Itzhak Choshniak

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 The temperatures of the arterial blood and the brain in black Bedouin goats were measured continuously by miniature data loggers. The animals were either euhydrated or dehydrated to 75–80% of the initial body mass by withholding water for 3–4 days during exposure to intense solar radiation. The daily blood temperature means and maxima of were significantly(More)
1. The transport characteristics of the chicken coprodeum have been examined in vitro using the isolated mucosa. The short-circuit current (I(sc)), the transepithelial electrical potential difference (p.d.), the unidirectional transmural fluxes (J(ms), J(sm)) of sodium and chloride measured in the short-circuited state, and the unidirectional influx of(More)
Golden spiny mice, which inhabit rocky deserts and do not store food, must therefore employ physiological means to cope with periods of food shortage. Here we studied the physiological means used by golden spiny mice for conserving energy during food restriction and refeeding and the mechanism by which food consumption may influence thermoregulatory(More)
Daily circadian rhythms of body temperature (Tb) and oxygen consumption (VO2) were measured in two murid species, which occupy extremely different habitats in Israel. The golden spiny mouse (Acomys russatus) is a diurnal murid distributed in arid and hot parts of the great Syrio-African Rift Valley, while the broad-toothed field mouse (Apodemus mystacinus)(More)
Desert rodents face periods of food shortage and use different strategies for coping with it, including changes in activity level. Golden spiny mice (Acomys russatus) inhabit rock crevasses and do not dig burrows nor store food. When kept under 50% food restriction most, but not all, golden spiny mice defend their body mass by physiological means. We tested(More)
Food availability and quality in desert habitats are spatially and temporally unpredictable, and animals face periods of food shortage. The golden spiny mouse (Acomys russatus) is an omnivorous desert rodent that does not hoard food, requiring it to withstand such periods by physiological means alone. In response to food restriction, plasma leptin(More)
Energy conservation is a key adaptation for desert survival in the Bedouin goat. When food is scarce, metabolism is reduced and body weight can be maintained indefinitely on less than one-half of normal intake. We hypothesized that metabolism would be turned down during both rest and exercise, but it was not. It was low when animals rested and returned to(More)
Factors determining the digestive efficiency of donkeys were studied in animals fed either a low quality roughage (wheat straw: 77.1% neutral detergent fibre, 2.8% crude protein) or a high quality forage (alfalfa hay: 47.5% neutral detergent fibre, 22.7% crude protein). The neutral detergent fibre (NDF) intake when fed wheat straw was 1693 +/- 268 g(More)
The nitrogen economy of the Nubian ibex (Capra ibex nubiana), a ruminant that inhabits harsh deserts, was studied in the laboratory when fed three diets of different quality. Even on the low quality roughage (wheat straw) the ibex was found capable of balancing its nitrogen economy. On feeds low in protein, recycling of urea played a major role in helping(More)
Three lactating and three non-lactating black Bedouin goats were subjected to four days of water deprivation or to hemorrhage. Four days of water deprivation caused body wt losses of 32 and 23% and plasma volume losses of 30 and 34% in lactating and non-lactating goats respectively. Plasma osmolality increased 17 and 15% in lactating and non-lactating(More)