The study was conducted in an official park in the municipality of Pilar-AL (09˚35'50"S; 35˚57'24"W).

A total of 40 male Nellore oxen were used, with an average age of two years and an average weight of 420.0 kg. The animals received the same food management, being raised on pasture of Brachiaria grass (Brachiaria decumbens) and supplemented with mineralized salt for cattle and water ad libitum. On the day before the evaluations, all the animals were moved to vaquajada field and housed in pens inside the cattle farm. In the park, there was shading, and the cattle had access to water, mineral salt and forage (chopped elephant grass, Pennisetum purpureurn Schum.) ad libitum. In these pens, the oxen were housed for 48 hours; 24 hours before and after the races, for clinical, behavioral and radiographic analyses. The cattle had already experienced management in these facilities and pens on different occasions previously, principally for health management practices.

The cattle were periodically managed for the sanitary control of parasitic diseases such as mandatory vaccinations, such as those for the prevention of clostridiosis (polyvalent SYMPTAN, Boehringer Ingelheim Animal Health, Campinas-SP) and foot-and-mouth disease (OurovacAftosa, OurofinoSaúde Animal, Cravinhos—SP)—Brazil) following the manufacturer’s instructions.

To perform this experiment, the cattle underwent clinical and radiographic examination on two occasions:

· Pre-race of the horse or M-1: animals were evaluated in the containment area (“brete”) from the displacement of the rest pen to the containment area, where palpations of the lymph nodes and locomotor limbs were performed, followed by radiographic examinations and placement of the individual tails conical harness protector;

· Post-race or M-2: the arrival of the cattle in the containment area (“brete”), where the conical tail protector was removed, palpation of the lymph nodes and locomotor limbs was performed, followed by radiographic examinations and exit of the “brete” towards the corral of rest. In the resting pens, animals were monitored and evaluated clinically by the system of 5 domains [9] for a total of 48 hours, 24 hours before and 24 hours after the horse racing. All runs were performed on a standard track with soft sand for a length of 150 m.

In the clinical examination, the cattle were subjected to the following assessments: heart rate, respiratory rate, rectal temperature, mucosal color and skin characteristics (alopecia, lesions and ectoparasites), palpable lymph nodes (size, consistency, sensitivity and temperature). The locomotor system was also highlighted, with the animal being evaluated step by step to observe the presence of lameness, symmetry of the thoracic and pelvic limbs, increases in bone, joint and tendon volume, presence of wounds and bruises. Besides, in the evaluation of the 5 Domains, environmental, nutritional, health, behavioral and mental parameters were observed [9].

At the end of the radiographic examinations, the cattle were restrained at the brete, as described above, and radiographs were obtained in the latero-lateral and dorso-ventral positions, with the device positioned at a distance of 90 cm from the tail, using digital Rx equipment (Portable Orange 90 kV with Scanner FCR system Fuji Film). To monitor the animals, in phases M-1 and M-2, were identified with a cattle wax marker (Raidl-Maxi, RAIDEX Gmbh, Dettingen/Erms, Germany). The conical tail protector (MMC Tails’ Protectors LTDA, Teresina-PI, Brazil) was used individually following the manufacture orientations.

Digital radiographic images were recorded on a flash drive and converted into a jpeg format for individual analysis by three veterinarians who did not know the type of challenge in the cattle were subjected to and the knowledge of the results of the other two evaluators. The radiographic analysis followed the evaluation protocol that took into account the following items: morphological alteration, deviation, reduction of intervertebral space, subcutaneous radiolucency, cleft, complete or partial fracture, radiolucent image and loss of vertebral pattern. For the radiograph evaluations, three veterinarians with experience in radiographic examinations were used, where each veterinarian analyzed the radiographs of the tail of 40 cattle in two positions, totaling 80 images per veterinarian.

Results were tabulated in an Excel spreadsheet, and descriptive statistics were applied using the relative and absolute values and expressed as the mean ± standard deviation.

In the present study, when examining the skin, lymph nodes and mucous membranes, no changes were found in the parameters evaluated in the pre- and post-race cycles. The initial clinical evaluation also showed that the cattle used here were in good health, before any exercise. Also, the analysis of the locomotor system did not show changes in the parameters studied during the experimental period, and there were no abnormalities in the movements of getting up, after the fall, or in walking to the rest curral.

Lameness is sometimes detected in cattle after transport or when they are housed in unsanitary conditions. Lameness is the third most important disease in dairy cows, where cattle with a lower body score and inadequate housing system had a significant association with more limb injuries [10]. In contrast, in the beef industry, most episodes of lameness are observed in packing plants, and probably due to housing in commercial feedlots and transportation, and these authors showed that the most common location for lameness disease was the foot (~85%) [11]. However, Silveira et al (2018) [12] showed that beef farms in the Amazon region in Brazil, when they have inadequate facilities (corral and pasture), bovines have a significant amount of foot disorders, especially in the hind limbs. The cattle used in this research had a good body score and are housed in pasture. They walk from their pastures to the management corral for the vaquejada, and the type of accommodation and general management on the farms in the Northeast region of Brazil can contribute animal welfare. It should be noted that beef cattle in Brazil are largely raised and fattened on pasture until they are transported to slaughterhouses.

