ABSTRACT The objective of this study was to assess a training protocol employed in the Brazilian Northeast region for fitness conditioning of vaquejada horses. For 12 months, 24 Quarter Horses were evaluated under a completely randomized split-plot experimental design in which the plots comprised three age groups: horses at two, three, and four years of age. The split plots were made up of six fitness tests carried out every other month. The fitness test protocol consisted of five levels of protocol exercises on a standard vaquejada track. Prior to the tests with fasted animals, we collected blood samples to determine muscle enzymes (aspartate aminotransferase, creatine kinase, and lactate dehydrogenase). During the tests, heart rate, speed, and distance run were recorded using a heart rate monitor. Next, the results were used to calculate speed at which each horse reached 150 bpm (V150), speed at which each horse reached 200 bpm (V200), maximum heart rate (HRmax), maximum speed (Vmax), recovery time needed for the heart rate of horses to return to half the maximum value reached during the fitness tests (HR50%), and recovery time needed for the heart rate of horses to return to baseline values (HRbasal). No difference was found among the age groups for V150, HRmax, Vmax, HR50%, HRbasal, or muscle enzymes. By the final stage of training, the V200 of the three-year-old horses was higher than that of the four-year-old foals. During training, all groups exhibited increases in serum concentrations of muscle enzymes and reductions in efficiency to recover heart rate after exercise. The training protocol assessed is unable to maintain proper fitness for competitions throughout the year.

RESUMO: Objetivou-se analisar as alterações demográficas e biométricas dos animais registrados da raça Mangalarga, ao longo das décadas. Foram utilizadas informações de 206.428 equinos Mangalarga, extraídas do sistema de registro genealógico da Associação Brasileira de Criadores de Cavalos da Raça Mangalarga. Dos animais nascidos entre 1930 e 2018, foram consideradas informações referentes ao sexo, data de nascimento, pelagem, localização do criatório, pontuação obtida no ato do registro genealógico e três medidas corporais dos equinos. Utilizando a medida de altura à cernelha e os perímetros torácico e de canela foram calculados cinco índices morfométricos. Os resultados foram submetidos à análise de variância, utilizando delineamento inteiramente ao acaso em esquema de parcelas subdivididas, sendo as parcelas compostas pelos sexos e as subparcelas constituídas pelas décadas de seleção. Entre 1930 e 1990 houve aumento progressivo na emissão de registros genealógicos, com destaque para as décadas de 70 e 80, quando se registrou maior taxa de crescimento do rebanho. Em 2018 identificou-se criatórios da raça Mangalarga em 23 estados brasileiros, sendo o Estado de São Paulo detentor do maior rebanho, seguido de Minas Gerais e Bahia. Entre 1970 e 2018 registrou-se aumento na altura à cernelha das fêmeas, garanhões e machos castrados, que se tornaram 5,1 cm, 3,1 cm e 2,1 cm mais altos, respectivamente. Enquanto o perímetro torácico dos garanhões aumentou 3,3 cm, o perímetro de canela das fêmeas reduziu 0,34 cm. Concluiu-se que a raça Mangalarga está distribuída por todo o Brasil, com destaque para a região sudeste. Independente do sexo, a seleção aplicada à raça tornou os equinos Mangalarga mais altos. Além disso, os garanhões ficaram mais pesados e com maior perímetro torácico e as fêmeas tornaram-se hipométricas.

ABSTRACT: This study analyzed the demographic and biometric changes in registered animals of the Mangalarga breed over the decades. Information from 206,428 Mangalarga horses born between 1930 and 2018 extracted from the genealogic registry system of the Associação Brasileira de Criadores de Cavalos da Raça Mangalarga was employed. The data referred to sex, birth date, fur coat, breeding site location, score achieved at genealogic registration, and three body measurements. Height at withers and the thoracic and cannon bone circumferences were used to calculate five morphometric indices. Results were submitted to analysis of variance using a completely randomized split-plot design where the plots comprised the sexes and the split-plots comprised the decades of selection. Between 1930 and 1990, genealogic registrations progressively increased, particularly in the 1970s and 80s, when the herd experienced the highest growth rate. In 2018, Mangalarga breeding sites were reported in 23 Brazilian states and the states of São Paulo, Minas Gerais, and Bahia held the largest herds. Between 1970 and 2018, the height at withers of mares, stallions, and geldings increased by 5.1, 3.1, and 2.1 cm, respectively. The thoracic circumference of stallions increased by 3.3 cm and the cannon bone circumference of mares decreased by 0.34 cm. It is concluded that the Mangalarga breed is found across Brazil, especially in the Southeast region. Irrespective of sex, the selection of the breed has led to taller Mangalarga horses. In addition, the stallions became heavier and gained thoracic circumference, while mares became hypometric.

