RESUMO

The behavior of ruminants can influence their productive efficiency. The aim of this study was to evaluate the behavior of young zebu and composite bulls kept in pasture production systems, either in a crop-livestock-forest integration or without afforestation. The work was carried out in São Carlos, Brazil (21°57'42″ S, 47°50'28″ W), in a high-altitude tropical climate, from March to July, 2022. Forty young bulls were evaluated, being 20 Nelore (Bos indicus) (342.5 ± 36.6 kg BW; 16.9 ± 1.8 months) and 20 Canchim (5/8 Bos taurus × 3/8 Bos indicus) (338.4 ± 39.8 kg BW; 19.1 ± 1.9 months), equally distributed in full-sun (FS) and integrated crop-livestock-forestry (ICLF) production systems. Behavior was monitored uninterruptedly by an acoustic sensor and accelerometer attached to a collar, and complemented by direct visual assessment, in two one-day campaigns per month. Serum cortisol concentration was assessed monthly. Statistical analyses were conducted using a general linear model at a 5% significance level (SAS, version 9.4). The ICLF system had a milder microclimate and favored thermal comfort. Natural shading influenced grazing, resting, and rumination time. The Canchim bulls were more active when moving and grazing (p < 0.05), even at the hottest times of the day. In turn, the Nelore bulls spent more time resting at all times (p < 0.001), which was shown to be an adaptive strategy in response to environmental stimuli. The Canchim bulls had a longer rumination time than the Nelore bulls (p < 0.001), due to their longer grazing time. The frequency of water and mineral mixture intake did not differ between genotypes, regardless of the production system (p > 0.05). There was no difference in the serum cortisol concentrations of the Nelore and Canchim bulls kept in FS or ICLF (p = 0.082). Thus, young bulls of the different genotypes showed different behaviors, regardless of whether they were kept on pasture without afforestation or in an integrated crop-livestock-forestry system.

RESUMO

The objective of the study was to evaluate energy or energy/protein supplementation in the ewe diet, in the last third of gestation, on maternal placental and endocrine characteristics, as well as its effects on the behavior of neonatal lambs and productive performance until weaning. A total of 128 ewes were used, and the experimental diet was fed from 100 days gestation until lambing, with the birth of 172 lambs. The ewes were distributed into three treatments: CTL (control, n = 43) with metabolizable energy (ME) and crude protein (CP) intake according to NRC (1985); ME (energy supplementation, n = 44) plus 21% ME; and MECP (energy/protein supplementation, n = 41) plus 26% ME and CP. Body weight, body condition score, serum hormone concentrations, placental characteristics, lamb performance and behavior, and production efficiency of the ewe from lambing to weaning were measured. ME and MECP ewes were heavier before (p = 0.006) and just after lambing (p = 0.002) and had higher serum triiodothyronine (p = 0.001) and cortisol (p = 0.004) concentrations on the day of lambing. ME ewes had higher placental efficiency (p = 0.036) and lower total cotyledon weight (p = 0.011). ME and MECP diets increased both lamb birth weight (p = 0.015) and weaning weight (p = 0.009). Production efficiency at birth and at weaning was not influenced (p > 0.05) by treatments. Lamb behavior was influenced by the ME and MECP diets, reducing the time to kneel (p ≤ 0.05), to try to stand (p ≤ 0.05), and the latency to stand (p ≤ 0.005). It is concluded that overnutrition in the last third of gestation was positive for the ovine production system, with improved production rates, hormonal profile, placental characteristics, and neonatal behavior.

RESUMO

A ovinocultura é uma importante atividade que produz proteínas de alto valor biológico, mas seus ganhos podem ser reduzidos em função do estresse ambiental. Isso reforça a importância de se estudar a relação entre o ambiente térmico e o animal, identificando animais mais adaptados e férteis, e melhores práticas de manejo. O ovino (Ovis aries) é um animal homeotérmico, que mantem sua temperatura corporal em equilíbrio dinâmico. Quando em estresse calórico, os ovinos usam mecanismos sensíveis e latentes para dissipar o calor acumulado, com destaque para o redirecionamento do fluxo sanguíneo, a ofegação e a sudorese. O escroto desempenha importante crucial na termorregulação dos testículos, os quais precisam funcionar sob em até 6,0oC abaixo da temperatura interna corpórea. A hipertermia testicular compromete a espermatogênese, reduz a concentração seminal, a motilidade progressiva e a viabilidade espermática. Ainda, leva a aumento dos defeitos morfológicos espermáticos, na produção de espécies reativas de oxigênio e na fragmentação do DNA espermático, diminuindo a capacidade fecundante. Tecnologias disruptivas para monitoramento do ambiente de produção, da termorregulação e do bem-estar dos animais já são realidade e se encontram em expansão, favorecendo a tomada de decisões em tempo real e o desempenho reprodutivo dos ovinos.

