Study of the mutation causing type 1 polysaccharide storage myopathy in a Mangalarga Marchador population used in breeding programs / Estudo da mutação causadora da miopatia por acúmulo de polissacarídeo tipo 1 em uma população de cavalos Mangalarga Marchador utilizados em programas de melhoramento

The Mangalarga Marchador (MM) breed, which originated in Brazil, constitutes the largest number of horses in the country. The animals are versatile and used in several sports because of major investments made for the genetic improve-ment of the breed. In recent decades, advances in molecular techniques enabled the identification of genetic diseases in hor-ses. Conducting molecular tests and determining the occurrence of mutations are fundamental for the early identification and prevention of abnormalities. Among the known genetic diseases that occur in horses, the c.926G>A mutation in the GYS1gene that causes type 1 polysaccharide storage myopathy (PSSM1) stands out, because it has been identified in several breeds of horses. Although myopathy is common in MM horses, the occurrence of the c.926G>A mutation in the GYS1 gene has not yet been evaluated. The lack of knowledge about the possible presence of PSSM1 averts the adoption of control measures to prevent the spread of the disease in MM horses. Therefore, the aim of this study was to verify the occurrence of the muta-tion that causes PSSM1 in MM horses used in breeding programs. Blood DNA was extracted and the region of the GYS1gene containing the mutation was amplified and sequenced. No mutation in the GYS1 gene was found in the evaluated sam-ples. However, since clinical signs of myopathy are frequently observed in MM horses, further studies, including histological analysis, are necessary to establish the underlying causes. In addition, if there is a genetic pattern of occurrence, molecular studies should be considered.(AU)

A raça Mangalarga Marchador (MM), originária do Brasil, constitui a raça de maior número de equinos no país. Os animais são versáteis e utilizados em diversos esportes devido aos seus grandes investimentos em melhoramento genético. Nas últimas décadas, o avanço das técnicas moleculares permitiu a identificação de doenças genéticas em cavalos. A realização de testes moleculares e a determinação da ocorrência de mutações são fundamentais para a identificação precoce e prevenção de anormalidades. Dentre as doenças genéticas conhecidas em equinos, destaca-se a mutação c.926G>A no gene GYS1 causadora da miopatia por acúmulo de polissacarídeo tipo 1 (PSSM1), pois foi identificada em diversas raças equinas. Embora a miopatia seja comum em cavalos MM, a ocorrência da mutação c.926G>A no gene GYS1 ainda não foi avaliada. A falta de conhecimento sobre a possível presença de PSSM1 inviabiliza a adoção de medidas de controle para prevenir a disseminação da doença em equinos MM. Portanto, o objetivo deste estudo foi verificar a ocorrência da mutação causadora de PSSM1 em cavalos MM utilizados em programas de melhoramento. O DNA sanguíneo foi extraído e a região do gene GYS1contendo a mutação foi amplificada e sequenciada. Nenhuma mutação no gene GYS1 foi encontrada nas amostras avaliadas. No entanto, como sinais clínicos de miopatia são frequentemente observados em cavalos com MM, mais estudos, incluindo análises histológicas, são necessários para estabelecer as causas subjacentes. Além disso, se houver um padrão genético de ocorrência, estudos moleculares devem ser considerados.(AU)

Taxa de recuperação embrionária em éguas Mangalarga Marchador inseminadas com sêmen refrigerado / Embryonic recovery rate in Mangalarga Marchador mares inseminated with refrigerated semen

O acompanhamento reprodutivo da espécie equina tem sido cada vez mais aplicado na aplicade de diversos países, resultando em melhores índices reprodutivos para a espécie e em animais de linhagens selecionadas. Nos programas de transferência de embrião, a taxa de recuperação embrionária consiste em um parâmetro essencial a fim de verificar o sucesso da técnica. Por conseguinte, este trabalho propõe-se a avaliar as taxas de recuperação embrionária de éguas doadoras submetidas à inseminação artificial com sêmen refrigerado de maneira a complementar os dados relacionados ao assunto. Conforme os dados coletados durante a estação de monta de agosto de 2018 a fevereiro de 2019, obteve-se 129 lavados uterinos provenientes de 20 éguas e 83 embriões recuperados. Desse modo, a taxa de recuperação embrionária obtida foi de 64,34%. Diante dos dados apresentados neste estudo, conclui-se que a aplicabilidade da técnica de recuperação embrionária visando o uso do sêmen refrigerado na inseminação artificial de éguas se mostra promissora, pois permite o transporte de material genético de alto valor entre propriedades sem interferir drasticamente nos índices dos programas de reprodução.

The reproductive monitoring of the equine species has been increasingly applied in several countries, resulting in better reproductive rates for the species and in animals from selected strains. In embryo transfer programs, the embryo recovery rate is an essential parameter to verify the technique success. Therefore, the present work proposes to evaluate the embryo recovery rates of donor mares submitted to artificial insemination with refrigerated semen to complement the data related to the subject. According to the data collected during the breeding season for the period from August 2018 to February 2019, 129 uterine washes were obtained from 20 mares and 83 recovered embryos. Thus, the embryonic recovery rate obtained was 64.34%. Given the data presented in this study, it is concluded that the applicability of the embryonic recovery technique aiming at the use of refrigerated semen in artificial insemination of mares is promising, as it allows the transport of high-value genetic material between properties without interfering dramatically in breeding program indexes.

Ultrasonography of the stomach and small intestine in healthy Mangalarga Marchador horses from birth to 5 years of age / Ultrassonografia de estômago e intestino delgado de equinos Mangalarga Marchador saudáveis desde o nascimento até cinco anos de idade

The aim of the study was to describe location, sonographic characteristics and measures of the stomach and small intestine of equines at different ages. Abdominal ultrasonography was performed on 88 healthy equines of either sex, aged 1, 7 and 15 days, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11 months and 1, 3 and 5 years, with 20 animals per group. Location, characteristics and measurements of stomach, duodenum and jejunum were evaluated. Descriptive statistics were performed for each measurement and the percentile for each age was analyzed. The work showed the growth and characteristics of the organs evaluated over time. Adult animals showed a minimum of 4 duodenal movements per minute. It was possible to locate the organs evaluated in all animals. The detailed ultrasound examination of these organs allowed gathering information that could be used to assist in the care of future patients.

