Suchergebnisse

Bees play an important role in maintaining biodiversity by promoting the pollination of numerous plant species. Recent global climate changes are affecting the average air temperature, thereby altering the biological processes of many species. The objective of this study was to evaluate the adaptation of Apis mellifera L. bees to temperature increases and their responses to thermal homeostasis in the colony. Research was performed at the Federal University of Paraíba Laboratory of Bees using three treatments: Control, 33 °C and 40 °C. For the latter two treatments, colonies were kept in a 24 m² climate chamber with an opening at the hive entrance, giving the bees access to the outside environment. The following parameters were evaluated: difference between internal and external hive temperature, thorax surface temperature and total protein concentration in the hemolymph. Internal colony temperature varied according to the external hive temperature. Nurse bees that care for larvae exhibited higher heat production, expressed as thorax surface temperature. Total protein content in the hemolymph was highest in the 40 °C treatment and decreased with ambient temperature. External hive temperature influences internal hive temperature, and nurse bees have higher capacities for thermogenesis.

This study aimed to evaluate the sexual behavior of 'Morada Nova' breeding sheep reared in the Brazilian semi-arid during dry and rainy seasons in a semi-intensive system. The behavioral data were gathered from 4 rams and 114 ewes, among which 55 during the rainy season and the other 59 females in the dry season. The behavioral observations were conducted from 6 am to 5 pm, during both periods. The observations were carried out continuously and split into 'event' (execution frequency) and 'state' (execution time). During the rainy season, the breeding sheep showed the most efficient sexual behavior, with a shorter reaction time (RT) and less frequent mount attempts (MA), being of 122 sec and 2.97, respectively. However, throughout the dry period, some sexual behaviors such as sniffing the urogenital of females (SUF), penis exposure (EXP), head tossing (HT), and courting of females (FC) became more frequent, mainly in the afternoon, as with the flehmen response (FR). Male courting behavior was more evident in the rainy season during the end of the day, remaining less active during the dry period. Sexual behavior intensity in 'Morada Nova' sheep varies throughout the day, especially in the dry season.

The objective of the present study was to evaluate the effect of four water salinity levels on the ingestive behavior of non-castrated crossbred Santa Inês sheep. Thirty-two non-castrated crossbred Santa Inês sheep in feedlot, at seven months of age and initial average weight of 21.76±1.25 kg, were used in the experiment. The experimental design was completely randomized, with four treatments and eight replicates. Four concentrations of salts in the water fed to the animals were evaluated: low (640 mg/l); medium (3,188 mg/l); high (5,740 mg/l) and very high (8,326 mg/l) levels of total dissolved solids (TDS). For the ingestive behaviors, the animals were observed every ten minutes, for 24 hours, to determine the time spent feeding, ruminating and idle. Also, cud chewing and the average number of defecations and urinations and the frequency of water ingestion were determined. The time spent feeding, ruminating and idle were not changed by the salinity levels in the water. Dry matter intake, neutral detergent fiber intake, total chewing time, total cud chews per day, number of daily meals, average duration of each meal and number of defecations per day did not change either. However, feeding and rumination efficiency in grams of DM/h, water intake and number of urinations were linearly affected, whereas the variables rumination efficiency in grams of NDF/h, grams of dry matter per cud, grams of neutral detergent fiber per cud, number of cuds, number of chews per cud and chewing time per cud presented quadratic effect. The different levels of total dissolved solids (640; 3,188; 5,740; and 8.326 mg/l) in the water fed to the sheep did not cause alterations in their ingestive behavior. In conclusion, water with up to 8,326 mg TDS/l can be an alternative strategic and seasonal method to water crossbred Santa Ines sheep.

This study characterized the thermal environment and assessed the physiological aspects of acclimatization of Sindhi and Guzerat heifers in a tropical environment (Brazil) under shade. Eight Sindhi and eight Guzerat purebred heifers (Bos indicus) had their physiological traits measured twice a day (9:00 a.m. and 2:00 p.m.). Environmental data during the experimental period were collected at two-hour intervals between 5:00 a.m. and 5:00 p.m. The temperature-humidity (THI) and the black globe temperature-humidity (BGHI) indices were calculated, and surface temperature (St), respiratory rate (Rr), and rectal temperature (Rt) were collected, being used to estimate heat loss by cutaneous (Ec) and respiratory (Er) evaporation. In the warmer parts of the day (1:00 and 3:00 p.m.), the THI and BGHI reached values of 80.26 and 81.25, respectively. There was no significant difference in rectal temperatures between the breeds, but higher values were observed in the afternoon. Heat transfer by cutaneous evaporation reached 118.71±12.91 W.m-2 and 103.43±6.82 W.m-2 at 2:00 p.m. for the Sindhi and Guzerat heifers, respectively. Under these conditions (air temperature was between 29 and 30°C), 84% of the total latent heat loss in Sindhi and Guzerat heifers was represented by Ec. It can be concluded that Sindhi and Guzerat heifers can maintain homeothermy with minimal thermoregulatory effort under shade conditions in a tropical environment.

The welfare of dairy cows is a major global concern, due to its impact on cow health and productivity, as well as public health. The aim of this study was to identify the main problems related to welfare in dairy herds managed on pasture in the state of Paraíba, Brazil. For this investigation, a cross-sectional study was conducted in 12 dairy farms in the municipalities of Areia, Alagoa Grande, Serraria, and Pilões, Paraíba, Brazil. Each farm was visited only once, recording the number of cows in the herd, type and number of milkings per day, daily milk yield, and access time to the pasture. Body condition score, cleanliness score, bodily injuries, and qualitative behavioral assessment (QBA) were measured. A total of 335 dairy cows were evaluated; herds ranged from 14 to 43 lactating cows, with an average milk yield of 8.4 ± 3.25 kg day-1. Of the 335 cows observed, 26% had a low body condition score, 82% had bodily injuries, and 20% had dirt on their legs. For the QBA, a principal component analysis (PCA) indicated that PC1 had a high correlation mainly with positive body expressions (e.g., sociable, active, and happy), and PC2 was associated with negative terms of body expression (e.g., apathetic, frustrated, and fearful). In conclusion, evaluating indicators of cows' body condition, bodily injury, and cleanliness highlighted the importance of promoting improvements in pasture, management, and housing conditions to enable better performance, health, and welfare of the animals.