The Effect of Stirrup Iron Style on Normal Forces and Rider Position

The stirrup iron has the potential to modify the forces experienced by a horse and rider during ridden exercise. A range of stirrup designs are available, but no previous studies have investigated if these modifications influence riders’ position and interaction with the horse. Novel flexible (F) or flexible and rotatable (FR) irons versus traditional (T) stirrups may positively impact the welfare and performance of the horse and rider. Four riders rode using the three stirrup types (T, F, and FR). Hip, knee, and ankle angles and toe position from film, and the normal force exerted bilaterally on force sensors on the stirrups tread were evaluated at the highest (HP) and lowest point (LP) of the posting trot (n = 4) and canter (n = 2). Statistics included Shapiro-Wilk’s test, Friedman’s test, and Wilcoxon signed rank test (significant at P < .05). No significant difference was seen between joint angles, toe position, or forces between the types of stirrups. At the HP, mean hip, knee, and ankle angles were 169.4° ± 10°, 150.7° ± 9.7°, and 94.5° ± 9.6°, and 139.1° ± 9.6°, 123.9° ± 10.9°, and 92.7° ± 9.5° at the LP. Riders had an 8.74° ± 6.66° difference of right versus left joints. Right toes rotated more laterally (P = .02) regardless of stirrup type. The mean trot and canter forces applied (N)/body weight (N) were 0.72 ± 0.15 (HP), 0.19 ± 0.15 (LP), and 0.18 ± 0.05 (canter). Riders shortened the stirrup leathers with F or FR. Stirrup style minimally impacted rider position or the forces experienced; however, forces differed by gait. Future studies regarding how a rider’s experience and painful joints may contribute to asymmetries are warranted.     

Information-Seeking Preferences of the Colorado Equine Industry for Distribution of Disease Outbreak Information

The purpose of this study was to learn how perceptions of accuracy and availability of sources affect how members of the Colorado equine industry seek both everyday information and information during an equine disease outbreak. A survey was distributed by email and social media to members of Colorado-based equine organizations. A total of 256 survey responses were obtained from individuals representing a spectrum of ages and roles in the Colorado equine industry. Survey participants predominantly identified as female (95.3%) and their industry role as a horse owner (41%) or a competitive (25.8%) or pleasure (13.3%) rider. Younger survey participants reported greater (P < .0001) use of social media, and both participant age (P < .015) and information source (P < .0001) affected the perception of resource accuracy. In the event of an equine disease outbreak, industry role was an important factor (P = .003) in the selection of news sources, whereas age was not (P = .19). Many participants (56%) identified disease symptoms/signs to be the most important information to be sought during a disease outbreak and most (69.9%) preferred state or veterinary resources for this information. The identification of why Colorado equine industry members access information from specific sources may guide animal health and extension professionals to tailor their online presence to best meet the communication needs of the Colorado equine industry.     

The 2011 South Dakota Equitarian Survey and Comparative Analysis of Equine Welfare on a South Dakota Native American Reservation

Economic stress and geographic isolation are barriers to proper veterinary care for horses on Native American reservations. The 2011 South Dakota (SD) Equitarian Survey was distributed to 135 equine veterinarians in SD to detect perceptions of effectiveness and best methodologies for improving reservation equine welfare. There was a positive correlation (P < .005) between the perceived importance and effectiveness of increased veterinary access and the importance of free care and owner knowledge in changing the health and welfare of SD’s reservation equine population. Thirty-nine percent of respondents claimed to have an interest in providing help for reservation equines; those with no veterinary experience on reservations tended not to have interest (P = .05). Previous experience practicing on a reservation impacted how crucial they believed horse owner knowledge or awareness was in changing the health and welfare of reservation equines (P < .04). The most commonly noted health threat and strength were poor nutrition and the absence of internal disease, respectively. In a subsequent analysis, 299 horses on the Cheyenne River Sioux Reservation were observed for welfare indicators and divided into groups by use: saddle, production, bucking stock, and performance. Average body condition score was 5 of 9 and did not differ between the four groups. Coat (P < .001) and hoof (P < .007) conditions varied between groups, with optimal conditions in the performance and saddle horse groups, respectively. Variable hoof, coat, and vaccination practices among the groups of reservation equines present an opportunity for health care education and welfare improvement.     