Sheep farming is a relevant activity that provides proteins of high biological value, but its gains can be reduced due to environmental stress. This reinforces the importance of studying the relationship between the thermal environment and the animal, identifying more adapted and fertile animals, and better management practices. Sheep (Ovis aries) are homeothermic animals and thus maintain their body temperature in a state of dynamic balance. Under heat stress, sheep dissipate accumulated heat through sensitive and latent mechanisms, primarily using redirection of blood flow, panting and sweating. The scrotum plays a crucial role in the thermoregulation of the testicles, which need to be maintained up to 6.0oC below the body core temperature. Testicular hyperthermia impairs spermatogenesis, reduces seminal concentration, progressive motility and sperm viability. Furthermore, it leads to an increase in sperm morphological defects, in the production of reactive oxygen species, and in sperm DNA fragmentation, reducing the fertilizing capacity. Disruptive technologies for monitoring the production systems, animal thermoregulation and welfare are already a reality and are expanding, favoring realtime decision making and the reproductive performance of sheep.

Assuntos

RESUMO

The monitoring of body temperature is important for the diagnosis of the physiological state of the animal, being dependent on available methods and their applicability within production systems. This work evaluated techniques to monitor the body temperature of beef cattle kept on pasture and their ability to predict internal temperature. Twenty-three adult bovine females were monitored for six months, and collection data carried out in eleven campaigns (D0-D10) twelve days apart. During collections, the surface temperatures of ear base (ET, oC) and ocular globe (OGT, oC) were measured by infrared thermography, and the subcutaneous temperature (ST, oC) was measured with the use of transponder containing an implantable microchip. Rectal temperature (RT, oC) was considered as a reference for body temperature. Temperature and Humidity Index (THI), Black Globe Temperature and Humidity Index (BGHI) and Radiant Heat Load (RHL, W/m2) were calculated. ET (33.32 ±â€¯0.12 °C), ST (36.10 ±â€¯0.07 °C), OGT (37.40 ±â€¯0.06 °C) and RT (38.83 ±â€¯0.03 °C) differed significantly (P˂0.05). There was positive correlation of RT with OGT (r = 0.392), ET (r = 0.264) and ST (r = 0.236) (P˂0.05). Considering the bioclimatic indicators, the highest magnitude correlations were observed between ET and THI (r = 0.71), ET and BGHI (r = 0.65), and ET and RHL (r = 0.48). The use of microchip represented a practical method, but with limited predictability. On the other hand, infrared thermography proved to be safe and non-invasive, presenting greater precision for inference of internal body temperature. ET was more influenced by meteorological conditions.

Assuntos

RESUMO

This study aimed to evaluate behavioral aspects of Santa Inês sheep in pasture in humid tropical climate. In order to do so, nine Santa Inês sheep were kept on pasture, exposed to the climate directly, without shade, for 24 days, with 12 alternate days in each period (dry and raining) in 2015. The behavioral parameters evaluated were: food consumption, standing idleness, lying idle and rumination. Observations occurred from 08:00 A.M. to 05:55 P.M. The experimental was a completely randomized design (CRD) with two treatments (rainy season and dry period), nine replications, one animal per experimental unit. To understand the correlations of the behavioral parameters with the climatic variables, Pearsons correlation was performed. Approximate average values between the rainy and dry periods for the behavioral variables were observed, but there was a greater intake in the volume of water in the dry period (9.59L/sheep). Also, there were significant differences in the behavior of the animals throughout the day. In the hottest time of the day, at 02:00 P.M., there was standing idle of 25.83min., lying idle of 1.21min., and spent less time-consuming food (27.08min.) in relation to other schedules. We concluded that the sheep had similar behavioral parameters in the rainy and dry periods, but when we observe the times of the days, the behaviors are different. The main activity recorded was grazing, and the variables, temperature and relative humidity of the air influence differently between the seasons, being more marked in the dry period.(AU)