ABSTRACT The present study used mobile bags to estimate horse nutrient digestibility of tropical grasses found in semi-arid areas of the Brazilian Northeast region. Five female mixed-breed horses with a mean weight of 400±23 kg were assigned to a 5×5 Latin square design with five periods of seven days and five grasses: Tifton 85 hay ( Cynodon spp. ), sixweeks threeawn ( Aristida adscensionis Linn.), Alexandergrass ( Brachiaria plantaginea (Link) Hitchc), capim-de-raiz ( Chloris orthonoton Doell), and Sabi grass ( Urochloa mosambicensis ). The nutrient content of forages was determined prior to inoculation in horses and after recovery of mobile bags from feces. The digestibility coefficients were determined from the difference between the inoculated and recovered material. The dry matter, organic matter, mineral matter, crude protein, neutral detergent fiber, and acid detergent fiber contents of the grass species were analyzed. Digestibility data were subjected to analysis of variance using the Statistical Analysis System (SAS, version 9.0) software. Higher dry matter digestibility coefficients were observed in Tifton 85 (74.61%), Alexandergrass (74.30%), and capim-de-raiz (68.88%) than in sixweeks threeawn (48.40%) and Sabi grass (52.89%). The highest crude protein digestibility coefficients were found for Alexandergrass (95.70%), Tifton 85 (93.50%), and sixweeks threeawn (93.35%). Sixweeks threeawn had lower apparent mineral matter digestibility than the other grasses. The digestibility coefficients of Alexandergrass and capim-de-raiz indicate that those grasses have potential to be used in equine feed.

ABSTRACT This study aimed to determine the participation frequency and competitive performance of Campolina and Mangalarga Marchador horses in national shows concerning marcha type, sex, and age. To that end, the trial results of national horse shows between 2007 and 2017, comprising 1,781 Campolina and 5,239 Mangalarga Marchador animals, were extracted from the databases of the breeders’ associations of each breed. The results regarding participation frequency in these events and the performance achieved by horses were grouped by breed, marcha type, sex, and age group and then subjected to frequency distribution tests. In both breeds, most animals attended only one national show. However, when the specimens were separated by marcha type, sex, and age, it was observed that 54.39% of marcha batida Campolina males competed twice, with greater participation of adult horses (41.41%) than of young ones (22.22%). For Mangalarga Marchador, irrespective of gait type, the proportion of adult horses (67.22%) that competed was higher than that of young ones (25.63%). For marcha picada competitors, the proportion between young (13.97%) and adult (81.91%) was even higher. It was concluded that, over their competitive careers, most horses of either breed attended only one national show, that marcha picada animals usually compete only when adults, and that marcha batida females compete more often when young. In addition, the age group in which competitors achieve their best performances varies according to the specimen.

Resumo: O objetivo deste trabalho foi avaliar o efeito da anemia infecciosa equina (AIE) no desempenho físico de equinos da região do Pantanal brasileiro. Foram avaliados 16 machos, divididos em dois grupos: 8 soronegativos (G1) e 8 soropositivos (G2) para AIE. Dois testes de esforço progressivo foram realizados, antes (T1) e após (T2) 42 dias de treinamento. Foram registrados frequência cardíaca, concentração de lactato, distância percorrida e níveis de hematócrito. Em ambos os testes, o G1 percorreu uma distância maior. No T2, o G2 apresentou menores níveis de hematócrito e menor velocidade obtida a diferentes concentrações de lactato e frequências cardíacas. O desempenho atlético dos equídeos avaliados é afetado pela anemia infecciosa equina.

