Faurie, Alida S.

Blue duikers and red duikers have very similar rumen anatomy. In both species the rumen is a simple, plesiomorphic, sacculated S-shaped tube, while the ostia are large and the ruminal pillars weak. These specialisations facilitate rapid digesta passage. The rumens are densely papillated, and the fungiform papillae are highly vascular to aid absorption. Many of the adaptations are characteristic of concentrate selectors. Total concentrations of numeral fatty acids are lower in the red duiker than the blue duiker. Propionic and butyric acid concentrations are higher in the blue duiker than the red duiker while acetic acid concentration are greater in red duikers. Caecal concentrations of volatile fatty acids (especially acetic acid) are greater than those in the rumen of the blue duiker, but likely contribute less energy to metabolism because of the small size of the caecum relative to that of the rumen

The chapter, "The thermal physiology of the ruminant fetus" was written by the listed authors including Alida Faurie (Douglas College Faculty). This volume contains 26 chapters in sections on regulation of feed intake, rumen microbiology and fermentation, nutrient absorption and splanchnic metabolism, tissue maintenance and utilization of endogenous body reserves, tissue growth, reproduction, pregnancy and lactation, ruminant physiology and genetics, and host resistance to parasites and pathogens. The chapters are the plenary papers presented at the IX International Symposium on Ruminant Physiology in Pretoria, South Africa during October 1999. This chapter discusses the fetal body temperature homeostasis, feto-maternal thermal relationship, birth-related changes in body temperatures, and preterm labour and abortion in ewes.

Maternal and fetal body temperatures were measured in five Boer goats, of mean mass 64 +/- 8 kg, using temperature-sensitive radiotelemeters implanted intra-abdominally. Body temperatures were recorded every 5 min. Throughout the last month of gestation, fetal temperature was approximately 0.6 (o)C higher than that of the mother, in normal laboratory conditions (ambient air temperature: 21-24 (o)C). This feto-maternal temperature difference between the goat fetus and its mother is similar to that found in other mammals, including sheep. When the pregnant goats were subjected to short-term heating and cooling, the difference between maternal and fetal body temperatures changed. Thus the mean difference between fetal and maternal body temperatures decreased from 0.4 to 0.2 (o)C during 2 h of heating, while it widened from 0.3 to 0.7 (o)C during 6 h of cooling. These data support the idea that the fetus is thermally protected from excursions of body temperature during changes in the mother's thermal environment. Reports of goat stock losses and abortions during cold spells in their natural habitats may be the result of more severe and/or prolonged cold exposures that not only adversely affect fetal or maternal body temperature, but also influence other aspects of metabolism.

The fetus is thermally clamped to its mother, and susceptible to infectious agents arising in maternal or amniotic tissue. We review the consequences of maternal fever and infection for the fetus. Possible consequences include noxious fetal hyperthermia, cytokine-induced damage to tissues and premature labour or abortion. [ABSTRACT FROM AUTHOR]

We measured core body temperatures of three pregnant ewes and their fetuses by means of chronically implanted temperature-sensitive data loggers. In standard laboratory conditions (dry-bulb temperature 20–22°C) core body temperatures of pregnant sheep and their fetuses during the last trimester of pregnancy demonstrated a constant feto-maternal temperature gradient, and a daily thermal circadian rhythm for the mother and fetus with a small amplitude (<1°C). When the same pregnant ewes were transferred to a natural field habitat where dry-bulb temperature varied between 7°C and 27°C in a 24 h period, there was a marked increase in the amplitude of ewe nychthemeral temperature rhythms (∼2°C). There was similarly an increase in fetal temperature rhythms, but the variations were smaller. Immediately after birth in the field, the core temperature of newborn lambs fell by up to 4.5°C. Thereafter, newborn lambs increased their core body temperatures and appeared to regulate core temperature and daily temperature rhythms at the same levels that they were as fetuses. Only in the second month post-birth do lamb core temperatures and temperature rhythms begin to resemble those of adult sheep. We have shown that fetal thermal protection, which is evident in ewes housed in in-door conditions, persists in natural field conditions also, where fetuses appear to be more protected from night-time falls- than daytime rises in maternal core temperature.