Variability of scores in the 2008 Olympic dressage competition and implications for horse training and welfare

Olympic dressage involves “an intimate unity between a human and a non-human” and is scored by a subjective judging process, under the auspices of the Fédération Equestre Internationale whose Code of Conduct declares the welfare of the horse as paramount. Dressage is of particular interest to equitation scientists and equine ethologists because it embodies the full range of the stimulus-response contingencies that operate in all of the Olympic disciplines. In Fédération Equestre Internationale dressage competition, collective marks are awarded across four domains immediately after each performance. Collective marks are designed to summarize the performance of horse and rider and must reflect the qualities of the entire performance. They are derived from the observation of the judges of the separate test movements. The 4 collective marks include: (1) paces; (2) impulsion; (3) submission; and (4) the rider's position and seat; correctness and effect of the aids (rider signals). The definition of submission in this context makes reference to lightness and other qualities that align with optimal ridden horse welfare. We assessed the characteristics of these marks in horses competing in the 2008 Olympic Games Grand Prix (GP; n = 46) and Grand Prix Special (GPS; n = 25) dressage competitions. We also examined the effect of judge location and used Pearson correlation coefficients to explore relationships between collective marks and test-movement scores. All 4 collective marks correlated with each other significantly (P < 0.001). The weakest correlation was between paces and submission (r = 0.22) and the strongest between impulsion and rider position scores (RPS) (r = 0.59). In the GP, paces and submission scores were less correlated with test movement scores than the impulsion and RPS scores. In the GPS, submission scores were less correlated with individual movements than the other collective marks. Indeed, they failed to significantly correlate with 19 of 32 movement scores (P < 0.05). RPS varied most in the GP (standard deviation = 0.73) whereas submission scores varied most in the GPS (standard deviation = 0.65). A REML analysis across both competitions showed all collective marks were significant in predicting final percentage scores but submission (F = 31.27) made the least significant contribution (paces, F = 61.3; impulsion, F = 69.77; RPS F = 53.01; P < 0.001 for all values). These results speak of considerable variability in judging and suggest that, despite the relevance of submission to horse welfare, judges have considerable difficulty scoring in this domain and aligning their scores with overall performance.     

A brief note on the information-seeking behavior of UK leisure horse owners

Equine welfare charities have identified the education of (primarily novice) horse owners as the principal route to tackling the majority of equine welfare problems in the United Kingdom. To reach and educate owners effectively, we must understand where they seek advice about issues that arise when owning or caring for a horse. Questions regarding information-seeking behavior were included in an Internet survey completed by a convenience sample of 1,326 UK leisure horse owners, recruited online and through electronic and postal mail shots to equestrian clubs and establishments. The questions asked where the owners sought advice regarding 4 different subject areas: horse behavior, health, stable care, and training. Respondents were asked to select their main sources of information from a list of 7—books/magazines, vet/farrier, instructor, Internet/forums, friends/family, tack shops, and other. Although books/magazines were the most frequently used information source across all 4 subject areas overall, there were differences between the 4 subject areas in the most commonly selected sources (χ² = 992, P < 0.001) and the number of sources consulted (χ² = 254, P < 0.001). Vets/farriers were the source consulted most frequently for health advice (Z = ?13.32, P < 0.001), instructors for training advice (Z = ?3.93, P < 0.001), and books/magazines for advice regarding both behavior (Z = ?9.49, P < 0.001) and stable care (Z = ?8.26, P < 0.001). Despite the survey mode and that many participants were recruited online, Internet/forums were only the third to the fifth most used of the 7 information sources, depending on the subject area. Logistic regression analyses identified significant associations between owner demographics (age, self-rated skill level, and self-reported rider type) and the likelihood of selecting a particular source for advice regarding a specific subject area. The findings have important implications for those trying to reach the horse-owning population to disseminate research findings and ultimately improve the welfare of their horses.     