Abstract: The objective of this work was to evaluate the effects of equine infectious anemia (EIA) on the physical performance of equines from the Brazilian Pantanal region. A total of 16 males were evaluated, divided into two groups: 8 seronegative (G1) and 8 seropositive (G2) for EIA. Two graded exercise tests were carried out before (T1) and after (T2) 42 days of training. Heart rate, lactate concentration, distance covered, and hematocrit level were recorded. In both tests, G1 covered a greater distance. In T2, G2 had lower hematocrit levels and lower speeds reached at different lactate concentrations and heart rates. The athletic performance of the evaluated equines is affected by equine infectious anemia.

ABSTRACT This study aimed to verify whether the criterion of exhibition contests adopted for Campolina and Mangalarga Marchador breeds has been successful in recent years, i.e., if the subsequent generations have the morphology recommended by the standard of the breed allied with high-quality marcha, a four-beat ambling gait. The classifications achieved by each horse during national horse shows in morphology and gait contests underwent Spearman's correlation to verify the number of contests with a correlation between the classifications in the two judgments and those with no correlation. Next, the number of contests with or without such correlation underwent a frequency distribution test considering the variables breed, year, age, marcha category, and sex. Spearman's correlation coefficient (r) of contests with a correlation was also used as a parameter. A difference was observed among years of evaluation only for Mangalarga Marchador horses, with a greater number of contests with correlations between morphological and ambling gait performances between 1998 and 2004. On both breeds, the correlation was found in more contests among foals than adult horses. When Spearman's correlation coefficients were compared, Campolina contests exhibited a higher r than Mangalarga Marchador, 68.14 and 63.68%, respectively. Only Mangalarga Marchador males had higher r value than females, 67.27 and 59.73%, respectively. The contest criterion adopted by Campolina and Mangalarga Marchador associations to select superior individuals does not correlate, in subsequent generations, with the morphology recommended by the standard of the breeds with high-quality marcha progress in the same individuals.

ABSTRACT The objective of this study was to examine serum retinol and some mineral (zinc, iron, calcium, phosphorus, magnesium, and copper) levels in seven Mangalarga Marchador colts aged 329.48 days, reared on pasture in the city of Montes Claros, MG, Brazil, during the dry season. Equines were evaluated for four periods of 45 days during the total study period of five months. The foals had access to Panicum maximum cv. Tanzania pasture, while water and mineral salt lick were provided ad libitum. Blood samples were taken to determine serum retinol and levels of minerals, along with pasture samples to quantify beta-carotene in the grass. The results indicated that retinol levels varied (2.87 to 1.97 µg/dL) and remained below the standard levels. The levels of zinc, iron, calcium, and phosphorus did not vary significantly with average values of 36.79 µg/dL, 77.32 µg/dL, 10.33 mg/dL, and 9.99 mg/dL, respectively. However, zinc and calcium remained below standard concentrations of 60-120 µg/dL and 10.8-13.5 mg/dL, respectively, since the beginning of the study. On the other hand, copper and magnesium levels decreased over time (97.76 to 77.56 mg/dL and 2.86 to 2.21 µg/dL, respectively), but showed normal levels for horses during the research. Beta-carotene in grass showed a downward trend over time from 38.53 to 0.09 mg/kg of dry matter. The results also indicated a significant relationship between serum retinol and serum copper levels. Vitamin A supplementation is necessary whenever foals are fed pastures during the dry season.

RESUMO: A raça Mangalarga Marchador é responsável pelo maior rebanho de equinos do país e tem alcançado crescente expansão nacional e internacional. Apesar disso, é escassa a produção científica sobre a evolução dessa raça e não existem estudos sobre as transformações morfométricas que ocorreram ao longo de sua formação. Neste contexto, o presente estudo objetivou avaliar a evolução das medidas morfométricas da raça Mangalarga Marchador entre 1970 e 2010. Foram utilizadas informações arquivadas na Associação Brasileira dos Criadores do Cavalo Mangalarga Marchador de 23148 machos e 92980 fêmeas, em delineamento experimental inteiramente ao acaso. Os seis tratamentos foram constituídos pelos animais mensurados de 1970 a 1979, 1980 a 1989, 1990 a 1994, 1995 a 1999, 2000 a 2004 e 2005 a 2010, respectivamente. As medidas avaliadas foram: alturas na cernelha e garupa, comprimentos da cabeça, pescoço, dorso-lombo, garupa, espádua e corpo, larguras da cabeça e da garupa, além de perímetros torácico e da canela. Ao longo do período avaliado observou-se nos machos e fêmeas redução do perímetro torácico, dos comprimentos da cabeça, dorso-lombo, garupa e espádua e das larguras de cabeça e garupa. Nos machos houve também redução no comprimento do pescoço e aumento no perímetro da canela. Nas fêmeas verificou-se aumento no comprimento do corpo. Ao longo do tempo, a seleção da raça conferiu aos animais menor cabeça, maior estatura e menor comprimento do tronco. No entanto, houve redução de medidas importantes para sua funcionalidade, como o comprimento da espádua e do perímetro torácico.

