Navegando por Assunto "Bioclimatologia animal"

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Acesso aberto (Open Access)
Avaliação de sistema silvipastoril através do desempenho produtivo de búfalos manejados nas condições climáticas de Belém, Pará
(Universidade Federal do Pará, 2005-06-03) CASTRO, Anderson Corrêa; LOURENÇO JÚNIOR, José de Brito; http://lattes.cnpq.br/2919433679918544
A development was lead to study the relations between productive, physiological variable and of animal comfort of buffalos and factors of the physical environment, in silvipastoril system, involving african mahogany (Khaya ivorensis) and indian nim (Azadirachta indica) and intensive rotation grazing of Cynodon nlemfuensis, in the period of may of 2003 the november of 2004, in the Unit of Animal Research "Senator Alvaro Adolpho", Embrapa Eastern Amazon, Belem, Para state, in the climatic type Afi, with the rainier of december to may and less rainy time, of june to november. The area of experimental pasture, 5,4 ha, is divided in six plots, with animal permanence of five days and 25 days of rest. Had been used 26 buffaloes Murrah race, no castrated, with age between 231 and 303 days. Descriptive analysis of the experimental data was effected, for attainment of averages, shunting line standard, minimum and maximum values, correlations and variances, considering weight gain, availability and chemical composition of the pasture, physiological variable of the animals, climatic variable, development of the forest essences, Comfortal Index (CI) and Temperature – humidity Index (THI). Excellent performance of the experimental animals was observed, with 0.911 average gain of kg/day and 510 kg of final alive weight. In the periods more and less rainy, the availability, the crude protein levels of stem, leaf and entire plant and the digestibility "in vitro" of the dry and the organic matter of the pasture had been satisfactory, taking care of the minimum necessities for maintenance and detached productive performance. Occurred interferences of the meteorological variable in the cardiac beatings, respiratory frequency, rectal temperature and ruminal movement of the animals. The CI exceeded the critical level, mainly in the period less rainy, as well as the THI levels had been raised, supplanting considered of emergency, indicating the necessity of practical of manipulation of the physical environment to raise the animal performance. The development of the forest essences already supplies better ambience to the animals, in function of the shade, which contributes for the reduction of thermal stress and promotes better performance productive of the buffalos.
Acesso aberto (Open Access)
Respostas termográficas em touros bubalinos submetidos à coleta de sêmen e avaliados sob condições agrometeorológicas no trópico úmido
(Universidade Federal do Pará, 2014-04-30) BARROS, Daniel Vale; LOURENÇO JÚNIOR, José de Brito; http://lattes.cnpq.br/2919433679918544; GARCIA, Alexandre Rossetto; http://lattes.cnpq.br/2678267039338224
Buffalo (Bubalus bubalis) livestock is mostly performed in the intertropical zone, where high temperatures prevail. Therefore the knowledge about buffaloes physiology on tropical environments and their possible responses due to tropical climate changes are essential. The objective of the study was to evaluate the variation in thermal comfort, physiological, hematological, seminal parameters and the superficial temperatures of buffalo bulls raised on humid tropical climate (Afi, Köppen classification). Ten buffaloes were kept in collective paddocks with free access to shade. During five months, data were registered from climatological meteorological station and three distinct dataloggers installed inside the stalls for calculating the Temperature and Humidity Index (THI). Respiratory rate (RR), heart rate (HR), rectal temperature (RT), superficial temperature of the eye (GLO), superficial temperature of the scrotum (ESC), superficial temperature of the right flank (FLd) and left flank (FLe) were registered. The Benezra´s Comfort Index (ICB) was also calculated. Semen collection was performed weekly by artificial vagina and blood sampling for assessment of blood counts were done monthly. The mean maximum of air temperature was 31.5°C and maximum a verage relative humidity was 93.2%. The THI was different only between periods (P<0.05). The RR, HR and ICB showed significant difference over the months and between shifts (P <0.05). RT differed between periods and reduced along months with lower value in August (37.8 ± 0.7°C). RT, GLO, FLd, FLe and ESC showed no diffe rence (P<0.05) for both periods and months. The hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, gross motility and sperm vigor showed significant differences (P<0.05) along the months. The highest correlations between THI and superficial temperatures were between ITUmed and FLdmed (0.77; P<0.0001), ITUmed and FLemed (0.75; P<0.0001), ITUmed and GLO (0.72; P<0.0001), and ITUmed and ESC (0.41; P<0.0001). The highest correlation between internal temperature and surface temperature was TR and GLOmax (0.58; P<0.0001). Significant correlations were found between ICB and FR (0.97; P<0.0001), ICB and FC (0.89; P<0.0001), FC and FR (0.87; P<0.0001), THI and integrity of the plasma sperm membrane (-0.17; P<0.05). The results showed that animals had variations in thermal comfort and increased superficial temperature in the hottest periods of the day, however they were able to maintain homeothermy. Finally, the infrared thermography can be used as a noninvasive and auxiliary technique in studies about animal physiology and thermoregulation.