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The aim of this study was to compare, during milking, the bacteriomes of goat milk from farms in Mexico representing traditional and semi-intensive production systems. Metagenomic DNA was isolated from pooled milk samples collected at different milking stages, and following 16S rRNA-targeted sequencing, alpha (Shannon H’ and Simpson D) and beta (Bray–Curtis) diversity indices were calculated. Within the semi-intensive system, fore-stripping showed lower diversity (H’ = 1.5 vs. H’ = 4.0) but greater evenness (D = 0.5 vs. D = 0.8) than the milking stage. In contrast, no differences between stages in the traditional system were observed. The Bray–Curtis index revealed that the use of the semi-intensive system explained 99.4% of the variability, while the traditional system accounted for only 0.5%. In the semi-intensive system, fore-stripping was dominated by Mesoplasma (51.9%) and Staphylococcus (42.1%), whereas Enterococcus (27.2%) and Lactococcus (18.5%) prevailed during milking. Meanwhile, in the traditional system, Pseudomonas (46.9% and 22.7) and Lactococcus (22.7% and 29.2%) predominated in both stages. Management practices strongly influence the microbiological profile of milk, leading to changes in not only the diversity and abundance of pathogenic bacteria but also in the presence of beneficial lactic acid bacteria and, hence, the overall expected milk quality.

Cattle temperament is a complex and economically relevant trait. The objective of this study was to identify genomic regions and genes associated with cattle temperament. From a Brahman cattle population of 1,370 animals evaluated for temperament traits (Exit velocity-EV, Pen Score-PS, Temperament Score-TS), two groups of temperament-contrasting animals were identified based on their EV-average values ±1/2 standard deviation (SD). To be considered in the calm group, the EV of females ranged between 0.16-1.82 m/s (n = 50) and the EV of males ranged between 0.4-1.56 m/s (n = 48). Females were classified as temperamental if their EV ranged between 3.13-7.66 m/s (n = 46) and males were classified as temperamental if their EV ranged between 3.05-10.83 m/s (n = 45). Selected animals were genotyped using a total of 139,376 SNPs (GGP-HD-150K), evaluated for their association with EV. The Genome-Wide Association analysis (GWAS) identified fourteen SNPs: rs135340276, rs134895560, rs110190635, rs42949831, rs135982573, rs109393235, rs109531929, rs135087545, rs41839733, rs42486577, rs136661522, rs110882543, rs110864071, rs109722627, (P<8.1E-05), nine of them were located on intergenic regions, harboring seventeen genes, of which only ACER3, VRK2, FANCL and SLCO3A1 were considered candidate associated with bovine temperament due to their reported biological functions. Five SNPs were located at introns of the NRXN3, EXOC4, CACNG4 and SLC9A4 genes. The indicated candidate genes are implicated in a wide range of behavioural phenotypes and complex cognitive functions. The association of the fourteen SNPs on bovine temperament traits (EV, PS and TS) was evaluated; all these SNPs were significant for EV; only some were associated with PS and TS. Fourteen SNPs were associated with EV which allowed the identification of twenty-one candidate genes for Brahman temperament. From a functional point of view, the five intronic SNPs identified in this study, are candidates to address control of bovine temperament, further investigation will probe their role in expression of this trait.

