EFFECTS OF PSYCHOLOGICAL STRESS, ACUTE COLD STRESS, AND DIET ON FORESTOMACH CONTRACTIONS IN CATTLE

Studies were made on forestomach contraction frequencies as affected by diet (brome hay, alfalfa hay, alfalfa silage and barley concentrate diet), acute cold stress and acute psychological stress. Four 15-mo-old steers fitted with ruminal fistulae were used in a 4 × 4 Latin square design. Diets did not influence contractile frequencies of the forestomachs, and did not interact with the effects of the stresses. Acute cold stress and psychological stress both produced significant increases of forestomach contraction frequencies and of heart rate. Key words: Cold stress, psychological stress, forestomach contractions, heart rate

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Binary symbolic dynamics analysis to detect stress-associated changes of nonstationary heart rate variability

Scientific Reports ◽

10.1038/s41598-020-72034-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Conrad Spellenberg ◽

Peter Heusser ◽

Arndt Büssing ◽

Andreas Savelsbergh ◽

Dirk Cysarz

Keyword(s):

Heart Rate ◽

Heart Rate Variability ◽

Psychological Stress ◽

Symbolic Dynamics ◽

Acute Stress ◽

Stress Test ◽

Autonomic Regulation ◽

Rr Interval ◽

Cardiac Autonomic Regulation ◽

Acute Psychological Stress

Abstract Psychological stress may have harmful physiological effects and result in deteriorating health. Acute psychological stress acts also on cardiac autonomic regulation and may lead to nonstationarities in the interbeat interval series. We address the requirement of stationary RR interval series to calculate frequency domain parameters of heart rate variability (HRV) and use binary symbolic dynamics derived from RR interval differences to overcome this obstacle. 24 healthy subjects (12 female, 20–35 years) completed the following procedure: waiting period, Trier Social Stress Test to induce acute psychological stress, recovery period. An electrocardiogram was recorded throughout the procedure and HRV parameters were calculated for nine 5-min periods. Nonstationarities in RR interval series were present in all periods. During acute stress the average RR interval and SDNN decreased compared to rest before and after the stress test. Neither low frequency oscillations (LF), high frequency oscillations (HF) nor LF/HF could unambiguously reflect changes during acute stress in comparison to rest. Pattern categories derived from binary symbolic dynamics clearly identified acute stress and accompanying alterations of cardiac autonomic regulation. Methods based on RR interval differences like binary symbolic dynamics should be preferred to overcome issues related to nonstationarities.

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Heart rate reactivity to acute psychological stress predicts higher levels of PTSD symptoms during the COVID-19 pandemic

Psychosomatic Medicine ◽

10.1097/psy.0000000000000848 ◽

2020 ◽

Vol Publish Ahead of Print ◽

Author(s):

Annie T. Ginty ◽

Danielle A. Young ◽

Alexandra T. Tyra ◽

Page E. Hurley ◽

Ryan C. Brindle ◽

...

Keyword(s):

Heart Rate ◽

Psychological Stress ◽

Ptsd Symptoms ◽

Heart Rate Reactivity ◽

Acute Psychological Stress

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FLOW AND SOLUBLE PROPORTIONS OF ZINC, MANGANESE, COPPER AND IRON IN THE GASTROINTESTINAL TRACT OF SHEEP FED CORN OR ALFALFA SILAGES

Canadian Journal of Animal Science ◽

10.4141/cjas83-019 ◽

1983 ◽

Vol 63 (1) ◽

pp. 163-171 ◽

Cited By ~ 3

Author(s):

M. IVAN ◽

D. M. VEIRA ◽

M. IHNAT

Keyword(s):

Trace Elements ◽

Gastrointestinal Tract ◽

Formic Acid ◽

Key Words ◽

Terminal Ileum ◽

Rumen Fluid ◽

Latin Square ◽

Corn Silage ◽

Apparent Absorption ◽

Alfalfa Silage

A set of four sheep, each fitted with a rumen cannula and a re-entrant cannula in the ascending duodenum and terminal ileum, were used for collection of rumen, duodenal and ileal digesta. A second set of four normal sheep was used for collection of feces and urine. The sheep were fed corn silage, urea-added corn silage, formic acid-treated alfalfa silage or wilted alfalfa silage in latin square design. Soluble proportions of manganese in rumen fluid, ileal digesta and feces were much lower on alfalfa silages than on corn silages although the soluble proportions in the duodenal digesta were not different. The soluble proportions of zinc, copper and iron were not as consistent as those of manganese. The apparent absorption of zinc was negative on alfalfa silages, and was associated with the lower soluble proportion of zinc in duodenal digesta and higher in the ileal digesta, as compared to corn silages. The apparent absorption of iron was much higher on corn silages than on alfalfa silages. Addition of urea to corn at ensiling resulted in an improvement of apparent absorption of copper. Key words: Trace elements, solubility, absorption, corn silage, alfalfa silage, sheep

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