Influence of monensin on some metabolic responses of cattle fed a restricted intake of lucerne hay during heat exposure

1991 ◽  
Vol 31 (3) ◽  
pp. 301
Author(s):  
JC O'Kelly
Keyword(s):  
Body Temperature ◽  
Thyroid Hormones ◽  
Plasma Concentrations ◽  
Heat Exposure ◽  
Ruminal Fermentation ◽  
Free T4 ◽  
Metabolic Derangement ◽  
Normal Body Temperature ◽  
Ruminal Fluid ◽  
Brahman Steers

The effects of monensin supplement (33 mg/kg feed) on ruminal fermentation and body metabolism were studied in Brahman steers fed 5 kg lucerne hay daily at thermoneutral temperature (24�C) and after heat exposure [I day at 31�C (acute) or 5 days at 37�C (chronic)]. At 24�C, monensin lowered the concentrations of ammonia and protozoa in ruminal fluid and increased the plasma concentration of cholesterol but did not affect the circulating levels of urea, glucose, insulin, thyroxine (T4), triiodothyronine (T3), free T4 and free T3. Acute heat exposure lowered the plasma concentrations of thyroid hormones. Chronic heat exposure increased body temperature, the rate of dry matter digestion in the rumen and urinary nitrogen and allantoin excretion and lowered the plasma concentrations of cholesterol and differentially lowered the concentrations of the thyroid hormones. An increase in the concentration of ammonia in ruminal fluid was the only response to monensin at elevated body temperature that was uncharacteristic of its effects at normal body temperature. The results indicate that a monensin treatment of 33 mg/kg feed does not have any adverse effects on steers suffering metabolic derangement during hyperthermia.

Thyroid hormone concentrations in the plasma of fed and fasted Brahman and Hereford steers

1994 ◽  
Vol 34 (4) ◽  
pp. 439
Author(s):  
JC O'Kelly ◽  
WG Spiers
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Plasma Concentrations ◽  
Free T4 ◽  
Rumen Metabolism ◽  
Body Tissues ◽  
Breed Differences ◽  
Feeding Regimes ◽  
Ad Libitum ◽  
Brahman Steers

Plasma concentration patterns of thyroxine (TJ, free T4 (FT4), triiodothyronine (T3), and free T3 (FT3) were determined in Brahman steers fed lucerne hay ad libitum and in Brahman and Hereford steers fed restricted intakes of lucerne hay at the rate of either 208 g/h before fasting for 72 h or 250 g/h before fasting for 96 h. In Brahmans fed ad libitum, the plasma concentrations of all thyroid hormone fractions were significantly (P<0.01) correlated with one another and with feed intake. Within breeds, the concentrations of thyroid hormones were higher (P<0.001) when animals were fed at 250 g k than at 208 g/h. During both hourly feeding regimes T4, FT4, T3, and FT3 concentrations were higher (P<0.001) in Brahmans than in Herefords. Fasting after both hourly feeding regimes lowered (P<0.001) the concentrations of T4 about 53% in Brahmans and 30% in Herefords, while FT4, T3, and FT3 were lowered about 68% in Brahmans and 50% in Herefords. Consequently, thyroid hormone concentrations were significantly lower in Brahmans than in Herefords after 72 h fasting but did not differ significantly between breeds after 96 h fasting. The present results, together with those of our previous work showing breed differences in rumen metabolism, support the concept that, in Hereford and Brahman steers fed the same amount of hay in a thermoneutral environment, breed differences in plasma concentrations of thyroid hormones originate from quantitative differences in the supply of nutrients from the rumen to body tissues.

Metabolic effects of safflower oil given as a supplement for steers fed roughage diets at restricted intake

1990 ◽  
Vol 30 (5) ◽  
pp. 585 ◽  
Author(s):  
JC O'Kelly ◽  
WG Spiers
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Plasma Concentrations ◽  
Metabolic Effects ◽  
Safflower Oil ◽  
Plasma Urea ◽  
Body Protein ◽  
Rumen Temperature ◽  
Ruminal Fluid ◽  
Brahman Steers