The influence of rider:horse bodyweight ratio and rider-horse-saddle fit on equine gait and behaviour: A pilot study

The effect of rider weight on equine welfare and performance requires further investigation. The objective of this prospective, cross-over, randomised trial was to assess gait and behavioural responses of horses to riders of similar ability, but different bodyweights. Six nonlame horses in regular work were ridden by each of four riders: Light (L), Moderate (M), Heavy (H) and Very Heavy (VH). Saddle fit was assessed subjectively throughout the study. Each horse was ridden twice by riders L and M, and once by rider H. Rider VH rode five horses once and one twice. Each horse-rider combination undertook a standardised, 30-min ‘dressage-test' which was abandoned if we observed lameness grade ≥ 3/8 in one limb, grade ≥ 2/8 in ≥ 2 limbs, or ≥ 10/24 behavioural markers of pain. Horses were reassessed in hand 45–60 min after any abandonment. Mean rider bodyweights, body mass index (BMI) values and rider:horse bodyweight percentages for the L, M, H and VH riders were respectively: 60.8, 77.8, 91.0, 142.1 kg; 23.2, 28.0, 26.3, 46.9 kg/m²; 10.0–11.7%, 12.8–15.0%, 15.3–17.9%, 23.6–27.5%. All 13 H and VH rider tests (lameness, n = 12; behaviour, n = 1) and one of 12 M rider tests (lameness) were abandoned. Lameness was confirmed using inertial measurement unit data. All horses trotted sound after test abandonment and completed the study moving well when ridden. Limitations of the study were saddle fit was not ideal in all horse-rider combinations and abandonment criteria were subjective. The conclusions and clinical relevance of the study were that large riders can induce temporary lameness and behaviours consistent with musculoskeletal pain. This may relate to rider bodyweight and/or weight distribution. Riders M and H had similar BMI but markedly different test abandonment rates, therefore bodyweight is likely to be more relevant than BMI. Further work is required to determine if horse fitness, adaptation to heavier weights and better saddle fit for heavier/taller riders will increase horses' weight-carrying capacity.     

Functional Electrical Stimulation (FES) and the Effect on Equine Multifidi Asymmetry

Asymmetry of the multifidi has been correlated with scoliosis and back pain in humans and has been investigated as a factor in equine back pain as well. The purpose of this study was to determine if FES would affect the symmetry of equine thoracolumbar multifidi when compared to controls. Twelve horses received 24 FES treatments bilaterally over the thoracolumbar region for 8 weeks. Twelve additional control horses received no FES treatments. Ultrasonographic measurements of the cross-sectional area (CSA) of the multifidi of the treatment horses at seven thoracolumbar levels were compared to determine the change in left and right asymmetry post-FES. The same measurements during the same period were also taken in the control group. All measurements were blinded for evaluation. Statistical significance was assessed utilizing two-sided, matched-pairs t-tests, and Welch’s (unequal variances) t-test (alpha = 0.05). Multiple comparisons were accounted for using the Sidak correction. A significant improvement in multifidi asymmetry was observed, post-FES, at all seven thoracolumbar levels, with no evidence of asymmetry improvement in the control group. The difference between mean improvements of the treatment and control groups was statistically significant (P < .001). FES significantly improved the symmetry of equine multifidi, and evidence was provided for the effectiveness of FES at each of seven thoracolumbar levels. The improvement in symmetry appeared to result from increases, decreases, and maintenance of the CSA of the left and right multifidi in various combinations. The FES protocol used in this study has the potential to improve spinal function and assist in reducing back pain in horses.     

An equine joint friction test model using a cartilage-on-cartilage arrangement

This study describes an equine joint friction test using a cartilage-on-cartilage arrangement and investigates the influence of age and load on the frictional response. Osteochondral plugs were extracted from equine shoulder joints (2–5 years, n = 12; 10–14 years, n = 15), and mounted in a pin-on-disc tribometer. The frictional response was then measured under constant conditions (2 N; 20 °C; 5 mm/s), and with increasing load (2 N, 5 N, 10 N). In all experiments, the friction coefficient of young cartilage was significantly (P < 0.001) smaller than obtained from old cartilage, while the application of a greater load resulted in a significant (P < 0.001) decrease in friction coefficient only in old cartilage. It was concluded that cartilage ageing was responsible for an increase in friction coefficient under these experimental conditions. Moreover, where young cartilage lubrication remained stable, cartilage ageing may have been responsible for lubrication regime change. The cartilage-on-cartilage model could be used to better understand lubrication regime disturbances in healthy and diseased equine joints, and to test the efficacy of various bio-lubricant treatments.     

