Gastrointestinal motility and plasma hormone and metabolite responses to acute cold stress and somatostatin-14 in sheep

1991 ◽  
Vol 71 (4) ◽  
pp. 1079-1086 ◽  
Author(s):  
R. A. Christensen ◽  
J. J. Kennelly ◽  
R. J. Christopherson
Keyword(s):  
Gastrointestinal Motility ◽  
Cold Exposure ◽  
Average Duration ◽  
Apparent Effect ◽  
Orthogonal Contrasts ◽  
Ewe Lambs ◽  
Acute Cold Exposure ◽  
The Individual ◽  
Key Words Cold ◽  
Somatostatin 14

Effects of intrajugular infusions of somatostatin-14 (SS-14) (8.9, 18.4, and 37.3 ng min−1 kg−1 BW) or saline were studied in three acutely (2 h) cold-stressed (0 °C) ewe lambs (39.8 ± 1.8 kg BW) fed a barley soybean meal diet at 25.6 g DM d−1 kg−1 BW. Acute cold exposure transiently increased (P < 0.001) and rewarming decreased (P < 0.001) recticular contraction frequency, with no effect of SS-14. The duration of duodenal irregular spiking activity was decreased (P < 0.05) by SS-14 at doses of 18.3 and 37.3 ng min−1 kg−1 and was not affected by cold exposure. This resulted in a decrease (P < 0.05) in the average duration of the individual migrating myoelectric complex. Cold exposure increased (P < 0.01) plasma concentration of free fatty acids (FFA). Orthogonal contrasts of the changes during somatostatin infusion indicated linear increases in glucose and linear and cubic increases in FFA concentrations in plasma (P < 0.05). Infusion of somatostatin had no effect on basal concentrations of growth hormone, insulin, or glucagon but produced linear reductions in plasma insulin and glucagon responses during cold exposure (P < 0.05). Somatostatin modestly influenced hormone and metabolite concentration during acute cold exposure without apparent effect on body temperature. Key words: Cold, somatostatin, sheep, gastrointestinal motility, glucagon, insulin

EFFECT OF SOMATOSTATIN AND CHRONIC COLD EXPOSURE ON HORMONAL AND METABOLITE CONCENTRATION, METABOLIC RATE, THERMOREGULATION, AND GUT MOTILITY IN SHEEP

1990 ◽  
Vol 70 (4) ◽  
pp. 1073-1083 ◽  
Author(s):  
R. A. CHRISTENSEN ◽  
R. J. CHRISTOPHERSON ◽  
J. J. KENNELLY
Keyword(s):  
Gastrointestinal Motility ◽  
Heat Production ◽  
Cold Exposure ◽  
Plasma Concentrations ◽  
Plasma Free Fatty Acid ◽  
Whole Body ◽  
Ewe Lambs ◽  
Whole Body Metabolism ◽  
Glucagon And Insulin ◽  
Key Words Cold

The effect of somatostatin-14 (SS-14) (6.7 ng min−1 kg−1 BW) on hormone and metabolite concentrations, gastrointestinal motility, thermoregulation, and heat production was studied in five ewe lambs (45.8 ± 2.8 kg BW) adapted to either thermoneutral (TN) (17.4 °C) or chronic cold (CC) (− 0.9 °C). Lambs received a barley:soybean diet at 25.6 g DM d−1 kg−1 BW. Environmental temperature and SS-14 infusion had no effect on the frequency or duration of components of the duodenal migrating myoelectric complex (MMC), although cold exposure increased (P < 0.05) total number of contractions within the MMC. CC increased (P < 0.05) heat production by 41%, while SS-14 decreased (P < 0.05) heat production by 4% in both environments. Plasma concentrations of free fatty acids (P < 0.05) were increased during cold exposure. In response to SS-14 infusion plasma free fatty acid levels increased (P < 0.05) in the TN environment, while their level declined in the cold environment. Growth hormone, glucagon, and insulin concentrations were not influenced by cold exposure or SS-14 infusion. CC increased plasma T3 concentration but this response was abolished by SS-14. Thus, in lambs fed a concentrate diet, somatostatin at low doses slightly reduces whole body metabolism, possibly by an influence on thyroid hormones. Key words: Cold, somatostatin, gastrointestinal motility, sheep, metabolism, thyroid