Supplements of safflower oil (300 mL/day) were given to groups of steers fed 4 different diets. Hereford steers were fed 6 kg/day lucerne hay (LH) or LH + 33 mg/kg monensin (LHM). Brahman steers were fed 4 kg/day low quality hay (DA) or DA + 1 kg sucrose + 60 g urea + 2.7 g sulfur (DAS). Metabolic measurements were made when the animals were fed an equal portion of the daily ration at hourly intervals. On all diets, safflower oil had no affect on rumen temperature, pH or the concentrations of volatile fatty acids in ruminal fluid. Safflower oil increased concentrations (mg/L) of microbial lipid in ruminal fluid (LH, 160.4 v. 317.1; LHM, 266 v. 541.7; DA, 194.6 v. 321.8; DAS, 172.8 v. 440.5) and increased plasma concentrations (�g/mL) of non-esterified fatty acids (LH, 117.2 v. 180.1; LHM, 101.1 v. 189.5; DA, 218.2 v 325.4; DAS, 197.4 v 311.4), especially 18:1 trans- 11 and polyunsaturated acids. In steers fed DA and DAS, safflower oil reduced protozoal numbers and increased the bacterial mass in ruminal fluid, and increased water intake and the daily amounts of urinary allantoin excreted. The addition of safflower oil to all diets depressed plasma urea concentrations (mg/L) (LH, 233 v. 203; LHM, 236 v. 191; DA, 74.6 v. 47.6; DAS, 96.6 v. 54). The excretion of daily amounts (mg/kg liveweight) of urinary urea increased in animals fed DA (3.5 v. 10.0) and DAS (6.2 v. 13.6) but decreased in those fed LH (208.8 v. 187.9) and LHM (188.8 v. 158.1). Safflower oil supplementation conserved body protein, accelerated liveweight gains in animals fed LH and LHM diets and retarded liveweight loss in those fed DA and DAS diets.

Changes in lipid metabolism in genetically different types of calves during chronic hyperthermia

1973 ◽  
Vol 30 (2) ◽  
pp. 211-220 ◽  
Author(s):  
J. C. O'Kelly
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Body Temperature ◽  
Rectal Temperature ◽  
Plasma Cholesterol ◽  
Plasma Concentrations ◽  
Water Metabolism ◽  
Control Groups ◽  
Normal Body Temperature ◽  
Bull Calves

1. The effects of chronically raised body temperature on lipid metabolism were studied in groups of 3-month-old British (Shorthorn × Hereford) and Zebu (Africander × British) bull calves. Calves in control groups at ambient temperature were pair-fed to calves housed in a climate room.2. In control groups, concentrations of plasma cholesterol and phospholipid were significantly higher and the excretion of fatty acids 14:0, 16:0 and 18:0 was lower in the Zebu than in the British calves.3. In the climate room the constant daily environmental temperature required to maintain an increase in rectal temperature of 1·3° was 33° for British and 38° for Zebu calves. Changes in respiration rate, water metabolism and nitrogen metabolism associated with hyperthermia were similar in both breeds.4. Hyperthermia in all animals was associated with lowered plasma concentrations of cholesterol and phospholipid and increases in the ratio of free to total cholesterol. It was without effect on the circulating concentrations of non-esterified fatty acids and about twice the amount of fat was excreted without change in its fatty acid composition.5. The results showed that, when control of normal body temperature was lost, increased rectal temperature led to similar metabolic changes in animals of both breeds.

scholarly journals The association of TSH and thyroid hormones with lymphopenia in bacterial sepsis and COVID-19

2021 ◽  
Author(s):  
Inge Grondman ◽  
Aline H de Nooijer ◽  
Nikolaos Antonakos ◽  
Nico A F Janssen ◽  
Maria Mouktaroudi ◽  
...  
Keyword(s):  
Thyroid Hormones ◽  
Thyroid Function ◽  
Plasma Concentrations ◽  
Bacterial Sepsis ◽  
Free T4 ◽  
Reactive Protein ◽  
Severe Infections ◽  
Absolute Lymphocyte Counts ◽  
And Function

Abstract Context Lymphopenia is a key feature of immune dysfunction in patients with bacterial sepsis and COVID-19 and associated with poor clinical outcomes, but the cause is largely unknown. Severely ill patients may present with thyroid function abnormalities, so-called non-thyroidal illness syndrome (NTIS), and several studies have linked TSH and the thyroid hormones thyroxine (T4) and triiodothyronine (T3) to homeostatic regulation and function of lymphocyte populations. Purpose To test the hypothesis that abnormal thyroid function correlates with lymphopenia in patients with severe infections. Methods Retrospective analysis of absolute lymphocyte counts, circulating TSH, T4, free T4 (FT4), T3, albumin and inflammatory biomarkers was performed in two independent hospitalized study populations: bacterial sepsis (n=224) and COVID-19 patients (n=161). A subgroup analysis was performed in patients with severe lymphopenia and normal lymphocyte counts. Results Only T3 significantly correlated (rho=0.252) with lymphocyte counts in patients with bacterial sepsis and lower concentrations were found in severe lymphopenic compared to non-lympopenic patients (n=56 per group). Severe lymphopenic COVID-19 patients (n=17) showed significantly lower plasma concentrations of TSH, T4, FT4 and T3 compared to patients without lymphopenia (n=18), and demonstrated significantly increased values of the inflammatory markers interleukin-6, C-reactive protein and ferritin. Remarkably, after one week follow-up, the majority (12/15) of COVID-19 patients showed quantitative recovery of their lymphocyte numbers, while TSH and thyroid hormones remained mainly disturbed. Conclusion Abnormal thyroid function correlates with lymphopenia in patients with severe infections, like bacterial sepsis and COVID-19, but future studies need to establish whether a causal relationship is involved.