The Influence of Topically Applied Oil–Based Palatants on Eating Behavior in Horses

Palatants may be added to equine feed and medication either during or after manufacturing to enhance product acceptance. Prior studies have examined a variety of palatants but results have been limited and inconsistent. Therefore, the objective of this research was to evaluate topically applied oil–based palatants on feeding preferences in horses. Stock-type horses (n = 10) were used in this paired preference test across a two-phase study. Phase one compared six palatants (banana, anise, peppermint, apple, spearmint, and orange) to a control (corn oil), whereas phase two compared preference among palatants (anise, apple, and peppermint). Feeding stocks were utilized and horses were allowed 15 seconds for olfaction followed by 3 minutes for consumption. Variables recorded included first diet sniffed and consumed, first action, aversive behaviors, excessive salivation, and consumption. Each trial was also video-recorded and number of chews were counted. Data were analyzed using chi-square and t tests in SAS version 9.4 with P < .05 established as significant. Findings from phase one reveal excessive salivation was observed less frequently (P < .05) for most palatants with the exception of peppermint and orange. Orange negatively impacted palatability indicated by less consumption when compared with the control (P = .02), although there was no impact on chews per gram. No difference between control and treatment diets for first sniff or first consumed was observed when analyzed individually in either phase one or two, although there was a moderate positive correlation (ф = 0.39, P = .04) between olfaction and consumption during the peppermint and anise comparison. Consumption as the first action was consistent across all trials (P < .05). Anise was preferred over apple and peppermint as indicated by higher total consumption (P < .05) in phase two. These data indicate that oil-based palatants can affect feed preferences in horses with increased palatability from anise and decreased palatability from orange flavors.     

Metabolomic Profile of Allantoic and Amniotic Fluid in Late-term Gestational Mares Characterized by 1H-nuclear Magnetic Resonance Spectroscopy

The amniotic and allantoic fluid compartments in the mare serve essential roles throughout pregnancy and parturition. Although the global metabolomic profile of amniotic fluid in women has been extensively characterized, current data for equine fetal fluids are limited. Therefore, the goal of this study was to characterize the global metabolomic profile of equine allantoic and amniotic fluid through nuclear magnetic resonance spectroscopy. Fetal fluids were collected between 270 and 295 days of gestation from 12 pregnancies through ultrasound-guided transabdominal puncture. A total of 24 samples (n = 10 allantoic fluid; n = 9 amniotic fluid; n = 5 admixed fluid) were analyzed by one-dimensional proton (¹H) and two-dimensional (¹H-¹³ C) nuclear magnetic resonance spectroscopy. Metabolites were integrated and compared between fluid types using a Kruskal–Wallis test at P < .05 significance. A total of 28 distinct metabolites were found in allantoic and admixed fluid, whereas 23 metabolites were identified in amniotic fluid. Allantoic fluid contained significant elevations (P < .05) in the metabolites betaine, creatine, creatinine, citrate, histidine, nitrophenol, tryptophan, π-methylhistidine, and unknown metabolite #1 compared with amniotic fluid, whereas amniotic fluid contained statistically increased concentrations of the metabolite lactate compared with allantoic fluid (P = .003).     

