Genome-wide diversity, linkage disequilibrium, and admixture in the main Colombian Creole pig breeds.

Colombian Creole pigs have adapted to tropical conditions for over 500 years. They have been modified by natural and artificial selection in different regions. At present, the diversity and current introgression status are unknown. The objective was to estimate the genomic diversity, linkage disequilibrium, population structure, and admixture of four Colombian pig breeds and their relationship with other breeds worldwide. Three Colombian pig breeds (SPE-San Pedreño, 11 samples; ZUN-Zungo, 11 samples; CM-Casco de Mula, ten samples) from the conservation nucleus and one biotype not recognized as a breed (CCH-Criollo Chocoano, seven samples) were genotyped using the Illumina GGP-Porcine80K chip. Open-access data from seven international breeds were also included. Colombian Creole pigs showed moderate genetic differentiation (FST 0.14) globally, but several groups of animals separated, suggesting local clustering due to geographical isolation or different founding effects. Colombian Creole pigs showed breed imprinting and specific grouping in all analyses except for CCH, which, like the Ecuadorian Creole, was a cluster of admixtures. The Colombian Creole pigs revealed a significant relationship with the Iberian pig and some other breeds to varying degrees. However, good maintenance of the conservation nucleus was evidenced. Potential adaptive genes, mainly related to immunological functions, were found, according to FST and pcadapt analyses. This study provides a foundation and scientific data for policy decisions on zoogenetic resources.

Genome-wide association study for reproduction traits in Colombian Creole Blanco Orejinegro cattle.

The profitability of the beef cattle production system relies heavily on reproductive traits. Unfortunately, certain traits, such as age at first calving (AFC), calving interval (CI), and gestation length (GL), can pose challenges in traditional breeding programs because of their low heritability (0.01-0.12) and sex-limited characteristics. Another important aspect is the conservation of the genetic resources of animals adapted to the Colombian regions, which implies the preservation and rational use of the creole breeds in the country market. Therefore, this study aimed to identify genomic regions in the creole cattle breed Blanco Orejinegro (BON) that influence the reproductive traits in females. The dataset comprised 439 animals and 118,116 single-nucleotide polymorphisms' (SNPs) markers. The GS3 program was used to identify the SNP effects employing the BAYES Cπ methodology. The number of SNPs with effect for AFC was 25, 1527 for CI, and 23 for GL. Some of the genes found associated with reproductive and growth traits as well as immune response and environmental adaptation ECE1, EPH, EPHB2, SMARCAL1, IGFBP5, IGFBP2, FCGRT, EGFR, MUL1, PINK1, STPG1, CNGB1, TGFB1, OXTR, IL22RA1, MYOM3, OXTR, CNR2, HIVEP3, CTPS1, CXCL8, FCGRT, MREG, TMEM169, PECR, and MC1R. Our results evidenced a high contribution of the genetic architecture of the Colombian creole cattle breed Blanco Orejinegro that may impact should be included in implementing genetic improvement and conservation programs.

Antibody seropositivity for Neospora caninum in Blanco Orejinegro cattle in Colombia and factors associated with the infection.

Neosporosis is a parasitic disease that causes abortions and economic losses in bovine production systems, but no studies have been found concerning its effect on the Creole cattle breed, Blanco Orejinegro (BON). The aim of this research was to establish the serological status of Colombian BON cattle against Neospora caninum and to determine the factors associated with seropositivity. Blood samples were taken from 363 animals from 13 herds in six states of Colombia, and analyzed by indirect ELISA using a commercial test. Information on sex, herd, generation group, and state was recorded. A survey was carried out with 26 questions related to productive, reproductive, and health factors per herd. A logistic regression analysis was performed and the ORs for significantly associated variables were estimated using the R software. General seropositivity of 73.5% (95% CI 68.6-77.9%) was obtained, and sex, age group, and herd were the variables significantly associated with seropositivity (p < 0.05). For the sex variable, seroprevalence levels of 79.6% (95% CI 74.3-84.1%) were recorded for females and 54.5% (95% CI 43.6-65.1%) for males. Herd seroprevalence varied between 58.3 and 95.8%, and the last generation showed the lowest positivity (51.2%, 95% CI 42.1-60.2%). The inadequate disposal of fetuses was a risk factor, while carrying out serological tests to new animals that enter the herd, the use of new gloves and palpation utensils for each animal, supplementation, and stabling were stated as protective factors. No effect of positivity was found in the last calving interval. The implementation of bovine neosporosis control programs to support breeding and conservation programs of the BON breed in Colombia is recommended.