Estudos da coloração do pelame em relação às respostas produtivas de ovinos mestiços sob estresse calórico

Abstract

Objetivou-se avaliar as respostas produtivas de 30 ovinos mestiços ½Santa Inês + ½Dorper, com idade média de quatro meses, 15 com pelame preto e 15 com pelame branco, submetidos a estresse térmico. Os animais sofreram exposição à radiação solar direta durante uma hora (14h00 – 15h00) por semana durante oito semanas. Foram feitas as medições de altura do dorso, altura da garupa, largura do tórax, largura da garupa, perímetro do tórax, perímetro da coxa, perímetro da garupa e perímetro escrotal. Os animais foram abatidos e houve a pesagem dos seguintes componentes: sangue, pele, fígado, coração, rins, cabeça, patas, pulmão, trato gastrointestinal e vazio, testículos e pênis/uretra. Foram avaliados os pesos de carcaça quente e carcaça fria e calculadas as perdas por resfriamento e rendimento de carcaça quente e carcaça fria, além dos cortes comerciais: paleta, perna, pescoço, lombo e costela. Também foram avaliados o acabamento e conformação da carcaça e avaliação da cor, marmoreio, textura e espessura de gordura subcutânea. Os ovinos pretos apresentaram maior peso de rins e menor peso de testículos, carcaça quente, paleta, perna, costela e menor medida de largura da garupa em relação aos animais de pelame branco. O estresse térmico pode provocar distúrbios no metabolismo dos ovinos, afetando sua condição corporal e alterando seu desenvolvimento.

Effect of the environment and diet on the physiological variables of sheep in the Brazilian semi-arid region

“…This fact can be explained by the smaller size of Somalis sheep, which present a higher relative body surface, which is favorable for heat dissipation when compared to larger animals, such as Dorper x Somalis. Moreover, Somalis sheep have a white pelage on most of the body, which provides a higher reflectivity and less heat absorption by the skin when compared to animals with darker pelage (DANTAS et al, 2015), as in sheep of the breed Morada Nova.…”

Ambience of Sheep Submitted to Different Breeding Environments and Global Temperatures

“…The thermal comfort zone (TCZ) for sheep is TA between 15 and 30°C and RH between 50 and 70% (Baêta & Souza, 2010;Eustáquio Filho et al, 2011). The amplitude of the TA and RH at certain times is above the TCZ, requiring to the animals to activate thermoregulatory mechanisms for thermal maintenance, facts observed by Oliveira et al (2013), Dantas et al (2015), Furtado et al (2017) and Torres et al (2017).…”

“…The globe temperature assists in the determination of the BGHI, but a black body has a greater absorptive capacity of the solar radiation (α= 0.97) (ABNT: 15220, 2005), which may result in BGHI values above the animal comfort condition; however, some physiological activities of the animals are sufficient to provide thermal equilibrium Engenharia Agrícola, Jaboticabal, v.38, n.6, p.829-834, nov./dec. 2018 (Dantas et al, 2015, Furtado et al, 2017, Torres et al, 2017. Therefore, the use of gray globe temperature in obtaining the BGHI can generate more coherent information about the animal conditions, considering the superficial characteristics that promote the thermal changes, such as the animals coat/skin coloration (Dantas et al, 2015), as well as the exposure conditions to thermal radiation, full sun or shaded environments (Oliveira et al, 2013).…”

“…2018 (Dantas et al, 2015, Furtado et al, 2017, Torres et al, 2017. Therefore, the use of gray globe temperature in obtaining the BGHI can generate more coherent information about the animal conditions, considering the superficial characteristics that promote the thermal changes, such as the animals coat/skin coloration (Dantas et al, 2015), as well as the exposure conditions to thermal radiation, full sun or shaded environments (Oliveira et al, 2013).…”

Productive, physiological and behavioral sheep profiles housed on facilities with different roofs in the Amazon region

“…The Brazilian Amazon region is characterized by high rainfall, with high temperatures and relative humidity, where sheep are raised in extensive and semi-intensive systems and, in some regions and times of the year, they are confined to the adult stage to improve rates of productive and reproductive (Furtado et al 2017). As a result, Santa Inês sheep and its crossbreeds have a high degree of rusticity and adaptability (Oliveira et al 2015;Pantoja et al 2017;Furtado et al 2020), but as endothermic animals, they depend on ambient temperature to regulate body temperature, with thermal discomfort being one of the factors responsible for their low productivity (Moraes et al 2020).…”