O objetivo deste estudo foi descrever localização topográfica, características e medidas ultrassonográficas de estômago e intestino delgado de equinos em diferentes idades. Foi realizado um exame ultrassonográfico abdominal em 20 equinos saudáveis de ambos os sexos, com idades de um, sete e 15 dias, um, dois, três, quatro, cinco, seis, sete, oito, nove, 10 e 11 meses e um, três e cinco anos. A localização, as características e as medidas de estômago, duodeno e jejuno foram avaliadas. Foi realizada a estatística descritiva para cada medida e analisado o percentil para cada idade. O trabalho mostrou o crescimento e as características dos órgãos avaliados ao longo do tempo. Animais adultos apresentaram um mínimo de quatro movimentos por minuto de duodeno. Foi possível localizar os órgãos avaliados em todos os animais. O exame ultrassonográfico detalhado desses órgãos permitiu agrupar informações que poderão ser usadas para auxiliar no atendimento a futuros pacientes.

Growth predictability models in Mangalarga marchador horses / Modelos de previsibilidade de crescimento em cavalos Mangalarga marchador

This study evaluated the suitability of the Brody, logistic, and quadratic response plateau models to describe chest and cannon girth data obtained cross-sectionally in Mangalarga Marchador horses, in order to select the best model and predict the growth and maturity of males and females of this breed. Data were collected from 230 horses aged 6 to 176 months, divided by sex and age (16 age classes). The studied models were compared according to each quality evaluator by computing the adjusted coefficient of determination (R²adj) and residual standard deviation (RSD) with R statistical software. The chest girths obtained by the models ranged from 172.06 (males) to 181.50 cm (females) (Brody), 172.51 (males) to 181.89 cm (females) (logistic), and 177.67 (males) to 183.09 cm (females) (plateau). For cannon girth, the values were 18.18 (females) to 19.33 cm (males) (Brody), 18.11 (females) to 19.41 cm (males) (logistic), and 18.70 (females) to 19.40 cm (males) (plateau). The logistic model was best suited to describe the growth in chest girth of male and female Mangalarga Marchador horses. For cannon girth growth, the model best suited for males was the logistic model, and the one best suited for females was the Brody model.

RESUMO: O objetivo deste estudo foi avaliar o ajuste dos modelos Brody, Logístico e Platô de resposta quadrática aos dados de perímetros torácico e de canela em equinos Mangalarga Marchador obtidos pelo método transversal, a fim de selecionar o melhor modelo e predizer sobre o crescimento e a maturidade de machos e fêmeas desta raça. Foram utilizados dados de 230 equinos de seis a 176 meses de idade que foram divididos por sexo e em 16 classes de idade. Os modelos estudados foram comparados segundo os avaliadores de qualidade: coeficiente de determinação ajustado (R²adj) e desvio padrão residual (DPR), utilizando-se o software estatístico R. Os perímetros torácicos obtidos pelos modelos variaram de 172,06 a 181,50 cm (Brody), 172,51 a 181,89 cm (Logístico) e 183,09 a 177,67 cm (Platô) para fêmeas e machos, respectivamente. Para o perímetro de canela os valores variaram de 18,18 a 19,33 cm (Brody), 18,11 a 19,41 cm (Logístico) e 18,70 a 19,40 cm (Platô) para fêmeas e machos, respectivamente. O modelo logístico é mais indicado para expressar o crescimento em perímetro torácico de machos e fêmeas da raça Mangalarga Marchador. Já para a variável perímetro de canela, o modelo mais indicado para os machos foi o modelo Logístico e para as fêmeas o modelo de Brody.

Mammary gland secretion pH and electrolytes in prepartum Mangalarga Marchador mares / [Concentrações de pH e eletrólitos na secreção da glândula mamária de éguas Mangalarga Marchador no período pré-parto]

The objective of this study was to determine pH and the concentrations of Calcium (Ca2+), Magnesium (Mg2+), Chloride (Cl-), Sodium (Na+), Potassium (K+) and Calcium (Ca2+) in the mammary gland secretion in pre-foaling Mangalarga Marchador (MM) mares to determine the best method to predict parturition in the breed. Forty-two pregnant MM mares were evaluated once daily from 310 days of gestation until parturition. Mammary gland secretion pH, measured by pH meter and pH paper strip, Mg2+, Ca2+ and Cl- levels significantly changed during the last 10 days prior to parturition (p<0.05). The lowest pH mean value (pH meter=6.67±0.42; pH strip=6.23±0.53) and significantly higher mean concentrations of Ca2+ (12.6±5.8mmol/L) and Mg2+ (10.93±3.66mmol/L) were obtained 24 hours prior to foaling (p<0.0001). Chloride levels reduced significantly 8 days prior to parturition (p<0.0001) but remained unchanged until the due date. Mammary gland pH secretion, measured by pH meter and pH paper strip, was effective to predict parturition. Quantitative pH values obtained with the pH meter had a greater accuracy in comparison to pH paper strips, but a strong correlation was found between both methods. Calcium and magnesium were the only electrolytes that changed in concentration immediately prior to parturition and are better indicators of when not to expect foaling.

O objetivo deste estudo foi determinar o pH e as concentrações de cálcio (Ca2+), magnésio (Mg2+), cloro (Cl-), sódio (Na+) e potássio (K+) na secreção da glândula mamária de éguas Mangalarga Marchador (MM) no período pré-parto, a fim de determinar o melhor método para predizer proximidade do parto na raça. Quarenta e duas éguas MM foram avaliadas diariamente a partir dos 310 dias de gestação até o parto. O pH, aferido pelo pHmetro e por fitas reagentes, e os eletrólitos Ca2+, Mg2+ e Cl- apresentaram diferenças significativas em suas concentrações nos últimos 10 dias pré-parto (P<0,05). A diminuição significativa dos valores médios de pH (pHmetro= 6,67±0,42; fitas reagentes= 6,23±0,53) e o aumento significativo nas concentrações médias de Ca2+ (12,6±5,8mmol/L) e Mg2+ (10,93±3,66mmol/L) foram observados 24 horas pré-parto (P<0,0001). As concentrações de cloro diminuíram significativamente oito dias antes do parto (P<0,0001), porém continuaram sem alteração até o momento da parição. O pH da secreção foi eficaz para predizer o momento do parto. Valores quantitativos obtidos por meio do pHmetro apresentaram maior acurácia em comparação às fitas de pH, porém obteve-se forte correlação entre os dois métodos. Cálcio e magnésio foram os únicos eletrólitos que apresentaram alterações significativas no pré-parto imediato e são indicadores mais precisos de quando não esperar o parto.

