Equine Rolling Behavior: Thermoregulation Mechanism After Exercise and Substrate Preference.

Rolling is a natural behavior of equids that is beneficial to their well-being. However, more intensive domestic environments offer fewer opportunities for animals to roll, neglecting its importance. We believe that the inclusion of recreational areas for animals, containing substrates and conditions that encourage the occurrence of natural behaviors, is essential to promote their well-being. Therefore, we evaluated the preference of horses (Equus caballus; n = 8) and mules (E. asinus x E. caballus; n = 8) for different rolling substrates (sand, grass, manure), and the influence of this behavior on thermoregulation after exercise. Horses rolled preferentially on grass, whereas mules preferred sand, both of which were cooler substrates when compared to manure. In addition, the temperature of the animals significantly reduced after rolling. Thus, horses and mules must roll for thermoregulation after exercise, choosing cooler and more efficient substrates for heat dissipation. The differences in preferences between mules and horses showed particularities between the equine species and its hybrid, which is important for management that is focused more on the individual animal.

Assessment of qualitative and quantitative parameters of healthy thyroid gland in adult horses by magnetic resonance imaging.

In humans and pets, magnetic resonance imaging (MRI) provides important adjunctive anatomic information about the thyroid and its adjacent structures. To the best of our knowledge, however, no studies have been reported regarding the use of MRI for thyroid evaluation in horses. The aim of this study was to obtain qualitative and quantitative parameters of healthy thyroid gland in adult horses by MRI. Eleven horses were submitted to thyroid MRI evaluation. The healthy thyroid of these animals was ensured by normal examinations performed before (free thyroxine and ultrasound) and after (cytology) to MRI. It was concluded that the dorsal spin-echo T1-weighted, fast spin-echo T2-weighted, sagittal STIR and a three-dimensional T1-weighted gradient echo were the sequences that best characterized the thyroid lobes. Qualitatively, there was a significant variation in the elliptical format of some lobes considering the sagittal plane, which oscillated between rounded and flattened conformation. Excellent reproducibility of the quantitative thyroid parameters obtained was verified. The thyroid gland total volume mean of observers was 14.31 cm3 (±0.69). In relation with comparisons between quantitative parameters of left and right lobes, only differences regarding their respective lengths were observed. Thus, we can infer that the difference in some thyroid lobes format can be explained by the significant variation identified between left and right lobes lengths.

Development, Validation, and Reliability of a Sedation Scale in Horses (EquiSed).

The lack of standardization of sedation scales in horses limits the reproducibility between different studies. This prospective, randomized, blinded, horizontal and controlled trial aimed to validate a scale for sedation in horses (EquiSed). Seven horses were treated with intravenous detomidine in low/high doses alone (DL 2.5 µg/kg + 6.25 µg/kg/h; DH 5 µg/kg +12.5 µg/kg/h) or associated with methadone (DLM and DHM, 0.2 mg/kg + 0.05 mg/kg/h) and with low (ACPL 0.02 mg/kg) or high (ACPH 0.09 mg/kg) doses of acepromazine alone. Horses were filmed at (i) baseline (ii) peak, (iii) intermediate, and (iv) end of sedation immediately before auditory, visual and pressure stimuli were applied and postural instability evaluated for another study. Videos were randomized and blindly evaluated by four evaluators in two phases with 1-month interval. Intra- and interobserver reliability of the sum of EquiSed (Intraclass correlation coefficient) ranged between 0.84-0.94 and 0.45-0.88, respectively. The criterion validity was endorsed by the high Spearman correlation between the EquiSed and visual analog (0.77), numerical rating (0.76), and simple descriptive scales (0.70), and average correlation with head height above the ground (HHAG) (-0.52). The Friedman test confirmed the EquiSed responsiveness over time. The principal component analysis showed that all items of the scale had a load factor ≥ 0.50. The item-total Spearman correlation for all items ranged from 0.3 to 0.5, and the internal consistency was good (Cronbach's α = 0.73). The area under the curve of EquiSed HHAG as a predictive diagnostic measure was 0.88. The sensitivity of the EquiSed calculated according to the cut-off point (score 7 of the sum of the EquiSed) determined by the receiver operating characteristic curve, was 96% and specificity was 83%. EquiSed has good intra- and interobserver reliabilities and is valid to evaluate tranquilization and sedation in horses.

