Impacts of Adiposity on Exercise Performance in Horses

Initial Impact of Different Feeding Methods on Feed Intake Time in Stabled Icelandic Horses

The natural behaviour of horses is to spend the majority of their time on feed intake The feeding of stabled horses is, however, often far from that, as their feed intake is limited to their nutritional requirements. In order to approach their natural foraging time, it is important to extend the feed intake time of stabled horses. The aim of this study was to estimate if the feed intake time differs when feeding haylage in a haynet, hayball, metal corner manger, or from the box floor. The experimental design consisted of a Latin square, occurred across four days with four adult Icelandic horses and four treatments. Horses were stabled in individual boxes and fed 7 kg of high-energy haylage in two even meals while the intake time was recorded. The feed intake time per kg DM was shorter from the manger or the box floor than from a haynet or hayball (81 or 85 min versus 94 or 96 min; p < 0.05). It can be concluded that feeding haylage in a hayball or in a haynet can increase the feed intake time by 13% per day (12 min/kg DM/day) when compared to the more traditional methods. Thus, with simple alternatives, it is possible to extend the feed intake time of stabled horses.

Relationships between total adiponectin concentrations and obesity in native-breed ponies in England

BACKGROUND

Equine metabolic syndrome is a collection of risk factors associated with an increased risk of endocrinopathic laminitis. All affected animals display insulin dysregulation and some may show adiponectin dysregulation and/or excessive adiposity. However, the relationship between obesity and hypoadiponectinaemia in equids remains unclear.

OBJECTIVES

To investigate the relationship between obesity and circulating plasma total adiponectin (TA) concentrations in native-breed ponies in England.

STUDY DESIGN

Secondary data analysis.

METHODS

Data collected for three previous studies were retrospectively analysed and cohorts were pooled where possible (maximum sample size: n = 734 ponies). Correlations between [TA], age, and morphometric measures were assessed using Spearman's correlation coefficient. [TA] was compared between animals of different body condition score (BCS) classification (ideal-weight, overweight, and obese), breed, and body shape using Kruskal-Wallis with Dunn's post hoc tests, and sex using Mann-Whitney U test. The proportions of obese and ideal-weight ponies with basal hyperinsulinaemia and/or hypoadiponectinaemia were compared using a Chi-square test of homogeneity and post hoc z-test. Logistic regression was used to identify factors that may discriminate ponies with hypoadiponectinaemia.

RESULTS

[TA] was weakly positively correlated with BCS, height, weight, and weight:height ratio (Spearman's ρ = 0.14-0.29, p < 0.05). There were significant differences in [TA] in ponies with different BCS group classification, body shape, and breed. A greater percentage of obese (54.6%) than ideal-weight ponies (33.1%, p < 0.001) had both normal [TA] and [basal insulin], and a greater percentage of ideal-weight (38.6%) than obese ponies (16.5%, p < 0.001) showed hypoadiponectinaemia. Weight:height and BCS group were significant variables in a logistic regression of hypoadiponectinaemia but model fit and predictive accuracy were poor.

MAIN LIMITATIONS

Retrospective study design, only native-breed ponies included.

CONCLUSIONS

Morphometric measures such as BCS do not closely reflect [TA]. Circulating [TA] and [basal insulin] should be determined in all animals with predisposing factors, regardless of obesity status.

Effect of Exercise Conditioning on Countering the Effects of Obesity and Insulin Resistance in Horses-A Review

Obesity is an important health concern in horses, along with humans and companion animals. Adipose tissue is an inflammatory organ that alters the insulin-signaling cascade, ultimately causing insulin dysregulation and impaired glucose metabolism. These disruptions can increase the risk of metabolic disease and laminitis in horses and may also impact energy metabolism during exercise. A single bout of exercise, along with chronic exercise conditioning, increases insulin sensitivity and glucose disposal via both contraction- and insulin-mediated glucose uptake pathways. Regular exercise also increases calorie expenditure, which can facilitate weight (as body fat) loss. This paper explores the metabolic pathways affected by adiposity, as well as discusses the impact of exercise on insulin metabolism in horses.

