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Neonatal lamb behaviour and thermoregulation with special reference to thyroid hormones and phosphorous element: Effect of birth weight and litter size
2018
R. A. Darwish | S. M. El-Bahr
New-born lambs have limited energy reserves and need a rapid access to colostrum to maintain homeothermy and survive. The object of this study was to investigate the importance of neonatal lamb behaviour in the maintenance of its body temperature and survival. The time taken to stand and suck after birth and rectal temperatures were determined in 72 crossbred lambs (progeny of crossing 1/2 Rhamani and 1/2 Finnish). In addition, blood samples were collected at 1, 24 and 72 h after birth. The obtained sera were assayed for thyroid hormones (T3 and T4), known to be involved in heat production and phosphorous element (ph) which is essential for energy metabolism. The obtained results revealed that, low birth weight and triplet lambs were behaviourally less active at birth and had less T3, T4, Ph and body temperatures values over the first 3 days of life than lambs of heavy or medium birth weight and single or twin lambs. Thus, light weight and triplet lambs were highly susceptible to hypothermia and were exposed to high rate of mortality (18.75 and 16.66%) during the neonatal period than other lambs (3.84, 10.00, 4.55, and 9.38 %, respectively). Therefore, the present study concludes that neonatal lamb behaviour, specifically success in standing and obtaining colostrum are extremely important for thermoregulation and survival of the neonate.
Mostrar más [+] Menos [-]Special cutaneous vascular elements in one-humped camel (Camelus dromedarius)
2016
Mohammad Rashad Fath-Elbab | Alaa Sayed Abou-Elhamd
Objective: The aim of this study was to investigate the histomorphological structure and functional significance of various special regulatory devices of the vascular terminal branches of the skin in one-humped camel (Camelus dromedarius). Materials and methods: Skin samples from different body parts (e.g., front, neck and shoulder, back, belly, chest, thigh, flank and tail) of camel were used in this study. The samples were stained with Harris hematoxylin and trichrome stain. Semithin sections were also prepared from these samples. Results: The vascular elements demonstrated in the current study included- throttle arteries within the dermis on the level of the hair papillae, glomus bodies within the dermis on the level mid-length of the hair follicles, medium-sized arteries on the level of the secretory end-pieces of the epitrichial sweat glands, and tufts of spirally-oriented arterioles in the nearby of the hair follicles. Conclusions: These vascular elements are either designed to control blood pressure (Hemo-dynamic mechanism) or patterned to control body temperature (Thermo-regulatory mechanism). [J Adv Vet Anim Res 2016; 3(2.000): 106-111]
Mostrar más [+] Menos [-]Pre-warming following premedication limits hypothermia before and during anesthesia in Sprague-Dawley rats (Rattus norvegicus)
2021
Rufiange, Maxime | Leung, Vivian S. Y. | Simpson, Keith | Pang, Daniel S. J.
In humans and other mammals, general anesthesia impairs thermoregulation, leading to warm core blood redistributing to the periphery. This redistribution is an important contributor to hypothermia that can be reduced with pre-warming before anesthesia. Additionally, sedation following premedication has been associated with hypothermia in dogs. In a prospective, randomized, cross-over study, 8 adult male and female rats (weighing 388 to 755 g) were sedated with intramuscular ketamine-midazolam-hydromorphone, then placed in an unwarmed cage or warmed box for 14 minutes, followed by 30 minutes of isoflurane anesthesia with active warming. Core body temperature was monitored throughout. After sedation, warmed rats gained 0.28°C ± 0.13°C and unwarmed rats lost 0.19°C ± 0.43°C, a significant difference between groups (P = 0.004). After anesthesia, warmed rats maintained higher core temperatures (P < 0.0001) with 2/8 and 6/8 of warmed and unwarmed rats becoming hypothermic, respectively. Pre-warming during sedation and active warming during general anesthesia is effective in minimizing hypothermia.
Mostrar más [+] Menos [-]Effects of weather variables on thermoregulation of calves during periods of extreme heat
2014
Theurer, Miles E. | Anderson, Daivd E. | White, Brad J. | Miesner, Matt D. | Larson, Robert L.
