Abstract: An immunoglobulin G (IgG) was spray-dried on a Büchi 190 laboratory spray-dryer at inlet and outlet air temperatures of 130 and 190°C, respectively. The IgG solution contains initially 115mg/ml IgG plus 50mg/ml sorbitol. After dialysis, at least 80% of low molecular weight component was removed. After spray-drying the dialyzed IgG and immediate redissolution of the powder, an increase in aggregates from 1 to 17% occurred. A major shift towards increase β-sheet structure was detected in the spray-dried solid, which, however, reverted to native structure on redissolution of the powder. A correlation between aggregation determined by size exclusion chromatography and alterations in secondary structure determined by Fourier transformation infra-red spectroscopy could not therefore be established. On spray-drying a non-dialyzed, sorbitol-containing IgG only some 0.7% aggregates were formed. The sorbitol is therefore evidently able to stabilize partially the IgG during the process of spray-drying. Addition of trehalose to the liquid feed produced quantitatively the same stabilizing action on the IgG during spray-drying as did the sorbitol. This finding again points towards a water replacement stabilization mechanism. The IgG spray-dried powder prepared from the dialyzed liquid feed showed continued substantial aggregation on dry storage at 25°C. This was substantially less in the non-dialyzed, sorbitol-containing spray-dried powder. Addition of trehalose to both dialyzed and non-dialyzed system produced substantial improvement in storage stability and reduction in aggregate formation in storage. The quantitative stabilizing effect of the trehalose was only slightly higher than that of the sorbitol. Taken together, these results indicate that both the sorbitol and trehalose stabilize the IgG primarily by a water replacement mechanism rather than by glassy immobilization. The relevance of this work is its questioning of the importance of the usually considered dominance of glassy stabilization of protein in dried systems of high glass transition temperature, such as trehalose. The low glass transition temperature sorbitol produces almost equal process and storage stability in this case.

Abstract: The objective was to evaluate the efficacy of gymnastic training (GYM) and dynamic mobilization exercises (DMEs) on stride length (SL) and epaxial muscle size in therapy horses. Nine cross-bred hippotherapy horses that performed three, 25-minute therapeutic riding sessions per week throughout the study period were randomly assigned to three experimental groups: a control group in which the horses were sedentary with no additional physical activity; a group that performed DMEs; and a group that performed both DMEs and additional GYM including pelvic tilting, backing, turning in small circles, and walking over a raised rail to strengthen the abdominal and pelvic stabilizer muscles. The exercises were performed 3 days per week for 3 months, with evaluations at the start and end of the study. Stride quality was assessed by measuring SL and tracking distance (TD). Epaxial muscle size was monitored by ultrasonographic measurement of m. longissimus dorsi (LD) thickness and m. multifidi (MM) cross-sectional area. Paired t tests were used to compare within groups across time, and between groups were detected using analysis of variance with Tukey post hoc test. When walking at 1.3 m/s, SL and TD at walk increased significantly (P < .05) in horses subjected to GYM. Thickness of LD did not change in any group, but cross-sectional area of MM increased significantly by 3.55 cm2 (DME) and 3.78 cm2 (GYM). It was concluded that GYM training improved stride quality and DME-stimulated MM hypertrophy which has been shown to improve intervertebral joint stability in other species.

Abstract: Although housing horses in single stalls limits their natural behavior to a great extent, this housing system is widespread in Germany, especially for competition horses. To improve the welfare of this system, free exercise on pastures or paddocks is deemed suitable, but it is also feared because of injuries and decreased willingness or motivation to perform. In the present study, three treatments were investigated with regard to their effect on the behavior of six competition horses in the stable, behavior during training, and on their degree of stress: daily training without free exercise (no turnout [NT]), solitary turnout for 2 hours after training, and 2-hour turnout in groups of two after training (group turnout). The horses' behavior in the stable was continuously analyzed through video recordings (2 pm to 6 am) on 3 days at the end of each treatment. The degree of stress was evaluated daily by heart rate variability at rest. The behavior during training was evaluated by a questionnaire answered by the riders, and the distance covered during training was measured by global positioning system. When NT was allowed, the horses showed less lying in the stable compared with the treatments with turnout. Heart rate variability measurements resulted in great individual differences, but generally, there was a higher degree of stress shown with the treatment NT according to the following parameters: standard deviation of inter-beat-intervals (SDNN), square root of the mean of the sum of the squares of differences between successive inter-beat-intervals (RMSSD), and ratio between low frequency and high frequency (LF/HF). The willingness to perform was evaluated as being slightly better in the treatments with turnout than in the treatment without turnout.

Abstract: Abstract The role of leader in polygynous species has been solely attributed to the male for some time, but recent studies shown decision making to be distributed within the group. However, the specific reproductive strategy and behavioural repertoire of males in polygynous species such as horses may mean that these individuals still have the potential to play a specific role during decision-making. To investigate this subject, we thoroughly studied the behaviour of two domestic stallions during collective movements of their group. We found that they initiated rarely and sometimes failed to recruit the entire group. When departing as followers, they did not accelerate the joining process. Both stallions preferentially occupied the rear position and exhibited numerous monitoring behaviours. Herding behaviours were performed by only one stallion and mostly occurred outside movement context. Finally, we removed this herding stallion from its group to evaluate how the group dynamic changed. As a result, half of the collective movements were five times slower and mares were more dispersed in comparison when the stallion was in the group. Overall, our results suggest that, the two stallions maintained their role of group monitors from departure to arrival. Their influence on the movement dynamic was indirect and did not play a specific role in the process of decision making.

Abstract: Development of a widely accepted vocabulary referring to various types of social learning has made important contributions to decades of progress in analyzing the role of socially acquired information in the development of behavioral repertoires. It is argued here that emergence of a consensus vocabulary, while facilitating both communication and research, has also unnecessarily restricted research on social learning. The article has two parts. In the first, I propose that Thorndike, 1898, Thorndike, 1911 definition of imitation as “learning to do an act from seeing it done” has unduly restricted studies of the behavioral processes involved in the propagation of behavior. In part 2, I consider the possibility that success in labeling social learning processes believed to be less cognitively demanding than imitation (e.g. local and stimulus enhancement, social facilitation, etc.) has been mistaken for understanding of those processes, although essentially nothing is known of their stimulus control, development, phylogeny or substrate either behavioral or physiological.