Economic utility of Colombian Romosinuano cattle.

The objective of this study was to quantify the economic utility in Romosinuano production systems by developing a bioeconomic model assumed cow-calf, cow-calf plus stocker (CCPS), and complete cycle operations. Each system produced males for sale and females for replacement. Input parameters were established from breed data collected by AGROSAVIA. Revenues were estimated using the official cattle price, and production costs were quantified per activity. In the results, for cow-calf operations, the maximum economic utility was 244.12 USD. CCPS, yielded 231.86 USD, and Complete cycle, 268.94 USD. The genetic progress per generation for W240, W480, W24 and CI was + 3.8 kg, + 5 kg, + 5.9 kg, and -1 d, respectively. The price of livestock was the sensitized variable with the greatest impact on maximum economic utility (± 118.64 USD to ± 155.44 USD), followed by mineral supplementation (16.31 USD to ± 37.34 USD). The sensitized variables with the lowest impact were food (± 1.62 USD to ± 1.8 USD) and health plan supplies (± 6.03 USD to ± 9.13 USD). It is concluded that economic utility defined as a composite trait influenced by the characteristics that shape it favors genetic progress and the identification of animals with optimal performance in different bovine production systems.

Selection indexes using principal component analysis for reproductive, beef and milk traits in Simmental cattle.

Selection indexes in dual-purpose cattle should include beef, milk and reproductive traits. The principal component analysis is a multivariate technique that allows researchers to explore relationships between explanatory variables and traits of interest. The objective of this study was to construct selection indexes for tropical dual-purpose Simmental cattle based on principal components. The evaluated traits were weight at 8 months of age; age at first calving; cumulative first-lactation milk yield at 60, 150, 210 and 305 days; and first calving interval. The selection indexes were estimated as the sum of the products of the estimated breeding values for the seven traits times their respective eigenvectors for the first three principal components. The three selection indexes from principal components analysis generated favourable expected genetic progress for all the traits. However, a selection index with a high expected genetic progress for all traits could not be obtained. The principal component analysis allows breeders to have a selection index that simultaneously improves milk, beef and reproductive traits in dual-purpose Simmental cattle. Because a selection index yielding high expected genetic progress for all traits could not be achieved, the decision to use a specific selection index will depend on the specific conditions of the market, the local needs and the farmer preference.

Population structure and genetic diversity in Colombian Simmental cattle.

A vital requirement to design and implement a breeding program is to know the structure and genetic diversity of a population. The aim of this study was to characterize population structure and genetic diversity of the Colombian Simmental cattle. The pedigree file included 27,985 animals born from 1975 to 2017. The level of genetic diversity and breed structure was evaluated through probabilities of gene origin expressed via effective number of founders, ancestors and founders genomes. The inbreeding rates and the degree of genetic connectivity were estimated using a regression analysis and a genetic drift variance analysis, respectively. The lowest effective number of founders and ancestors were 50 and 38 by year, respectively. The average inbreeding by year of birth decreased from 5.06% in 1980 to 2.25% in 2017. The dairy line genetic contributions in the overall population increased significantly in the last 37 years, and the beef line contribution decreased. Regarding the genetic connectivity, Colombian regions (administrative divisions) with the largest cattle population had higher values. The results indicate that the availability of European and North American bulls contributes to genetic diversity by increasing the effective number of founders over time in the Colombian Simmental cattle population. However, the intensive use of relatively few founders causes an unbalanced genetic contribution and the loss of genetic diversity by gene pool erosion.

Genetic selection indices for growth traits in Blanco-Orejinegro cattle.

Selection indices are used in genetic improvement programs, with the purpose of selectins simultaneous for several economically important traits. The objective of this study was to construct equations for selection indices in the Blanco-Orejinegro (BON) breed and to determine the index that would generate the greatest genetic progress. The information used included birth weight (BW), body weights adjusted to 120, 240, 480, and 720 days old (W120, W240, W240, 480 and W720, respectively), age at first calving (AFC) and interval between first and second calving (IBC) estimated breeding values. Two Smith and Hazel indices were calculated using variances (I1) and literature (I2), with a part two indices designed using information from experts and breeders (I3 and I4). All the indices favored the reduction of weight at birth. The I1 focused mainly on W120 and I2, I3 and I4 focused on 720. In general, the estimated indices obtained similar reliability and expected genetic differences I1 generated a decrease in direct BW. I2 generated the largest increases in BW and AFC. I3 and I4 generated positive changes in growth and reproductive traits, with I3 generating the greatest genetic gains in the population, especially for W240.

Genetic parameters and trends for growth traits in Blanco Orejinegro cattle.

