Abstract: Twelve ponies were fed their total daily ration either as one large meal or divided into six small meals. Pre- and post-feeding behavior was recorded six times a day. Blood samples were taken for 30 min before and two hr after the meal. Plasma protein increased from 7.0 to a peak of 7.3 g/dl with small meals and from 7.3 to 8.1 g/dl with large meals, and returned to pre-feeding levels by 90 min post-feeding. Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. These rapid and short-lived increases indicate a decrease in plasma volume. Plasma osmolality rose with feeding from 283 to 285 mosmoles/kg with small meals and from 281 to 288 mosmoles/kg with large meals. Water availability had no significant effect on blood changes. Digestibility and rate of passage were measured with chromic oxide, but there were no differences. Vocalizing (neighing) and walking occurred more often before than after feeding, while eating bedding and engaging in other oral behaviors were more frequent after feeding.

Abstract: Forty-one Dutch Warmblood immature horses were used in a study to quantify temperamental traits on the basis of heart rate (HR) and heart rate variability (HRV) measures. Half of the horses received additional training from the age of 5 months onwards; the other half did not. Horses were tested at 9, 10, 21 and 22 months of age in a novel object and a handling test. During the tests, mean HR and two heart variability indices, e.g. standard deviation of beat-to-beat intervals (SDRR) and root mean square of successive beat-to-beat differences (rMSSD), were calculated and expressed as response values to baseline measures. In both tests, horses showed at all ages a significant increase in mean HR and decrease in HRV measures, which suggests a marked shift of the balance of the autonomic nervous system towards a sympathetic dominance. In the novel object test, this shift was more pronounced in horses that had not been trained. Furthermore, statistical analysis showed that the increase in mean HR could not be entirely explained by the physical activity. The additional increase in HR, the nonmotor HR, was more pronounced in the untrained horses compared to the trained. Hence, it is suggested that this nonmotor HR might be due to the level of emotionality. HR variables showed consistency between years, as well as within the second year. These tests bring about a HR response in horses, part of which may indicate a higher level of emotionality; and horses show individual consistency of these HR variables over ages. Therefore, it is concluded that mean HR and HRV measures used with these tests quantify certain aspects of a horse's temperament.

Abstract: This study investigated three methods of water supply on drinking preference and behavior in six Standardbred geldings (2-9 years, 505+/-9 kg). The water sources were buckets (B), pressure valve (PV), and float valve (FV) bowls. In an initial drinking preference test, PV was tested at three flow rates: 3, 8, and 16 l/min (PV3, PV8, and PV16), and FV at 3 l/min (FV3). Water intake was measured in l and presented as the percentage of the total daily water intake from each of two simultaneously presented alternatives. The intake from PV8 was greater than from both PV3 (72+/-11% vs. 28+/-11%) and PV16 (90+/-4% vs. 10+/-4%). All horses showed a strong preference for B, 98+/-1% of the intake compared to 2+/-1% from PV8. Individual variation in the data gave no significant difference in preference between the two automatic bowls. In the second part of the study, drinking behavior and fluid balance were investigated when the horses drank from FV3, PV8, and B for 7 consecutive days in a changeover design. Despite a tendency for an increase in total daily drinking time from FV3, the daily water intake was significantly lower (43+/-3 ml/kg) than from PV8 (54+/-2 ml/kg) and B (58+/-3 ml/kg). Daily net water gain [intake-(fecal+urinary output)] was only 0.5+/-3 ml/kg with FV3, resulting in a negative fluid balance if insensible losses are included. These results show that the water supply method can affect both drinking behavior and fluid balance in the horse.

Abstract: The pressures of developing and maintaining intricate social relationships may have led to the evolution of enhanced cognitive abilities in many nonhuman primates. Knowledge of the dominance ranks and social relationships of other individuals, in particular, is important in evaluating one's position in the rank hierarchy and affiliative networks. Triadic interactions offer an excellent opportunity to examine whether decisions are taken by individuals on the basis of such knowledge. Allogrooming supplants among wild female bonnet macaques (macaca radiata) usually involved the subordinate female of a grooming dyad retreating at the approach of a female dominant to both members of the dyad. In a few exceptional cases, however, the dominant member of the dyad retreated; simple non-cognitive hypotheses involving dyadic rank differences and agonistic relationships failed to explain this phenomenon. Instead, retreat by the dominant individual was positively correlated with the social attractiveness of her subordinate companion (as measured by the duration of grooming received by the latter from other females in the troop). This suggests that not only does an individual evaluate relationships among other females, but does so on the basis of the amount of grooming received by them. Similarly, the frequency of approaches received by any female was correlated with her social attractiveness when she was the dominant member of the dyad, but not when she was the subordinate. This indicated that approaching females might be aware of the relative dominance ranks of the two allogrooming individuals. In logistic regression analyses, the probability of any individual retreating was found to be influenced more by her knowledge of her rank difference with both the other interactants, rather than by their absolute ranks. Moreover, information about social attractiveness appeared to be used in terms of correlated dominance ranks. The nature of knowledge acquired by bonnet macaque females may thus be egotistical in that other individuals are evaluated relative to oneself, integrative in that information about all other interactants is used simultaneously, and hierarchical in the ability to preferentially use certain categories of knowledge for the storage of related information from other domains.

Abstract: In two adult horses doses of 0.02-0.03 mg/kg diazepam, intravenously, increased 1 hr intake 54-75% above control levels. Intake was stimulated when the diet was a high grain, calorically dense one and also when the diet was a high fiber, calorically dilute one. Two young rapidly growing weanling horses showed an even more pronounced stimulation of intake. Following diazepam 1 hr intake was increased 105-240% above control lelvels. Promazine at a dose of 0.5 mg/kg also stimulated intake in adult horses, but not as markedly as did diazepam. A transquilizer and a neuroleptic appear to have a stimulatory eff upon short-term intake in horses.