Hillidge, C. J., & Lees, P. (1975). Cardiac output in the conscious and anaesthetised horse. Equine Vet J, 7(1), 16–21.
Abstract: Cardiac output in the horse was measured before and at predetermined times during 2-hour periods of thiopentone-halothane and thiopentone-diethyl ether anaesthesia. Left ventricular stroke volume was decreased to a similar extent during anaesthesia with each volatile agent, but a greater reduction in cardiac output occurred during halothane anaesthesia. This finding reflected the differing effects of halothane and ether on heart rate, a slight bradycardia occurring with the former agent while ether produced a small degree of tachycardia. The latter effect was attributed to enhanced sympathoadrenal activity. Changes in cardiac output and stroke volume were considered in relation to other factors, including arterial blood pH and tensions of oxygen and carbon dioxide. Positive correlations between some of these variables and cardiac function were established. With both volatile agents the reductions in stroke volume and cardiac output were related to the duration of anaesthesia, being greatest during the early stages. Possible reasons for the tendency of stroke volume and cardiac output to return towards control levels are discussed.
|
|
Bannikov, A. G. (1975). Recent status of the wild ass in Mongolia. IUCN Bulletin, 6(4), 16.
|
|
Western D,. (1975). Water availability and its influence on the structure and dynamics of a savannah large mammal community. E Afr Wildl J 1, 3, 265–288.
|
|
Ruckebusch Y,. (1975). The hypnogram as an index of adaptation of farm animals to changes in their environment. App Anim Ethol, 2, 3–18.
|
|
FRASER AF et al,. (1975). An exploratory ultrasonic study on quntitative foetal kinesis in the horse. Appl Anim Ethol, 1, 395–404.
|
Mitchell, D., Kirschbaum, E. H., & Perry, R. L. (1975). Effects of neophobia and habituation on the poison-induced avoidance of exteroceptive stimuli in the rat. J Exp Psychol Anim Behav Process, 1(1), 47–55.
Abstract: Two experiments on the role of neophobia in poison-induced aversions to exteroceptive stimuli are reported. In Experiment 1, rats were given either 10 or 25 days of habituation to the test situation prior to conditioning. Those animals with the longer habituation period avoided a complex of novel exteroceptive stimuli while those with the shorter habituation period did not. In Experiment 2 rats initially avoided the more novel of two containers, but gradually came to eat equal amounts from both. A single pairing of toxicosis with consumption from either the novel or the familiar container reinstated the avoidance of the novel container in both cases. The results were discussed in terms of an interaction between habituation and conditioning procedures. It was suggested that previously reported differences between interoceptive and exteroceptive conditioning effects may have been influenced by the differential novelty of the two classes of stimuli in the test situation. It was further suggested that non-contingently poisoned control groups should routinely be included in poison avoidance conditioning studies.
|
Klingel, H. (1975). Social organization and reproduction in equids. J Reprod Fertil Suppl, (23), 7–11.
Abstract: There are two distinct types of social organization and, accordingly, two types of mating systems in equids. In the horse, Plains zebra and Mountain zebra, the adults live in non-territorial and cohesive one-male groups and in stallion groups. The family stallions have exclusive mating rights which are respected by all others. In Grevy's zebra and in the African and Asiatic wild asses, the stallions are permanently territorial and have exclusive mating rights within their territories. Ecological and evolutionary aspects are discussed.
|
|
Klingel H,. (1975). Die soziale Organisation der Equiden. Verh Dtsch Zool Ges in Karlsruhe, , 71–80.
|
|
Rossdale Pd,. (1975). Das Pferd, Fortpflanzung und Entwicklung. Karger 1975, .
|
|
Welsh Da,. (1975). Population, behavioural, and grazing ecology of the Sable Island, Nova Scotia. Ph.D. thesis, Dalhousie University, Halifax.
|