Dietary supplementation with inulin improves lactation performance and serum lipids by regulating the rumen microbiome and metabolome in dairy cows

This study investigated the effects of inulin on rumen fermentation parameters, ruminal microbiome and metabolites, as well as lactation performance and serum indexes in dairy cows. Sixteen Holstein dairy cows with similar body conditions were randomly divided into 2 groups (n = 8 per group), with inulin addition at 0 and 200 g/d per cow. The experiment lasted for 6 weeks, including a 1-week adaptation period and a 5-week treatment period. At the end of the experimental period, the milk, serum and rumen fluid were sampled and analyzed. The microbiome and metabolome in the rumen fluid were analyzed via 16S rRNA sequencing and untargeted metabolomics, respectively. The results showed that supplementation with inulin (200 g/d per cow) increased the milk yield (P = 0.001), milk protein (P = 0.032), lactose rate (P = 0.004) and proportion of saturated fatty acids (SFA) in milk (P < 0.001), but decreased the proportion of unsaturated fatty acids (USFA) (P = 0.041). Rumen pH (P = 0.040) and the concentration of NH₃–N (P = 0.024) were decreased; however, acetate (P < 0.001), propionate (P = 0.003), butyrate (P < 0.001) and lactic acid (LA) (P = 0.043) were increased. The total cholesterol (TC) (P = 0.008) and triglycerides (TG) (P = 0.01) in serum were also reduced. Additionally, inulin addition elevated the relative abundance of several beneficial symbiotic and short-chain fatty acid (SCFA)-producing bacteria, such as Muribaculaceae (false discovery rate [FDR]-adjusted P < 0.01), Acetitomaculum (FDR-adjusted P = 0.043), and Butyrivibrio (FDR-adjusted P = 0.036), while elevating the levels of L-lysine (FDR-adjusted P = 4.24 × 10⁻³), L-proline (FDR-adjusted P = 0.0158), and L-phenylalanine (FDR-adjusted P = 0.027). In contrast, several pathogens and ruminal bacteria abundant in high-fat diets, such as Escherichia-Shigella (FDR-adjusted P = 0.022), Erysipelotrichaceae__UCG-004 (FDR-adjusted P < 0.01) and RF39 (FDR-adjusted P = 0.042) were decreased along with the reduction of lysophosphatidylcholine (LysoPC) (18:1 (9Z)) (FDR-adjusted P = 1.03 × 10⁻³), LysoPC (16:0) (FDR-adjusted P = 0.0108), LysoPC (18:2 (9Z, 12Z)) (FDR-adjusted P = 1.65 × 10⁻³) and 8-methylnonenoate. In conclusion, dietary inulin supplementation could increase the relative abundance of commensal microbiota and SCFA-producing bacteria, upregulate amino acidmetabolism and downregulate lipid metabolism in the rumen of dairy cows, which might further improve lactation performance and the level of serum lipids.     

Does Coenzyme Q10 Exert Antioxidant Effect on Frozen Equine Sperm?

During semen cryopreservation, the sensitivity of equine sperm to oxidative stress is increased by the eliminated seminal plasma. Thus, antioxidant addition to the semen extender can be helpful to the sperm survival after freezing and thawing. This work aimed to test whether coenzyme Q10 (CoQ10) added in different concentrations to the INRA 82 freezing extender has antioxidant function on equine sperm to improve its fertilizing ability. Semen samples from five stallions were frozen with the extenders: (T1) INRA 82, control, (T2) T1+ 5 μM CoQ10, (T3) T1+ 25 μM CoQ10, and (T4) T1+ 50 μM CoQ10. After sample thawing, sperm motility and kinetics characteristics were evaluated using a computer-assisted sperm analysis and sperm membrane functionality and integrity were evaluated with a hypo-osmotic swelling test and an epifluorescence microscopy, respectively. The nitrite (NO₂^-) and hydrogen peroxide (H₂O₂) concentrations of the semen samples were measured with spectrophotometry. There was no difference on the sperm characteristics among all treatments (P > .05). However, the 25 μM CoQ10 (T3) decreased NO₂⁻ concentration (6.7 ± 2.2 μM/μg protein) compared with the treatments T1, T2, and T4 (64.3 ± 3.7, 59.4 ± 5.3, 45.1 ± 8.6 μM/μg protein), respectively, as well H₂O₂ concentration (1.8 ± 0.3 μM/μg protein) compared with the control (4.6 ± 0.4 μM/μg protein) and 5 μM CoQ10 treatments (4.8 ± 0.2 μM/μg protein, P < .05). In conclusion, 25 μM CoQ10 plays a significant role as antioxidant to the frozen equine sperm, decreasing NO₂⁻ and H₂O₂ concentrations. Thus, its addition to the INRA 82 freezing extender may be beneficial to the fertilizing ability of equine semen.     