ABSTRACT: The Mangalarga Marchador breed accounts for the largest horse herd in Brazil and has been experiencing national and international expansion. Nevertheless, there is little scientific production on the evolution of this breed and there are no studies on the morphometric transformations that took place during its formation. In this context, the present study aimed to assess the evolution in morphometric measures of the Mangalarga Marchador breed between 1970 and 2010. The research used information archived at the Brazilian Association of Mangalarga Marchador Breeders from 23,148 males and 92,980 females in a completely randomized experimental design. The six treatments consisted of the animals measured between 1970 and 1979, 1980 and 1989, 1990 and 1994, 1995 and 1999, 2000 and 2004, and 2005 and 2010, respectively. The measures assessed were: height at withers and croup, length of the head, neck, back, croup, shoulder, and body, width of the head and croup, thoracic circumference, and cannon circumference Over the period analyzed, males and females experienced a reduction in thoracic circumference, in the lengths of the head, back, croup, and shoulder, and in the widths of the head and croup. In the males, neck length and cannon circumference also decreased, while body length increased in females. Over time, breed selection led to smaller head, higher stature, and shorter trunk length. However, important measures for the breed's functionality, such as shoulder length and thoracic circumference, decreased.

The objective of this study was to assess the effects of supplementation with Saccharomyces cerevisiae on the performance of Mangalarga Marchador equines and to verify the effectiveness of the aerobic training protocol adopted. The study used 14 Mangalarga Marchador mares in a completely randomized split-plot design. The plots were made up of two treatments (groups Probiotic and Control) and the split plots comprised two maximal-effort physical tests applied both before and after the six weeks of training. The animals' spirometric parameters, heart rate, and plasma lactate levels were assessed. No difference was found between the Probiotic and Control groups in any of the parameters assessed. A difference was found in the physical tests for time-to-fatigue, aerobic and anaerobic thresholds, speed at which plasma lactate levels reached 2 and 4 mmol/L, speed at which the heart rate reached 200 bpm, and the lactate level at 30 min of the recovery period. Supplementation with Saccharomyces cerevisiae has no effect on physical conditioning of Mangalarga Marchador mares and the aerobic training protocol adopted increases the animals' aerobic and anaerobic capacity.

Objetivou-se comparar as medidas morfométricas do rebanho atual de fêmeas Mangalarga Marchador (MM) com os exemplares campeões. O delineamento experimental foi inteiramente ao acaso, sendo os tratamentos constituídos pelo rebanho atual de fêmeas da raça MM, representado por todas as éguas registradas entre 2000 e 2012 que tiveram suas medidas armazenadas no banco de dados do Serviço de Registro Genealógico da Associação Brasileira de Criadores do Cavalo Mangalarga Marchador, totalizando 51993 animais; e pelas campeãs da raça, representadas por 266 animais campeões. Foram avaliadas a altura na cernelha e na garupa, comprimento da cabeça, pescoço, espádua, dorsolombo, garupa e corpo, largura da cabeça e da garupa e perímetro torácico e da canela. As medidas lineares foram relacionadas ao comprimento da cabeça, de acordo com o Sistema Eclético de Proporções. Os resultados das 12 medidas lineares foram submetidos à análise de variância e as médias comparadas pelo teste de Fisher (p<0,05). Em relação ao rebanho atual de fêmeas MM, as éguas campeãs da raça apresentaram maior comprimento da cabeça, corpo, pescoço, dorso-lombo e garupa, altura na cernelha e na garupa, largura da garupa e perímetro torácico e da canela. Concluiu-se que embora apresentem maiores medidas lineares, as éguas campeãs MM são proporcionalmente semelhantes ao rebanho atual de fêmeas da raça.