Determination of breeding criteria for gait proficiency in leisure riding and racing dromedary camels: a stepwise multivariate analysis of factors predicting overall biomechanical performance

To date, the biomechanical dynamics in camelids have not been addressed, although it might be a factor that can affect selection and breeding in this species. Therefore, the aim of this article is to conduct curve fitting and discriminant canonical analysis to identify the mathematical function that best captures the dynamics of camel locomotion and to study the impact of kinematic, morphometric, physiological, and phaneroptic variables on gait performance in leisure riding and racing activities in dromedaries, respectively. The cubic function emerged as the most suitable mathematical model to represent the locomotive behavior of camels. Various factors were found to play a pivotal role in the athletic performance of leisure riding and racing dromedary camels. Concretely, angular measurements at the distal fore and rear extremity areas, pelvis inclination, relative volume of the hump, impact forces of the front limbs, post-neutering effects, and the kinematic behavior of the scapula, shoulder, carpus, hip, and foot are the factors that greatly impact gait performance in leisure riding and racing camels. The biomechanical performance at these specific body regions has a profound impact on weight absorption and minimization of mechanic impact during camel locomotion, static/dynamic balance, force distribution, energy of propulsion, movement direction and amplitude, and storage of elastic strain in leisure riding and racing dromedaries. In contrast, other animal- and environment-dependent factors do not exert significant influence on camel gait performance, which can be attributed to species-specific, inherited adaptations developed in response to desert conditions, including the pacing gait, broad foot pads, and energy-efficient movements. The outcomes of our functional data analysis can provide valuable insights for making informed breeding decisions aimed at enhancing animal functional performance in camel riding and racing activities. Furthermore, these findings can open avenues for exploring alternative applications, such as camel-assisted therapy.

Obesity during Pregnancy in the Horse: Effect on Term Placental Structure and Gene Expression, as Well as Colostrum and Milk Fatty Acid Concentration

In horses, the prevalence of obesity is high and associated with serious metabolic pathologies. Being a broodmare has been identified as a risk factor for obesity. In other species, maternal obesity is known to affect the development of the offspring. This article is a follow-up study of previous work showing that Obese mares (O, n = 10, body condition score > 4.25 at insemination) were more insulin resistant and presented increased systemic inflammation during pregnancy compared to Normal mares (N, n = 14, body condition score < 4 at insemination). Foals born to O mares were more insulin-resistant, presented increased systemic inflammation, and were more affected by osteoarticular lesions. The objective of the present study was to investigate the effect of maternal obesity on placental structure and function, as well as the fatty acid profile in the plasma of mares and foals, colostrum, and milk until 90 days of lactation, which, to our knowledge, has been poorly studied in the horse. Mares from both groups were fed the same diet during pregnancy and lactation. During lactation, mares were housed in pasture. A strong heat wave, followed by a drought, occurred during their 2nd and 3rd months of lactation (summer of 2016 in the Limousin region, France). In the present article, term placental morphometry, structure (stereology), and gene expression (RT-qPCR, genes involved in nutrient transport, growth, and development, as well as vascularization) were studied. Plasma of mares and their foals, as well as colostrum and milk, were sampled at birth, 30 days, and 90 days of lactation. The fatty acid composition of these samples was measured using gas chromatography. No differences between the N and O groups were observed for term placental morphometry, structure, or gene expression. No difference in plasma fatty acid composition was observed between groups in mares. The plasma fatty acid profile of O foals was more pro-inflammatory and indicated an altered placental lipid metabolism between birth and 90 days of age. These results are in line with the increased systemic inflammation and altered glucose metabolism observed until 18 months of age in this group. The colostrum fatty acid profile of O mares was more pro-inflammatory and indicated an increased transfer and/or desaturation of long-chain fatty acids. Moreover, O foals received a colostrum poorer in medium-chain saturated fatty acid, a source of immediate energy for the newborn that can also play a role in immunity and gut microbiota development. Differences in milk fatty acid composition indicated a decreased ability to adapt to heat stress in O mares, which could have further affected the metabolic development of their foals. In conclusion, maternal obesity affected the fatty acid composition of milk, thus also influencing the foal's plasma fatty acid composition and likely participating in the developmental programming observed in growing foals.