Objective-To determine effects of ambient temperature, relative humidity, wind speed, relative barometric pressure, and temperature-humidity index (THI) on nasal submucosal and rectal temperatures in cattle during extreme summer conditions. Animals-20 black crossbred beef heifers (mean body weight, 217.8 kg). Procedures-Nasal submucosal and rectal temperatures were monitored every 2 hours for 24 hours on 3 nonconsecutive days when ambient temperature was forecasted to exceed 32.2°C. Ambient temperature, relative humidity, wind speed, and relative barometric pressure were continuously monitored at a remote weather station located at the research facility. The THI was calculated and used in the livestock weather safety index (LWSI). Relationships between nasal submucosal or rectal temperature and weather variables were evaluated. Results-Nasal submucosal and rectal temperatures were related to all weather variables monitored. A positive relationship was determined for ambient temperature and THI with both nasal submucosal and rectal temperatures. A negative relationship was evident for nasal submucosal and rectal temperature with relative humidity, wind speed, and relative barometric pressure. Nasal submucosal and rectal temperatures increased with increasing severity of LWSI category. Conclusions and Clinical Relevance-Effects of environmental conditions on thermoregulation in calves exposed to extreme heat were detected. The positive relationship between nasal submucosal temperature and ambient temperature and THI raised concerns about the efficacy of intranasal administration of temperature-sensitive modified-live virus vaccines during periods of extreme heat. Environmental conditions must be considered when rectal temperature is used as a diagnostic tool for identifying morbid cattle.
Mostrar más [+] Menos [-]Using a Sprinkler Fan System for Cooling Heat-stressed Goats under Desert Conditions.
2023
Diya Saleh AL-Ramamneh
Goats' health, productivity, and behavior are drastically altered during heat stress. Heat dissipation methods become inadequate when environmental temperatures exceed an animal's internal body temperature. Recently there has been increasingly interested in strategies to reduce thermal stress on livestock. Sprinklers may help reduce accumulated heat and improve goat heat dissipation. Ten indigenous adult dry does were randomly assigned to two treatment groups, the non-cooling group as a control and the treatment group with two sprinkler and fans cooling systems. Feed and water consumption, breathing rate, rectal, external, and ambient temperatures, and relative humidity were recorded daily. For two weeks of the investigation, body weight was recorded once a week. The results showed that the control group consumed more water, and the ratio of water drunk/ dry matter intake tended to be higher than the treatment counterparts. Neither group showed significant differences in dry matter intake. Respiratory rates were greater in the control group compared to the treatment counterpart. Despite the marked difference between climatic conditions of both groups' rooms, no significant difference in rectal body temperatures was found. The temperatures of the eyes and legs were not significantly different in either group. In contrast, the calculated correlation between the rectal temperature with the highest value was found for the negative relation with rump and neck temperature. In conclusion, spraying goats and continual air movement under dry weather alleviate heat stress and improves goat welfare.
Mostrar más [+] Menos [-]Влияние препарата Эквикар на восполнение потери электролитов при повышенном потоотделении
2009
Finogenov, A.Yu. | Finogenova, E.G., National Academy of Sciences. Scientific and Practical Center of Animal Breding (Belarus). The S.N. Vyshelesskij Inst. of Experimental Veterinary Medicine
For the determination of efficiency of a new produced in the Republic of Belarus preparation Ehkvikar there was modeled a test with a diaphoresis of guinea pigs by means of their staying in a thermostat at a temperature of 45-50 deg C in course of 30 minutes. Before and after the test there was taken a blood test for its analysis. Results of the experiment showed that together with sudo the animals lost 1-2 % of their body. There was stated the increasing of all blood corpuscles as well as lowering in 1,3-1,47 times of such elements as chlorine, sodium, potassium, and also T lymphocytes and bursa-derived lymphocytes. Application Ehkvikar promoted the stabilization of biochemical and morphological parameters of blood, and also the immune status of laboratory animals. Thus, Ehkvikar preparation promoted the compensation of losses of electrolytes with sudor of guinea pigs and in future can be studied by an example of horses for completion of electrolytes losses in the conditions of increased physical exercises.
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