The study aimed to compare the morphometric measures of the current herd Mangalarga Marchador (MM) female with champions breed, using as parameters the breed standard and the Eclectic System of Proportions for saddle horse. The experimental design was randomized, and the treatments were the current herd MM female, represented by all mares registered between 2000 and 2012 that had your measurements stored in the database service studbook of breed, totaling 51993 animals, and the champions breed, represented by 266 mares champions. Were evaluated measures of height at withers and at rump, length of the head, neck, dorse, rump, shoulder and body, width of head and of rump, thoracic perimeter and cannon perimeter. The mean linear measurements were related to the length of the head, according to Eclectic System of Proportions. The results were submitted to analysis of variance and the means were compared by Fisher's test (p<0.05). Regarding the current herd of females MM, the champions breed showed greater length of the head, body, neck, dorse and rump, height at withers and at rump, width of rump and thoracic and cannon perimeter. It was concluded that although larger, the champions Mangalarga Marchador mares are proportionally similar to the current herd.

A raça Mangalarga Marchador (MM), valorizada por apresentar como andamento a marcha, vem se destacando nas atividades funcionais, como as provas de marcha. Considerando a escassez de informações sobre a fisiologia esportiva dos equinos marchadores, a elaboração de protocolos de treinamento e de testes físicos torna-se fundamental e, nesse contexto, as concentrações dos gases e eletrólitos sanguíneos constituem informações adicionais para o monitoramento das alterações metabólicas induzidas pelo exercício. Objetivou-se avaliar as respostas hemogasométricas e a concentração sanguínea de eletrólitos de éguas MM, durante teste de esforço máximo em esteira, realizado antes e após o treinamento - ensaio 1 e entre um teste de esforço máximo em esteira e um teste de intensidade crescente a campo - ensaio 2. Foram avaliadas a concentração plasmática de lactato, o pH sanguíneo, as pressões sanguíneas de oxigênio e de dióxido de carbono, as concentrações sanguíneas dos íons bicarbonato, sódio (Na+), potássio (K+) e cálcio (Ca++). O delineamento foi em blocos ao acaso em esquema de parcelas subdivididas. No primeiro ensaio, as distâncias percorridas pelos equinos nos testes antes e após o treinamento resultaram em redução (p<0,05) do pH sanguíneo e na concentração de Ca++ e aumento (p<0,05) nas concentrações de K+ e Na+. No segundo ensaio, a influência do tipo de teste realizado e a temperatura ambiental resultaram em redução (p<0,05) do pH sanguíneo e aumento (p>0,05) nas concentrações de K+ e Ca++. Após o treinamento, éguas MM apresentam alterações mais intensas do pH e das concentrações dos eletrólitos.

The Mangalarga Marchador (MM) breed, valued for its marcha pace, has been excelling in functional activities such as marcha course. Considering the lack of information about sports physiology of the marcha horses, the development of training protocols and physical testing becomes essential and, in this context, the concentrations of blood gases and electrolytes provide additional information for the monitoring of metabolic changes induced by exercise. The goal of the study was to assess the hemogasometric responses and blood electrolyte concentration in MM mares during maximal effort treadmill tests carried out before and after training (trial 1) and between a maximal effort treadmill test and an incremental field test (trial 2). The trials assessed plasma lactate concentration, blood pH, oxygen and carbon dioxide blood pressures, and blood concentrations of the ions bicarbonate, sodium (Na+), potassium (K+), and calcium (Ca++). The study followed a randomized block in a split-plot design. In the first trial, the distances walked by the equines in the tests before and after training caused decrease (p<0.05) in pH and Ca++ concentration and increase in the concentrations of K+ and Na+. In the second trial, the influence of the type of test and the ambient temperature caused decrease (p<0.05) in pH and increase in the concentrations of K+ and Ca++. After training, MM mares had greater changes in pH and electrolyte concentrations.