Aspects of olfactory, auditory, visual and tactile communication were investigated in five Elephantulus species (E. brachyrhynchus, E. edwardii, E. intuft, E. myurus, E. rupestris) ar.d Macroscelides proboscideus, facilitating comparisons among species and genera. The purpose of this study was to determine whether species specific patterns of communication could be identified in the southern African elephant-shrews. Scent galnd structure and location was investigated to determine whether species specific differences existed and to relate gland location to marking behaviour. Prominent scent glands were found in the oral angel, foot pads, anogenital region and tail of all elephant-shrew specIes. Marking behaviours such as sandbathing, digging and anal dragging correlated strongly with sent gland location, but no glandular size and/or structural differences were apparent among the different elephant-shrew species. Species specific differences in marking frequencies did exist among the six elephant-shrew taxa, but were unrelated to glandular development. Choice chamber preference tests indicated that Elephantulus species preferred conspecific odours, with males showing higher levels ofdiscrimination than females. Audible vocalizations and footdrumrning were investigated and compared in the sex elephant-shrew taxa. Distinct differences were present in the acoustic repertoires of the southern African elephant-shrew species. Footdrumming showed very clear species specific patterns, and footdrumming characteristics were compared with an existing morphological phenogram to derive a possible path o f evolution for footdrumming. Visual and tactile communication were investigated by analysis of frequencies and sequences of behavioural acts. A comparison of male-female interactions of the different taxa showed differences in behavioural frequencies both between males and females of a species, and among the different species. Discriminant function analysis showed clear species specific patterns in the visual! tactile signalling systems of southern African elephant-shrews, and this was more clearly defined in males. Elephant-shrews showed higher levels of aggressive behaviour in interspecific encounters, indicating a possible role of aggression as a premating isolating mechanism between species. However, no differences in aggressive behaviour between allopatric and sympatric male- female interactions could be discerned . Elephant-shrew males showed high frequencies o f submissive behaviour in intraspecific encounters, which may be a strategy to reduce aggression in conspecific females. Species specific patterns of behaviour were found to exist in all three modes of communication investigated, and may all act to some extent as premating isolation mechanisms between species. However, many of these patterns are very subtle and it is suggested that a combination of all sensory modalities act together to form each species' signalling system.

Infection causes fever and suppression of appetite, a combination of effects which threatens normal growth in infected children. We have used an animal model to study the effects on growth of recurrent simulated Gram-positive bacterial infection. After weaning, 10 guinea pig pups underwent surgery under general anaesthesia for the implantation of temperature-sensitive radiotelemeters and thereafter were assigned to receive intramuscular injections of either 50 μg/kg muramyl dipeptide (MDP), or sterile saline. During a 30-day period corresponding to their rapid growth phase, the pups were given eight injections. MDP resulted in fevers of about 1.5 °C on each occasion, but no significant change in body temperature occurred after saline injections. Food intake was suppressed during each febrile episode such that 24-h intake was significantly lower on days of injections of MDP, compared to days between MDP injections in the same animals, and compared to that of animals injected with saline. The rate of weight gain of the MDP-injected guinea pigs was significantly lower than that of the control group and failed even to achieve a rate similar to the saline-injected group in their more adult-like growth phase. Plasma zinc concentration was significantly lower in MDP-compared to saline-injected animals sampled 8 days after the last injection. Our results show that recurrent fever during the growth phase of young guinea pigs results in irreversible growth failure, and that reduced food intake on days when the animals were febrile was at least partly responsible for this reduced rate of growth.

We exposed Dorper-cross ewes at 􏰀120–135 days of gestation to a hot (40°C, 60% relative humidity) and a cold (4°C, 90% relative humidity) environ- ment and to treadmill exercise (2.1 km/h, 5° gradient) and measured fetal lamb and ewe body temperatures using pre- viously implanted abdominal radiotelemeters. When ewes were exposed to 2 h of heat or 30 min of exercise, body temperature rose less in the fetus than in the mother, such that the difference between fetal and maternal body temper- ature, on average 0.6°C before the thermal stress, fell signif- icantly by 0.54 􏰁 0.06°C (SE, n 􏰂 8) during heat exposure and by 0.21 􏰁 0.08°C (n 􏰂 7) during exercise. During 6 h of maternal exposure to cold, temperature fell significantly less in the fetus than in the ewe, and the difference between fetal and maternal body temperature rose to 1.16 􏰁 0.26°C (n 􏰂 9). Thermoregulatory strategies used by the pregnant ewe for thermoregulation during heat or cold exposure appear to protect the fetus from changes in its thermal environment.