Evaluation of Mangalarga Marchador foal development in the first year of life / Avaliação do desenvolvimento de potros da raça Mangalarga Marchador em seu primeiro ano de vida

The purpose of this study was to examine the development pattern of Mangalarga-Marchador foals by determination of muscle development and deposition of adipose tissue associated with the evaluation of blood-based biomarkers. Thus, 72 Mangalarga Marchador foals (ages ranged from 1-12 mo) were randomly selected and divided into 12 age groups (n=6 per group), evaluated monthly. The thickness of the Longissimus dorsi (LD) and rump fat (RF) were determined through an ultrasound performed on each foal's left side. Such parameters were used to calculate the percentage of body fat (BF), fat mass (FM), and fat-free mass (FFM). Morphometric measurements were taken on the foal's right side using a tape measure and a hypsometer. Blood samples were collected for determinations of total proteins, albumin, triglycerides, cholesterol, urea, creatinine, and glucose. Morphometric measurements, the thickness of the LD and RF, weight, BF, FM, and FFM showed differences between age groups (P<0.001). Muscle development and fat deposition in subcutaneous tissue were greater between six and 12 months and average weight gain and FFM were proportionally greater between one and six months. We concluded that morphometric measurements increase steadily and linearly during the first 12 months of life, indicating that it is feasible to use the linear regression formula. Moreover, significant differences between age and biochemical biomarkers may be attributed to nutritional and digestive physiology adaptations during these periods.(AU)

O objetivo desse estudo foi examinar o padrão de desenvolvimento de potros Mangalarga Marchador através da determinação do desenvolvimento muscular e da deposição de tecido adiposo associado com avaliação de biomarcadores sanguíneos. Assim, 72 potros Mangalarga Marchador (idades entre 1 e 12 meses) foram selecionados ao acaso e divididos em 12 grupos etários (n=6/grupo), avaliados mensalmente. A espessura do Longissimus dorsi (LD) e da cobertura de gordura da garupa (RF) foi determinada através de ultrassonografia realizada do lado esquerdo de cada animal, tais parâmetros foram usados para calcular percentagem de gordura corporal (BF), massa de gordura (FM) e massa livre de gordura (FFM). Mensurações morfométricas foram obtidas do lado direito de cada potro, usando fita métrica e hipômetro. Amostras sanguíneas foram obtidas para determinações de proteínas totais, albumina, triglicérides, colesterol, uréia, creatinina e glicose. Medidas morfométricas, espessura de LD e RF, peso corporal, BF, FM e FFM mostraram diferenças entre os grupos etários (P<0,001). O desenvolvimento muscular e a deposição de gordura no tecido subcutâneo foram maiores entre 6 e 12 meses e a média de ganho de peso e de FFM foi proporcionalmente maior entre entre 1 e 6 meses . Foi possível concluir que as medidas morfométricas aumentam de forma constante e linear nos primeiros 12 meses de vida, indicando que é factível usar fórmulas de regressão linear. Ainda, diferenças significativas entre idade e biomarcadores bioquímicos podem ser atribuídos às adaptações nutricionais e digestivas durante esses períodos.(AU)

Assessment of occlusal ridges in premolar teeth before and after dental treatment in equines / [Avaliação das cristas oclusais de dentes pré-molares antes e após o tratamento dental em equinos]

Occlusal ridges of equines appeared in the evolutionary process of the species to increase its capacity of grazing and trituration. The difference in hardness of dental tissues (cementum, dentin, and enamel) and masticatory pressure on the occlusal surface of the hypsodont tooth promote the appearance of sharp occlusal ridges. The aim of this study was to measure and compare the height of the occlusal ridges (HOR) of the fourth premolar (Triadan 408) before and after odontoplasty. Ten Mangalarga Marchador mares aged 5 to 12 years, under extensive management, were evaluated by measuring the HOR in Triadan 408, using plaster models before, immediately after (D0), 15 days (D15) and 50 days (D50) after odontoplasty. Immediately after the procedure the HOR was only 21.9% of the HOR before the occlusal equilibration; however, in 15 days after odontoplasty, 65.9% of HOR was already reestablished and 80.3% after 50 days of the procedure. HOR in the buccal side resurfaced before the lingual HOR, suggesting a higher masticatory pressure of these buccal points. Results of the present study indicate that 15 days after the dental treatment, equines already have food trituration capacity, since HOR is apparent on the occlusal surface of the premolars that underwent odontoplasty.

Cristas oclusais de equinos surgiram no processo evolutivo da espécie para aumentar sua capacidade de pastejo e trituração. A diferença na dureza dos tecidos dentários (cemento, dentina e esmalte) e a pressão mastigatória na superfície oclusal do dente hipsodonte promovem o aparecimento de cristas oclusais afiadas. O objetivo deste estudo foi medir e comparar a altura das cristas oclusais (HOR) do quarto pré-molar (Triadan 408) antes e após a odontoplastia. Dez éguas Mangalarga Marchador de cinco a 12 anos, sob manejo extensivo, foram avaliadas pela mensuração da HOR no Triadan 408, utilizando-se modelos de gesso antes, imediatamente após (D0), 15 dias (D15) e 50 dias (D50) após a odontoplastia. Imediatamente após o procedimento, a HOR era de apenas 21,9% da HOR antes do equilíbrio oclusal; entretanto, em 15 dias após a odontoplastia, 65,9% da HOR já estava restabelecida e 80,3% após 50 dias do procedimento. HOR na face vestibular ressurgiu antes da HOR lingual, sugerindo maior pressão mastigatória nestes pontos vestibulares. Os resultados do presente estudo indicam que 15 dias após o tratamento odontológico, os equinos já apresentam capacidade de trituração dos alimentos, uma vez que a HOR é aparente na superfície oclusal do pré-molar que foi submetido à odontoplastia.

Retrospective study of cutaneous neoplasms in horses treated at the Livestock Development Center of the Federal University of Bahia / Estudo retrospectivo das neoplasias cutâneas em equinos atendidos no Centro de Desenvolvimento da Pecuária da Universidade Federal da Bahia

The aim of this study was to determine the prevalence of cutaneous neoplasms in horses treated at the Center for the Development of Livestock at the Federal University of Bahia, as well as to correlate it with the coat color, breed, and age of the animal. For that, the attendance records for the last ten years were reviewed. When evaluating the files, 13 cases of cutaneous tumor in horses confirmed by histopathology and cytology were observed. The most prevalent skin tumors were sarcoid (38.5%), melanoma (23%), and fibrosarcoma (15.4%). Regarding the equine coat color, gray and sorrel horses were the most frequent with 30.7% and 23.1% of cases, respectively. As for the equine breed, the mangalarga marchador was the most prevalent (38.4%). Regarding age, 38.46% of the horses were up to 5 years old, 30.77% of the animals were between 4 and 10 years old, and 30.76% were between 11 and 16 years old. In the end, it can be concluded that sarcoid and melanoma were the most prevalent neoplasms.