O trabalho avaliou o efeito da suplementação com leveduras na dieta de equinos em treinamento, sobre a digestibilidade dos nutrientes e o desempenho metabólico dos animais. Doze equinos foram distribuídos em 2 grupos: Pr (equinos que receberam 20 g de probióticos diariamente) e Controle. A dieta foi composta de volumoso (haylage) e concentrado comercial e todos os equinos foram treinados durante 6 semanas. A digestibilidade dos nutrientes foi avaliada utilizando o indicador LIPE® (7 dias) e a coleta de fezes foi realizada durante cinco dias. Foi analisado MS, PB, DE, P, FDN, FDA, HCEL e lignina. Antes e após o treinamento, todos os cavalos foram submetidos a um teste incremental ergoespirométrico. Os equinos que receberam leveduras vivas apresentaram um aumento (p <0,05) de 4,1% na digestibilidade da HCEL. Após o treinamento, ambos os grupos apresentaram maior tolerância à fadiga, com um aumento na AT e no VO2max. O treinamento melhorou o desempenho dos animais, e a digestibilidade da hemicelulose e DE foi maior no grupo Pr, mas esses aumentos não melhoraram o desempenho desses animais.

This research analyses the yeast supplementation effect on the digestibility of nutrients and metabolic performance in training horses. Twelve horses were assigned into 2 groups: Pr (20 g of probiotics daily per horse) and control. The diet consisted of roughage (haylage) and commercial rations and all horses were trained for 6 weeks. LIPE® indicator was used during 7 days and feces collected for five days to determine nutrient digestibility. DM, CP, DE, P, NDF, ADF, HCEL and lignin were determined. All horses were subjected to incremental ergospirometry test before and at the end of training. Horses that received live yeast showed an increase (p<0.05) of 4.1% in the digestibility of HCEL. After training, both horse groups presented higher tolerance to fatigue, with an increase in AT and VO2max. The training improved animal performance, hemicellulose digestibility and DE was higher in Pr, but these increases did not improve the performance of these animals.

Objetivou-se avaliar os parâmetros sanguíneos, o consumo de matéria seca e as características fecais de equinos alimentados com dietas hiperlipidêmicas. Foram utilizados 15 equinos em delineamento experimental inteiramente casualizado, com três tratamentos e cinco repetições. As dietas utilizadas foram: dieta sem inclusão de óleo de soja (controle); dieta com inclusão de 8,5% de óleo de soja; dieta com inclusão de 19,5% de óleo de soja. O ensaio teve duração de 34 dias, sendo 30 dias de adaptação dos equinos às dietas e quatro dias de coleta de amostras. As amostras sanguíneas para avaliação hematológica e bioquímica foram coletadas no 34° dia, as características das fezes foram avaliadas no 33° e no 34° dia do ensaio e, a partir do 30° dia, o consumo de matéria seca (CMS) foi avaliado. Os equinos alimentados com as dietas hiperlipidêmicas apresentaram aumento no número de eritrócitos e redução no volume corpuscular médio (P<0,05). O nível de hemoglobina dos equinos avaliados diferiu (P<0,05) somente entre os animais que consumiram as dietas de controle e com inclusão de 8,5% de óleo de soja, com menor valor na dieta de controle de 9,5d dL-1. A inclusão de 19,5% de óleo de soja na dieta elevou os níveis séricos de triglicerídios nos equinos. Houve redução no CMS diário de 1,9 e 2,8kg, nos equinos alimentados com as dietas com 8,5 e 19,5% de óleo de soja em relação à dieta de controle de 9,0kg MS. A produção fecal diária reduziu em 0,7 e 1,1kg MS, nos equinos alimentados com as dietas com 8,5 e 19,5% de óleo de soja, respectivamente, em relação à dieta de controle de 3,4kg MS. A utilização de dietas hiperlipidêmicas para equinos com inclusão de óleo de soja possibilita a redução do consumo dietético e o aumento da disponibilidade plasmática de triglicerídeos sem a ocorrência de diarreias ou alteração das características das fezes.