Background: The search for gene and marker effects on economically important traits is aimed not only to understanding the genetic architecture of complex traits but also to applying the information to breeding schemes. Objective: To analyze the effect of two temperament-related SNPs (rs109576799 located in the DRD3 gene, and rs43696138 in the HTR2A gene) on feeding performance of Mexican beef cattle. Methods: One hundred and thirty-six young beef bulls were included in a centralized feed efficiency performance test based on residual feed intake (RFI), with 20 d for adaptation and 70 d of feed efficiency testing. In addition to feeding traits, temperament was assessed at the beginning of the trial using pen score (PS) and exit velocity (EV). All animals were genotyped with two markers located in the HTR2A and DRD3 genes, and an association analysis was conducted between these genotypes and the measured traits. Results: For Brangus breed, a significant association was obtained between average daily gain (ADG; p=0.019), and the rs43696138 marker, resulting in higher gains for homozygous genotype GG (1.69 ± 0.04 kg), when compared to the heterozygous genotype GA (1.54 ± 0.04 kg). Conclusion: The previously reported association of these markers with temperament was not confirmed in the evaluated breeds; however, the rs43696138 marker showed an effect on a feeding performance trait. Further studies are needed to determine the effect of this and other markers on both RFI and temperament.Keywords: beef cattle, feed efficiency, residual feed intake, single nucleotide polymorphism, temperament.  Resumen Antecedentes: La búsqueda de efectos genéticos y marcadores de rasgos económicamente relevantes no solo se basa en el interés biológico de comprender la arquitectura genética de rasgos complejos, sino también en aplicar la información en los esquemas prácticos de mejoramiento. Objetivo: Analizar el efecto de dos SNPs relacionados con el temperamento (rs109576799 localizado en el gen DRD3, y rs43696138 localizado en el gen HTR2A) sobre la eficiencia alimenticia en el ganado bovino mexicano. Métodos: Ciento treinta y seis toretes de carne jóvenes fueron sometidos a una prueba de comportamiento alimenticio basada en el consumo residual de alimento (RFI), con 20 d de adaptación y 70 d de prueba para la eficiencia alimenticia. Además de los rasgos de comportamiento alimenticio, se evaluó el temperamento de los animales al inicio de la prueba, mediante la evaluación de comportamiento en el corral (PS), y la velocidad de salida (EV). Todas las muestras se tipificaron con dos marcadores localizados en los genes DRD3 y HTR2A para posteriormente realizar un análisis de asociación de los genotipos con los rasgos evaluados. Resultados: En la raza Brangus, se observó una asociación significativa de la media de ganancia diaria de peso (ADG, p=0,019) con el marcador rs43696138, localizado en el gen HTR2A, resultando en mayores ganancias para el genotipo GG (1,69 ± 0,04 kg) en comparación con los toros heterocigóticos GA (1,54 ± 0,04 kg). Conclusión: No se confirmó la asociación de estos marcadores previamente reportados con el temperamento en las razas evaluadas; sin embargo, el marcador rs43696138 mostró efecto en un rasgo de comportamiento alimenticio. Se necesitan más estudios para determinar el efecto de éste y otros marcadores en el consumo residual de alimento (RFI) y el temperamento.Palabras clave: consumo residual de alimento, eficiencia alimenticia, ganado de carne, polimorfismo de un solo nucleótido, temperamento.  Resumo Antecedentes: A busca de efeitos genéticos e marcadores de características economicamente relevantes não se baseia apenas no interesse biológico de compreender a arquitetura genética de traços complexos, mas também na aplicação da informação nos esquemas práticos de melhoria. Objetivo: Analisar o efeito de dois SNPs relacionados ao temperamento (rs109576799 localizado no gene DRD3 e rs43696138 localizado no gene HTR2A) sobre a eficiência nutricional no gado mexicano. Métodos: Cento e trinta e seis touros jovens foram submetidos a um teste de comportamento alimentar com base na entrada de alimentação residual (RFI), com 20 d de adaptação e 70 d de teste para eficiência de alimentação. Além dos traços de comportamento alimentar, o temperamento dos animais foi avaliado no início do teste, através da avaliação do comportamento na caneta (PS) e da velocidade de saída (EV). Todas as amostras foram digitadas com dois marcadores localizados nos genes DRD3 e HTR2A para posteriormente realizar uma análise de associação dos genótipos com os traços avaliados. Resultados: Na raça Brangus, observou-se uma associação significativa do ganho diário médio (ADG, p = 0,019) com o marcador rs43696138, localizado no gene HTR2A, resultando em maiores ganhos para o genótipo GG (1,69 ± 0,04 kg), em comparação com os touros heterozigóticos GA (1,54 ± 0,04 kg). Conclusão: A associação destes marcadores previamente relatados com o temperamento nas raças avaliadas não foi confirmada; no entanto, o marcador rs43696138 mostrou um efeito sobre uma característica de comportamento alimentar. Mais estudos são necessários para determinar o efeito deste e outros marcadores com ingestão alimentar residual (RFI) e temperamento.Palavras-chave: consumo residual de alimentos, eficiência alimentar, gado bovino, polimorfismo de nucleotídeo único, temperamento.

