BackgroundAmerican Creole cattle presumably descend from animals imported from the Iberian Peninsula during the period of colonization and settlement, through different migration routes, and may have also suffered the influence of cattle directly imported from Africa. The introduction of European cattle, which began in the 18th century, and later of Zebu from India, has threatened the survival of Creole populations, some of which have nearly disappeared or were admixed with exotic breeds. Assessment of the genetic status of Creole cattle is essential for the establishment of conservation programs of these historical resources.Methodology/Principal FindingsWe sampled 27 Creole populations, 39 Iberian, 9 European and 6 Zebu breeds. We used microsatellite markers to assess the origins of Creole cattle, and to investigate the influence of different breeds on their genetic make-up. The major ancestral contributions are from breeds of southern Spain and Portugal, in agreement with the historical ports of departure of ships sailing towards the Western Hemisphere. This Iberian contribution to Creoles may also include some African influence, given the influential role that African cattle have had in the development of Iberian breeds, but the possibility of a direct influence on Creoles of African cattle imported to America can not be discarded. In addition to the Iberian influence, the admixture with other European breeds was minor. The Creoles from tropical areas, especially those from the Caribbean, show clear signs of admixture with Zebu.Conclusions/SignificanceNearly five centuries since cattle were first brought to the Americas, Creoles still show a strong and predominant signature of their Iberian ancestors. Creole breeds differ widely from each other, both in genetic structure and influences from other breeds. Efforts are needed to avoid their extinction or further genetic erosion, which would compromise centuries of selective adaptation to a wide range of environmental conditions.

Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding.

Conservation and improvement strategies in farm animals should be based on a combination of genetic and phenotypic characteristics. Genotype data from 30 microsatellites were used to assess the genetic diversity and relationships among five Cuban cattle breeds (Siboney de Cuba, Criollo Cubano, Cebú Cubano, Mambí de Cuba and Taíno de Cuba). All microsatellite markers were highly polymorphic in all the breeds. The expected heterozygosity ranged from 0.67 ± 0.02 in the Taíno de Cuba breed to 0.75 ± 0.02 in the Mambí de Cuba breed, and the observed heterozygosity ranged from 0.66 ± 0.03 in the Cebú Cubano breed to 0.73 ± 0.02 in the Siboney de Cuba breed. The genetic differentiation between the breeds was significant (p < 0.01) based on the infinitesimal model (F(ST)). The exact test for Hardy-Weinberg equilibrium within breeds showed a significant deviation in each breed (p < 0.0003) for one or more loci. The genetic distance and structure analysis showed that a significant amount of genetic variation is maintained in the local cattle population and that all breeds studied could be considered genetically distinct. The Siboney de Cuba and Mambí de Cuba breeds seem to be the most genetically related among the studied five breeds.

ResumenEn el presente estudio se presentan los primeros resultados de la determinación de la estructura genética de tres poblaciones de ganado bovino autóctono cubano: Criollo de Cuba, Cebú Cubano y Siboney de Cuba, para los loci de seis proteínas lácteas (CASA1, CASAB, CASA2, CASK, LAA y LGB). Se analizaron un total de 150 individuos (50 por cada raza), mediante análisis de ADN por PCR-RFLP.Se calcularon las frecuencias alélicas para cada locus así como condiciones de equilibrio de Hardy-Weinberg. Fueron identificados los alelos CASA1C y LAAA como evidencia de la presencia de genes de Bos indicus en las tres poblaciones cubanas. Se comprobó la existencia de elevada variabilidad en cada población lo que constituye un elemento importante para trazar estrategias de mejoramiento y/o conservación genética.

Artisan fresh cheese producing farms from six provinces of Cuba were studied to identify the presence of bacterial hazards and the results are presented in this research communication. The bacterial hazards identified in milk and cheese respectively were: Listeria spp. (9.5 and 18.9%), Bacillus cereus (23.2 and 24.2%), Escherichia coli O157 (12.6 and 13.7%), Salmonella spp. (10.5 and 17.9%), and Staphylococcus aureus (29.5 and 51.6%). Listeria monocytogenes was not detected. Nine Salmonella serotypes corresponding to Salmonella enterica subsp. enterica and Salmonella enterica subsp. arizonae were isolated, whereas Salmonella Anatum was present most often. Biofilm formation by the isolated species and enterotoxin production by S. aureus strains demonstrated the pathogenic potential of the identified bacterial hazards. Results proved the presence of bacterial hazards in the raw milk and cheeses analyzed, so that good manufacturing practices must be accomplished throughout the entire production process in order to avoid the occurrence of foodborne diseases in the population.