This research aimed to evaluate blood parameters, dry matter intake and faeces characteristics in horses fed with high fat diets. Fifteen horses were used in a completely randomized design with three diets and five repetitions. The diets were: diet without soybean oil inclusion (control); diet with of 8.5% soybean oil inclusion; diet with 19.5% soybean oil inclusion. The trial had 34 days of duration, 30 days to diet adaptation and four days for samples collection. Blood samples were taken at 34th day to hematological and biochemical evaluation. Faeces characteristics were evaluated from 33rd and 34th day and dry matter intake (DMI) were evaluated from 30th to 34th of essay. Horses fed with high fat diet increased number of erythrocytes and reduced mean corpuscular volume in blood (P<0.05). Blood levels of hemoglobin differ (P<0.05) only in horses fed with control diet or diet with 8.8% soybean oil inclusion, with lower value in control diet of 9.5g dL-1. Serum triglycerides were more available in horses fed diet with 19.5% soybean oil inclusion. Reduced DMI, of 1.9 and 2.8kg, were observed in horses fed diet with 8.5% and 19.5% soybean oil inclusion respectively in relation to control diet, with DMI of 9.0kg/day. Fecal production were reduced, to 0.7 and 1.1kg DM, in horses fed diets with 8.5% and 19.5% soybean oil inclusion in relation to control diet, of 3.4kg DM. High fat diets for horses with soybean oil inclusion reduced dietetic intake and increased serum triglycerides levels without diarrheas or faeces characteristics alterations.

Este trabalho teve como objetivo avaliar a capacidade tamponante (CT), o pH e a consistência das fezes em equinos submetidos à sobrecarga dietética com amido. Seis equinos adultos foram submetidos à sobrecarga com infusão gástrica de 17,6g de amido kg-1 de peso corporal através de sonda nasogástrica. Amostras fecais foram coletadas, antes e quatro, oito, 12, 16, 20, 24, 28, 32 e 36 horas pós-sobrecarga, e imediatamente submetidas à avaliação do pH, da CT e da consistência. Os resultados de pH foram comparados pelo teste t de student (P<0,05). Já os resultados da CT e consistência fecal foram comparados pelo teste de Kruskal-Wallis (P<0,05) e submetidos à análise de regressão e correlação de Spearman em função do tempo após a sobrecarga. Houve redução (P>0,05) no pH fecal ao longo de 36 horas pós-sobrecarga, com valores médios variando de 6,09 a 4,46. A partir do modelo pH = 6,083 - 0,003t - 0,001t² (R² = 0,634), houve decréscimo de 0,004 no pH fecal a cada hora, de 0,028 a cada quatro horas e de 1,404 ao final de 36 horas após a sobrecarga, respectivamente. Além do pH, houve redução (P<0,05) na CT das fezes, em função do tempo após a sobrecarga. Observou-se correlação positiva (r=0,65; P<0,0001) entre o pH e a CT das fezes. Todos os equinos apresentaram fezes de consistência normal (escore 3) até a oitava hora após a sobrecarga. Posteriormente, esses animais apresentaram redução na consistência fecal (P<0,05) até 36 horas. Os resultados demonstram que a sobrecarga dietética com amido promove redução na consistência fecal, na capacidade tampão e consequentemente no pH das fezes em equinos.

This study aimed to evaluate buffer capacity (BC), pH and faeces consistency of horses submitted to dietetic starch overload. Six crossbreed mature horses were submitted to starch overload with gastric infusion of 17.6g starch kg-1 body weight through nasogastric tube. Faecal samples were collected, before and at 4, 8, 12, 16, 20, 24, 28, 32 and 36 hours post-overload, and immediately submitted to evaluation of pH, BC and consistency. The pH data were compared by t student test (P<0.05). The BC and fecal consistency were compared by Kruskal-Wallis test (P<0.05) and submitted to regression analysis and Spearman correlation in function of the time after overload. There was faecal pH decreased along 36 hours post-overload (P>0.05), with means values varying from 6.09 to 4.46. Based on the model pH = 6.083 - 0.003t - 0.001t² (R² = 0.634), faecal pH decreased 0.004 per hour, 0.028 to each four hours and 1.404 at 36 hours after overload, respectively. As pH, faeces BC decreased (P<0.05) in function of the time after overload. Positive relationship was observed (r = 0.65; P<0.0001) between pH and BC of faeces. All horses presented normal consistency faeces (score 3) until eight hours after overload, following by reduction (P<0.05) up to 36 hours. Results demonstrated that starch overload reduce faecal consistency, buffer capacity and pH in horses faeces.