The South-Central region of Mexico has experienced a sizeable introduction of purebred horses for recreational aims. A study was designed to assess effective population sizes and genetic diversity and to verify the genetic integrity of four horse breeds. Using a 12-microsatellite panel, Quarter Horse, Azteca, Thoroughbred and Creole (CRL) horses were sampled and analysed for diversity and genetic structure. Genetic diversity parameters showed high numbers of heterozygous horses but small effective population sizes in all breeds. Population structure results suggested some degree of admixture of CRL with the other reference breeds. The highly informative microsatellite panel allowed the verification of diversity in introduced horse populations and the confirmation of small effective population sizes, which suggests a risk for future breed integrity.

Beef is an excellent source of nutrients; unfortunately, most nutritional recommendations suggest limiting or even avoiding it. Studies have shown that the fatty acid composition of meat influences weight loss. This randomized controlled clinical trial evaluated the anthropometric and serum lipid changes after a food intervention that included frequent beef consumption (120 g consumed four days/week for four weeks). Volunteers were randomly assigned to the commercial or Wagyu-Cross beef groups, with the latter beef possessing higher fat and MUFA contents. Both groups exhibited reductions in body measurements and lipid profiles; however, the Wagyu-Cross group exhibited greater changes in weight (−3.75 vs. −2.90 kg) and BMI (−1.49 vs. −1.03) than the commercial group, without a significant difference between them. No significant group differences in lipid profiles were observed; however, the Wagyu-Cross group exhibited a more favorable change in decreasing the TC concentration (−7.00 mg/dL) and LDL-C concentration (−12.5 mg/dL). We suggest that high MUFA beef could be included in weight-loss programs since it does not affect weight loss and hasn’t a negative influence on lipid metabolism.

The white-tailed deer (Odocoileus virginianus) is an important, sustainable-use species in Mexico; 14 subspecies are widely distributed throughout the Mexican territory. The criteria for classifying subspecies is based on morphological features throughout their geographical range; however, the complete genetic characterization of Mexican subspecies has not been established. The objective of the present work is to report the mitogenomes of 9 of the 14 white-tailed deer subspecies from Mexico and identify their unique variations. Typical vertebrate mitogenomes structures (i.e., 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes) were observed in the studied subspecies. The greatest numbers of polymorphisms were identified in the D-loop, ND4, ND5, CYTB/COI, ATP6, and COIII genes. Phylogenetic analyses showed that the southern and southeastern subspecies were distinct from the central and northern subspecies; the greatest genetic distances were also observed between these 2 groups. These subspecies-specific variations could be useful for designing a strategy to genetically characterize the studied subspecies. El venado cola blanca es una de las especies de mayor importancia dentro del aprovechamiento de la fauna silvestre de México, donde se distribuyen de manera natural 14 subespecies. Actualmente, estas subespecies se han clasificado de acuerdo a sus variaciones fenotípicas que presentan a lo largo de su rango de distribución, sin embargo no se ha establecido la caracterización genética completa de las mismas. Es por esto que el objetivo del presente estudio es reportar los mitogenomas de 9 de las 14 subespecies de venado cola blanca, así como identificar las variaciones únicas de cada subespecie. En las 9 subespecies se observó la estructura típica de los mitogenomas de vertebrados (13 genes que codifican para proteínas, 22 ARNt, 2 ARNr). Los genes con mayor polimorfismo fueron D-loop, ND4, ND5, CYTB/COI, ATP6 y COIII. El análisis filogenético mostró la separación de las subespecies del sur y sureste de las subespecies del centro y norte del país, a su vez las distancias genéticas entre estos dos grupos fueron las más altas. Estas variaciones subespecie-específicas podrían ser útiles para diseñar una estrategia para caracterizar genéticamente las subespecies estudiadas.

