RESUMO: A região Norte de Minas possui a produção de leite limitada, principalmente em função da seca, no entanto, esta é a base econômica da agricultura familiar que sustenta a região. Assim, realizou-se um estudo com o objetivo de avaliar o efeito do ambiente térmico sobre as respostas fisiológicas de vacas ¾ Holandês-Zebu, na região do semiárido mineiro a fim de se verificar a adaptabilidade destes animais. O experimento foi conduzido no verão e inverno, na fazenda Bela Vista localizada no município de Verdelândia (MG), onde foram avaliadas 10 vacas ¾ Holandês x Zebu (HxZ), em cada época. O ambiente térmico foi caracterizado por meio de medições diárias da temperatura do ar, umidade relativa do ar, índice de temperatura de globo e umidade e carga térmica radiante. Os parâmetros fisiológicos: frequência respiratória e cardíaca, temperatura de superfície corporal e temperatura retal, espessura, cor e densidade do pelame, e comprimento dos pelos foram mensurados antes da ordenha matutina, em função das estações do ano, diariamente, durante 15 dias. As variáveis e índices climáticos foram superiores no verão e no período da tarde. A frequência respiratória e a espessura do pelame não diferiram estatisticamente, no entanto as demais variáveis foram superiores no verão. As variáveis climáticas induziram diferenças nos parâmetros fisiológicos, mas foram assimiladas pelos animais, o que permite concluir que as vacas ¾ HxZ adaptam-se ao clima do semiárido mineiro sem manifestarem situação de estresse térmico.Palavras-chave: agricultura familiar, ambiência, bovinos leiteiros, cruzamento genético. PHYSIOLOGICAL RESPONSES AND ADAPTABILITY OF ¾ HOLSTEIN X ZEBU COWS TO SEMIARID CLIMATEABSTRACT: The northern region of Minas Gerais has limited milk production, mainly due to drought, however, this is the economic base of family agriculture that sustains the region. Thus, a study was carried out to evaluate the effect of the thermal environment on the physiological responses of Holstein-Zebu cows in the semi-arid region of Minas Gerais in order to verify the adaptability of these animals. The experiment was conducted in the summer and winter at the Bela Vista farm located in the Verdelândia city (MG), where 10 cows ¾ Holstein x Zebu (HxZ) were evaluated in each season. The thermal environment was characterized by means of daily measurements of air temperature, relative humidity, air temperature index and humidity and radiant thermal load. The physiological parameters: respiratory and heart rate, body surface temperature and rectal temperature, thickness, hair color and density, and hair length were measured before morning milking, as a function of the seasons of the year for 15 days. Climatic variables and indexes were higher in the summer and in the afternoon. The respiratory rate and the pelt thickness did not differ statistically, however the other variables were higher in the summer.

O objetivo foi avaliar a variação anual das características morfológicas de pelame de vacas mestiças Holandesas x Gir, ½ e ¾ de Holandês da região de Salinas - Minas Gerais. As características morfológicas do pelame estudadas foram: espessura da capa, comprimento médio dos pelos e densidade numérica. A coleta de pelos foi realizada em cada estação climática (primavera, verão, outono e inverno). A caracterização climática das estações do ano foram obtidas a partir dos dados disponibilizados pelo Instituto Nacional de Meteorologia (Inmet). Os dados para as características morfológicas do pelame foram submetidos à análise de variância seguindo um delineamento inteiramente casualizado em esquema fatorial (dois graus de sangue e quatros estações climáticas). Encontrou-se efeito de estação do ano, demonstrando que o pelame das vacas mestiças se ajusta com as variáveis ambientais. E o comprimento e número de pelos/cm² apresentaram-se maiores nos animais ¾ Holandês. Conclui-se que os animais mestiços estudados possuem pelame curto, pouco denso e bem assentado, principalmente no verão. Os animais ½ Holandês apresentaram pelame menos denso e mais curto que os animais ¾ Holandês.

The objective was to determine zoometric indices, correlate, and predict body weight based on the biometric measurements of F1 Dorper × Santa Inês (F1 D × SI) ewes created extensively. Were 25 F1 D × SI sheep monitored, with ages varying from 2 to 9 months. Body weight, thoracic perimeter, belly perimeter, body length, withers height, rump height, rump width, and rump length were measured on a monthly basis and zoometric indices were estimated from them. Descriptive data analysis, Pearson's correlation, and regression analysis were performed. The biometric measurements and zoometric indices of F1 D × SI ewes indicate an animal of aptitude for cutting, with good conformation. In addition, they demonstrate favorable aspects for reproduction, a fundamental characteristic in the selection of matrices. Body weight has a high and positive correlation for all characteristics analyzed, with values ranging from 0.74 of the rump length to 0.88 of the thoracic perimeter. The regressions for all biometric measurements were highly significant (P <0.0001) with an emphasis on the thoracic perimeter that has the highest coefficient of determination (R² = 0.77), the other measures presented below 0.70. It was concluded that F1 Dorper × Santa Inês ewes have characteristics for meat production and for reproduction. Also, of the biometric measurements, the thoracic perimeter can be used to predict the body weight of F1 Dorper × Santa Inês ewes.

The aim of this study was to evaluate the behavioral and physiological responses of dairy cows and their interaction with the milker in two types of milking systems. The experiment was conducted in two farms, in the Coração de Jesus city, Brazil, where the surface temperature (TS, °C), rectal temperature (TR, °C), respiratory rate (RR, breaths.min -1 ) and heart rate (HR, beats.min -1 ) of 44 crossbred cows during the morning shift on twelve days of data collection at each farm. It was monitored the meteorological variables: the black globe temperature (TGN, °C), air temperature (TAR, °C), relative humidity (RH, %) and wind speed (V, m.s -1 ). Observations about human behavior, negative patterns (tapping, yelling, and pushing) and positive patterns (talking, groping, and naming) were made without people being aware of their nature. The behavioral data observed in the animals were: vocalization (VOC), defecation (DEF), micturition (MIC) and movement (MOV) and milking time (TOR) was also recorded. The physiological variables were significant among farms, except heart rate. The talking, naming, pushing and shouting actions were not significant, only groping and hitting. The behavior occurrences VOC, MIC, and MOV of cows were low. The TO presented a positive correlation (P <0.01) with TS, TR, and HR and negative correlation (P <0.01) with RR. Under the conditions of this experiment, the type of milking system influenced the physiological responses. The milking system of type "bucket at the bottom" provided greater contact between the milker and the cow, leading to a greater negative interaction reflected by the defecation behavior.

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