Effect of artificial shading on performance and reproductive parameters of semi-confined young Brangus bulls / Efeito do sombreamento artificial no desempenho e parâmetros reprodutivos de novilhos Brangus em semiconfinamento

Thirty Brangus bulls were used in a 90-d study to assess the effect of artificial shading on the performance and reproductive characteristics of semi-confined cattle. Animals were kept in four one-ha paddocks in two groups of eight for shade treatment (5 m²/animal of 80% solar block shade cloth) and two groups of seven animals in no-shade treatment. Each treatment had two homogeneous groups, each divided into heavy-bulls (351-450 kg) and light-bulls (300-350 kg). Time spent under shade, time standing, average daily gain, testicular development and sperm quality were investigated. Animals spent 24% of the daylight under the shade and no-shaded bulls spent more time standing (P < 0.05). No difference was found in average daily gain (P > 0.05) and testicular development between shaded and no-shaded animals. However, scrotal perimeter was higher for shaded light animals compared to no-shaded light bulls (P < 0.10). Sperm motility increase during the experimental period for shaded animals (P < 0.05) and sperm abnormalities were higher for the shaded ones (P < 0.05). Although the results did not indicate pronounced benefits on cattle performance, this resource was an important alternative because it appears to provide an improvement in some reproductive parameters and ensure a better thermal comfort to the animals.

Foi avaliado o efeito do sombreamento artificial sobre o desempenho produtivo e reprodutivo de animais semiconfinados em trinta novilhos Brangus durante o período de 90 dias. Os animais foram mantidos em quatro piquetes de 1 ha cada, divididos em dois grupos de oito animais cada no tratamento sombra (5 m2/animal de tela de sombreamento de polipropileno com 80% de retenção solar) e dois grupos no tratamento sem acesso à sombra com sete animais em cada. As variáveis analisadas foram: o tempo gasto na sombra, o tempo em pé, ganho de peso, desenvolvimento testicular e qualidade espermática. Os animais passaram 24% do dia sob a sombra e os que não tiveram acesso à sombra permaneceram mais tempo em pé (P < 0,05). Não foi encontrada diferença no ganho de peso (P > 0,05) e no desenvolvimento testicular entre animais com acesso à sombra e os que não tinham acesso. No entanto, o perímetro escrotal foi maior para os animais submetidos ao sombreamento comparado com novilhos sem acesso à sombra (P < 0,10). A motilidade espermática aumentou durante o período experimental para os animais com acesso a sombra (P < 0,05), porém as anormalidades espermáticas também foram maiores para este grupo (P < 0,05). Embora os resultados não indiquem claramente os benefícios relacionados ao uso de sombreamento no desempenho produtivo de bovinos semiconfinados, este recurso se mostra como uma alternativa importante, pois proporcionou melhoria de alguns parâmetros reprodutivos e propiciou um melhor conforto térmico para os animais.

Equilíbrio de cavalos da raça Quarto de Milha participantes da modalidade de três tambores por meio de proporções corporais / Balance of Quarter Horses participating in the barrel racing modality by using body proportions

Baseado no conceito de que cavalos equilibrados possuem simetria entre suas regiões anatômicas, o objetivo deste trabalho foi introduzir um método de avaliação do equilíbrio de equinos atletas por meio de proporções corporais. Foram mensuradas doze medidas lineares, utilizando fita métrica, em 234 cavalos da raça Quarto de Milha durante provas de três tambores. A partir dessas mensurações, construíram-se nove proporções corporais, dadas pela razão entre duas medidas específicas. Para cada proporção, considerou-se o efeito do sexo, do peso, da idade e do grau de sangue; na verificação dos testes de significância, empregou-se a estatística F, adotando P<0,05. Verificou-se que as medidas lineares do comprimento da articulação escápulo-umeral à tangente vertical do processo espinhoso da quinta vértebra torácica; da distância da tangente axial do processo espinhoso da quinta vértebra torácica à quinta vertebra lombar; e da distância da tangente vertical oblíqua da margem dorsal da região femoro-tíbio-rotuliana à articulação intertársica foram as principais responsáveis pela desproporcionalidade dos cavalos avaliados. O efeito do sexo foi significativo para quatro das nove proporções avaliadas (R1, R2, R3 e R4), sendo que as fêmeas apresentaram-se mais distantes do conceito de equilíbrio, quando comparadas aos machos.

