 vs. 38%) and STD (82 vs. 74%). The diet containing 30% roughage led to higher (P < 0.05) DMD (67 vs. 65%) and CPD (35 vs. 33%) in comparison with the 70% roughage diet, but did not differ (P > 0.05) in STD (78%). Inclusion of glycerin at 20% of the total DM increased the utilisation of dietary DM without affecting the fibrous fraction of the diet. Glycerin supplementation in diets containing 70% roughage improves neutral detergent fibre digestibility.

Water and electrolyte transport by rabbit esophagus

1975 ◽  
Vol 229 (2) ◽  
pp. 438-443 ◽  
Author(s):  
DW Powell ◽  
SM Morris ◽  
DD Boyd
Keyword(s):  
Sodium Transport ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrolyte Transport ◽  
Potential Difference ◽  
Sodium Absorption ◽  
Bathing Solution ◽  
Electrical Potential Difference

The nature of the transmural electrical potential difference and the characteristics of water and electrolyte transport by rabbit esophagus were determined with in vivo and in vitro studies. The potential difference of the perfused esophagus in vivo was -28 +/- 3 mV (lumen negative). In vitro the potential difference was -17.9 +/- 0.6 mV, the short-circuit current 12.9 +/- 0.6 muA/cm2, and the resistance 1,466 +/- 43 ohm-cm2. Net mucosal-to-serosal sodium transport from Ringer solution in the short-circuited esophagus in vitro accounted for 77% of the simultaneously measured short-circuit current and net serosal-to-mucosal chloride transport for 14%. Studies with bicarbonate-free, chloride-free, and bicarbonate-chloride-free solutions suggested that the net serosal-to mucosal transport of these two anions accounts for the short-circuit current not due to sodium absorption. The potential difference and short-circuit current were saturating functions of bathing solution sodium concentration and were inhibited by serosal ouabain and by amiloride. Thus active mucosal-to-serosal sodium transport is the major determinant of the potential difference and short-circuit current in this epithelium.

Repeatability of in vitro digestibility assays of forages when using fresh, frozen or freeze-dried cow faeces instead of sheep rumen liquor as sources of micro-organisms

1995 ◽  
Vol 1995 ◽  
pp. 110-110 ◽  
Author(s):  
S Akhter ◽  
E Owen ◽  
M K Theodorou ◽  
S L Tembo ◽  
E R Deaville
Keyword(s):  
Freeze Drying ◽  
Rumen Fluid ◽  
In Vitro Digestibility ◽  
Two Stage ◽  
Freeze Dried ◽  
Fresh Frozen ◽  
Sheep Rumen ◽  
Micro Organisms

Previous studies (El Shaer, Omed and Axford, 1987; Akhter, Owen, Fall, O'Donovan and Theodorou, 1994) with the two-stage in vitro procedure of Tilley and Terry (1963) have shown a high correlation between digestibilities of forages as determined using either sheep rumen liquor, sheep faeces or cow faeces as the microbial inoculum. In the first study of the of the present investigation one objective was to examine the repeatability of these digestibility measurements when made on different occasions. A second objective was to assess whether the correlations between faecal and rumen fluid based inocula could be improved if microorganisms were obtained from pairs rather than individual animals. The objective in the second study using forages of known in vivo digestibility, was to investigate the effect of freezing or freeze-drying of faeces on the repeatability of digestibilities of forages determined in vitro using micro-organisms from cow faeces.

EFFECT OF FORMALDEHYDE TREATMENT OF SOYBEAN MEAL ON RATES OF PROTEIN DEGRADATION AND MICROBIAL PROTEIN CONCENTRATION IN THE BOVINE RUMEN

1983 ◽  
Vol 63 (1) ◽  
pp. 181-190 ◽  
Author(s):  
S. MAHADEVAN ◽  
R. M. TEATHER ◽  
J. D. ERFLE ◽  
F. D. SAUER
Keyword(s):  
Soybean Meal ◽  
Latin Square ◽  
Experimental Period ◽  
Ammonia Concentration ◽  
Bovine Rumen ◽  
Rumen Degradation ◽  
Formaldehyde Treatment ◽  
Highly Correlated

Four rumen-fistulated cows were fed concentrate:corn silage (40: 60) diets in a 4 × 4 latin square design experiment. The diets differed in the soybean meal or soybean meal treated with 0.1, 0.3 or 0.6% (wt/wt) formaldehyde. Rumen contents were collected hourly from 0900 h to 1600 h with an additional sample at half an hour after the 1100 h feeding on 3 days in the second week of each 2-wk experimental period. The maximum ammonia concentration in rumen contents decreased with increasing levels of formaldehyde used to treat the soybean meal. From 1130 to 1200 h the rates of ammonia appearance in the rumen contents were different (P < 0.05) for all four diets. Treatment of soybean meal with between 0.1 and 0.3% (wt/wt) formaldehyde reduced its in vitro degradation by rumen protease by about 50% compared with the untreated control. The rates of in vivo ammonia appearance and in vitro proteolysis were highly correlated (r = 0.966, P < 0.01) between 1130 h and 1200 h. These rates of rumen ammonia appearance reflected the in vivo rate of proteolysis. Both bacterial and protozoal protein content decreased significantly at the higher levels of formaldehyde treatment. There was a negative correlation (r = − 0.63, P < 0.01) between protozoal and bacterial protein. Key words: Formaldehyde, soybean meal, bovine, rumen, degradation, protease

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