Since 1940, efforts have been made to preserve the Blanco Orejinegro (BON) cattle breed by maintaining gene banks. Nine years ago, a BON genetic improvement program was implemented to increase genetic gain based on control of productivity and the use of performance tests, polygenic and genomic evaluations, and selection indices. The objective of this study was to estimate genetic parameters and trends for growth traits by using polygenic (PM) and genomic-polygenic (GPM) models. Productive information from the years 1980 to 2019 was used. The following data were used: 7,304 birth weight (BW) records, 1,281 records of body weight adjusted to 120 days (W120), 4,791 records of weight adjusted to 240 days (W240), 3,339 records of weight adjusted to 480 days (W480), and 1,364 records of weight adjusted to 720 days (W720). The relationship matrix included 13,612 pure animals belonging to the Colombian Corporation for Agricultural Research - AGROSAVIA and the Producer Network program. A total of 1,224 individuals were genotyped with chips of different densities and all were imputed up to 50,932 SNPs. Polygenic and genomic-polygenic models were used to estimate genetic parameters and correlations between the genetic values estimated by each model. A generalized additive model with smoothing was used to estimate trends of genetic values from 1980 to 2019. Heritabilities between 0.29 and 0.40, genetic correlations between 0.13 and 0.94, and phenotypic correlations between 0.23 and 0.72 were observed. Close-to-zero genetic growth was observed for BW and W120. Genetic trends for the other traits were positive, with higher growth in the last 7 years. The heritabilities observed in this population indicate that the traits measured would respond to selection. Greater genetic progress can be achieved in W240, W480, and W720 by continuing with genetic evaluations and developing performance tests and strategies to make genetic material readily available to producers.

Prioridades de atención en zonas rurales en escenarios posconflicto: un análisis de minería de texto / Attention priorities in rural areas in post-conflict scenarios: a text mining analysis

RESUMEN Las herramientas automatizadas de análisis de texto resumen grandes volúmenes de información y permiten generar, de forma eficiente, conocimiento a partir de datos desestructurados, como las opiniones. El objetivo de este trabajo fue identificar prioridades en comunidades afectadas por el conflicto armado, utilizando ejercicios participativos de 13 municipios de Antioquia, Colombia. Se analizaron 15.534 opiniones, de 9.765 personas; tras una limpieza de texto, se describió el uso, la asociación, la diferenciación y la importancia de los términos, según los enfoques temáticos y tipos de opinión expresados, utilizando minería de texto en R. Se encontró que las prioridades giraban en torno a la disponibilidad de infraestructuras, dotación e insumos, ya que eran las problemáticas más mencionadas por las comunidades y correspondía con la realidad territorial; por otra parte, las oportunidades estaban representadas, principalmente, por los recursos naturales y humanos. El análisis de minería de texto del ejercicio participativo permitió identificar las prioridades de las comunidades, a nivel socioeconómico, de forma satisfactoria; sin embargo, la preparación de la información requiere mucho trabajo y los resultados se deben revisar cuidadosamente, para asegurar su coherencia. Que la información pueda ser analizada por agentes externos a la colección de datos, representa otra ventaja de esta herramienta.

ABSTRACT Automated text analysis tools summarize large volumes of information and allow efficient generation of insights from unstructured data such as opinions. The objective of this work was to identify priorities in communities affected by the armed conflict using participatory exercises in 13 municipalities of Antioquia, Colombia. 15,534 opinions from 9,765 people were analyzed. After a text cleaning, the use, association, differentiation and importance of the terms were described according to the thematic approaches and types of opinion expressed using text mining in R. It was found that the priorities revolved around the availability of infrastructures, endowment and inputs, since they were the most mentioned problems by the communities, and that this corresponded to the territorial reality. On the other hand, the opportunities were mainly represented by natural and human resources. The text mining analysis of the participatory exercise allowed to identify the priorities of the communities at the socio-economic level in a satisfactory way. However, the preparation of the information is labor intensive and the results must be carefully reviewed to ensure consistency. Another advantage of this tool is that the information can be analyzed by external agents to the data collection.

Influence of attitudes and behavior of milkers on the hygienic and sanitary quality of milk.

Recognizing how human behaviors affect the milk process can be useful to understand variations in hygienic and sanitary parameters in bulk tank milk. Furthermore, this knowledge could be used to design management programs that guarantee milk quality, favoring the optimization of such processes. Forty-six milkers from the same number of dairy farms in Antioquia province (Colombia) were interviewed to establish the main factors associated to milk quality. Technical knowledge, motivations, and behavior of the personnel and its effect on hygienic and sanitary quality of milk were evaluated. Quality was assessed in terms of colony-forming units (CFU) and somatic cell count (SCC) in bulk tank milk. Two factors from a multivariate mixed data analysis were evaluated. One of those factors explained 9.51% of the total variability, related with in-farm availability and use of tools and the relationships between milker and manager. The other factor, associated with work environment and recognition, explained 6.97% of the total variability. The variables that best explained CFU levels were Knowledge of the udder condition at milking, and Milking type (parlor or pasture). The SCC was associated to knowledge of animal handling, schooling of milkers, milking site, and the groups derived from the cluster analysis by farm. In conclusion, milker attitudes and behaviors can affect CFU and SCC in bulk tank milk.

Caracterización de Sistemas de Producción Industrial de Pollo de Engorde en el Departamento de Santander-Colombia / Characterization of Broiler Production Systems in Santander Province-Colombia / Caracterização dos Sistemas deProdução Industrial de Frango de Corte no Departamento de Santander-Colômbia

Resumen Introducción: La producción de pollo de engorde es de gran interés para el departamento de Santander dada su alta participación dentro del PIB pecuario, lo que lo constituye en el principal centro avícola nacional. Es importante conocer las condiciones bajo las cuales se realiza la producción de pollo de engorde e identificar el potencial que tienen estos sistemas de producción. Objetivo: caracterizar los sistemas de producción industrial de pollo de engorde ubicados en el departamento de Santander. Materiales y métodos: Para el desarrollo del trabajo se contó con información proveniente de 79 predios avícolas los cuales se encontraban ubicados en 4 provincias: Metropolitana, Soto, Guanentá y Yariguíes. Se realizó un análisis de clúster y se generó un índice de adopción tecnológica. Resultados: Se encontró que existe variación en la adopción de tecnologías, siendo las más frecuentes las tecnologías blandas. Santander obtuvo un índice de adopción tecnológica bajo. Conclusiones: El sector avícola del departamento de Santander posee un bajo índice de adopción tecnológica, lo cual sugiere la necesidad de evaluar el efecto que esto tiene sobre los resultados productivos con miras al incremento de la productividad a largo plazo en la zona.