Efficacy of a Combination of Apolectol,Live Yeast (Saccharomyces cerevisiae [CNCM I-1077]), and Magnesium Hydroxide in the Management of Equine Gastric Ulcer Syndrome in Thoroughbred Racehorses: A Blinded,Randomized, Placebo-Controlled Clinical Trial

To date, prevention of equine gastric ulcer syndrome (EGUS) has relied on management changes or pharmaceutical agents. The identification of an alternative means of prevention would be useful. Therefore, the objective of this study was to evaluate the combination of Apolectol, a live yeast (Saccharomyces cerevisiae [CNCM I-1077]), and magnesium hydroxide for the prevention of development of, or exacerbation of existing, EGUS in Thoroughbred racehorses. Twenty-four Thoroughbred racehorses without significant gastric ulceration (grade, ≤2 of 4) were identified on gastroscopy. Treated horses received 95 g Apolectol, 2 g S. cerevisiae, and 20 g magnesium hydroxide 1–4 hours before exercise. Control horses received 95 g of a feed pellet as a placebo. Gastroscopy was repeated at 24–27 days. There was no change in squamous (P = .45) or glandular (P = 1.0) ulcer grade over time in horses in the treatment group. In the placebo group, ulcer grade increased in both the squamous (P = .04) and glandular (P = .19) mucosa but only reached significance in the squamous mucosa group. Worsening of the ulcer grade was more likely in the placebo group in the glandular (P = .04) but not in squamous (P = .10) mucosa. The combination studied may be an effective prophylactic against EGUS development or exacerbation.     

Markers for Predicting Overweight or Obesity of Broodmares

Obesity has become of great concern to all equine community from both veterinary and welfare points of view. For estimating obesity markers of brood mares, 17 mares with body conditions were subjected to blood sampling and ultrasound examination to measure rump fat for 6 consecutive weeks. Body length (L), girth (G), and height (H) were measured to estimate body weight (BW), body fat %, body fat mass (BFM) and body mass index (BMI). Mares were classified into three groups according to body condition score (BCS) and rump fat thickness (RF). Overweight mares (O) had BCS >7 and RF >7 mm, moderate (M) had BCS and RF >3 to ≤7, and emaciated (E) had BCS and RF ≤ 3 mm. Glucose, triglycerides, nitric oxide (NO), insulin, insulin-like growth factor-I (IGF-1), leptin, ovarian hormones, and thyroid hormones were measured. Results revealed that BCS, G, L, L × G × H, BW, RF, fat %, and BFM correlated significantly (P < .0001) with body condition. Tetraiodothyronine concentrations of E mares were significantly high (P = .04), but triiodothyronine concentrations tended (P = .07) to be low. Insulin (P = .06) and IGF-1 (P = .07) concentrations tended to be high in O mares. Moderate mares had the highest leptin concentrations (P = .007), but E mares had the lowest P4 concentrations (P = .01). Overweight mares had nonsignificantly high glucose, NO, and triglycerides. In conclusion, back fat and morphometric measurements are the easiest and simple assessment of overweight and obesity. Obese and overweight mares showed slight hyperinsulinemia, hypertriglyceridemia, and hyperglycemia. Hyperleptinemia alone is not indicative of obesity.     

Effects of Equine Chorionic Gonadotropin on Ovulatory and Luteal Characteristics of Mares Submitted to an P4-Based Protocol of Ovulation Induction With hCG

