Abstract: Weaning foals marks a stressful event in horses' lives. Limited research exists regarding different housing methods post-weaning and the long-term implications on horse behavior and welfare. The purpose of this study was to monitor behavior and physiological stress markers in horses weaned individually in solid partition box stalls versus horses weaned in small groups and housed in paddocks. Both treatment groups underwent maternal deprivation stress, but the stalled weanlings had the additive effects of social isolation which prevented them from performing social behaviors. Quarter Horse weanlings from the Michigan State University, Merillat Equine Center, average age 4.5 months, were weaned in 13.4 m2 box stalls (n=6) or in groups of three in a 992 m2 paddock, which had very limited grazing forage and an open shelter available (n=6). Subjects were fed concentrate and hay to National Research Council recommendations. A time budget for 31 observed behaviors was developed. Behavioral observations were made 2 days per week, approximately 6 h per day, for the duration of the 56 days study. Instantaneous samples were recorded every 5 min on each observation day, with equal division between the two treatment groups (n=35 scans per horse per observation day). Focal data were recorded continuously between scans to provide a more detailed ethogram. On each observation day, fecal samples were collected to measure 11,17-dioxoandrostanes, an indicator of glucocorticoid metabolite concentration. Regarding the fecal 11,17-dioxoandrostanes, there was no discernible treatment difference either immediately post-weaning or at the conclusion of the 56 days study. Interestingly, all 12 weanlings showed a 4 week post-weaning increase in 11,17-dioxoandrostanes. The reason for this peak was unclear. Behavioral observations demonstrated a significantly different time budget in paddock-housed weanlings than in stall-housed weanlings (P<0.0001). Paddock-housed weanlings displayed a time budget more like a feral horse time budget, showing more time spent moving and less time spent lying. Paddock-housed weanlings, who had the option of selectively engaging in a broader range of behaviors, showed strong motivation to graze and be near conspecifics. Stalled weanlings spent significantly more time engaged in aberrant behaviors: licking or chewing the stall/shed wall, kicking at the stall/shed wall, pawing, and bucking/rearing bouts (P<0.03). Based on the variety of behaviors shown, the ability to engage in strongly preferred behaviors, and freedom from aberrant behavior, we conclude that the paddock-reared, group-housed weanlings had better welfare. However, there was insufficient evidence to conclude that the stalled weanlings had poor welfare.

Abstract: Fifty-eight Holstein heifer calves were assigned to one out of three treatment groups after having nursed by their mothers for the first week: BN) individual hutch, bucket with nipple n=25; DF)loose housing pen, machine milk feeder, n=16; NC) loose housing pen, nursing cow, n=17. After weaning at 8 weeks, all calves were kept in group pens. At 15 weeks of age, the behaviour in the 6-unit maze (16.4 – 4.5 m) was determined. On the first observation day, the calves were tested five times (the first one for training); on the second day there were four runs. The calves had to solve two tasks. In task A, the passage was open on the left side, and on the right side (task B) on the next day. We were testing the following hypothesis: the speed of traversing the maze is affected by the rearing system. The slowest were NC calves. On the first day (task A), the average time to traverse the maze among treatments DF (43.9 s), BN (53 s) and NC (111.3 s) was different (F = 8.26*, P = 0.0007). On the second day (task B), the averages were: BN 77.1 s, DF 83.8 s and DC 166.6 s (F=8.17*, P = 0.0008). The results indicate that the feeding method and housing used to rear calves may have a significant impact on their maze behaviour.

Abstract: In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1+/-0.49 days was evident. Colt foal pregnancies were significantly (P<0.001) longer (346.2+/-0.72) than fillies (342.4+/-0.65). Month of birth had a significant effect on gestation length in all foals (P<0.001). With foals born in January having the shortest gestation lengths and those born in April the longest. Mare age, year of birth, stallion age, stud farm and the interval between ovulation and mating had no significant effect. It is concluded that (i) the gestation length range (315-388 days), all resulting in viable foals is noteworthy and of clinical importance when considering the classification of dysmaturity in foals, (ii) mares carrying colt foals due to be born in the middle of the breeding season (April) are likely to have the longer gestation lengths.

Abstract: An early training procedure commonly termed “foal imprint training” is widely promoted in the horse industry. However, there have been no published scientific investigations of its efficacy. This study determined the effects of a training procedure on foals and their reaction to stimuli used in the early training procedure, and to a novel stimulus, at 1, 2 and 3 months of age. Twenty-five foals received a standard training procedure at 2, 12, 24, and 48 h after birth. After the training procedure, the foals received minimal additional handling that included veterinary treatments and occasional relocation. Twenty-two foals born over the same time period served as controls. All 47 (25 trained, 22 control) foals were tested at 1 month of age. Only 20 were available for testing at 2 months of age, and nine were available at 3 months. Percentage change from baseline heart rate, time required to complete exposure to each stimulus (foals that were more reactive took longer) and the behavior of each foal during the introduction of each stimulus were recorded. Overall, the control foals tended to receive lower (better) behavioral scores at 1 and 2 months of age. Foals that underwent the training procedure tended to require less time to complete exposure to the stimulus and had lower heart rates during exposure to the stimuli at 1 and 2 months of age. By 3 months of age, there were no significant differences between trained and control foals for any measures. Early training was not efficacious in this study.

Abstract: The aim of this study was to investigate social behaviour in differently reared stallions in their respective environments; one group of stallions was reared under typical domestic conditions whereas the other group was reared and lives under natural conditions. The domestic group consisted of 19, 2-year-old stallions (Equus caballus), which were all weaned at 4 months of age and experienced either individual or group housing facilities before being pastured with the other similarly aged stallions. The natural living and mixed age group of Przewalski stallions (E. przewalskii) consisted of 13 stallions, most of which were juveniles (n=11, <=4 years; n=2, >9 years). The domestic group was studied in a 4-ha enclosure at the Danish Institute of Agricultural Sciences and the Przewalski group under free-ranging conditions in a 75-ha enclosure in the Askania Nova Biosphere Reserve, Ukraine. Behavioural data was collected during 168 h of direct observation. The occurrence of 14 types of social interactions was recorded and group spacing behaviour was studied using nearest neighbour recordings. In spite of very different environments, reflecting domestic and natural rearing conditions, many similarities in behaviour was found. Play and play fight behaviour was very similar in the two stallion groups. Quantitative differences were found in social grooming since Przewalski stallions groomed more frequently (P=0.004), and in investigative behaviours, since domestic stallions showed more nasal (P=0.005) and body sniffing (P<0.001), whereas Przewalski stallions directed more sniffing towards the genital region (P<0.001). These differences may, however, be attributed to environmental factors and in the period of time the stallions were together prior to the study period. Quantitative differences appeared in some agonistic behaviours (kick threat, P<0.001; and kick, P<0.001), but data do not support earlier findings of Przewalski horses being significantly more aggressive than domestic horses. In general, Przewalski stallions engaged in more social interactions, and they showed less group spacing, i.e. maintained a significantly shorter distance between neighbours (P<0.001). The study indicates that also domestic horses, which have been reared under typical domestic conditions and allowed a period on pasture, show social behaviour, which is very similar to that shown by their non-domestic relatives.