Objetivou-se com este trabalho determinar a prevalência de neoplasias cutâneas em equinos atendidos no Centro de Desenvolvimento da Pecuária da Universidade Federal da Bahia, bem como correlaciona-la com a pelagem, raça e idade do animal. Para tanto revisou-se as fichas de atendimento dos últimos dez anos. Ao avaliar as fichas, observou-se 13 casos de tumor cutâneo em equinos confirmado por histopatologia ou citologia. Os tumores cutâneos mais prevalentes foram sarcoide (38,5%), melanoma (23%) e fibrossarcoma (15,4%). Com relação a pelagem, equinos tordilhos e alazões foram os mais frequentes com 30,7% e 23,1% dos casos, respectivamente. Quanto as raças, a mangalarga marchador foi a mais prevalente (38,4%). Em relação a idade, 38,46% dos equinos possuíam até 5 anos de idade, 30,77% dos animais apresentavam idade entre 4 e 10 anos e, 30,76% apresentavam idade entre 11 e 16 anos. Ao fim, pode-se concluir que o sarcoide e o melanoma foram as neoplasias mais prevalentes.

Effect of different concentrations of Trolox® in association with docosahexaenoic acid on equine semen freezing

The aim of this study was to evaluate the association of different concentrations of Trolox® and the addition of a fixed concentration of DHA in the freezing of semen of Mangalarga Marchador stallions. To that end, 16 ejaculates were frozen in the following extenders: E1) BotuCrio® (BC; Control); E2) BC + 50 ngml-1 DHA + 30 µM Trolox® (BCDHA30T); E3) BC + 50 ngml-1 DHA + 40 µM Trolox® (BCDHA40T); E4) BC + 50 ngml-1 DHA + 50 µM Trolox® (BCDHA50T). All the tested extenders were similar in preserving different kinematic parameters, cell functional integrity, compacted DNA, and high and intermediate mitochondrial activity (P>0.05). However, sperm cryopreserved in BCDHA40T showed higher velocities than sperm frozen in the control extender (P<0.05). The 30 µM concentration of Trolox® was worse for sperm motility and the 50 µM concentration of Trolox® did not adequately preserve the structural integrity of the membranes in an extender containing DHA when compared to the BotuCrio® (P<0.05) extender. The use of Trolox® in freezing extenders containing DHA did not maximize the effect of BotuCrio®, except for in the case of sperm velocity parameters when at a concentration of 40 µM.(AU)

Síndrome cólica em equinos induzida por ingestão de cana de açúcar / Equine colic syndrome induced by the ingestion of sugarcane

Background: Equine colic syndrome comprises numerous conditions associated with abdominal pain in horses. Impaction, a common cause of this manifestation, is strongly related to these animals' diet. Highly fibrous diets such as sugarcane can predispose horses to colic. The clinical condition can be worsened by fermentative processes, which lead to dysbiosis, circulatory disorders and even endotoxemia. The aim of this study was to report 4 cases of colic syndrome among 8 horses that underwent an experiment to adapt them to a sugarcane-based diet, and to correlate the animals' clinical conditions to the forage they ingested. Cases: Eight male castrated Mangalarga Marchador horses, between 5.5 and 7 years old, were subjected to an experiment to test the feasibility of sugarcane as forage. Four of these horses were taken to the Large Animal Veterinary Hospital (HVGA) of the Federal Rural University of Rio de Janeiro for treatment of abdominal signs of discomfort a few days after the exclusive consumption of sugarcane, in a proportion of 1.75% of live weight in dry matter. The animals' symptoms ranged from behavioral signs indicative of pain to changes in vital parameters and structure of the feces, as well as changes revealed by transrectal palpation. Three of the 4 cases presented impaction in the small colon, and 1 of the horses also presented impaction in the right dorsal colon and rostral displacement of the pelvic flexure, with accumulation of contents in the right ventral colon and sternal flexure. Two of the cases were treated medically, while the other 2 required surgical intervention. The clinical condition of all the patients evolved favorably and they were discharged between 2 and 18 days. Discussion: Colic originating in the digestive system is a syndrome strongly associated with management, especially with respect to confinement, nutrition, and parasite control. During the experiment, 4 of the 8 horses fed with sugarcane presented with colic syndrome. The low quality of sugarcane fiber is due to the high degree of lignification of the plant cell wall, which favors accumulation of ingesta. The poor digestibility and sweet taste of this roughage favor increased consumption. Furthermore, its high sucrose content, associated with an increased rate of passage in the small intestine, alters the intestinal microbiome, and hence, the fermentation byproducts and pH of the ingesta. High intestinal content, allied to longer retention times in the colon and activation of the renin-angiotensin-aldosterone system, promote greater dryness of the ingesta, predisposing the occurrence of impactions in the most distal portion of the large intestine. Intestinal distension and mesenteric traction caused by the accumulation of contents and gases trigger pain, which can worsen due to displacement of the large colon. Small colon impaction, which is easily identified by transrectal palpation, evolves gradually and its treatment, both clinical and surgical, tends to have a favorable prognosis. The need for alternative food sources for horses is a growing demand; however, sugarcane as an exclusive roughage has been shown to be unsafe for horses. The low quality of the fiber and the high sucrose content of this forage can alter the digestive physiology of horses through changes in the passage rate, microbiome and motility of digesta, predisposing them to intestinal dysfunction, ingesta compaction and displacement of the large colon.