Also, in the thoracic and pelvic limbs, no asymmetry or increased bone, joint and tendon volume was detected, and there were no wounds or bruises during the pre- and post-run inspection. In addition, when the cattle were at rest, animals with suspended or dragged limbs or asymmetries resulting from joint displacements or fractures were not observed. Such observed evidence allows to interpret the efficiency of the soft sand mat in the range where the animals are placed, thus absorbing the impact of the fall and avoiding serious injuries to the animals. Upon palpation of the animals’ bodies, only one animal showed an increase in volume in the dorsal region of the tail but was kept in the vaquejada test because it did not present pain, discomfort or any type of reaction when this area was palpated with some pressure.

The mean values for heart rate (HR), respiratory rate (RR) and rectal temperature were 126 ± 32.1 bpm, 39 ± 6.45 mpm and 39.6˚C ± 0.7˚C, respectively, and reflect cattle movements. Between the rest pen and the retention cage on a sunny day in a tropical region, they were tachycardic and tachypneic according to the comparison with the parameters for animals at rest [13] [14]. The use of brete restraint for varying periods can also cause temporary stress and consequently excitation, which eventually results in considerable variations in respiratory and heart rates. Therefore, researchers should seek other ways of measuring these parameters, such as the use of cardiac monitors, which are minimally invasive and can store these clinical signs with confidence.

It is also known that Nellore cattle are better adapted to tropical conditions in Brazil; however, this group of animals may have more difficulties for handling when contained than European cattle. Therefore, it should be noted that cattle may exhibit changes in the heart and respiratory rate due to exposure to periods in the sun or when they are manipulated, which causes great excitement [15] [16]. However, when the stressor is removed, the animals should return to normal. In the present study, it was not possible to obtain the HR, RR and rectal temperature in the free animals in the rest pen, but in the inspection before and after the races observed them with normal feeding and drinking water, in addition to the animals ruminating and playing, which were excellent indicative of the welfare conditions of cattle when combined with other evaluations performed here, as described in the literature [4] [9].

Evaluating the radiographic findings, it was observed that the presence of subcutaneous radiolucency (2.1%) (Figure 1) and reduction of the intervertebral space (8.35%) (Figure 2) were the most frequent in M-2; therefore, when studied the findings in M-1 from M-2, this higher frequency was maintained (Table 1). Radiographic finding, may suggest the presence of intervertebral disc diseases, when associated with pain, paresis or paralysis [17]. Post-race clinical examination was not able to detect pain or edema in the tail area of greater contact with the conical tail protector, which can rule out some type of injury in the radiographed area. It should also be noted that the highest frequency of these findings occurred at M-2, soon after the removal of the conical tail protector and when the cattle were excited by running, which made it difficult to contain it and its tail for radiographic examination and thus interfered with the quality of the images. Also, it is important to observe that Nellore have a typical behavior, which is very different from the European breeds.

Still, in the radiographic evaluations, it was observed that the item fracture/partial fracture (Figure 3) presented a low frequency (<0.5%), when the total findings of this item in M-1 are removed, to those observed in M-2. Only one observation of partial fracture/fracture was observed in M-2, and it was precisely

Observations: *80 radiographic images were analyzed by each veterinarian (n = 3) in pre- and post-race, totaling 240 analysis per period of the race; M-1^T: total of the findings and their frequencies in the pre-race; M-2^T: total of the findings and their frequencies in the post-race.

in the bovine that there was swelling in the tail but no pain on palpation. When evaluating the incomplete fractures (Figure 4), morphological changes (Figure 5) and deviation of the vertebral feed (Figure 6), there were no differences in the frequency between M-1 and M-2.

Different authors noted that fractures can involve any part of the spine, but the most common sites are the vertebral bodies, transverse processes and spinous processes. However, fractures and fissures in the tail bones, when they are more distal, can occur in management situations. Fractures can cause a sudden narrowing of the intervertebral disc space, and radiographically, the vertebrae may appear smaller than normal when a compressive fracture occurs. Dislocations or partial dislocations of the spine may occur with or without fractures, and sub-luxations may be accompanied by a decrease in the intervertebral space. These traumatic injuries to the spine and spinal cord often occur in veterinary and human medicine, leading to devastating sequelae, such as partial or complete loss of motor, sensory and visceral functions [18]. Some of these clinical signs are not related to a fracture of the tail bones, but pain with edema is frequent when these areas of the body are injured.

Consequences of the spinal cord trauma, depending on the injured segment,

can lead to permanent disability, death or euthanasia [18] [19]. External impacts may result in fracture, subluxation, vertebral dislocation, hemorrhage, hematoma, spinal edema, compressive lesions, and spinal or associated root laceration, which result in different degrees of neurological dysfunction [20] [21]. However, none of the evaluated cattle showed such lesions.