Abstract Introduction: Broiler production is of great interest to Santander given its high participation in the livestock GDP of this province, which makes it the main Colombian poultry center. It is important to know the conditions under which broiler production takes place and to identify the potential of these production systems. Objective: To characterize the industrial broiler production systems located in Santander province. Methods: Information from 79 poultry farms located in 4 provinces (Metropolitana, Soto, Guanentá and Yariguíes) was used. A cluster analysis was performed, and a technology adoption index was generated. Results: Variations in technology adoption were observed. The most frequently adopted were soft technologies. The technology adoption rate for the overall province was low. Conclusions: The poultry sector of the department of Santander has a low technology adoption index, which suggests the need to evaluate the effect that this has on the productive results, with a view to increasing productivity in the long term.

Resumo Introdução: A produção de frangos de corte é de grande interesse para o departamento de Santander, devido à sua elevada participação no PIB da pecuária, o que o torna como o principal pólo avícola nacional. É importante conhecer as condições em que ocorre a produção de frangos de corte e identificar o potencial que esses sistemas de produção possuem. Objetivo: Caracterizar os sistemas de produção industrial de frangos de corte localizados no departamento de Santander. Materiais e Métodos: Para o desenvolvimento do trabalho, foram disponibilizadas informações de 79 granjas avícolas localizadas em 4 províncias: Metropolitana, Soto, Guanentá e Yariguíes. Uma análise de cluster foi realizada e um índice de adoção de tecnologia foi gerado. Resultados: Constatou-se que há variação na adoção de tecnologias, sendo as mais frequentes as tecnologias leves. O Santander obteve um baixo índice de adoção de tecnologia. Conclusões: O setor avícola do departamento de Santander tem um baixo índice de adoção tecnológico, o que sugere a necessidade de avaliar o efeito que isso tem nos resultados produtivos, com vistas a aumentar a produtividade no longo prazo.

Semiparametric Modeling of Daily Ammonia Levels in Naturally Ventilated Caged-Egg Facilities.

Ammonia concentration (AMC) in poultry facilities varies depending on different environmental conditions and management; however, this is a relatively unexplored subject in Colombia (South America). The objective of this study was to model daily AMC variations in a naturally ventilated caged-egg facility using generalized additive models. Four sensor nodes were used to record AMC, temperature, relative humidity and wind speed on a daily basis, with 10 minute intervals for 12 weeks. The following variables were included in the model: Heat index, Wind, Hour, Location, Height of the sensor to the ground level, and Period of manure accumulation. All effects included in the model were highly significant (p<0.001). The AMC was higher during the night and early morning when the wind was not blowing (0.0 m/s) and the heat index was extreme. The average and maximum AMC were 5.94±3.83 and 31.70 ppm, respectively. Temperatures above 25°C and humidity greater than 80% increased AMC levels. In naturally ventilated caged-egg facilities the daily variations observed in AMC primarily depend on cyclic variations of the environmental conditions and are also affected by litter handling (i.e., removal of the bedding material).

Population genetic structure of two herds of Aberdeen Angus cattle breed in Colombia / Estructura genética poblacional de dos hatos de ganado bovino Aberdeen Angus en Colombia / Estrutura genética da população de dois rebanhos da raça Aberdeen Angus na Colômbia

Abstract Background: Two biotypes of Aberdeen Angus cattle breed, known as Old Type and New Type, that differ in their origin and beef production are formally recognized. In Colombia, this breed has been commercialized for approximately 80 years. Studies on the origin, kinship and levels of genetic diversity of this breed in Colombian herds are scarce, yet important for planning crossing and management strategies. Objective: To measure the genetic diversity and structure of two Colombian herds of Old Type and New Type biotypes of Aberdeen Angus from Huila and Cundinamarca provinces and assess mitochondrial introgression with other breeds. Methods: A set of ten microsatellites and sequences of the Mitochondrial Control Region were characterized. Estimators of genetic diversity and population differentiation along with tests of population assignment were applied. Results: Nuclear loci were highly polymorphic as shown by the Polymorphic Information Content (0.599) and the Probability of Identity (1.896 10-08). Both populations were highly diverse and clearly differentiated into two groups corresponding to the Old Type and New Type phenotypes. In contrast, mitochondrial data failed to distinguish these two groups and showed extensive admixture. Conclusions: This study optimized a set of ten highly polymorphic nuclear markers that may be used for parentage and population genetic studies of Aberdeen Angus. Genetic differentiation in these loci agreed with phenotypic differences of the Old and New Types. However, mitochondrial data indicated ancestry of multiple European breeds in the origin of Colombian Aberdeen Angus.