Necrose tissular em equino associada ao uso de fenilbutazona / Tissue necrosis in equine associated with use of phenylbutazone

Background: Wounds that occur with tissue necrosis and that result from the application of medications through the most diverse accesses are described as drug skin medical embolism or Nicholas syndrome in human medicine, with wide description. In veterinary medicine, this subject has not yet been described extensively and specifically in veterinary medicine, especially regarding to wounds that occurred after the application of non-intravenous medications in horses, even though these lesions are recurrent in the clinical routine. This report aims to describe a case of skin necrosis in a horse, due to phenylbutazone infection. Case: A 7 year-old Mangalarga Marchador horse, weighing 400 kg, was admitted to the Veterinary Hospital for Large Animals of the Universiade Federal Rural do Rio de Janeiro (UFRRJ), with a history of phenylbutazone injection to the left side of the neck. The animal had an extensive wound on the neck and face on the left side and was characterized by the presence of cold and devitalized skin, with a hardened and parched appearance and that easily detached. During the anamnesis, a single administration of 10 mL of a non-steroidal anti-inflammatory drug based on phenylbutazone was reported intramuscularly for about 10 days to control the pain resulting from the claudication present for 14 days. The medication was administered in the region of the lateral border of the neck, on the left side. After drug administration, the animal presented an increase in volume at the application site. After 24 h, the lesion spread from the inoculation region, extending to the head and chest of the animal. During debridement, it was found that the lesion did not reach the underlying muscle tissue. In addition to the wound, the animal had upper eyelid palsy, lower lip, and auricular ptosis. Treatment with surgical debridement of devitalized tissue, topical application of ozonated sunflower oil, ketanserin, and a free skin graft was instituted. During hospitalization, the animal had a corneal ulcer in the left eye with an unfavorable prognosis due to paralysis of the upper eyelid, with enucleation of the affected eyeball. The animal was under veterinary care for 180 days and was discharged when his wound was already in an advanced stage of healing. Discussion: The history of the application of phenylbutazone intramuscularly and the location and characteristics of the lesion presented by the patient in the present report suggest that this animal presented aseptic tissue necrosis resulting from the administration of non-steroidal anti-inflammatory drugs, phenylbutazone. Although aseptic tissue necrosis, better known as Nicolau's syndrome or drug embolism cutis, is widely characterized and described in this species, there are studies in the literature that reproduce the syndrome in pigs and rabbits. Phenylbutazone was able to cause arterial damage, mainly in the tunica intima of the artery in which the medication was administered, with perivascular inflammatory infiltrate and subsequent skin necrosis at the site of administration. In addition to the skin lesion, the animal started to show signs compatible with the left facial nerve lesion, evidenced by the immobility of the upper eyelid and labial and ear ptosis. This resulted in corneal ulceration and subsequent enucleation. The animal also developed chewing difficulty in the first months of hospitalization. This dysfunction may be due to a lesion of the mandibular nerve, responsible for innervating the masticatory muscles and the oral mucosa. However, the animal showed improvement in this aspect, no longer showing this condition after 90 days of hospitalization. The treatment used was successful in healing the wound.

Estimation of genetic parameters and trends for morphometric traits in Brazilian Mangalarga Marchador horses

The objective of this work was to estimate genetic parameters and evaluate genetic trends over 26 years for morphometric traits in Mangalarga Marchador horses. Twelve morphometric traits were evaluated (withers and croup heights; length of head, body, shoulder, croup, neck, back, and loins; width of head and croup, and cannon bone and thorax perimeters). These traits were evaluated in 38,341 animals born between 1987 and 2012 and with a relationship matrix of 77,719 animals. Gibbs sampler was used to obtain samples of the posterior distributions of genetic parameters under animal models. Genetic trends were estimated by regression of estimated breeding values in function of birth year. The heritabilities of all traits were moderate to high and ranged from 0.27 to 0.48. However, the additive genetic coefficients of variation were low, ranging from 1.23 to 3.82%. The genetic trends of all the studied traits were significant, but of low magnitude. Negative genetic trend was observed for body length, while positive genetic trends were estimated for the other 11 traits. Although additive genetic differences accounted for a significant part of the phenotypic differences, genetic gains in the population were limited by low phenotypic variability. Therefore, it is necessary to develop data collection strategies to increase phenotypic and genetic variability in the population, such as the inclusion of animals that do not meet breed standard, but which have parents registered in the breeders' association, in the database.

Scrotal thermographic profile and seminal characteristics of Mangalarga Marchador stallions bred in the Atlantic Rainforest biome / [Perfil termográfico escrotal e características seminais de garanhões Mangalarga Marchador criados no bioma Mata Atlântica]

The objective of this study was to determine the scrotal thermographic profile and to verify the influence of temperature and humidity of the humid tropical climate on testicular temperature and seminal quality of Mangalarga Marchador stallions. The thermal profiles of the proximal, middle, and distal zones of the testicles and total surface temperature (TSTT) were recorded using an FLIR E60bx thermal imager. The average air temperature (°C) and relative humidity (%) were obtained 1, 5, 9, 33, and 66 days before semen collection and showed a mean value of 26.5±2.4 and 80.4±6.0 respectively. The scrotal surface temperature was close to 34°C and there was no variation with the age of the stallion, reproductive activity, and characteristics of the ejaculate (P>0.05). The only significant correlations obtained were between TSTT and minor defects (R = 0.41; P<0.05), between TSTT and total defects (R = 0.46; P<0.01), and between TSTT and percentage of morphologically normal sperm (R = -0.46; P<0.05). It was concluded that the Mangalarga Marchador stallions maintained the testicular temperature within favorable conditions for spermatogenesis, demonstrating the efficiency of testicular thermoregulation mechanisms in the Atlantic Forest biome.

O objetivo deste estudo foi determinar o perfil termográfico escrotal e verificar a influência da temperatura e da umidade do clima tropical úmido na temperatura testicular e na qualidade seminal de garanhões Mangalarga Marchador. Os perfis térmicos das zonas proximal, média e distal dos testículos e a temperatura da superfície total (TSTT) foram registrados usando-se um termovisor FLIR E60bx. A temperatura média do ar (° C) e a umidade relativa (%) foram obtidas um, cinco, nove, 33 e 66 dias antes da coleta de sêmen e apresentaram valor médio de 26,5 ± 2,4 e 80,4 ± 6,0, respectivamente. A temperatura da superfície escrotal foi próxima a 34°C, e não houve variação com a idade do garanhão, a atividade reprodutiva e as características do ejaculado (P>0,05). As únicas correlações significativas obtidas foram entre TSTT e defeitos menores (R=0,41; P<0,05), entre TSTT e defeitos totais (R=0,46; P<0,01), e entre TSTT e porcentagem de espermatozoides morfologicamente normais (R=-0,46; P<0,05). Concluiu-se que os garanhões Mangalarga Marchador mantiveram a temperatura testicular dentro de condições favoráveis para a espermatogênese, demonstrando a eficiência dos mecanismos de termorregulação testicular no bioma Mata Atlântica.

