RESUMO
Objective: The objective of this study was to associate the 1016G > A variant of the melanocortin-4 receptor gene with lamb's weight, growth, and meat quality in the Colombian hair sheep breed. Materials and Methods: A total of 168 lambs, weights were measured at birth weight (BW), at weaning adjusted weaning weight (AWW), at 6 months [adjusted weight (AW180)], at slaughter adjusted slaughter weight (ASW), daily weight gain preweaning daily gain (preWDG), and postweaning daily gain (postWDG) weaning, and after slaughter, pH, texture, and cook-loss (CL) in the longissimus thoracis et lumborum (LTL) muscle according to the American Meat Science Association methodology. The 1016G > A genotypes were obtained by sequencing. Genotypic and allele frequencies, heterozygosities, and Hardy-Weinberg equilibrium (HWE) were estimated. Using a generalized linear model, the genotype and the allelic substitution effect were associated with the evaluated traits. Results: The heterozygous genotype (0.48) and G allele (0.61) were the most frequent. Heterozygosities were similar (0.47), indicating HWE. The genotype affected the BW (p < 0.05), with a higher value for the GG genotype (2.69 kg). AWW (12.75 kg), AW180 (19.67 kg), and ASW (31.21 kg) weights and daily weight gain (preWDG = 115.41 gm; postWDG = 96.16 gm) were not associated. Average pH, Warner-Bratzler shear force, and CL were 5.75 units, 49.46 N, and 32.02%, with no genotype effect. The G > A substitution only affected BW at -388 gm (p < 0.05). Conclusion: The 1016G > A variant is polymorphic and affects the BW but not other growth traits or the meat quality of the LTL muscle.
RESUMO
In Colombia, works performed with the colombian creole donkey (CCD) have shown a possible danger of extinction. The above, associate with an alarming decrease in its inventory and a reduction in genetic diversity. Thus, morphological characterization could be the first step for future conservation plans to conduct a repopulation. Therefore, this work aimed to characterize the zoometric and ethnological traits of CCD in five natural subregions of the department of Sucre. 20 males from each of the natural subregions from Sucre (Golfo de Morrosquillo: GM, Montes de María: MM, Mojana: MO, San Jorge: SJ, Sabanas: SA) with an age average of 4.7 ± 1.0 years old and weight estimated between 126.0 ± 19.4 kg were recorded and were submitted to 28 morphometric measurements. Descriptive statistics, analysis of variance between subregions, and hierarchical grouping for statistical analysis were performed. Also, five ethnological indices and five productive indices were estimated. The results showed that most of the zoometric variables varied significantly between subregions. The values assessed were similar to other creole donkey breeds. The hierarchical grouping analysis allowed the creation of two groups with geographic proximity. The structural homogeneity and morphostructural harmony found within the subregions were medium-low. However, when analyzing all the CCD measurements together, medium to high morphostructural uniformity and harmony were evidenced. The ethnological indices allow us to classify the CCD as a longlinear, hypermetric, dolichocephalic, and concavilinear animal. In addition, the productive indices indicated that the CCD is a proportionate donkey, with good poise and aptitude for work.
Es posible que el asno criollo colombiano (ACC) se encuentre en peligro de extinción. La alarmante disminución de su inventario está reduciendo la diversidad genética. Así, la caracterización morfológica es un primer paso en futuros planes de conservación, con el objetivo de repoblación; por tanto, el objetivo de esta investigación fue caracterizar zoométricamente y etnológicamente el ACC, de las cinco subregiones naturales del departamento de Sucre. En 20 machos de cada una de las subregiones naturales del departamento de Sucre (Golfo de Morrosquillo: GM, Montes de María: MM, Mojana: MO, San Jorge: SJ, Sabanas: SA), con edad promedio de 4,7 ± 1,0 años y peso promedio estimado de 126,0 ± 19,4kg, se registraron 28 medidas morfométricas. En el análisis de datos, se consideró la estadística descriptiva, el análisis de varianza entre subregiones, análisis de agrupación jerárquica. También, se estimaron cinco índices etnológicos y cinco índices productivos. La mayoría de las variables zoométricas variaron significativamente entre subregiones, con valores similares a otras razas criollas. El análisis de agrupación jerárquica formó dos grupos con cercanía geográfica. La homogeneidad estructural y la armonía morfoestructural encontrada al interior de las subregiones fue media-baja; sin embargo, al analizar todo el ACC, la homogeneidad y la armonía morfoestructural fue media-alta. Los índices etnológicos clasifican al ACC como longilíneo, hipermétrico, dolicocéfalo y concavilíneo, mientras que los índices productivos indican de un asno proporcionado, de buenos aplomos y de aptitud al trabajo.