Resumen Antecedentes: Dentro de la raza Aberdeen Angus existen dos biotipos conocidos como Old Type y New Type, las cuales difieren en su origen y producción de carne. En Colombia, esta raza se ha venido comercializando desde hace aproximadamente 80 años. No obstante, aún no se han realizado estudios sobre su origen, parentesco y niveles de diversidad genética de esta raza en hatos colombianos, lo cual es importante para planear estrategias de cruce y manejo. Objetivo: Medir la diversidad y estructura genética de dos hatos colombianos de Aberdeen Angus Old Type y New Type de Huila y Cundinamarca y evaluar la introgresión mitocondrial con otras razas. Métodos: Se caracterizó un grupo de diez loci microsatélite y se secuenció la Región Control Mitocondrial. Se aplicaron estimadores de diversidad genética y diferenciación poblacional, junto con pruebas de asignación poblacional. Resultados: Los loci microsatélite fueron altamente polimórficos, tal como lo indicaron el Contenido de Información Polimórfica (0,599) y la Probabilidad de Identidad (1,896 10-08). Las poblaciones evaluadas de Aberdeen Angus en Colombia fueron altamente diversas y se diferenciaron claramente en dos grupos correspondientes a los fenotipos Old Type y New Type. En contraste, los datos mitocondriales no recobraron estos dos grupos y mostraron una amplia mezcla genética. Conclusiones: Este estudio optimizó un grupo de diez marcadores altamente polimórficos que pueden ser usados para estudios de parentesco y genética poblacional de Aberdeen Angus. La diferenciación genética en loci nucleares concordó con las diferencias fenotípicas entre Old y New Types, pero los datos mitocondriales indicaron ancestría de múltiples razas europeas en el origen del Aberdeen Angus colombiano.

Resumo Antecedentes: Dentro da raça Aberdeen Angus há dois biótipos conhecidos como Old Type e New Type, que diferem em sua origem e produção de carne. Na Colômbia, esta raça é comercializada há aproximadamente 80 anos. Entretanto, estudos sobre a origem, o parentesco e os níveis de diversidade genética desta raça em rebanhos colombianos ainda não foram realizados, o que é importante para o planejamento de cruzamentos e estratégias de manejo. Objetivo: Medir a diversidade genética e a estrutura de dois rebanhos colombianos de biótipos de Old Type e New Type de Aberdeen Angus de Huila e Cundinamarca e avaliar a introgressão mitocondrial com outras raças. Métodos: Um grupo de dez loci de microssatélites foi caracterizado e a Região de Controle Mitocondrial foi sequenciada. As estimativas de diversidade genética e diferenciação populacional foram aplicadas, juntamente com testes de designação populacional. Resultados: Os locus microssatélites foram altamente polimórficos, conforme indicado pelo Conteúdo de Infomação Polimórfica (0,599) e Probabilidade de Identidade (1,896 10-08). As populações avaliadas de Aberden Angus na Colômbia eram altamente diversificadas e claramente diferenciadas em dois grupos correspondentes aos fenótipos do Old Type e New Type. Em contraste, os dados mitocondriais não recuperaram esses dois grupos e mostraram um amplo mix genético. Conclusões: Este estudo otimizou um grupo de dez marcadores altamente polimórficos que podem ser usados para estudos genéticos de parentesco e população de Aberdeen Angus. A diferenciação genética nos loci nucleares concordou com as diferenças fenotípicas entre os Old e New Types, mas os dados mitocondriais indicam ancestralidade de várias raças européias na origem do Aberdeen Angus colombiano.

Comparison of random regression models, traditional animal model and with the inclusion of molecular markers in the estimation of genetic parameters in Colombian Holstein cattle / Comparação entre modelos de regressão aleatória, modelo animal tradicional e com a inclusão de marcadores moleculares na estimativa de parâmetros genéticos em bovinos da raça Holandesa Colombiana

The use of molecular markers to identify desirable genes in animal production is known as marker-assisted selection. The traditional genetic evaluation model uses the BLUP methodology; when genetic markers are included in the evaluation model, the methodology is known as M-BLUP. In contrast, random regression models (RRM), unlike the models based on production at 305 days, consider factors that change for each animal from one test to another. The objective of this study was to compare variance components, genetic parameters and breeding values for milk production, protein percentage and somatic cell score in Colombian Holstein cattle using BLUP, M-BLUP and RRM. For the estimation of genetic parameters and values, 2003 lactations corresponding to 1417 cows in 55 herds were used, and effects of the order of delivery, herd, and contemporary group were included. The three traits presented greater heritability under the MBLUP model: 0.44 for protein percentage, 0.27 for milk production and 0.28 for somatic cell score. This was because the genetic variance was greater when M-BLUP was used, which allowed a greater accuracy of the breeding value estimation in the three traits. Therefore, the model that includes information on molecular markers is more suitable for genetic evaluation in Colombian Holstein cattle.(AU)

O uso de marcadores moleculares para identificar genes desejáveis na produção animal é conhecido como seleção assistida por marcadores. O modelo tradicional de avaliação genética utiliza a metodologia BLUP, e quando os marcadores genéticos são incluídos no modelo de avaliação, a metodologia é conhecida como M-BLUP. Por outro lado, os modelos de regressão aleatória (RRM), ao contrário dos modelos baseados em produções a 305 dias, consideram fatores que mudam para cada indivíduo de um controle para outro. O objetivo deste estudo foi comparar componentes de variância, parâmetros e valores genéticos para produção de leite, percentagem de proteína e escore de células somáticas em gado holandês de Colômbia utilizando BLUP, M-BLUP e RRM. Para a estimativa de parâmetros e valores genéticos, foram utilizadas 2.003 lactações correspondentes a 1.417 vacas de 55 rebanhos e efeitos da ordem de parto, rebanho e grupo contemporâneo. Os três traços apresentaram maior hereditariedade no modelo MBLUP, 0,44 para percentagem de proteína, 0,27 para produção de leite e 0,28 para escore de células somáticas. Isso por causa da variância genética foi maior quando o M-BLUP foi utilizado, o que permitiu estimar maior precisão do valor genético nos três traços, portanto, o modelo que inclui informações sobre marcadores moleculares é mais adequado para avaliação genética em gado holandês colombiano.(AU)

Genetic Evaluation of Dual-Purpose Buffaloes (Bubalus bubalis) in Colombia Using Principal Component Analysis.