Supplement inclusion on post-weaning foals' (Mangalarga Marchador) diet with a protein supplement based on whey protein, glutamine, and lysine / Inclusão de suplemento proteico a base de whey protein, glutamina e lisina na dieta pós-desmame de potros mangalarga marchador

The objective of this study was to evaluate the partial replacement effect on body measurements (body mass, muscle thickness, and fat thickness) of the concentrated fraction of foals' diet with a protein supplement containing whey protein, glutamine, and lysine during the post-weaning period. Eighteen Mangalarga Marchador foals were randomly divided into two groups in the post-weaning phase, with nine animals each in the control group (CG) and the group receiving protein supplementation (WG). Based on 4% of their body weight (BW), the CG animals received a diet with roughage to concentrate in a ratio of 50:50, which composed of Cynodon sp. hay and a 15% crude protein (CP) commercial horse ration. The WG diet consisted of the same amount of hay used for the CG diet, half the amount of concentrate used in the CG diet, and 102 g of a protein supplement containing whey protein, glutamine, and lysine. During the experiment, five evaluations were performed, starting on the day of weaning (day 0), followed by evaluations conducted at 7, 14, 28, and 42 days after weaning. Body measurements, body mass, and thickness of the fat and muscle layers were assessed at each time point. The substitution of a portion of the commercial diet with protein supplement containing whey protein, glutamine, and lysine did not cause changes in the weight gain or linear measurements of Mangalarga Marchador foals during the post-weaning period; however, the change in diet increased muscle thickness and decreased fat thickness when compared to animals in the control group.(AU)

Objetivou-se com este estudo, avaliar a substituição de uma parte do concentrado da dieta por suplemento proteico contendo whey protein, glutamina e lisina sobre medidas corporais, massa corporal, espessura muscular e de gordura de potros da raça Mangalarga Marchador durante o pós desmame. Utilizou-se dezoito potros da raça Mangalarga Marchador, divididos aleatoriamente em dois grupos na fase pósdesmame, com 9 animais fazendo parte de Grupo Controle (GC) e outros 9 animais compondo o grupo que recebeu suplementação proteica (GW). Os animais do GC receberam uma dieta de proporção volumoso/ concentrado 50:50, considerando-se 4% do PV, composta por ração comercial com 15% PB e feno de Cynodon sp. A dieta do GW foi composta pela mesma quantidade de feno do GC, diferenciando-se na parte concentrada, que foi composta por 50% do concentrado oferecido ao grupo controle acrescido de 102g de suplemento proteico contendo whey protein, glutamina e lisina. Foram realizadas cinco etapas de avaliação de medidas corporais, massa corporal, espessura da camada de gordura e muscular, iniciando no dia do desmame (dia 0) e após 7, 14, 28 e 42 dias. A substituição de parte do concentrado comercial por suplemento proteico contendo whey protein, glutamina e lisina, não acarretou perdas em ganho de peso e medidas lineares de potros da raça Mangalarga Marchador durante o período de 42 dias após o desmame, mas promoveu ganhos em espessura muscular e diminuição de espessura de gordura quando comparados aos animais do grupo controle.(AU)

Hematological responses to hyperimmune plasma low dose administration in foals during weaning / Respostas hematológicas da administração de baixa dose de plasma hiperimune em potros no período de desmame

Weaning is a development stage that brings maternal independence, change of management and feeding, leading to immune deficit. The objective of this study was to evaluate the hematological and biochemical parameters of foals in weaning phase after intravenous administration of hyperimmune plasma (1 mL/Kg) in low dose. Ten foal weaned from the Mangalarga Machador breed were used, being divided in control (GC; n=5) and treated group (GT; n=5). The results obtained show that hematological and biochemical parameters of foals that received low doses of hyperimmune plasma were within the reference range for the equine species.

O desmame é uma fase do desenvolvimento que traz independência materna, mudança de manejo e alimentação, levando ao déficit imunológico. O objetivo deste estudo foi avaliar os parâmetros hematológicos e bioquímicos de potros em fase de desmame após administração intravenosa de plasma hiperimune (1 mL / Kg) em baixa dose. Foram utilizados dez potros des-mamados da raça Mangalarga Machador, sendo divididos em grupo controle (GC; n = 5) e grupo tratado (GT; n = 5). Os resul-tados obtidos mostram que os parâmetros hematológicos e bioquímicos de potros que receberam baixas doses de plasma hiperi-mune estavam dentro da faixa de referência para a espécie equina.

Hematological responses to hyperimmune plasma low dose administration in foals during weaning / Respostas hematológicas da administração de baixa dose de plasma hiperimune em potros no período de desmame

Weaning is a development stage that brings maternal independence, change of management and feeding, leading to immune deficit. The objective of this study was to evaluate the hematological and biochemical parameters of foals in weaning phase after intravenous administration of hyperimmune plasma (1 mL/Kg) in low dose. Ten foal weaned from the Mangalarga Machador breed were used, being divided in control (GC; n=5) and treated group (GT; n=5). The results obtained show that hematological and biochemical parameters of foals that received low doses of hyperimmune plasma were within the reference range for the equine species.(AU)

O desmame é uma fase do desenvolvimento que traz independência materna, mudança de manejo e alimentação, levando ao déficit imunológico. O objetivo deste estudo foi avaliar os parâmetros hematológicos e bioquímicos de potros em fase de desmame após administração intravenosa de plasma hiperimune (1 mL / Kg) em baixa dose. Foram utilizados dez potros des-mamados da raça Mangalarga Machador, sendo divididos em grupo controle (GC; n = 5) e grupo tratado (GT; n = 5). Os resul-tados obtidos mostram que os parâmetros hematológicos e bioquímicos de potros que receberam baixas doses de plasma hiperi-mune estavam dentro da faixa de referência para a espécie equina.(AU)

Adiposity and weight gain in Mangalarga Marchador horses subjected to hypercaloric diet

ABSTRACT: In recent years, several researchers have been studying obesity in national horse breeds; however, no studies demonstrating the dynamic of body and regional fat accumulation (adiposity) Mangalarga Marchador horses subjected to hypercaloric diets have been found. This study aimed to characterize the deposition of body and regional fat in horses with diet-induced weight gain. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9 ±1/9 (mean ±SD) were subjected to a hypercaloric, grain-rich diet for five months. Body weight and the following morphometric regional adiposity variables were analyzed: BCS, cresty neck scores (CNS), neck circumferences (NC) at 25, 50 and 75% of its length, and accumulation of subcutaneous adipose tissue at the base of the tail using ultrasonography (BTU). These data were collected at baseline and fortnightly after beginning the diet-induced weight gain until the end of the experiment. The effect of time on the variables was verified by analysis of variance (ANOVA) in randomized blocks or the Friedmans test, and the means were compared by the Tukeys test (p0.05). Exposure to hypercaloric diet promoted a mean weight gain of 27.45% (p 0.001). Significant values were observed for NC at 25 and 75% during the first 45 days of the experiment, and for NC at 50% during the first 30 days. BTU presented significant changes after 60 days, with an increase of 268% compared with the baseline value. These findings demonstrate the weight gain and the dynamic and magnitude of regional adiposity in Mangalarga Marchador horses subjected to hypercaloric diet.