SEASONAL CHANGES IN THE PHYSIOLOGICAL RESPONSE OF MAN TO AN ACUTE COLD STRESS

1967 ◽  
Vol 45 (1) ◽  
pp. 13-27 ◽  
Author(s):  
F. Girling
Keyword(s):  
Cold Stress ◽  
Heat Production ◽  
Cold Exposure ◽  
Seasonal Changes ◽  
Human Subjects ◽  
Minute Ventilation ◽  
Acute Cold Exposure ◽  
Air Temperatures ◽  
The Individual ◽  
Shivering Thermogenesis

Eight male human subjects, resting supine, and wearing swim trunks only, were exposed to an ambient temperature of 8.5 °C for 1 hour in the first week of each month from February 1964 to January 1965 inclusive. Skin, rectal, and air temperatures were measured with thermistor probes. Percentage oxygen in expired air and minute ventilation were measured, and heat production was calculated by Weir's method. Electrical activity from the muscles of all four limbs was measured to determine shivering response. Control values of resting respiration and heat production were obtained under comfortably warm conditions and showed marked seasonal variation, with minimum values in spring and maximum values in later summer. In the response to acute cold exposure, marked seasonal changes were found also which were superimposed on the seasonal changes in control values. The response to cold exposure indicated maximum acclimatization to cold in the spring and minimum in later summer. These results are discussed in terms of three modes of response to the cold stress: (i) insulative cooling, (ii) shivering thermogenesis, and (iii) nonshivering thermogenesis. The degree of acclimatization and temperature of exposure may determine the individual mode of response.

Tolerance of estrogen-treated rats to acute cold exposure

1979 ◽  
Vol 47 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. J. Fregly ◽  
D. L. Kelleher ◽  
D. J. Black
Keyword(s):  
Oxygen Consumption ◽  
Cold Exposure ◽  
Previous Experiment ◽  
Female Rats ◽  
Control Group ◽  
Maximal Rate ◽  
Acute Cold Exposure ◽  
Exposure To Cold ◽  
Rate Of Oxygen Consumption ◽  
Rate Of Cooling

Female rats treated chronically with ethynylestradiol (36 micrograms/kg per day) alone, and in combination with the progestational agent, norethynodrel (253 micrograms/kg per day), cooled significantly faster than controls when lightly restrained and exposed to air at 5 degrees C. Rate of cooling of rats given only norethynodrel was similar to that of the control group. In other studies, rate of oxygen consumption was determined for all groups during acute exposure to cold (14 degrees C). All estrogen-treated groups achieved the same maximal rate of oxygen consumption as control and norethynodrel-treated groups during cold exposure, but cooled significantly faster. Two groups of female rats were treated chronically with ethynylestradiol at two separate doses (36 and 61 micrograms/kg per day). An untreated group served as controls. Rate of oxygen consumption of all animals were measured during restraint and exposure to cold (18 degrees C). The estrogen-treated groups again achieved the same maximal rate of oxygen consumption as the control group, but also cooled significantly faster despite the fact that the cold stress was less severe than in the previous experiment. That estrogen-treated rats cooled faster than controls in both studies despite achieving a maximal rate of heat production which did not differ from controls suggests that reduced cold tolerance of estrogen-treated rats may be related to increased heat loss.