Genealogy and productive information of 48621 dual-purpose buffaloes born in Colombia between years 1996 and 2014 was used. The following traits were assessed using one-trait models: milk yield at 270 days (MY270), age at first calving (AFC), weaning weight (WW), and weights at the following ages: first year (W12), 18 months (W18), and 2 years (W24). Direct additive genetic and residual random effects were included in all the traits. Maternal permanent environmental and maternal additive genetic effects were included for WW and W12. The fixed effects were: contemporary group (for all traits), sex (for WW, W12, W18, and W24), parity (for WW, W12, and MY270). Age was included as covariate for WW, W12, W18 and W24. Principal component analysis (PCA) was conducted using the genetic values of 133 breeding males whose breeding-value reliability was higher than 50% for all the traits in order to define the number of principal components (PC) which would explain most of the variation. The highest heritabilities were for W18 and MY270, and the lowest for AFC; with 0.53, 0.23, and 0.17, respectively. The first three PCs represented 66% of the total variance. Correlation of the first PC with meat production traits was higher than 0.73, and it was -0.38 with AFC. Correlations of the second PC with maternal genetic component traits for WW and W12 were above 0.75. The third PC had 0.84 correlation with MY270. PCA is an alternative approach for analyzing traits in dual-purpose buffaloes and reduces the dimension of the traits.

Parámetros genéticos para crecimiento y reproducción en ganado Simmental mediante parentesco por pedigrí y genómico / Genetic parameters for growth and reproduction in Simmental cattle from pedigree and genomic relationship

RESUMEN Objetivo. Estimar parámetros genéticos para peso a los ocho meses de edad (W8M), edad al primer parto (AFC) y primer intervalo entre partos (FCI) usando parentesco genómico y por pedigrí. Materiales y métodos. Se utilizaron 481, 3063 y 1098 registros fenotípicos para W8M, AFC y FCI, respectivamente. La información genómica estuvo compuesta por una población de 718 animales genotipados con un chip que incluyó 30106 marcadores genéticos tipo polimorfismo de nucleótido simple (SNP). Modelos univariado y bivariado fueron construidos bajo la metodología del mejor predictor lineal insesgado convencional (BLUP) y genómico en una etapa (ssGBLUP). Resultados. Las heredabilidades para W8M, AFC y FCI variaron desde 0.25 a 0.26, 0.20 a 0.22 y 0.04 a 0.08, respectivamente. Los modelos de AFC y FCI con la metodología ssGBLUP disminuyeron ligeramente el error y aumentaron la varianza genética aditiva, respectivamente. Conclusiones. La inclusión de información genómica mejora levemente la precisión de las estimaciones genéticas en esta población. Sin embargo, una población de animales genotipados más grande y con mayor conectividad genética por parentesco permitiría aumentar para los criadores el potencial de la metodología ssGBLUP en ganado Simmental de Colombia.

ABSTRACT Objective. To estimate genetic parameters for weight at eight months of age (W8M), age at first calving (AFC) and first calving interval (FCI) using pedigree and genomic relationship. Materials and methods. Phenotypic data on 481, 3063 and 1098 animals for W8M, AFC and FCI were used, respectively. The genomic information came from a population of 718 genotyped animals with a density chip of 30,106 single nucleotide polymorphism markers (SNP). Univariate and bivariate models were used under the conventional (BLUP) and single step genomic best linear unbiased predictor (ssGBLUP) methodologies. Results. The heritabilities for W8M, AFC and FCI ranged from 0.25 to 0.26, from 0.20 to 0.22 and from 0.04 to 0.08, respectively. The AFC and FCI models under ssGBLUP slightly decreased the error and increased the additive genetic variance, respectively. Conclusions. The inclusion of genomic information slightly increases the accuracy of the genetic estimates in this population. However, a larger amount of genotyped animals and with a higher genetic relationship connectivity would allow breeders to increase the potential of the ssGBLUP methodology in Colombian Simmental cattle.

Influencia del ángulo de iluminación solar y la altura de la toma de la imagen multiespectral sobre la estimación de biomasa de pasto kikuyo / Influence of height and zenith angle of multispectral images on the estimation of kikuyo grass biomass

RESUMEN El objetivo de este estudio fue analizar la influencia del ángulo cenital de iluminación solar (mañana, mediodía y tarde) y la distancia (entre 10 y 50m) de imágenes multiespectrales de praderas de kikuyo, para la estimación de biomasa. Se capturaron datos espectrales de 40 muestras y se les calculó el índice de vegetación normalizada (NDVI) y la biomasa del forraje de las áreas fotografiadas. La relación de la biomasa con el NDVi, se hizo mediante modelos aditivos generalizados. Se encontró que es posible predecir la cantidad de biomasa con imágenes tomadas al mediodía y las alturas de vuelo analizadas (con R2 =0,99), indicando que el monitoreo de praderas puede incorporar información de sensores con bandas de rojo e infrarrojo cercano, tomadas entre las 12:00m y 1:00pm.

