Abstract: Father-daughter matings and its avoidance mechanism were analysed on the basis of data which gained from behavioural observations and paternity tests in Misaki feral horses from 1979 to 1994. Twelve stallions and their 51 daughters had 176 breeding seasons, but they lived in the different home range in 82 breeding seasons. About half of 1- to 3-year-old mares emigrated from natal area to the other and grew up there. Therefore, emigrations of young mares may result reduction of contacts and avoidance of inbreeding with their fathers. The stallions and their daughters lived in the same area in 94 breeding seasons, but there were no cases that daughters which left their natal harem groups before sexual maturity formed again stable consort relations with their natal harem stallions. It is possible that separation of young mares from their natal groups before sexual maturity may result avoidance of formation of consort relation with their fathers. Two father-daughter matings were observed in 124 paternity tests. These two daughters were born in the other harem groups than their father's and left their natal groups before maturity. After maturity, one of them formed a stable consort relation with her father and the other remained together with her father for 2 months in the breeding season. Both of them had not experience to have lived with their fathers before maturity. The persent result supports the hypothesis in wild and semi-wild horses that inbreedings between fathers and daughters may be avioded by the experience to have lived together before sexual maturity.

Abstract: Social dominance develops more slowly when young animals are kept in intact peer groups where they need not compete for resources. Learned generalizations may cause smaller and weaker animals to accept subordinate status readily when confronted with strangers that would be formidable opponents. Sexual hormones and sensitivity to them can influence the onset of aggression and status attained. After dominance orders are established, they tend to be stable in female groups but are less so in male groups. Psychological influences can affect dominance relationships when strangers meet and social alliances within groups may affect relative status of individuals. Whether status associated with agonistic behavior is correlated with control of space and scarce resources needs to be determined for each species and each kind of resource. When such correlations exists, competitive tests and agonistic behavior associated with gaining access to scarce resources can be useful to the observer in learning about dominance relationships rapidly. Examples are given to illustrate how estimates of social dominance can be readily attained and some strengths and weaknesses of the various methods.

Abstract: The effect of meal frequency on body fluid, glucose, triiodothyronine (T3), heart rate and behavior was measured in 10 ponies. A simple reversal design was used in which each pony received one meal/day (1X) for 2 wk and six meals/day (6X) for 2 wk. The total intake/day was held constant. Feeding was followed by a rise in plasma levels of glucose, T3, protein and osmolality. One large meal was followed by significantly greater changes in all of the variables than was a meal one-sixth the size. Plasma T3 rose from 41 +/- 5 (SE) ng/liter before feeding to 43 +/- 5 ng/liter following a small meal, but rose significantly higher, from 39 +/- 4 to 60 +/- 10 ng/liter, following a large meal. Glucose rose from 84 +/- 3 to 109 +/- 7 mg/dl following a small meal and rose significantly higher, from 83 +/- 3 to 154 +/- 11 mg/dl, after a large meal. Plasma protein rose from 6.55 +/- .14 to 6.62 +/- .16 g/dl following a small meal and from 6.45 +/- .14 to 6.99 +/- .11 g/dl following a large meal. Osmolality rose from 227 +/- 1 mosmol/liter before to 279 +/- 1 mosmol/liter following a small meal and significantly higher from 278 +/- 2 to 285 +/- 1 mosnol/liter following a large meal. Heart rate rose from 42 beats/min in the absence of feed to 50 beats/min when food was visible to the ponies and did not rise higher when eating began. There were no significant differences in the cardiac response to one large meal and that to a small meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Abstract: Eight pairs of pony mares were observed. Members of a pair were housed in adjacent stalls and fed hay ad libitum. The behavior of both ponies was recorded simultaneously in the morning (1000 to 1200 h) and afternoon (1400 to 1600 h) for a total of 117 h. The time budget was: 70.1 {+/-} 8.6% eating; 17.8 {+/-} 7.4% standing (including stand rest, stand alert and stand nonajert); 5.2 {+/-} 7.0% pushing hay; 2.9 {+/-} 1.2% walking; 1.9 {+/-} 2.9% drinking; 1.3 {+/-} 1.1% self-grooming; .2 {+/-} .3% defecating; .06 {+/-} .1% chewing nonfood items; .06 {+/-} .03% urination; .06 {+/-} .1% licking salt; .07 {+/-} .1% pawing hay; .6 {+/-} .7% lying and .07 {+/-} .08% stretching the neck over the stall wall dividing the ponies. While eating, the ponies lifted their heads 25.4 {+/-} 11.0 times/h. In less than one-half of the occasions when urination or defecation was observed, the ponies walked away from the spot where they had been eating to eliminate. During one-half of the observations, visual contact between the ponies was prevented by a solid partition between the stalls. The ponies spent significantly more time standing nonalert when the partition prevented visual contact (12 {+/-} 7%) than when visual contact could take place (6 {+/-} 3%, P<.05). When fresh hay was supplied in the mornings, the ponies spent similar amounts of time eating whether visual contact was allowed or not, but in the afternoon significantly more time was spent feeding when visual contact was allowed (73 {+/-} 4%) than when it was not (60 {+/-} 7%). Less time was spent eating, in the absence of visual contact, despite the presence of auditory and olfactory contact. Apparently social facilitation is important in maintaining feeding behavior in ponies. N1 -

Abstract: The maze learning ability of six pony foals that had been weaned at birth was compared to that of six foals reared normally. The foals' learning ability was also compared to their mothers' learning ability at the same task; the correct turn in a single choice point maze. The maze learning test was conducted when the foals were 6 to 8 mo old and after the mothered foals had been weaned. There was no significant difference between the ability of orphaned (weaned at birth) and mothered foals in their ability to learn to turn left (6 +/- .7 and 5.1 +/- .1 trials, respectively) or to learn the reversal, to turn right (6.7 +/- .6 and 6.2 +/- .6 trials, respectively). The orphan foals spent significantly more time in the maze in their first exposure to it than the mothered foals (184 +/- 42 vs 55 +/- 15 s. Mann Whitney U = 7, P less than .05). The mothers of the foals (n = 11) learned to turn left as rapidly as the foals (5.9 +/- .7 trials), but they were slower to learn to turn right (9.8 +/- 1.4 vs 6.4 +/- .4 trials, Mann Whitney U = 33, P less than .05), indicating that the younger horses learned more rapidly. There was no correlation between the trials to criteria of the mare and those of her foal, but there was a significant negative correlation between rank in trials to criteria and age (r = -65, P less than .05) when data from the mare and foal trials were combined. The dominance hierarchy of the mares was determined using a paired feeding test in which two horses competed for one bucket of feed. Although there was no correlation between rank in the hierarchy and maze learning ability, there was a correlation between body weight and rank in the hierarchy (r = .7, P less than .05). This may indicate either that heavier horses are likely to be dominant or that horses high in dominance gain more weight. Maternal deprivation did not appear to seriously retard learning of a simple maze by foals, although the orphans moved more slowly initially. The lack of maternal influence on learning is also reflected in the lack of correlation between the mare's learning ability and that of her foal. Young horses appear to learn more rapidly than older horses.