Based on the concept that horses have balanced symmetry between its anatomical regions, the aim of this study was to introduce a method of assessing the balance of equines through body proportions. Altogether twelve linear measurements, using metric tape, were measured in 234 horses Quarter Horses for evidence of barrel racing. From these measurements were built nine body proportions, each one given by the ratio of two specific measures, and the effects of sex, weight, age and degree of blood on the balance were evaluated. To check the significance tests we used the F statistic, considering P<0.05. It was found that the linear measurements ML2, ML3 and ML5 were mainly responsible for the disproportionality of the horses evaluated. The effect of sex was significant (P<0.05) for four proportions (R1, R3, R4 and R9) and females were more distant from the concept of balance than males.

Parâmetros fisiológicos do desempenho de cavalos de alta performance hidratados voluntariamente com água ou solução isotônica contendo carboidrato / Physiological parameters of high performance horses watered spontaneously with regular (ordinary) water or isotonic solution containing carbohydrate

Durante 8 semanas, no verão, 4 cavalos de alta performance treinados para enduro, realizaram exercício de resistência recebendo 2 tipos diferentes de hidratação, água ou solução isotônica contendo carboidrato, com o objetivo de comparar seus parâmetros fisiológicos. Somente as variáveis Tr, Fc, Fr, peso e proteína total, consumo, glicose, os eletrólitos K, Ca e a enzima muscular CK apresentaram efeito de distância. Dos demais parâmetros avaliados não foram identificados os efeitos de tratamento e de interação da distância com o tratamento estudado (P>0,05), concluindo assim que a solução isotônica contendo carboidrato não teve influencia na performance dos animais, quando comparada com a água.

During eight weeks, in summer, four endurance trained high performance horses were worked in resistence exercise, recieving two different types of hydratatio, water or an isotonic solution containing carbohydrates, with the objective to compare their performance physiological parameters. Only the RT (rectal temperature), HR (heart rate), RR (respiratory rate), weight, total protein, glucose, the electrolytes K, Ca and the muscular enzyme CK presented distance effect. The others parameters evaluated, there weren’t any identified effects of treatment and of the interaction between distance and treatments, with a significancy level of 5%, and it was concluded that the isotonic solution containing carbohydrate didn’t have any significant influence on the animal’s performance when compared to water.

Parâmetros fisiológicos do desempenho de cavalos de alta performance hidratados voluntariamente com água ou solução isotônica contendo carboidrato / Physiologics parameters of high performance horses voluntery hydrated with water or isotonic solicion contend carbohydrate

objetivo: Comparar os parâmetros fisiológicos do desempenho de cavalos de performance, realizando 3 diferentes níveis de intensidade de exercícios resistência (enduro), hidratados voluntariamente com água ou com uma solução isotônica contendo carboidrato. Métodos: Durante 8 semanas, no verão, 4 cavalos treinados para enduro foram trabalhados em três diferentes intensidades de exercício de resistência, recebendo tipos diferentes de hidratação. Resultados: No presente experimento, em todos parâmetros fisiológicos avaliados, não foram identificados os efeitos de tratamento e de interação da distância com os tratamentos (água e solução isotônica) nos três níveis de intensidade estudados (P>0,05). Somente os parâmetros Tr, Fc, Fr, peso, glicose e proteína total, nos três exercícios, apresentaram efeito de distância. Os eletrólitos K, Ca e a enzima muscular CK apresentaram efeito de distância exercício de alta intensidade. Conclusão: A solução isotônica contendo carboidrato não teve influencia na performance dos animais, quando comparada com a água