The white-tailed deer (Odocoileus virginianus) occurs over a broad latitudinal range from South America to Canada. Thirty-eight subspecies are recognized, 14 of which occur in Mexico. Genetic studies in Latin America are lacking and the diversity and structure of white-tailed deer in Mexico are unknown. We sampled white-tailed deer from 13 sites in the range of 5 subspecies occurring in Mexico, O. v. texanus, O. v. carminis, O. v. veraecrucis, O. v. sinaloae, and O. v. yucatanensis. We estimated genetic diversity and structure based on 12 microsatellite DNA loci. Observed heterozygosity (HO) was comparable to that of white-tailed deer in the United States (HO = 0.53–0.64), with the exception of O. v. yucatanensis (HO = 0.41). We observed statistically significant genetic structure among all 13 sites (FST = 0.15). Analysis of molecular variance revealed that grouping sites by subspecies (FSC = 0.09) or geographic region (FSC = 0.13–0.14) explained a moderate portion of genetic variation. However, no higher-level group minimized differentiation among populations within the subspecies or regional groups (FST = 0.16–0.20). Pairwise genetic distances among sites were correlated with geographic distance (r2 = 0.38), but some geographically proximate sites were genetically differentiated (FST > 0.20), especially in the Yucatan. Deer in the Yucatan were genetically differentiated from other subspecies and had comparatively lower genetic diversity, consistent with the biogeographic history of the region. Populations of white-tailed deer in Mexico are subject to a range of management challenges. Additional research is needed to understand the effect of management on the diversity and genetic structure of white-tailed deer. El venado de cola blanca (Odocoileus virginianus) se distribuye en un amplio rango latitudinal desde el sur de América hasta Canadá. De las 38 subespecies reconocidas, 14 habitan en México. Debido al número limitado de estudios genéticos en Latinoamérica, la diversidad y estructura poblacional del venado de cola blanca en México es desconocida. En este estudio, muestreamos venado de cola blanca de 13 sitios ubicados dentro del rango de distribución de 5 subespecies de México, O. v. texanus, O. v. carminis, O. v. veraecrucis, O. v. sinaloae, and O. v. yucatanensis. La diversidad y estructura genética fue estimada con 12 marcadores microsatélites. La heterocigosidad observada fue comparable a lo observado en el venado de cola blanca de Norteamérica (HO = 0.53–0.64), con excepción de O. v. yucatanensis (HO = 0.41). Se observó una estructura genética significativa entre los 13 sitios de muestreo (FST = 0.15). El análisis de varianza molecular reveló que los sitios de muestreo agrupados por subespecie (FSC = 0.09) o región geográfica (FSC = 0.13–0.14) explicaron una porción moderada de la variación genética. Sin embargo, la diferenciación entre las poblaciones no fue minimizada a un nivel de agrupamiento mayor, es decir dentro de subespecies o grupos regionales (FST = 0.16–0.20). La distancia genética entre sitios de muestreo estuvo correlacionada con la distancia geográfica (r2 = 0.38), pero algunos sitios geográficamente próximos estuvieron genéticamente diferenciados (FST > 0.20), especialmente en Yucatán. El venado de cola blanca de Yucatán fue diferenciado genéticamente de las otras subespecies y fue comparativamente el de menor diversidad genética, lo cual es consistente con la historia biogeográfica de la región. Las poblaciones de venado cola blanca en México están sujetas a diversos retos de manejo. Por lo tanto, se requiere de investigación adicional para comprender el efecto sobre su diversidad y estructura genética.

The white-tailed deer (Odocoileus virginianus) occurs over a broad latitudinal range from South America to Canada. Thirty-eight subspecies are recognized, 14 of which occur in Mexico. Genetic studies in Latin America are lacking and the diversity and structure of white-tailed deer in Mexico are unknown. We sampled white-tailed deer from 13 sites in the range of 5 subspecies occurring in Mexico, O. v. texanus, O. v. carminis, O. v. veraecrucis, O. v. sinaloae, and O. v. yucatanensis. We estimated genetic diversity and structure based on 12 microsatellite DNA loci. Observed heterozygosity (H^sub O^) was comparable to that of white-tailed deer in the United States (H^sub O^ = 0.53-0.64), with the exception of O. v. yucatanensis (H^sub O^ = 0.41). We observed statistically significant genetic structure among all 13 sites (F^sub ST^ = 0.15). Analysis of molecular variance revealed that grouping sites by subspecies (F^sub SC^ = 0.09) or geographic region (F^sub SC^ = 0.13-0.14) explained a moderate portion of genetic variation. However, no higher-level group minimized differentiation among populations within the subspecies or regional groups (F^sub ST^ = 0.16-0.20). Pairwise genetic distances among sites were correlated with geographic distance (r^sup 2^ = 0.38), but some geographically proximate sites were genetically differentiated (F^sub ST^ > 0.20), especially in the Yucatan. Deer in the Yucatan were genetically differentiated from other subspecies and had comparatively lower genetic diversity, consistent with the biogeographic history of the region. Populations of white-tailed deer in Mexico are subject to a range of management challenges. Additional research is needed to understand the effect of management on the diversity and genetic structure of white-tailed deer. [PUBLICATION ABSTRACT]