ABSTRACT The objective of this study was to analyze the effect of solar zenith angle (morning, noon and afternoon) and the distance (between 10 and 50m) of the multispectral images of kikuyo grasslands for biomass estimation. Spectral data from 40 samples were captured and the normalized vegetation index (NDVI) and the forage biomass of the photographed areas were calculated. The relationship of the biomass with the NDVi was made using generalized additive models. It was found that it is possible to predict the amount of biomass with images taken at noon and the flight heights analyzed (with R2 = 0.99), indicating that grassland monitoring can incorporate sensor information with red and near infrared bands taken between 12:00m and 1:00 pm.

Estimación de la calidad y cantidad de pasto kikuyo (Cenchrus clandestinum (Hochst. ex Chiov.) Morrone) usando imágenes multiespectrales / Estimation of the quality and quantity of Kikuyo grass (Cenchrus clandestinum (Hochst. Ex Chiov.) Morrone) using multispectral images

RESUMEN La evaluación de las praderas destinadas a ganadería es esencial para la productividad de los animales. Los datos de sensores multiespectrales remotos aerotransportados (SM) permiten construir índices de vegetación (VI, por sus siglas en idioma inglés) y relacionarlos con características fisiológicas y biofísicas de las pasturas. El objetivo fue evaluar VI para la estimación de la cantidad y calidad de pasto kikuyo en sistemas lecheros, del norte de Antioquia, Colombia. Se calcularon 10 diferentes VI, con 168 muestras de pasto kikuyo. Las muestras fueron pesadas, para estimar la biomasa verde (BV) y analizadas por espectroscopia del infrarrojo cercano, para los contenidos de proteína bruta (PB), fibra en detergente neutro (FDN) y fibra en detergente ácido (FDA). Los datos, se analizaron usando componentes principales (CP) y modelos aditivos generalizados suavizados. Las variables que más contribuyeron a la formación de la primera componente principal (CP1) fueron el índice de vegetación de diferencia normalizada (NDVI), el índice de vegetación simple (RVI), el índice de vegetación de diferencia normalizada verde (GNDVI), el índice clorofílico verde (Clg) y la BV del pasto kikuyo. Para la segunda componente principal (CP2) fueron el índice de vegetación de diferencia normalizada borde del rojo (RNDVI), el índice borde del rojo de clorofila (Clrg) y PB, FDN y FDA del pasto kikuyo. La BV fue explicada por el NDVI y PB por el RNDVI. La estimación obtenida para FDN y FDA del pasto kikuyo no fueron precisas.

ABSTRACT The evaluation of grazing lands is essential to improve livestock productivity. Data from multispectral airborne sensors allow calculating vegetation indexes (VI) and relating them to physiological and biophysical characteristics of the pastures. The objective of this study was to evaluate the usefulness of VI to estimate the quantity and quality of Kikuyu grass in dairy farms of northern Antioquia, Colombia. We calculated 10 different VI using 168 samples of Kikuyu grass. The samples were weighted to estimate green biomass (BV) and analyzed by near infrared spectroscopy for the contents of crude protein (PB), neutral detergent fiber (FDN) and acid detergent fiber (ADF). Data were analyzed using principal components (CP) and smoothed generalized additive models. The variables that contributed most to the formation of the first principal component (CP1) were the Normalized Difference Vegetation Index (NDVI), the Simple Vegetation Index (RVI), the Normalized Difference Vegetation Green Index (GNDVI), the Green Chlorophyll Index (Clg) and the BV of Kikuyu grass. The mayor contributors to the second principal component (CP2) were the Normalized Red-Edge Vegetation Index (RNDVI), the Red-Edge Chlorophyll Index (Clrg), and the PB, NDF and FDA of Kikuyu. The NDVI explained the BV, and the RNDVI explained the PB. The FDN and FDA estimations in Kikuyu were not precise.

Efecto de la temperatura ambiente en la temperatura superficial de zonas negras y blancas del pelaje de un hato de vacas holstein en el departamento de Antioquia, Colombia / Effect of ambient temperature on the surface temperature of black and white areas of the coat in a herd of Holstein cows in the department of Antioquia, Colombia / Efeito da temperatura ambiente na temperatura superficial de zonas negras e brancas da pelagem de um rebanho de vacas holstein no estado de Antioquia, Colômbia

Resumen El artículo reporta la evaluación del efecto de la temperatura ambiente, la humedad relativa, la radiación solar y la velocidad del cuerpo bajo el índice THSW en la temperatura superficial de áreas blancas y negras del pelaje de vacas holstein. Se utilizó información de 5 vacas holstein en producción de la finca El Recreo, ubicada en el municipio de Abejorral, Colombia. Se les tomó la temperatura superficial cada 2 h durante 15 días en 10 sitios diferentes: línea dorsal anterior, media y posterior, flanco derecho e izquierdo, pecho, cuello derecho e izquierdo, vulva y glándula mamaria, con termómetro infrarrojo. Para evaluar el efecto de la temperatura ambiente en la corporal se utilizó un índice que involucra la temperatura, la humedad, la radiación y la velocidad del viento (THSW) y para el análisis estadístico se utilizó un modelo mixto aditivo generalizado suavizado. El THSW encontrado fue de 10 y 27 °C. Las áreas muestreadas tuvieron una diferencia en la temperatura; las de color negro fueron las de mayor temperatura superficial. Oscilaron entre 32,5 y 35,8 °C para zonas blancas, y entre 34,5 y 40,5 °C para zonas negras. Los mayores valores de temperatura superficial para ambas zonas en todos los puntos se presentaron a mayores valores de THSW. Se concluye que el índice THSW tiene efecto diferenciado en la temperatura superficial corporal de acuerdo con el color del pelaje; los puntos negros fueron los que presentaron mayores temperaturas.