scholarly journals A novel mouse model of heatstroke accounting for ambient temperature and relative humidity

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Kazuyuki Miyamoto ◽  
Keisuke Suzuki ◽  
Hirokazu Ohtaki ◽  
Motoyasu Nakamura ◽  
Hiroki Yamaga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Body Temperature ◽  
Relative Humidity ◽  
Ambient Temperature ◽  
Core Body Temperature ◽  
Heat Exposure ◽  
Organ Damage ◽  
Core Body ◽  
The Impact ◽  
Treatment Water

Abstract Background Heatstroke is associated with exposure to high ambient temperature (AT) and relative humidity (RH), and an increased risk of organ damage or death. Previously proposed animal models of heatstroke disregard the impact of RH. Therefore, we aimed to establish and validate an animal model of heatstroke considering RH. To validate our model, we also examined the effect of hydration and investigated gene expression of cotransporter proteins in the intestinal membranes after heat exposure. Methods Mildly dehydrated adult male C57/BL6J mice were subjected to three AT conditions (37 °C, 41 °C, or 43 °C) at RH > 99% and monitored with WetBulb globe temperature (WBGT) for 1 h. The survival rate, body weight, core body temperature, blood parameters, and histologically confirmed tissue damage were evaluated to establish a mouse heatstroke model. Then, the mice received no treatment, water, or oral rehydration solution (ORS) before and after heat exposure; subsequent organ damage was compared using our model. Thereafter, we investigated cotransporter protein gene expressions in the intestinal membranes of mice that received no treatment, water, or ORS. Results The survival rates of mice exposed to ATs of 37 °C, 41 °C, and 43 °C were 100%, 83.3%, and 0%, respectively. From this result, we excluded AT43. Mice in the AT 41 °C group appeared to be more dehydrated than those in the AT 37 °C group. WBGT in the AT 41 °C group was > 44 °C; core body temperature in this group reached 41.3 ± 0.08 °C during heat exposure and decreased to 34.0 ± 0.18 °C, returning to baseline after 8 h which showed a biphasic thermal dysregulation response. The AT 41 °C group presented with greater hepatic, renal, and musculoskeletal damage than did the other groups. The impact of ORS on recovery was greater than that of water or no treatment. The administration of ORS with heat exposure increased cotransporter gene expression in the intestines and reduced heatstroke-related damage. Conclusions We developed a novel mouse heatstroke model that considered AT and RH. We found that ORS administration improved inadequate circulation and reduced tissue injury by increasing cotransporter gene expression in the intestines.

scholarly journals Human thermoregulatory responses during serial cold-water immersions

1998 ◽  
Vol 85 (1) ◽  
pp. 204-209 ◽  
Author(s):  
John W. Castellani ◽  
Andrew J. Young ◽  
Michael N. Sawka ◽  
Kent B. Pandolf
Keyword(s):  
Body Temperature ◽  
Rectal Temperature ◽  
Heat Production ◽  
Alternative Explanation ◽  
Cold Water ◽  
Metabolic Heat Production ◽  
Normal Body Temperature ◽  
Repeat Trial ◽  
Metabolic Heat ◽  
Made In

This study examined whether serial cold-water immersions over a 10-h period would lead to fatigue of shivering and vasoconstriction. Eight men were immersed (2 h) in 20°C water three times (0700, 1100, and 1500) in 1 day (Repeat). This trial was compared with single immersions (Control) conducted at the same times of day. Before Repeat exposures at 1100 and 1500, rewarming was employed to standardize initial rectal temperature. The following observations were made in the Repeat relative to the Control trial: 1) rectal temperature was lower and heat debt was higher ( P < 0.05) at 1100; 2) metabolic heat production was lower ( P < 0.05) at 1100 and 1500; 3) subjects perceived the Repeat trial as warmer at 1100. These data suggest that repeated cold exposures may impair the ability to maintain normal body temperature because of a blunting of metabolic heat production, perhaps reflecting a fatigue mechanism. An alternative explanation is that shivering habituation develops rapidly during serially repeated cold exposures.

