The Mangalarga Marchador (MM) breed naturally performs four-beat gaits known as “Marcha”. Kinematic analysis can provide insights for optimizing training and competition performance in this breed while potentially mitigating welfare concerns associated with extreme head and neck positions (HNPs) applied without an adequate understanding of their impacts. We examined how different HNPs affect the MM horse’s Marcha Batida gait. Four HNPs were evaluated: HPN1—loose reins, HPN2—the competition standard for MM, HPN3—an extremely elevated head and neck, and HPN4—a slightly behind-the-vertical position. Kinematic data were collected using an optoelectronic system, and diagonal dissociation, stride length, and step height were analyzed. HNP3 had the highest dissociation, shortest stride length, and higher step height compared to the other HNPs. HNP1 resulted in the longest stride length. HNP2 and HNP4 differed in diagonal dissociation. HNPs significantly impact the kinematics of the Marcha Batida gait in this cohort of Mangalarga Marchador horses. Our results confirm the benefits of HNP2, the recommended position for shows and competitions. Additionally, it discourages the use of HNP3 and reiterates the need for further research into HNPs in four-beat gaits, highlighting the importance of rider training and the careful selection of HNPs to optimize Marcha Batida performance.

This study aimed to provide a preliminary description of the sagittal and transverse plane kinematics of the thoracolumbar spine of Mangalarga Marchador (MM) horses performing the marcha batida gait, led in-hand. We evaluated the pattern of angular movement and the mean amplitude of six specific angles. An optoelectronic system was used for 3D kinematic analysis (19 cameras, 250 Hz). They were positioned around the horses and an acquisition volume of 16 × 4.8 × 3 meters was used. Eight retroreflective markers were fixed on the spine of the animals over thoracic vertebrae 8 (T8), 12 (T12), 15 (T15) and 18 (T18); over the lumbar vertebrae 3 (L3) and 5 (L5); over the 1st sacral vertebra (S1); and over the 1st coccygeal vertebra (CD1). Five trials, led from a halter, with three complete gait cycles were evaluated for each marcha batida horse. The 3D coordinates of the markers were filtered with a second-order, low-pass, Butterworth filter (10 Hz). Six angles: T8-T12-T15, T12-T15-T18, T12-T18-L5, T15-T18-L3, T18-L3-L5, and L3-S1-CD1 were obtained and projected in the sagittal (Flexion and Extension) and transverse (Lateral bending) planes. We calculated, for each angle to represent the spine movements, the mean and standard deviation of the range of motion (ROM, difference between the maximum and minimum values in a stride cycle). In order to describe the movement over an average stride cycle we calculated the mean curve of angle variation. The T8-T12-T15 angle presented the largest ROM in the transverse plane, while in the sagittal plane the T8-T12-T15, T12-T15-T18 and T12-T18-L5 angles presented the largest ROMs. The L3-S1-CD1 angle (lumbosacral region) presented the lowest ROM in both planes. A reduced flexion close to a neutral spine was found, predominantly during the diagonal support and in the cranial thoracic region. At the same time, the thoracolumbar region remains in an extension which is highlighted in the lumbosacral region. During the change of the support phase, the cranial thoracic region moved from a flexion to a slight extent, and the thoracolumbar region was flexed which is emphasized in the lumbosacral region. The lateral bending of the spine followed the direction of the diagonal supports. The small amplitude in the latero-lateral and dorsoventral movements of the thoracolumbar spine of MM horses during the marcha batida gait could contribute to the smooth and natural sensations experienced when riding in this gait. The lower mobility of these angles should be considered during the clinical examination of marcha batida-gaited horses.

The genetic diversity of Breton horses in Brazil is a critical concern, mainly due to the small population size and low number of births per year. Given that the inbreeding was overlooked by breeders for multiple generations, we estimated the genetic diversity of this population utilizing pedigree‐based measures of population diversity. A total of 1394 six‐generation pedigrees representing the full population of registered Breton horses in Brazil defined a total population (TP, N = 2679), with horses born between 2000 and 2022, reproductively active and alive, as reported by the breed association, representing the reference population (RP, N = 731). Using the R package PurgeR, we estimated inbreeding coefficient (F_ped), maternal inbreeding coefficient (F_da m), paternal inbreeding coefficient (F_sire), individual reproductive values, number of equivalents to complete generations (t), and unbiased ancestral inbreeding coefficient (Fa). We established the equivalent complete generations (ECG), effective population size (Ne), total number of founders (Nf), effective number of founders (Nfe), total number of ancestors (Na), effective number of ancestors (Nae), founder genomes (Ng), and the inbreeding coefficient estimated with effective population size (Ne) and generation numbers (t) (F_Ne:t), as well as Nfe/Nae and Nfe/Ng ratios for the RP. The RP inbreeding levels have stabilized, although they are still significantly rising by generation (t), and the Nfe/Ng ratio strongly suggests genetic drift. Pedigree‐based analysis demonstrates that only five stallions have sired 52.83% of the RP individuals, which along with the Nae value of 36.73 implies that the observed inbreeding can be arising from patrilines. Our results suggest that observed inbreeding is due to Popular Sire Effect, highlighting the importance of monitoring breeding schemes and genetic diversity to maintain health.

The conformation is directly related to the quality of the movements, and can direct the selection by equine aptitude. This study aimed to identify which are the morphometric measurements that explain the total variance available in the marcha batida and picada gaits of young Mangalarga Marchador horses. Analyses were performed by evaluating 20 linear measurements of 420 champion horses. Measures were separated by gender (male-M and female-F), type of marcha, (batida-MB e picada-MP) and divided into eight age groups. Principal component analysis (PCA) was used to identify which measurements were most important in determining marcha variance by selecting principal component (PC) which sum of eigenvalues was able to explain the minimum percentage of 80% of the total variation. The PC number varied randomly according to age groups, being 2 to 3 in both genders in MP, 3 to 4 for M-MB, and up to 5 for F-MB, suggesting lower overall variability in MP, and higher in F-MB. There was no defined pattern concerning the amount of PC per age group, demonstrating that each category may have independent variations. Although, some repetitions of variables occurred similarly in different ages, sexes, and marcha types, the responsibility for the highest occurrence of variation was the posterior cannon and gaskin length. The significant variance in the length of these segments, regardless of gender, age, and marcha, and the fact they are not measured daily suggested there is not only a lack of standardization of these segments, but there is also size compensation among them since the group evaluated is composed of breed champions.

The saddle is a particularly important piece of equipment when it comes to training horses. Any problem with this, or in its adjustment, can cause discomfort, pain and injury to the horses. The aim of this study was to analyze Australian saddles thermographically, in a quantitative way by quadrants, performing a primary detection of how pressure distribution occurs in Australian saddles commonly used in Mangalarga Marchador (MM) gaited horses during a basic riding course, in order to signal whether there is a need for a more complete assessment of saddle befitting this type of activity. For this purpose, ten similar Australian saddles used by ten MM horses were thermographically evaluated during a basic riding course. Thermographic images were obtained from the ventral face of the saddle before and after one hour of exercise. The images were divided into 9 quadrants and compared quantitatively before and after the ride. Quantitative analysis by quadrants including 3 central quadrants for assessing the gullet region was effective, providing the necessary detail for data analysis. Inappropriate contact of the gullet region with the animal’s back was demonstrated in 100% of the saddles, with the central quadrant of the gullet being the most affected, indicating the inadequacy of this type of saddle for MM in this activity. Therefore, there is a need for a more complete assessment of saddle befitting an Australian saddle type to this equestrian activity, aiming at improvements in animal welfare.