Abstract The article evaluates the effect of ambient temperature, relative humidity, solar radiation, and wind speed according to the THSW index on the surface temperature of the white and black areas of the coat of Holstein cows. The study used information of five Holstein dairy cows from the El Recreo farm, located in the municipality of Abejorral, Colombia. Surface temperature was measured with an infrared thermometer every 2 h during 15 days in 10 different sites: anterior, middle, and posterior dorsal line, right and left flank, chest, right and left neck, vulva, and mammary gland. To evaluate the effect of ambient temperature on body temperature, an index that involves temperature, humidity, solar radiation, and wind speed (THSW) was used, and for statistical analysis, a mixed generalized additive model. THSW was 10 and 27 °C. The sampled areas had a difference in temperature; being the black spots that had higher surface temperature. Temperature oscillated between 32.5 and 35.8 °C for white areas, and between 34.5 and 40.5 °C for black areas. Higher surface temperature values for both zones at all points had higher THSW values. It is concluded that the THSW index has a differentiated effect on body surface temperature according to the color of the coat, the black spots having higher temperatures.

Resumo O artigo reporta a avaliação do efeito da temperatura ambiente, a umidade relativa, a radiação solar e a velocidade do corpo sob o índice THSW na temperatura superficial de áreas brancas e negras da pelagem de vacas Holstein. Utilizou-se informação de 5 vacas Holstein em produção do sítio El Recreo, situada no município de Abejorral, Colomba. Tomou-se a temperatura superficial destes a cada 2 horas durante 15 dias em 10 lugares diferentes: linha dorsal anterior, media e posterior, flanco direito e esquerdo, peito, pescoço lado direito e esquerdo, vulva e glândula mamária, com termômetro infravermelho. Para avaliar o efeito da temperatura ambiente na corporal utilizou-se um índice que envolve a temperatura, a umidade, a radiação e a velocidade do vento (THSW) e para a análise estatístico utilizou-se um modelo misto aditivo generalizado suavizado. O THSW encontrado foi de 10 e 27 °C. As áreas amostradas tiveram uma diferença na temperatura; as de cor negra foram as de maior temperatura superficial. Oscilaram entre 32,5 e 35,8 °C para zonas brancas, e entre 34,5 e 40,5 °C para zonas negras. Os maiores valores de temperatura superficial para ambas zonas em todos os pontos, se apresentaram a maiores valores de THSW. Conclui-se que o índice THSW tem efeito diferenciado na temperatura superficial corporal de acordo com a cor da pelagem; os pontos negros foram os que apresentaram maiores temperaturas.

Milk quality: milking personnel associated factors / Calidad de la leche: factores asociados al personal vinculado al ordeño

ABSTRACT Objective. To identify factors associated with high and low Somatic Cell Counts (SCC) levels in bulk tanks of dairy farms in Southeast Brazil. Materials and methods. A total of 68 dairy herds with high and low bulk tank SCC levels were analyzed. Surveys and checklists were applied to the personnel regarding milking routines and equipment. Results. Milkers and management personnel explained up to 40.28% of the variability among herds, while the milker's well-being and stability explained up to 28%. Planning and organization were relevant for SCC, as well as the state of the equipment and the milking routine. According to separate analyzes of employees and owners, employees have greater variability in terms of knowledge on milk production, mastitis, milking routine, and experience. Conclusion. There are qualifying factors in milking systems in southeastern Brazil associated with milking personnel, equipment and milking routine. Understanding these factors will enable the implementation of strategies to produce better quality milk.

RESUMEN Objetivo. Identificar factores asociados a altos y bajos niveles de recuentos de células somáticas (RCS) en tanques de hatos lecheros del Sudeste de Brasil. Materiales y métodos. Se analizaron 68 hatos lecheros con niveles altos y bajos de RCS en tanque. Para identificar factores asociados al personal vinculado al ordeño y relacionarlos con RCS se aplicaron encuestas y listas de chequeo para la rutina y el equipo de ordeño. Resultados. El personal vinculado al ordeño, administración y gestión del productor explicaron hasta el 40.28% de la variabilidad entre rebaños, mientras que el bienestar y la estabilidad del ordeñador explicaron hasta el 28%. La planeación y organización del productor fueron relevantes en el RCS, al igual que el estado del equipo y la rutina de ordeño. Análisis separados de empleado y propietario permitieron concluir que existe mayor variabilidad para los primeros, diferenciándose por conocimientos en la producción de leche y el manejo de la mastitis, la rutina y la experiencia. Conclusión. Existen factores clasificatorios en los sistemas de ordeño del sudeste de Brasil asociados al personal, el equipo y la rutina de ordeño. El entendimiento de estos factores posibilitará la implementación de estrategias que permitan producir leche de mejor calidad.

