Biodiversity studies are more efficient when large numbers of breeds belonging to several countries are involved, as they allow for an in-depth analysis of the within- and between-breed components of genetic diversity. A set of 21 microsatellites was used to investigate the genetic composition of 24 Creole goat breeds (910 animals) from 10 countries to estimate levels of genetic variability, infer population structure and understand genetic relationships among populations across the American continent. Three commercial transboundary breeds were included in the analyses to investigate admixture with Creole goats. Overall, the genetic diversity of Creole populations (mean number of alleles = 5.82 ± 1.14, observed heterozygosity = 0.585 ± 0.074) was moderate and slightly lower than what was detected in other studies with breeds from other regions. The Bayesian clustering analysis without prior information on source populations identified 22 breed clusters. Three groups comprised more than one population, namely from Brazil (Azul and Graúna; Moxotó and Repartida) and Argentina (Long and shorthair Chilluda, Pampeana Colorada and Angora-type goat). Substructure was found in Criolla Paraguaya. When prior information on sample origin was considered, 92% of the individuals were assigned to the source population (threshold q ≥ 0.700). Creole breeds are well-differentiated entities (mean coefficient of genetic differentiation = 0.111 ± 0.048, with the exception of isolated island populations). Dilution from admixture with commercial transboundary breeds appears to be negligible. Significant levels of inbreeding were detected (inbreeding coefficient > 0 in most Creole goat populations, P < 0.05). Our results provide a broad perspective on the extant genetic diversity of Creole goats, however further studies are needed to understand whether the observed geographical patterns of population structure may reflect the mode of goat colonization in the Americas.

Brazilian goat breeds are believed to derive mainly from animals brought by Portuguese settlers since the 16th century. We used microsatellite markers in a sample of 436 animals to study genetic variability and differentiation of the six Portuguese (PT) and six Brazilian (BR) goat breeds currently recognized in the two countries. These breeds were also compared with an outgroup represented by a sample of Alpine (ALP) goats. The effective number of alleles and allelic richness were slightly higher in PT than in BR breeds. The global F(ST) was nearly 0.11 when PT and BR breeds were considered, with a mean pairwise F(ST) of about 0.03 among PT breeds, 0.07 among BR breeds and 0.15 between PT and BR breeds. The dendrogram illustrating relationships between populations and the correspondence analysis indicate the existence of two very distinct clusters, corresponding to the countries of origin of the breeds studied, which are nearly equidistant from the Alpine outgroup. The analysis with structure confirmed the separation between PT and BR breeds but suggests that some BR breeds, especially Graúna and Canindé, may share a common ancestry with PT breeds. The divergence observed between PT and BR breeds may result from founder effects and genetic drift but could also reflect the introduction in Brazil of goats originating from other regions, e.g., West Africa.

The effect of the natural weather conditions on respiratory rate, rectal temperature and hematologic parameters such as glucose, total cholesterol, triacylglycerol, total protein, albumin, globulin, red blood cells, microhematocrit, mean corpuscular volume, serum triiodothyronine (T 3 ) and thyroxine (T 4 ) levels was evaluated in red (RMN) and white (WMN) coat colored Morada Nova ewes, of different class of body condition score (CBCS), during the dry (from july to december) and wet (from january to june) seasons, which exhibited different (P<0.05) air temperature, relative humidity and radiant thermal load averages. Tukey's test was used and the difference considered was to P<0.05. Significant greater averages of respiratory rate were observed in the dry period compared to the rainy period (42.26±8.96 and 36.89±8.20 breaths min -1 , respectively), mainly in the RMN (45.54±8.23 breaths min -1 ) compared with the WMN (39.27±8.57 breaths min -1 ). No differences were observed in rectal temperature measurements between the dry and the wet periods (38.59±0.58 and 38.60±0.56 o C, respectively), but the WMN had higher values than the RMN (38.77±0.54 and 38.40±0.54 o C, respectively). The glucose and total cholesterol were higher in the wet season, with no variation due to breed variety and CBCS. The triacylglycerol did not change between breed varieties and seasons. The albumin was similar between varieties and in different seasons, being different in CBCS. Total protein and globulin serum were higher during the wet season, but total protein was higher and globulin was lower in better CBCS. T 3 and T 4 levels were higher in the rainy season (0.25±0.07 and 6.74±11.37 µg dL -1 , for T 3 and T 4 , respectively) than in the dry season (0.18±0.08 and 6.31±1.64 µg dL -1 , for T 3 and T 4 , respectively). The red blood cells showed no difference, but microhematocrit was higher in WMN and in the better CBCS and mean corpuscular volume was higher in the dry season. The concentration of T 3 was lower in the RMN than in the WMN (0.19±0.07 and 0.24±0.08 µg dL -1 , respectively), while T 4 did not differ between them (6.53±1.51 and 6.52±1.46 µg dL -1 , respectively). The Morada Nova sheep showed positive physiological responses to the heat stress, notably an increase of respiratory rate and a reduction of T 3 and T 4 levels. All another hematologic parameters analyzed were within the normal range for all sheep, indicating a good ability to cope with the climatic changes of the Brazilian semiarid region. Both varieties were heat tolerant, but the red variety required major adjustments to maintain homeothermy. Key words: Adaptation, blood metabolites, blood parameters, sheep, thermoregulatory responses, thyroid hormones ResumoNeste estudo foram avaliados os efeitos da época do ano nas características fisiológicas de frequência respiratória e temperatura retal e nos parâmetros hematológicos glicose, colesterol total, triglicerídeos, proteínas totais, albumina, globulina, contagem total de hemácias, hematócrito, volume corpu...

