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This review aimed to present the current status of the studies about the role of physiological, hematological, biochemical and hormonal variables on the blood of goats raised in adverse environments. Scientific work in recent years has allowed for the evaluation of how goats of distinct breeds react to edaphoclimatic effects to maintain homeothermy according to adaptability to the environment. The exposure of goats to heat stress causes changes in the physiological functions with impact on production and productivity of the animals. There is evidence that the central nervous system is sensitive to temperature changes, and some cells are agiler in the cold than in heat. In conclusion, we say that regardless of the breed, the raising environment and its climatic variables can trigger physiological, biochemical, hematological and hormonal alterations that result in a reduction of the heat production for maintenance of homeothermy. All these changes have a substantial impact on production and productivity.

Aim of study: Our objective was to investigate the mitochondrial DNA of local Brazilian goats to gain insights into the genetic composition of this precious genetic resource. Area of study: The study was developed in Brazil Material and methods: We analyzed a hypervariable region of the mitochondrial DNA of 83 goats belonging to four local Brazilian breeds, including Canindé (CAN-RN), Moxotó (MOX-CE), Marota (MAR-PI) and Azul (AZU-PE) as well as of exotic breeds raised in different states of the Federation. Sequences related to local Brazilian goats showed a dispersed distribution throughout the median-joining network, and clustering with sequences of exotic breeds occurred in some haplotypes. The obtained sequences were analyzed and compared with different haplogroups (A, B1, B2, C, D, F, and G) available on GenBank. Main results: The local Brazilian goat breeds showed significant diversity, with 16 (0.8240) haplotypes. Population structure analysis revealed substantial differences among breeds (p < 0.05). Mitochondrial lineage A was observed in Brazilian goats. Phylogeny showed European goats as the dominant stock for Brazilian goats, but there weare some haplotypes within haplogroup A, clustering with African and Asian haplotypes. Research highlights: These results could be suitable for creating a strategic conservation program, potentially benefitting future breeding programs.

Esta pesquisa teve o objetivo de determinar os índices de conforto térmico em instalações para ovinos, analisar os parâmetros fisiológicos e o gradiente térmico de quatro grupos genéticos, na região semiárida paraibana. Foram utilizados 40 animais, dez por grupo genético, que foram: Cariri, Morada Nova, Barriga Negra e Cara Curta, todas fêmeas, alojadas aleatoriamente em quatro apriscos. Os índices ambientais dentro das instalações, principalmente das 11 às 15 h, ficaram acima da zona de conforto térmico para ovinos adultos, com exceção da umidade relativa do ar, que ficou com média diária de 67,5%. A temperatura retal dos animais esteve dentro da faixa normal, sendo o grupo genético Morada Nova o que apresentou menor valor (38,6 ºC). A frequência respiratória dos animais em cada grupo genético ficou acima do valor recomendado, porém o Morada Nova apresentou o menor valor (43,5 mov min-1); em contrapartida, o Cariri e o Barriga Negra apresentaram os maiores valores (48,0 e 47,3 mov min-1, respectivamente). Os animais com pelagem mais escura e de maior porte, como os da raça Cariri, apresentaram maior gradiente térmico entre a temperatura do ar e a temperatura superficial. Os animais apresentaram alto índice de tolerância ao calor, ou seja, bem adaptados ao ambiente tropical, podendo o grupo genético Cariri ser caracterizado como o menos adaptado e o Morada Nova considerado o mais bem adaptado às condições experimentais.The objective of this research was to determine the thermal comfort indexes for sheep raising installations, analyze the physiological parameters and the thermal gradient of four sheep genetic groups in the semi-arid region of the state of Paraiba, Brazil. Forty animals were used, being ten individuals per genetic group; the groups were: 'Cariri', 'Morada Nova', 'Barriga Negra' and 'Cara Curta'. All of them females and randomly housed in four adequate installations. The environmental indexes inside the lodging, mainly from 11 a.m. to 13 p.m., remained above the thermal comfort zone for adult sheep, except for the relative humidity, that had a daily average of 67.5%. The rectal temperature of the animals was kept within the normal range, except for the genetic group 'Morada Nova' that presented the lowest values (38.6 ºC). The respiration frequency for each of the genetic group was above the normal value; with the 'Morada Nova' once again presenting the lowest values (43.5 mov min-1); the 'Cariri' and 'Barriga Negra' showed the highest frequency (48.0 and 47.3 mov min ¹, respectively). Animals with darker hair color and larger size, such as those belonging to the genetic group 'Cariri', presented a higher thermal gradient between air and body surface temperatures. Animals showed high tolerance to heat, in other words, they are well adapted to the tropical environment, except for the genetic group 'Cariri' that was the least adapted. The genetic group 'Morada Nova' was considered the best adapted group for the experimental conditions.