RESUMO: Nos últimos anos vários pesquisadores têm estudado obesidade em raças nacionais, contudo não se encontram estudos que demonstrem a dinâmica do acúmulo de gordura corporal e regional em equinos marchadores submetidos a dietas hipercalóricas. O objetivo deste trabalho foi caracterizar a deposição de gordura corporal e regional em equinos com obesidade induzida. Foram utilizados nove equinos adultos, Mangalarga Marchador com escore de condição corporal (ECC) inicial de 2,9±1/9 (média±DP) submetidos a dieta hipercalórica por 5 meses. Foram avaliados o peso corporal, e as variáveis de adiposidade como o ECC, escore de acúmulo de gordura na crista de pescoço (ECP), circunferência do pescoço a 25%, 50% e 75% de seu comprimento e o acúmulo de gordura subcutânea na base da cauda por ultrassonografia (UBC). Coletados antes do início do experimento e quinzenalmente após o início da indução do ganho de peso. O efeito do tempo sobre as variáveis foi verificado por análise de variância em blocos ao acaso ou teste de Friedman e as médias foram comparadas pelo teste de Tukey (P0,05). O tratamento promoveu aumento médio de peso de 27,45% (P 0,001). Já as circunferências de pescoço 25% e 75% apresentaram valores significativos nos 45 dias de experimento e a circunferência a 50% se destacou nos primeiros 30 dias. A UBC apresentou alterações significativas aos 60 dias de experimento, com um acréscimo de 268% em relação ao valor basal. Tais achados demonstram o ganho de peso, a dinâmica e a magnitude do acúmulo de gordura localizada em equinos Mangalarga Marchador submetidos à dieta hipercalórica.

Adiposity and weight gain in Mangalarga Marchador horses subjected to hypercaloric diet / Adiposidade e ganho de peso em equinos Mangalarga Marchador submetidos a dieta hipercalórica

In recent years, several researchers have been studying obesity in national horse breeds; however, no studies demonstrating the dynamic of body and regional fat accumulation (adiposity) Mangalarga Marchador horses subjected to hypercaloric diets have been found. This study aimed to characterize the deposition of body and regional fat in horses with diet-induced weight gain. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9 ±1/9 (mean ±SD) were subjected to a hypercaloric, grain-rich diet for five months. Body weight and the following morphometric regional adiposity variables were analyzed: BCS, cresty neck scores (CNS), neck circumferences (NC) at 25, 50 and 75% of its length, and accumulation of subcutaneous adipose tissue at the base of the tail using ultrasonography (BTU). These data were collected at baseline and fortnightly after beginning the diet-induced weight gain until the end of the experiment. The effect of time on the variables was verified by analysis of variance (ANOVA) in randomized blocks or the Friedman's test, and the means were compared by the Tukey's test (p≤0.05). Exposure to hypercaloric diet promoted a mean weight gain of 27.45% (p<0.001). Significant values were observed for NC at 25 and 75% during the first 45 days of the experiment, and for NC at 50% during the first 30 days. BTU presented significant changes after 60 days, with an increase of 268% compared with the baseline value. These findings demonstrate the weight gain and the dynamic and magnitude of regional adiposity in Mangalarga Marchador horses subjected to hypercaloric diet.(AU)

Nos últimos anos vários pesquisadores têm estudado obesidade em raças nacionais, contudo não se encontram estudos que demonstrem a dinâmica do acúmulo de gordura corporal e regional em equinos marchadores submetidos a dietas hipercalóricas. O objetivo deste trabalho foi caracterizar a deposição de gordura corporal e regional em equinos com obesidade induzida. Foram utilizados nove equinos adultos, Mangalarga Marchador com escore de condição corporal (ECC) inicial de 2,9±1/9 (média±DP) submetidos a dieta hipercalórica por 5 meses. Foram avaliados o peso corporal, e as variáveis de adiposidade como o ECC, escore de acúmulo de gordura na crista de pescoço (ECP), circunferência do pescoço a 25%, 50% e 75% de seu comprimento e o acúmulo de gordura subcutânea na base da cauda por ultrassonografia (UBC). Coletados antes do início do experimento e quinzenalmente após o início da indução do ganho de peso. O efeito do tempo sobre as variáveis foi verificado por análise de variância em blocos ao acaso ou teste de Friedman e as médias foram comparadas pelo teste de Tukey (P≤0,05). O tratamento promoveu aumento médio de peso de 27,45% (P<0,001). Já as circunferências de pescoço 25% e 75% apresentaram valores significativos nos 45 dias de experimento e a circunferência a 50% se destacou nos primeiros 30 dias. A UBC apresentou alterações significativas aos 60 dias de experimento, com um acréscimo de 268% em relação ao valor basal. Tais achados demonstram o ganho de peso, a dinâmica e a magnitude do acúmulo de gordura localizada em equinos Mangalarga Marchador submetidos à dieta hipercalórica.(AU)

Adiposity and weight gain in Mangalarga Marchador horses subjected to hypercaloric diet / Adiposidade e ganho de peso em equinos Mangalarga Marchador submetidos a dieta hipercalórica