RESUMO
The objective of this study was to evaluate the genetic diversity of ball-DRB3 gene in the Colombian creole Hartón del Valle cattle. A total of 93 Hartón del Valle (HV), 30 Lucerne (LUC), and 30 Holstein (HOL) animals were evaluated for DRB3 gene polymorphism using the PCR-SBT method. The number of alleles found were 27, 17 and 14 for HV, LUC, HOL, respectively. The most frequent alleles were DRB3*1101 (14.5%) in HV; LUC DRB3 * 0701 in LUC; and *1107, *1501 and *2301 in HOL (11.7%). Expected heterozygosity values were higher than observed, which resulted in a low fixing index, positive F IS (significant only for HV), and no significant deviations from Hardy- Weinberg equilibrium for LUC. The molecular analysis of variance reflected little variation between breeds (3%) and a moderate genetic differentiation (F ST = 0.056 p<0.01). Regarding sequence, LUC was the most diverse breed, no neutral selection is occurring, and none of the breeds is in selection equilibrium. Comparison with reports on other breeds showed high genetic diversity in Colombian breeds. We conclude that HV has high genetic diversity in BoLA-DRB3 locus. The cause of this polymorphism may be due in part to the origin of HV. This high variation can be maintained by selection equilibrium.
El objetivo de esta investigación fue evaluar la diversidad genética del gen BoLA-DRB3 en el ganado criollo Colombiano Hartón del Valle. En 93 animales Hartón del Valle (HV), 30 Lucerna (LUC) y 30 Holstein (HOL) se evaluó el polimorfismo del gen DRB3 usando la metodología PCR-SBT. Se encontraron 27 alelos en la raza HV, 17 en LUC y 14 en HOL. El alelo más frecuente en HV fue el DRB3*1101 (14,5%), en la raza LUC los alelos DRB3*0701, *1107, *1501 y *2301 al igual que el alelo DRB3*0701 en la raza HOL tuvieron la frecuencia más alta (11,7%). Los valores de heterocigocidad esperada fueron más altos que la observada, lo que se tradujo en un valor bajo del índice de fijación, valores de F IS positivos solo significativo en el HV y desviaciones del equilibrio de Hardy-Weinberg no significativos en LUC. El análisis de varianza molecular reflejó poca variación entre razas (3%) y una diferenciación genética moderada (F ST= 0,056 p<0,01). A nivel de secuencia se resalta que, la raza más diversa es LUC, que no se está presentando selección neutral y que ninguna de las razas se encuentra en equilibrio de selección balanceadora. La comparación con otras razas reportadas, mostró alta diversidad genética en las razas colombianas. Se concluye que la raza HV tiene alta diversidad genética en el locus BoLA-DRB3, que el origen del polimorfismo puede deberse en parte al origen de la raza y que esta alta variación puede ser mantenida mediante equilibrio de selección.
O objetivo desta pesquisa foi avaliar a diversidade genética do gene BoLA-DRB3 no gado crioulo colombiano Hartón del Valle. O estudo se fez com 93 animais Hartón del Valle (HV), 30 Lucerna (LUC) e 30 Holandês (HOL). Avaliou-se o polimorfismo do gene DRB3 utilizando a metodologia PCR-SBT. Encontraram-se 27 alelos na raça HV, 17 em LUC e 14 em HOL. O alelo com maior frequência em HV foi o DRB3*1101 (14,5%), na raça LUC os alelos DRB3*0701, *1107, *1501 e *2301 ao igual que o alelo DRB3*0701 na raça HOL tiveram a maior frequência (11,7%). Os valores de heterocigocidade esperada foram maiores que a observada, o que se traduz em um valor baixo do índice de fixação, valores de F IS positivos só foram significativos no HV e desvio do equilíbrio de Hardy- Weinberg foram não significativos em LUC. O Analice de variância molecular reflexou pouca variação entre raças (3%) e uma diferenciação genética moderada (F ST= 0,056 p<0,01). No nível de sequência destacasse que, a raça mais diversa é LUC, que não está apresentando seleção neutral e que nenhuma das raças encontra-se em equilíbrio de seleção balanceadora. Se comparar com outras raças reportadas, as raças colombianas exibiram uma alta diversidade genética. Conclui-se que a raça HV tem alta diversidade genética no locus BoLA DRB3, que a origem do polimorfismo pode se dever em parte àorigem da raça e que essa alta variação pode ser mantida mediante o equilíbrio de seleção.