The aim of this study was to evaluate the effect of equine chorionic gonadotropin (eCG) at the end of progesterone (P4) treatment on follicular and luteal characteristics during transition period (TP) and reproductive breeding season (RP). A total of 13 crossbred mares were distributed in two experimental groups in the spring and summer (n = 26). The animals received intravaginal P4 (1.9 g) releasing device from D0 to D10. On removal of P4 device, the mares received 400 IU of eCG (eCG group) or saline solution (control group). Human chorionic gonadotropin (hCG; 1.750 IU) was administered (DhCG) as soon as ovulatory follicle (OF) ≥35 mm was detected. Ovarian ultrasonography was performed from D0 until 15 days after ovulation. Blood samples were collected on D0, D5, D10, DhCG, 9 days after ovulation (CL9D), and 13 days after ovulation (CL13D). P4 and estradiol concentrations were assessed by chemiluminescence. Data were compared by Tukey test at P < .05. Ovulation rate was similar (P = .096) between seasons (RP = 100%; TP = 70%) but occurred earlier (P = .015) in RP (34.8 ± 10.1 hours) compared with TP (42.0 ± 10.4 hours). Interactions between season and treatment were observed for OF diameter (mm) (RP/control = 36.2 ± 1.8ab; RP/eCG = 32.9 ± 2.8 b; TP/control = 32.2 ± 1.2 b; TP/eCG = 37.2 ± 1.9a; P = .004) and for corpus luteum (CL) diameter (mm) on CL13D (RP/control = 25.4 ± 3.5a; RP/eCG = 22.5 ± 1.8ab; TP/control = 21.6 ± 4.9 b; TP/eCG = 27.4 ± 4.3a; P = .023), although no differences were observed for serum P4 on CL13D (RP/control = 6.0 ± 3.1 ng/mL; RP/eCG = 5.8 ± 0.9 ng/mL; TP/control = 3.6 ± 2.7 ng/mL; TP/eCG = 5.1 ± 2.3 ng/mL; P = .429) or for day of structural CL regression (RP/control = 12.8 ± 1.9; RP/eCG = 12.1 ± 1.1; TP/control = 11.0 ± 1.7; TP/eCG = 13.2 ± 2.0; P = .102). The application of eCG at the moment of P4 implant removal seemed to increase the capacity of luteal maintenance during spring TP. However, eCG treatment was worthless during the breeding season.     

Horses Could Perceive Riding Differently Depending on the Way They Express Poor Welfare in the Stable

This study investigated the relationships between four behavioral and postural indicators of a compromised welfare state in loose boxes (stereotypies, aggressive behaviors toward humans, withdrawn posture reflecting unresponsiveness to the environment, and alert posture indicating hypervigilance) and the way horses perceived riding. This perception was inferred using a survey completed by the usual riding instructor and during a standardized riding session (assessment of behaviors and postures, qualitative behavior assessment (QBA) and characterization of the horses’ locomotion using an inertial measurement unit). In accordance with ear and tail positions and the QBA, stereotypic and the most hypervigilant horses in loose boxes seemed to experience a more negative affective state during the riding session compared with nonstereotypic and less hypervigilant animals (P < .02 in all cases). Horses which were aggressive toward humans in loose boxes had higher scores regarding the occurrence of discomfort and defensive behaviors on the survey than nonaggressive horses (P = .03). They also presented higher dorsoventral accelerations at a canter during the riding session (P = .03), requiring the rider to increase his spinal movement (P = .005). These results suggest that aggressive horses may be harder to ride than nonaggressive animals. The expression of unresponsiveness to the environment in loose boxes was related to more reluctance to move forward, as assessed in the survey (P = .006). This study suggests that a compromised welfare state in the stable is related to horses having a more negative perception of riding. This perception could vary depending on the expression of poor welfare.     

The Effect of Different Vitrification and Staining Protocols on the Visibility of the Nuclear Maturation Stage of Equine Oocytes

In this study, we compared two staining protocols assessing the nuclear chromatin stage of equine oocytes after vitrification using permeable and nonpermeable cryoprotectants. Slaughterhouse-derived oocytes (n = 155) were obtained from a total of 32 mares and in vitro matured in M199 medium for 42 hours at 38.5°C in 5% CO_2. In the first experiment, two concentrations of Hoechst 33342 (HO) were tested (10 μg/mL; P1 and 2.5 μg/mL; P2) combined with 50 μg/mL of propidium iodide as staining protocols to evaluate the visibility of matured oocytes (n = 44). In the second experiment, 111 oocytes were evaluated using the staining protocol P2, before (C, control) and after vitrification following a two-step conventional protocol with (15% dimethyl sulfoxide, 15% ethylene glycol, and 0.5 M sucrose; V1) or without (1 M sucrose; V2) using permeable cryoprotectants. Our results showed that P2 provided a higher percentage of oocytes with outstanding visibility of the nuclear chromatin stage (52.17%; P < .05) in comparison with P1 (19.04%). In the second experiment, no cryoprotectant-free vitrified oocytes reached the metaphase II maturation stage. This result was significantly lower (P < .05) than conventional vitrification (15.38%) and both lower in comparison with the nonvitrified control group (42.11%). In conclusion, permeable cryoprotectant-free vitrification of equine oocytes obtained poor results and therefore cannot be considered an alternative to vitrification using permeable cryoprotectants. In addition, a staining protocol with a low concentration of HO is recommended to evaluate the nuclear chromatin stage of equine oocytes after in vitro maturation.     