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 BrazilMaterial 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.

The effect of the natural weather conditions on respiratory rate, rectal temperature and hematologic parameters such as glucose, total cholesterol, triacylglycerol, total protein, albumin, globulin, red blood cells, microhematocrit, mean corpuscular volume, serum triiodothyronine (T 3 ) and thyroxine (T 4 ) levels was evaluated in red (RMN) and white (WMN) coat colored Morada Nova ewes, of different class of body condition score (CBCS), during the dry (from july to december) and wet (from january to june) seasons, which exhibited different (P<0.05) air temperature, relative humidity and radiant thermal load averages. Tukey's test was used and the difference considered was to P<0.05. Significant greater averages of respiratory rate were observed in the dry period compared to the rainy period (42.26±8.96 and 36.89±8.20 breaths min -1 , respectively), mainly in the RMN (45.54±8.23 breaths min -1 ) compared with the WMN (39.27±8.57 breaths min -1 ). No differences were observed in rectal temperature measurements between the dry and the wet periods (38.59±0.58 and 38.60±0.56 o C, respectively), but the WMN had higher values than the RMN (38.77±0.54 and 38.40±0.54 o C, respectively). The glucose and total cholesterol were higher in the wet season, with no variation due to breed variety and CBCS. The triacylglycerol did not change between breed varieties and seasons. The albumin was similar between varieties and in different seasons, being different in CBCS. Total protein and globulin serum were higher during the wet season, but total protein was higher and globulin was lower in better CBCS. T 3 and T 4 levels were higher in the rainy season (0.25±0.07 and 6.74±11.37 µg dL -1 , for T 3 and T 4 , respectively) than in the dry season (0.18±0.08 and 6.31±1.64 µg dL -1 , for T 3 and T 4 , respectively). The red blood cells showed no difference, but microhematocrit was higher in WMN and in the better CBCS and mean corpuscular volume was higher in the dry season. The concentration of T 3 was lower in the RMN than in the WMN (0.19±0.07 and 0.24±0.08 µg dL -1 , respectively), while T 4 did not differ between them (6.53±1.51 and 6.52±1.46 µg dL -1 , respectively). The Morada Nova sheep showed positive physiological responses to the heat stress, notably an increase of respiratory rate and a reduction of T 3 and T 4 levels. All another hematologic parameters analyzed were within the normal range for all sheep, indicating a good ability to cope with the climatic changes of the Brazilian semiarid region. Both varieties were heat tolerant, but the red variety required major adjustments to maintain homeothermy. Key words: Adaptation, blood metabolites, blood parameters, sheep, thermoregulatory responses, thyroid hormones ResumoNeste estudo foram avaliados os efeitos da época do ano nas características fisiológicas de frequência respiratória e temperatura retal e nos parâmetros hematológicos glicose, colesterol total, triglicerídeos, proteínas totais, albumina, globulina, contagem total de hemácias, hematócrito, volume corpu...