RESUMO
This study aimed to evaluate the effect of environmental enrichment on the thermoregulatory and behavioral responses of goats raised in semi-arid conditions. 12 Saanen goats lactating, aged between 2 and 4 years, clinically healthy with a mean body weight of 31.4 ± 1.65 kg and body condition score between 2.0 and 2.5 were used. The types of enriched environments used were: 1) without environmental enrichment (control); 2) classical music;3) PET plastic bottles with corn;4) suspended tires;5) logs of wood; and 6) all objects simultaneously. The air temperature, black globe tempeature and humidity index, and radiant heat load were higher (P < 0.05) during treatment with all objects simultaneously. The respiratory rate (RR) was higher (P = 0.001) in the control treatment compared to those with environmental enrichment. The rectal temperature (RT) was higher in the control and acoustic groups (P < 0.05), however it was lower with all objects. The coat surface temperature (CST) was higher (P < 0.01) in the control group and lower in the treatment with music, tires, logs of wood, PET bottles and all objects. The behaviors lying down, drinking water, urination, ruminating while standing, and defecating were similar (P > 0.05) between treatments. The first two discriminant functions were significant (F1 and F2: P < 0.001) and discriminated 93.40% of the data variation. A static pattern was observed in the classification of goats in their group of origin for thermoregulatory and behavioral responses when a single type of enrichment was used with the formation of two more groups: (i) goats which had access to all enrichments simultaneously; and (ii) the control group. The offer of the diversity of various objects for environmental enrichment positively contributed to the thermoregulatory and behavioral responses, thereby providing well-being to the animals.
Assuntos
Regulação da Temperatura Corporal , Lactação , Animais , Feminino , Cabras/fisiologia , Umidade , TemperaturaRESUMO
The purpose of this study was to understand and discuss the relationships of the thermal environment, morphophysiological response, performance, and carcass traits of Brahman bulls from weaning at 18 months exposed to grazing conditions based on the physiological and evolutionary rationale behind the different proposals for the thermal adaptation of zebu cattle. Fifty-three uncastrated and clinically healthy bulls with birth and weaning weight of 34.0 ± 3.32 kg and 215.5 ± 44.75 kg, respectively, were evaluated. Fifteen canonical correlations were estimated, but only six were significant: thermal environment × thermoregulatory responses (rc = 0.4635; P = 0.0413); thermal environment × performance (rc = 0.4338; P = 0.0218); thermoregulatory responses × performance (rc = 0.5119; P = 0.0071); hair coat characteristics × performance (rc = 0.4939; P = 0.0273); hormone × carcass traits (rc = 0.5408; P = 0.0698); and performance × carcass traits (rc = 0.9644; P < 0.0001). Thermal environment, thermoregulatory responses and hair coat morphology influence of 18.81%, 21.49% and 24.40%, respectively, were found in the performance. We also concluded that (i) rectal temperature (RT) is a homoeothermic indicator; (ii) sweating rate (SR) is an important heat dissipation mechanism to explain the adaptation of zebu animals in the tropics and is related to weight at 550 days (W550); (iii) coat morphology, especially length (HL), diameter (HD) and hair density (ND) are related to animal performance; and (iv) hormonal profile, mainly T4, influences the carcass traits (yield, weight, subcutaneous fat and marble meat).
Assuntos
Bovinos , Pelo Animal , Criação de Animais Domésticos , Animais , Regulação da Temperatura Corporal , Brasil , Bovinos/anatomia & histologia , Bovinos/sangue , Bovinos/fisiologia , Hidrocortisona/sangue , Masculino , Temperatura , Tiroxina/sangue , Tri-Iodotironina/sangue , Clima TropicalRESUMO
This study had the following objectives: (i) to evaluate the thermoregulatory and behavioral responses of light laying hens supplemented with different types and dosages of phytases in the two day shifts; and (ii) to integrate the thermoregulatory and behavioral responses with performance of these birds raised in a hot environment. 270 light laying hens of the Hy-Line White lineage, with a body weight of 1.60 ± 0.092 kg were distributed in a completely randomized design in a 2 × 2 + 1 factorial model with two types of phytases (bacterial and fungal) and two dosages (450 and 900 FTU), and a control diet. The day shift (morning and afternoon) was considered as a fixed effect in the factorial arrangement. Principal component analysis (PCA), correspondence analysis (CA) and canonical discriminant analysis (CDA) were used. There was no interaction (P > 0.05) between phytases and dosages for thermoregulatory responses. Respiratory rate (RR), cloacal temperature (CT), and surface temperature with feathers (STWF) and featherless (STF) were higher (P < 0.001) in the afternoon. Birds show different thermoregulatory and behavioral responses in the two shifts of the day. We also observed that birds supplemented with bacterial and fungal phytase showed similar thermoregulatory and behavioral responses to the control group in both day shifts. Expression of the "eating" activity was greater in the morning, while the birds remained sitting longer in the afternoon. Egg production was higher (P < 0.001) in birds supplemented with bacterial phytase. The phytase dosages had no effect on thermoregulatory, behavioral or performance responses. Egg production, feed conversion per dozen eggs corresponded to 81.1% of the differences between bacterial and fungal phytase supplementation and group control. Thus, we conclude that: (i) phytase dietary supplementation has no effect on the thermoregulatory responses of laying hens reared in a hot environment; (ii) birds supplemented with bacterial phytase showed higher egg production; and (iii) phytases (450 and 900 FTU) do not interfere with productive, behavioral and thermoregulatory responses.