STUDY OF GHRELIN LEVELS IN HYPOTHYROID PATIENTS BEFORE AND AFTER TREATMENT

2021 ◽  
pp. 52-54
Author(s):  
Peeyush Yadav ◽  
G. G. Kaushik
Keyword(s):  
Treatment Group ◽  
Thyroid Hormones ◽  
Hdl Cholesterol ◽  
Metabolic Disturbances ◽  
Free T4 ◽  
Before And After ◽  
Group A ◽  
Group B ◽  
Serum Ghrelin ◽  
Hypothyroid Patients

Objective: Aim of the present study was to evaluate the levels of ghrelin in hypothyroid patients before and after treatment with L-thyroxine and to nd a possible relationship between ghrelin and thyroid hormones. Material & Methods: The present study was conducted on 100 hypothyroid patients (44 Males & 56 Females) before treatment (Group A) and after treatment (Group B) attending the outpatient clinics or admitted in wards of J.L.N. Hospitals, Ajmer. 100 healthy control subjects (Group C) of same age group of either gender were selected for the study. Blood samples were drawn from patients and controls, after overnight fast of at least 8 hours. Estimation of Serum Ghrelin, free T3, free T4, and TSH was done by using Enzyme- Linked Immunosorbant Assay (ELISA) technique. Total Cholesterol, Triglyceride, HDL – Cholesterol were measured by automated analyser (Beckman & Coulter's AU680). VLDL – Cholesterol, LDL – Cholesterol were calculated by Friedwald's formula. Differences in the parameters among the groups were analyzed by ANOVA test followed by its Tukey HSD post hoc analysis. Correlations between variables were tested using the Pearson rho (r: Correlation coefcient) correlation test. Results: Findings of the present study shows that the levels of serum fT3 (1.79 ± 0.29 pg/mL) and serum fT4 (0.34 ± 0.11 ng/dL) were signicantly lower in Group A compared to Group B (fT3 = 3.00 ± 0.32 pg/mL & fT4 = 0.81 ± 0.15 ng/dL) and Group C (fT3 = 3.12 ± 0.31 pg/mL & fT4 = 0.85 ± 0.11ng/dL) whereas serum TSH levels were signicantly higher in Group A (40.59 ± 13.55 μIU/mL) compared to Group B (5.34 ± 1.47 μIU/mL) and Group C (3.23 ± 1.04 μIU/mL). Levels of serum Ghrelin were signicantly higher in Group A (918.19 ± 48.47 pg/mL) compared to Group B (700.34 ± 46.35 pg/mL) and Group C (681.49 ± 35.80 pg/mL). A non signicant correlation of Ghrelin with S.fT4 and TSH was found in both Group A and Group B whereas S.fT3 and BMI shows a non signicant correlation in Group A in comparison to a signicant correlation in Group B. Conclusion: There is a reversible increase in the levels of serum ghrelin which became normalized after L-thyroxine substitution in hypothyroid patients. Alteration in the levels of serum ghrelin in thyroid disorders indicates a compensatory role of ghrelin in metabolic disturbances and also suggests a possible association between thyroid hormones and serum ghrelin levels.

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 &gt;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.

scholarly journals Comparison of Tympanic and Tail Temperatures in Angus and Brahman Steers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Dikmen S ◽  
Davila KMS ◽  
Rodriquez E ◽  
Scheffler TL ◽  
Oltenacu PA ◽  
...  
Keyword(s):  
Body Temperature ◽  
Repeated Measures ◽  
Core Body Temperature ◽  
The Body ◽  
Tympanic Temperature ◽  
Repeated Measure ◽  
Important Indicator ◽  
Significant Difference ◽  
Brahman Steers ◽  
Core Body

In cattle, core body temperature can be used as an important indicator of heat stress level. However, accurately recording core body temperature can be difficult and labor intensive. The objectives of the current study were 1) to compare the recorded tympanic and tail body temperature measurements in steers and 2) to determine the body temperature change of Angus and Brahman steers in a hot and humid environment. Data was analyzed using a repeated measure model where repeated measures were hourly tympanic and tail temperatures and their difference for individual steers during the day of the experiment. There was a significant breed effect (P=0.01), hour (P<0.0001) and breed by hour interaction (P<0.0001) for the tympanic temperature. Brahman steers, which are known to have superior thermotolerance, maintained a lower body temperature than the Angus steers during the afternoon under grazing conditions. In the Brahman steers there was only a minimal increase in the body temperature throughout the day, an evidence of the thermotolerance ability of the breed. In the Angus steers, which experienced an increase in their body temperature from hour to hour with a peak around 1600 hour; there was a significant difference between the tympanic and tail temperature during the times when the body temperature as measured by the tympanic recordings was the highest (1300 to 1700 hour). Our results indicate that the tympanic temperature can be used to accurately and continuously monitor core body temperature in a natural environment for up to several days and without disturbing the animal.

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