The effects of monensin on plasma concentrations and changes in plasma concentrations of energy metabolites and minerals over time were investigated using 24 multiparous Holstein cows. Cows were paired according to farm, predicted date of calving, and body condition score and were randomly allocated to two groups. Treated cows were given a ruminal bolus containing 32 g of monensin at 50 +/- 7 d before predicted calving. Treated cows had lower plasma concentrations of glucose, free fatty acid (FFA), and beta-hydroxybutyrate (BHBA) than did control cows before calving, indicating that monensin influenced energy metabolism. However, no significant differences in plasma concentrations of glucose, FFA, and BHBA were found between groups after calving. Plasma BHBA concentrations increased more before calving in control cows, and plasma FFA and urea concentrations increased significantly before calving in all cows. No significant differences in body weight, plasma concentrations of urea, or whole blood concentrations of glutathione peroxidase were detected between groups before or after calving. Plasma ceruloplasmin activity did not differ between groups before calving, but was significantly higher in treated cows after calving. Plasma concentrations of Ca did not significantly differ between groups before or after calving. Monensin altered both energy and mineral metabolism and has the potential to improve the health and production of dairy cows.

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Owner-reported behavioural observations form an essential part of the veterinarians’ diagnosis and treatment plan. The way we train and manage horses affects their behaviour and, in turn, their health and welfare. Current horse training and management practices are largely driven by traditional techniques and longstanding methodologies. These approaches generally lack an evidence base for evaluation purposes. The absence of evidence and evaluation contributes to the persistent use of risky practices and this, in turn, increases risk of potential harms for both horse and rider, and fuels questioning of the equine industry’s current social license to operate. Objective evidence is required to make training and management decisions based on demonstrable best practice. Large-scale experimental or intervention studies using horses are generally not practical because of the associated costs and logistics of gaining ethical approval. Small studies generally lack statistical power and are subject to the effects of many forms of bias that demand caution in the interpretation of any observed effects. An alternative to collecting large amounts of empirical data is the use of owner-reported observations via online survey. Horse owners are ideally placed to report on the domestic equine triad of training, management, and behaviour. The current article highlights three sources of potential bias in a systematic review of literature on large-scale online studies of horse owners’ observational reports that met the following selection criteria: English-language, published, peer-reviewed articles reporting on studies with over 1000 respondents and open access to the survey instrument. The online surveys were evaluated for three common forms of bias: recall, confirmation, and sampling bias. This review reveals that online surveys are useful for gathering data on the triad of horse training, management, and behaviour. However, current use of online surveys to collect data on equitation science (including horse training, management, and behaviour) could be improved by using a standardised and validated tool. Such a tool would facilitate comparisons among equine and equitation science studies, thus advancing our understanding of the impacts of training and management on horse behaviour. The authors of the current review suggest the use of a standardised behavioural and management assessment tool for horses. Such a tool would help define what constitutes normal behaviour within geographically disparate populations of horses, leading to improvements in rider safety and horse welfare.

Gender stereotypes shape human social interaction, often to the detriment of women and those who do not comply with normative expectations of gender. So far, little research has assessed the extent to which people apply gender stereotypes to animals, and the implications this may have for individuals and groups, particularly female animals. The current study investigated survey respondents' preference for horses to perform in different sport and leisure practices, based solely on ideas about the sex of the animal. An anonymous online survey explored the preferences of riders for mares, geldings and stallions for dressage, show-jumping and trail-riding, and reasons for their choice. A total of 1032 responses were received. Geldings were the preferred choice, being perceived as safe and reliable, followed by stallions who were valued for their supposed power, presence and good looks. Overall, mares were the least

Absorption of dietary calcium from the rumen is a quantitatively important process in calcium homeostasis of ruminants. In 3 separate experiments in dairy cows, we applied a technique developed in sheep to measure the rate of strontium (Sr) absorption from the rumen as an indicator of calcium absorption capacity. Absorption from the rumen after an oral dose of SrCl 2 resulted in a maximum plasma concentration of Sr after 1 h, whereas absorption from the small intestine after injection of SrCl 2 into the abomasum through a cannula occurred more slowly. The second experiment demonstrated that the calcium absorption capacity index of the rumen was significantly greater in 21 lactating Friesian cows (230 ± 66, mean ± SEM) than in 6 mature, nonlactating, nonpregnant heifers (101 ± 21, mean ± SEM). In a third experiment, we compared clinically normal cows at the onset of lactation with those that developed parturient paresis. In cows that developed severe hypocalcemia, plasma concentrations of 1,25(OH) 2 D were significantly elevated (144 ± 60 pg/mL vs. 90 ± 54 pg/mL; means ± SEM) and their rumen calcium absorption index was significantly decreased compared with that of clinically normal cows. Evidence suggested that mobilization of calcium from bone as lactation commenced was significantly depressed in paretic cows compared with those that did not show clinical signs of hypocalcemia. Moreover, ruminal stasis suppressed the absorption of calcium from the rumen. We conclude that measurement of Sr concentration in blood plasma after an oral dose of SrCl 2 into the rumen can be used as an index of rumen calcium absorption capacity under different states of calcium homeostasis.