Percepción de los agentes compradores y personas muestreadoras sobre el sistema de liquidación para pago de leche cruda en Antioquia / Perception of purchasing agents and sampling staff on the raw milk payment calculation system in Antioquia / Percepção dos agentes compradores e pessoas coletoras sobre o sistema de liquidação para pagamento do leite cru em Antioquia

Resumen Introducción. El sistema de pago por calidad promueve cambios que impactarán de manera positiva las formas actuales de producción y comercialización de leche. Objetivo. Analizar la percepción de los agentes compradores (AC) y tomadores de muestra (TM) sobre el sistema de liquidación de la leche cruda a los proveedores en Antioquia. Materiales y métodos. Se realizaron entrevistas a 14 funcionarios de los AC y se aplicaron 84 encuestas a TM. Para analizar la percepción de las personas se realizaron análisis de factor para datos mixtos y análisis de cluster jerárquico en componentes principales. Resultados. Se identificó que los AC no tenían mucho conocimiento de las resoluciones 17 del 2012 y 77 del 2015 del Ministerio de Agricultura y Desarrollo Rural; solo las empresas grandes y tecnificadas tenían mayor conocimiento. Los AC, en su mayoría, tenían una percepción positiva frente a la aplicación de estas; según ellos incentivarían al mejoramiento de la calidad de leche y el pago equitativo a los proveedores, y generarían mayor transparencia y confianza en la relación comercial con el proveedor. Los TM, en términos generales, no conocían las resoluciones, y manifestaron que tenían una buena relación con los AC y con los proveedores. Conclusión. Para los AC y los TM, el sistema de pago por calidad genera bienestar en la relación comercial con el proveedor y en sector lácteo en general, aunque puede ocasionar incertidumbre por los cambios en las formas de producción y comercialización.

Abstract Introduction. Payment per quality system generates changes that will positively impact current milk production and commercialization procedures. Objective. Analyze the perception of purchasing agents (PA) and sample testing staff (ST) on the raw milk payment calculation for suppliers in Antioquia. Materials and methods. 14 interviews were conducted with PA staff and 84 surveys were applied to ST. To analyze their perception, we used mixed data factor analysis and hierarchical cluster analysis of main components. Results. It was identified that with the exception of large highly technical companies, PA had little knowledge of Resolutions 17 of 2012 and 77 of 2015 from the Colombian Ministry of Agriculture and Rural Development. Most PA have a positive perception on the application of these resolutions; according to them, it would incentivize improvements in milk quality and a fair payment to suppliers, and would create more transparency and trust in the commercial relationship with the supplier. In general, ST did not know the resolutions and expressed that they have a good relationship with PA and suppliers. Conclusion. For PA and ST, the payment per quality system generates benefits in their commercial relationship with the supplier and the dairy sector in general, although it can cause uncertainties due to changes in production and commercialization procedures.

Resumo Introdução. O sistema de pagamento por qualidade promove mudanças que impactarão de maneira positiva as formas atuais de produção e comercialização do leite. Objetivo. Analisar a percepção dos agentes compradores (AC) e tomadores de amostra (TM) sobre o sistema de liquidação do leite cru aos fornecedores em Antioquia. Materiais e métodos. Se realizaram entrevistas a 14 funcionários dos AC e se aplicaram 84 enquetes a TM. Para analisar a percepção das pessoas se realizaram análise de fator para dados mistos e análise de cluster hierárquico em componentes principais. Resultados. Se identificou que os AC não tinham muito conhecimento das resoluções 17 de 2012 e 77 de 2015 do Ministério de Agricultura e Desenvolvimento Rural; só as empresas grandes e tecnificadas tinham melhor conhecimento. Os AC, na sua maioria, tinham uma percepção positiva frente à aplicação destas; segundo eles incentivariam ao melhoramento da qualidade do leite e o pagamento equitativo aos fornecedores, e gerariam maior transparência e confiança na relação comercial com o fornecedor. Os TM, em termos gerais, não conheciam as resoluções, e manifestaram que tinham uma boa relação com os AC e com os fornecedores. Conclusão. Para os AC e os TM, o sistema de pagamento por qualidade gera bem-estar na relação comercial com o fornecedor e no sector lácteo em geral, embora pode ocasionar incerteza pelas mudanças nas formas de produção e comercialização.

Genetic diversity and population structure of the Guinea pig (Cavia porcellus, Rodentia, Caviidae) in Colombia.

The aim was to establish the genetic diversity and population structure of three guinea pig lines, from seven production zones located in Nariño, southwest Colombia. A total of 384 individuals were genotyped with six microsatellite markers. The measurement of intrapopulation diversity revealed allelic richness ranging from 3.0 to 6.56, and observed heterozygosity (Ho) from 0.33 to 0.60, with a deficit in heterozygous individuals. Although statistically significant (p < 0.05), genetic differentiation between population pairs was found to be low. Genetic distance, as well as clustering of guinea-pig lines and populations, coincided with the historical and geographical distribution of the populations. Likewise, high genetic identity between improved and native lines was established. An analysis of group probabilistic assignment revealed that each line should not be considered as a genetically homogeneous group. The findings corroborate the absorption of native genetic material into the improved line introduced into Colombia from Peru. It is necessary to establish conservation programs for native-line individuals in Nariño, and control genealogical and production records in order to reduce the inbreeding values in the populations.