Este estudo objetivou avaliar aspectos comportamentais de ovinos Santa Inês criados em pasto em clima tropical úmido. Para tanto, foram utilizados nove carneiros Santa Inês, mantidos a pasto, expostos diretamente ao clima, sem sombra, durante 24 dias, sendo 12 dias alternados em cada período (seco e chuvoso) em 2015. Os parâmetros comportamentais avaliados foram consumo de alimento, ócio em pé, ócio deitado e ruminação. As observações ocorreram das 08:00h às 17h:55min. O delineamento experimental foi o inteiramente casualizado (DIC) com dois tratamentos (período chuvoso e período seco), nove repetições, um animal por unidade experimental. Para entender as correlações dos parâmetros comportamentais com as variáveis climáticas foi realizada a correlação de Pearson. Foram observados valores médios gerais aproximados entre os períodos chuvoso e seco para as variáveis comportamentais, porém, houve maior ingestão no volume de água no período seco (9,59L/ovino). Também, ocorreu diferença no comportamento dos animais ao longo do dia. No horário mais quente do dia, das 14h às 15h, registrou-se ócio em pé de 25,83min. e ócio deitado de 1,21min., e os animais passaram menor tempo consumindo alimento (27,08min.) em relação aos demais horários. Podemos concluir que os ovinos apresentaram parâmetros comportamentais semelhantes nos períodos chuvoso e seco, porém, quando observamos os horários dos dias, os comportamentos são diferentes. A principal atividade registrada foi o pastejo. As variáveis temperatura e a umidade relativa do ar influenciam de forma diferente o comportamento dos ovinos entre as estações do ano, sendo mais marcantes no período seco.(AU)

Assuntos

RESUMO

ABSTRACT: This study aimed to evaluate behavioral aspects of Santa Inês sheep in pasture in humid tropical climate. In order to do so, nine Santa Inês sheep were kept on pasture, exposed to the climate directly, without shade, for 24 days, with 12 alternate days in each period (dry and raining) in 2015. The behavioral parameters evaluated were: food consumption, standing idleness, lying idle and rumination. Observations occurred from 08:00 A.M. to 05:55 P.M. The experimental was a completely randomized design (CRD) with two treatments (rainy season and dry period), nine replications, one animal per experimental unit. To understand the correlations of the behavioral parameters with the climatic variables, Pearson's correlation was performed. Approximate average values between the rainy and dry periods for the behavioral variables were observed, but there was a greater intake in the volume of water in the dry period (9.59L/sheep). Also, there were significant differences in the behavior of the animals throughout the day. In the hottest time of the day, at 02:00 P.M., there was standing idle of 25.83min., lying idle of 1.21min., and spent less time-consuming food (27.08min.) in relation to other schedules. We concluded that the sheep had similar behavioral parameters in the rainy and dry periods, but when we observe the times of the days, the behaviors are different. The main activity recorded was grazing, and the variables, temperature and relative humidity of the air influence differently between the seasons, being more marked in the dry period.

RESUMO: Este estudo objetivou avaliar aspectos comportamentais de ovinos Santa Inês criados em pasto em clima tropical úmido. Para tanto, foram utilizados nove carneiros Santa Inês, mantidos a pasto, expostos diretamente ao clima, sem sombra, durante 24 dias, sendo 12 dias alternados em cada período (seco e chuvoso) em 2015. Os parâmetros comportamentais avaliados foram consumo de alimento, ócio em pé, ócio deitado e ruminação. As observações ocorreram das 08:00h às 17h:55min. O delineamento experimental foi o inteiramente casualizado (DIC) com dois tratamentos (período chuvoso e período seco), nove repetições, um animal por unidade experimental. Para entender as correlações dos parâmetros comportamentais com as variáveis climáticas foi realizada a correlação de Pearson. Foram observados valores médios gerais aproximados entre os períodos chuvoso e seco para as variáveis comportamentais, porém, houve maior ingestão no volume de água no período seco (9,59L/ovino). Também, ocorreu diferença no comportamento dos animais ao longo do dia. No horário mais quente do dia, das 14h às 15h, registrou-se ócio em pé de 25,83min. e ócio deitado de 1,21min., e os animais passaram menor tempo consumindo alimento (27,08min.) em relação aos demais horários. Podemos concluir que os ovinos apresentaram parâmetros comportamentais semelhantes nos períodos chuvoso e seco, porém, quando observamos os horários dos dias, os comportamentos são diferentes. A principal atividade registrada foi o pastejo. As variáveis temperatura e a umidade relativa do ar influenciam de forma diferente o comportamento dos ovinos entre as estações do ano, sendo mais marcantes no período seco.