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: The stabled (UK) or stalled (USA) horse is commonly fed a restricted-forage diet in contrast to the varied ad libitum high-fibre diet it evolved to consume. A low-forage diet has been linked to the performance of stereotypical behaviour and health problems including gastric ulceration and impaction colic (in cases where horses are bedded on straw). Provision of a diet closer to that which the horse is adapted to and which enables more natural feeding behaviour warrants investigation. This trial aimed to establish whether the behavioural effects observed in short-term trials when stabled horses were provided with a multiple forage diet persist over longer periods. It also aimed to develop a practical methodology for maintaining stabled horses under forage-enriched conditions. Nine horses (aged 5-20 years, various breeds), acting as their own controls, participated in an 18-day, cross-over, Latin Square designed trial, in which they received comparable weights of two dietary treatments: a Single Forage (SF, hay) diet and a Multiple Forage (MF) diet (three long-chop and three short-chop commercially available forages). Following a 2-day acclimatisation, horses were maintained on the forage treatments for 7 days. Horses were observed on alternate days, morning and afternoon, during the 25 min following forage presentation. Horses then crossed over onto their second treatment and, following a further 2 days' acclimatisation, the same protocol was followed for a further 7 days. Observations from video were made using The Observer 3.0(R) and SPPS (version 11). Horses on the MF treatment performed foraging behaviour significantly more frequently and for significantly longer periods than horses on the SF treatment. On the MF treatment horses sampled all forages during observations. However, there were significant differences in the frequency and duration of foraging on individual forages, indicating that horses demonstrated individual preferences for particular forages. Stereotypic weaving behaviour only occurred on the SF treatment. The results indicate that the potentially beneficial behavioural effects of short-term multiple forage provision do persist when horses are managed on a MF diet for a 7-day period. They suggest that a MF diet provides a means of enriching the stabled horse's environment, by offering variety and enabling patch foraging behaviour. The methodology proved practical for maintaining horses under forage-enriched conditions and could easily be adopted by horse owners to facilitate foraging behaviour.

Abstract: Sweating responses were examined in five horses during a standardized exercise test (SET) in hot conditions (32-34 degrees C, 45-55% relative humidity) during 8 wk of exercise training (5 days/wk) in moderate conditions (19-21 degrees C, 45-55% relative humidity). SETs consisting of 7 km at 50% maximal O(2) consumption, determined 1 wk before training day (TD) 0, were completed on a treadmill set at a 6 degrees incline on TD0, 14, 28, 42, and 56. Mean maximal O(2) consumption, measured 2 days before each SET, increased 19% [TD0 to 42: 135 +/- 5 (SE) to 161 +/- 4 ml. kg(-1). min(-1)]. Peak sweating rate (SR) during exercise increased on TD14, 28, 42, and 56 compared with TD0, whereas SRs and sweat losses in recovery decreased by TD28. By TD56, end-exercise rectal and pulmonary artery temperature decreased by 0.9 +/- 0.1 and 1.2 +/- 0.1 degrees C, respectively, and mean change in body mass during the SET decreased by 23% (TD0: 10.1 +/- 0.9; TD56: 7.7 +/- 0.3 kg). Sweat Na(+) concentration during exercise decreased, whereas sweat K(+) concentration increased, and values for Cl(-) concentration in sweat were unchanged. Moderate-intensity training in cool conditions resulted in a 1.6-fold increase in sweating sensitivity evident by 4 wk and a 0.7 +/- 0.1 degrees C decrease in sweating threshold after 8 wk during exercise in hot, dry conditions. Altered sweating responses contributed to improved heat dissipation during exercise and a lower end-exercise core temperature. Despite higher SRs for a given core temperature during exercise, decreases in recovery SRs result in an overall reduction in sweat fluid losses but no change in total sweat ion losses after training.