Macroscopic and Histological Morphology of the Equine Digital Cushion and Its Association with Subcutaneous Fat Thickness

This study evaluated the influence of the Body Condition Score (BCS) and subcutaneous fat thickness on the tissue composition of the digital cushion in horses. Sixty mixed breeds of Criollo horses (21 males and 39 females) were sent for slaughter. All animals were submitted to BCS analysis, through visual antemortem evaluation, and then ultrasound evaluation to estimate the subcutaneous fat thickness. Macroscopic analyses of the thoracic and a pelvic limb (weight, volume, and density of the hooves and digital cushions) were performed. In addition, measurements of the area of internal structures to the hoof and histological analyzes were carried out to measure the areas of adipose, fibroelastic, and collagen fibers of the digital cushion. There were no macroscopic differences in the digital cushion between thoracic and pelvic limbs or between genders (P > .05). Likewise, the histological characteristics between the limbs and the genders were similar (P > .05). There was no correlation between the weight, volume, and density of the digital cushion with the BCS (P > .05). A positive correlation was observed with the area of adipose tissue (P = .038, R² = 0.28) and a negative correlation with area of fibroelastic tissue (P = .005, R² = −0.37) and collagen fibers (P = .003, R² = −0.39). In conclusion, the adipose tissue, fibroelastic tissue, and collagen fibers of equine digital cushion alter their areas in the functions of the various subcutaneous fat patterns in horses.     

Practical considerations regarding the implementation of a temperament test into horse performance tests: Results of a large-scale test run

Considering the ever-growing demand of various breeding organizations for an objective, inexpensive, reliable, and easily conducted assessment of the behavior of horses, the aim of our study was to implement a novel-object test and a startling test into any kind of breeding performance testing to assess horses' temperament. Additionally, the influence of testing areas (familiar or unfamiliar), riders, and horse factors such as levels of training, breed, and age were of interest. Furthermore, recommendations for the practical implementation concerning the parameters should be given. Therefore, 1,028 horses over a period of 3 years participated in a temperament test consisting of 5 different stimuli. The horses were either ridden (61.8 %) or led by hand (38.2 %) by an unfamiliar professional rider (N = 43) or a familiar rider (N = 20). Live behavioral observations were taken by a trained observer. Overall, horses' scores for reactivity in the present temperament test were distributed over the whole scale, with lower means and higher standard deviations (6.7 ± 2.2-7.6 ± 2.1) than corresponding scores from the conventional personality evaluation in performance tests (7.7 ± 0.8-8.2 ± 0.5; P < 0.01). High correlations (r = 0.3-0.9; P < 0.001) between the scores for reactivity and the other behavioral parameters (emotional expression, activity, time to calm down, rider's aids) show a large influence of these parameters in assessing the horses' temperament. Factors like breed type, sex, and age had significant influences (P < 0.001) on different scores of the temperament test. In most cases, the rider or handler had no influence on the different scores assessed during the temperament test. The training level and the testing modus never had a significant influence on different scores. Only the testing station or location had a small influence on the scores for the stimulus “bridge” in some horses. Based on the results, it could be concluded that an implementation of a temperament tests into performance testing is possible during various types of testing procedure. Especially the assessment of reactivity, emotional expression, interest in the stimulus and rider's aids during and after passing the stimulus, as well as the time to calm down are important parameters for analyzing the horses' personality.