In recent years, several researchers have been studying obesity in national horse breeds; however, no studies demonstrating the dynamic of body and regional fat accumulation (adiposity) Mangalarga Marchador horses subjected to hypercaloric diets have been found. This study aimed to characterize the deposition of body and regional fat in horses with diet-induced weight gain. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9 ±1/9 (mean ±SD) were subjected to a hypercaloric, grain-rich diet for five months. Body weight and the following morphometric regional adiposity variables were analyzed: BCS, cresty neck scores (CNS), neck circumferences (NC) at 25, 50 and 75% of its length, and accumulation of subcutaneous adipose tissue at the base of the tail using ultrasonography (BTU). These data were collected at baseline and fortnightly after beginning the diet-induced weight gain until the end of the experiment. The effect of time on the variables was verified by analysis of variance (ANOVA) in randomized blocks or the Friedman's test, and the means were compared by the Tukey's test (p≤0.05). Exposure to hypercaloric diet promoted a mean weight gain of 27.45% (p<0.001). Significant values were observed for NC at 25 and 75% during the first 45 days of the experiment, and for NC at 50% during the first 30 days. BTU presented significant changes after 60 days, with an increase of 268% compared with the baseline value. These findings demonstrate the weight gain and the dynamic and magnitude of regional adiposity in Mangalarga Marchador horses subjected to hypercaloric diet.(AU)

Nos últimos anos vários pesquisadores têm estudado obesidade em raças nacionais, contudo não se encontram estudos que demonstrem a dinâmica do acúmulo de gordura corporal e regional em equinos marchadores submetidos a dietas hipercalóricas. O objetivo deste trabalho foi caracterizar a deposição de gordura corporal e regional em equinos com obesidade induzida. Foram utilizados nove equinos adultos, Mangalarga Marchador com escore de condição corporal (ECC) inicial de 2,9±1/9 (média±DP) submetidos a dieta hipercalórica por 5 meses. Foram avaliados o peso corporal, e as variáveis de adiposidade como o ECC, escore de acúmulo de gordura na crista de pescoço (ECP), circunferência do pescoço a 25%, 50% e 75% de seu comprimento e o acúmulo de gordura subcutânea na base da cauda por ultrassonografia (UBC). Coletados antes do início do experimento e quinzenalmente após o início da indução do ganho de peso. O efeito do tempo sobre as variáveis foi verificado por análise de variância em blocos ao acaso ou teste de Friedman e as médias foram comparadas pelo teste de Tukey (P≤0,05). O tratamento promoveu aumento médio de peso de 27,45% (P<0,001). Já as circunferências de pescoço 25% e 75% apresentaram valores significativos nos 45 dias de experimento e a circunferência a 50% se destacou nos primeiros 30 dias. A UBC apresentou alterações significativas aos 60 dias de experimento, com um acréscimo de 268% em relação ao valor basal. Tais achados demonstram o ganho de peso, a dinâmica e a magnitude do acúmulo de gordura localizada em equinos Mangalarga Marchador submetidos à dieta hipercalórica.(AU)

Insulin dysregulation in horses with induced obesity

ABSTRACT: Insulin deregulation (ID) is a central player in the pathophysiology of equine metabolic syndrome (EMS), which is associated with generalized and/or regional obesity. The objective of this experiment was to characterize the alterations in the hormonal profile in horses exposed to a hypercaloric diet. A total of nine Mangalarga Marchador adult horses with initial body condition score (BCS) of 2.9±1/9 (mean±SD) were submitted to a high calorie grain-rich diet for 5 months. The data was collected before the start of the experiment and every 15 days until the end of the experiment and glucose and insulin concentrations were measured in the plasma. Proxies G:I, RISQI, HOMA-IR and MIRG were calculated. The low-dose oral glucose tolerance test (OGTT) was performed and the total area under the glucose (GTA) and insulin (ITA) curves at three different timepoints (before inducing obesity, after 90 days and after 150 days) was used. Analysis of variance of the results was performed considering the time effects and the means were compared with repeated measures by the Tukeys test (P0.05). The ID was observed during the first 90 days of the experiment and was characterized as a decompensated ID, showing an increase of basal glucose and insulin plasma levels, changes in all proxies and a significant increase in GTA (P 0.001) and ITA (P 0.05). However, a clear compensation of the ID was evident after 150 days of experiment, which was supported by data from the insulin secretory response of cells of the pancreas that showed an increase in insulin plasma levels, after fasting or exposure to gastric glucose, with a concomitant decrease in fasting glucose and fructosamine levels, and a decrease of GTA and marked increase of ITA (P 0.0001) in the dynamic test. These findings confirm the occurrence of hyperinsulinemia associated with insulin deregulation in Mangalarga Marchador horses exposed to hypercaloric diets.

RESUMO: A desregulação insulínica (DI) é o ponto central dos mecanismos fisiopatológicos da síndrome metabólica equina (SME), que é associada à obesidade generalizada e/ou regional. O objetivo deste experimento foi caracterizar as alterações no perfil hormonal em equinos submetidos à dieta hipercalórica. Foram utilizados nove equinos Mangalarga Marchador adultos com escore corporal (EC) médio (±DP) inicial de 2,9±1 (escala de 1-9) submetidos à dieta hipercalórica atingindo um EC de 8,3±1 após cinco meses. Os dados foram coletados antes do início do experimento e com o intervalo de 15 dias até o final do experimento, os valores plasmáticos foram obtidos para mensuração das concentrações de glicose e insulina. Foram calculados os proxies G:I, RISQI, HOMA-IR e o MIRG. Foi realizado o teste de baixa dose de glicose oral (TBDGO) utilizando a área total sob a curva de glicose (ATG) e insulina (ATI) em três momentos, antes da indução a obesidade, após 90 e 150 dias. Os resultados foram submetidos à análise de variância considerando-se os efeitos de tempo e as médias comparadas com medidas repetidas pelo teste de Tukey, com o valor P0,05. A DI foi observada nos primeiros 90 dias de experimento, se caracterizando como um quadro de DI descompensada, apresentando um aumento dos níveis plasmáticos basais de glicose e insulina, pelas alterações em todos os proxies e com um aumento significativo da ATG (P 0,001) e ATI (P 0,05). Contudo, ficou evidente uma compensação do quadro de DI após 150 dias de experimento, sendo demonstrado pelos dados da resposta secretória insulínica das células do pâncreas, que se manifestaram pelo aumento dos níveis plasmáticos de insulina pós-jejum ou exposição à glicose gástrica com concomitante redução nos níveis de glicose e frutosamina pós-jejum e pela redução da ATG e pela marcada elevação de ATI (P 0,0001) no teste dinâmico. Tais achados comprovam a ocorrência de hiperinsulinemia associada à desregulação insulínica em equinos Mangalarga Marchador expostos a dietas à dieta hipercalórica.