METHOD FOR EVALUATING INDIVIDUAL CHARACTERISTICS OF MILK EJECTION OF COWS WHEN USING DIFFERENT MILKING TECHNOLOGIES

2021 ◽  
pp. 66-78
Author(s):  
V.P. MESHCHERYAKOV ◽  
◽  
YU.G. IVANOV ◽  
T.N. PIMKINA ◽  
E.V. ERMOSHINA
Keyword(s):  
Latent Period ◽  
Average Duration ◽  
Individual Characteristics ◽  
Maximum Intensity ◽  
Milk Ejection ◽  
Short Period ◽  
Robotic Milking ◽  
Automatic Milking Systems ◽  
Milking Machine ◽  
The Individual

The aim of the research is to study the possibility of using a latent period of the ejection of the first portion of milk in order to evaluate the individual characteristics of the milk ejection features of cows using the technology of bucket milking and robotic milking. Two experiments were conducted on cows of Black-Motley breed. Under the first experiment, the individual characteristics of the milk ejection were shown using the technology of bucket milking. Under the second experiment, they were determined for the technology of robotic milking. The first experiment was conducted on 12 mature cows. They were milked with a serial milking machine. The process of lactation was recorded by means of a bucket counter. The parameters of milk ejection were defined by analyzing the curve of lactation and making calculations. The second experiment was conducted on 30 first-calf heifers. Cows were milked on robotic installation the Astronaut A4 of Lely Company (the Netherlands). The data of the information system of herd management Lely T4C have been used for the analysis. Depending on the indicator of a latent period of the first milk portion ejection in both experiments three groups of cows (I–III) have been isolated. The ability of milk ejection in the first group was identified as high, in the second group – average and in the third group – low. Both experiments showed that the value of a latent period of the first milk portion ejection determined the milk ejection ability of cows. The increase in the period of the first milk portion ejection has been found among cows as their milk ejection ability decreses. The currently used milking technology shows that the reduced milk ejection among cows leads to the decrease in the indicators of the average and maximum intensity of milk ejection, the first two minutes of milking and also it leads to longer duration of milking. Using the robotic milking, the authors found that the first-calf heifers with the short period of the first milk portion ejection are characterized by the shortest duration of treating the teats and staying in the milking parlor, the average duration of milk ejection from the each quarter of the udder, as well as high values of the average and maximum intensity of milk ejection. The first-calf heifers with slow milking capacity are characterized by the longest duration of treating the teats and staying in the milking parlor, the average duration of milk ejection from the each quarter of the udder, as well as the lowest values of the average and maximum intensity of milk ejection. This suggests that the selection of first-calf heifers with high milk ejection ability will help to increase the productivity of automatic milking systems during the milking process. It is proposed to use the value of a latent period of the first milk portion ejection in the breeding activities.

Responses of cold- and warm-adapted dogs to infused norepinephrine and acute body cooling

1965 ◽  
Vol 209 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Tetsuo Nagasaka ◽  
Loren D. Carlson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cold Exposure ◽  
Nonshivering Thermogenesis ◽  
Mechanically Ventilated ◽  
Cold Adapted ◽  
Pentobarbital Sodium ◽  
Acute Cold Exposure ◽  
Increased Sensitivity ◽  
Body Cooling

Oxygen consumption, heart rate, and colonic, pinna, and paw temperatures were recorded continuously in warm-adapted (W-A) and cold-adapted (C-A) dogs anesthetized with pentobarbital sodium (30 mg/kg), paralyzed with Flaxedil (5 mg/kg per hr), and mechanically ventilated. The dogs were infused with norepinephrine (1.25 µg/kg per min) for 20 min at 30 C and after 45 min of acute cold exposure to 5 C. Oxygen consumption of C-A dogs increased with a slight increase in the heart rate during the initial 18–20 min of body cooling. O2 consumption decreased continuously during cold exposure in W-A dogs. Calorigenic effects of infused noradrenaline were similar in C-A and W-A dogs at 30 C and 5 C. Heart rate increased in W-A dogs at 30 and 5 C. These results show that nonshivering thermogenesis is well developed by cold acclimation in dogs, and suggest that the increase may be due to an increase in noradrenaline in blood rather than to increased sensitivity of the animals to the calorigenic effects of noradrenaline.

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