Características de la fibra de alpacas en la zona agroecológica seca en el altiplano peruano

The aim of this study was to evaluate the main physical characteristics and correlations of fibre diameter (FD), coefficient of variation (CVFD), comfort factor (CF) and itching factor (IF) of alpaca fibre in the dry agroecological zone of the Puno region, Peru. In total, 14 068 fibre samples were collected and analysed with the OFDA 2000 equipment. The factors sex (male, female), breed (Suri, Huacaya), age (DL: milk teeth; 2 DL: two teeth; 4D: four teeth; BLL: full mouth) and province (Melgar, Chucuito, Puno, El Collao, Lampa, San Román) through a factorial arrangement of 2×2×4×6 was evaluated. The FD was influenced by age, sex, breed and province (p<0.01), being smaller in alpacas DL (20.10 μm) and thicker in BLL (23.29 μm). In males it was 21.25 μm and in females 21.91 μm (p<0.05) and in Huacaya alpacas 21.25 μm and in Suri 22.21 μm (p<0.05). The CVFD and IF variables varied according to age, sex, breed and province (p<0.01), as did the CF, except for sex. The FD and FC showed (r=-0.89) high and negative correlation and the FD with CVFD had a low and negative correlation (r=-0.11). The IF and CF correlations were negative and high (r=-0.67). Alpacas from the dry agroecological zone of the Puno region produce good quality fibre with good potential for genetic improvement.El objetivo del estudio fue evaluar las principales características físicas y correlaciones del diámetro de fibra (DF), coeficiente de variación (CVDF), factor de confort (FC) y factor de picazón (FP) de la fibra de alpaca en la zona agroecológica seca de la región Puno, Perú. Se colectaron 14 068 muestras de fibra que fueron analizadas con el equipo OFDA 2000. Se consideraron los factores sexo (macho, hembra), raza (Suri, Huacaya), edad (DL: dientes de leche; 2 DL: dos dientes; 4D: cuatro dientes; BLL: boca llena) y provincia (Melgar, Chucuito, Puno, El Collao, Lampa, San Román) a través de un arreglo factorial de 2×2×4×6. El DF estuvo influenciado por la edad, sexo, raza y provincia (p<0.01), siendo de menor diámetro en alpacas diente DL (20.10 μm) y de mayor grosor en BLL (23.29 μm). En machos fue 21.25 μm y en hembras 21.91 μm (p<0.05) y en alpacas Huacaya 21.25 μm y en Suri 22.21 μm (p<0.05). Las variables CVDF y FP variaron según edad, sexo, raza y provincia (p<0.01), al igual que el FC con excepción del sexo. El DF y FC mostró (r=-0.89) correlación alta y negativa y el DF con CVDF tuvo una correlación baja y negativa (r=-0.11). Las correlaciones del FC y FP fueron negativas y altas (r=-0.67). Las alpacas de la zona agroecológica seca de la región de Puno producen una buena calidad de fibra con buen potencial para su mejoramiento genético

Identificación de marcadores SNP (polimorfismo de nucleótido único) asociados a la resistencia frente al virus de la necrosis pancreática infecciosa (IPN) en truchas arcoíris (Oncorhynchus mykiss)

Tesis para optar al Grado de Magíster en Ciencias Animales y Veterinarias.La necrosis pancreática infecciosa (IPN) es una enfermedad viral con un impacto negativo considerable en la acuicultura de la trucha arcoíris (Oncorhynchus mykiss).. El objetivo del presente trabajo ha sido detectar las regiones genómicas que explican la resistencia al virus de la necrosis pancreática infecciosa (IPNV) en truchas arcoíris. Un total de 2.278 peces provenientes de 58 familias de medios hermanos y hermanos completos fueron desafiados con virus lPN para inducir la enfermedad. De estos fueron genotipados 768 peces: 488 resistentes y 280 susceptibles. Para el genotipado se utilizó un microarreglo Axiom®, Affymetrix® de 57 mil marcadores de tipo polimorfismo de nucleótido único (SNP). Se realizó un análisis de asociación de genoma completo utilizando los datos fenotípicos y genotípicos de los peces desafiados. Se utilizaron modelos de regresión lineal y regresión logística. La heredabilidad para la resistencia al virus IPN calculada con información de pedigrí para el rasgo tiempo de muerte fue 0,39 y para el rasgo de supervivencia binaria fue 0,32, y usando información genómica fue de 0,46 y 0,45, respectivamente. El análisis de asociación indicó que la resistencia al virus IPN es un rasgo Oligogénico. Se detectó un SNP asociado de forma significativa al rasgo tiempo de muerte en el cromosoma 5. La proporción de la varianza fenotípica y heredabilidad explicada por este marcador fue de 0,035 y 0,076, respectivamente. El Sentrin-specific protease 5 (SENP5) podría ser un gen candidato implicado en la resistencia frente a este patógeno por encontrarse en las cercanías del SNP significativo. Debido a la reducida proporción de la varianza fenotípica explicada por el marcador detectado, concluimos que la incorporación de toda la información genómica, a través de la selección genómica, podría ser el enfoque más adecuado para acelerar el progreso genético en el mejoramiento de la resistencia frente al virus IPN en trucha arcoíris.Infectious pancreatic necrosis (IPN) is a viral disease with a considerable negative impact on rainbow trout aquaculture. The objective of the present work was to detect the genomic regions that explain the resistance to infectious pancreatic necrosis virus (IPNV) in rainbow trout (Oncorhynchus mykiss). A total of 2,278 fishes from 58 families of complete siblings were challenged with lPN virus to induce the disease. A total of 768 fishes, 488 resistant and 280 susceptible, were genotyped with an Axiom® microarray, Affymetrix® of 57,000 single nucleotide polymorphism (SNP) markers. A complete genome association analysis was performed using the phenotypic and genotypic data of the challenged fishes. Linear regression and logistic regression models were used. The heritability for IPN virus resistance calculated with pedigree information for time of death trait was 0.39 and for the binary survival trait was 0.32, and using genomic information was 0.46 and 0.45, respectively. Association analysis indicated that resistance to IPN virus is an oligogenic trait. A SNP was significantly associated with the day-of-death trait on chromosome 5. The proportion of the phenotypic variance and heritability explained by this marker was 0.035 and 0.076, respectively. Sentrin-specific protease 5 (SENP5) could be a candidate gene involved in resistance to this pathogen because it is found near to the significant SNP. Due to the reduced proportion of the phenotypic variance explained by the detected marker, we conclude that the incorporation of all genomic information, through genomic selection, could be the most appropriate approach to accelerate genetic progress in the improvement of resistance to IPN virus in rainbow trout.Financiamiento: Proyecto CORFO-INNOVA (12PIE - 17669)

Apparent digestibility of dry matter, organic matter, protein and energy of native Peruvian feedstuffs in juvenile rainbow trout (Oncorhynchus mykiss)

Abstract Trout production is a growing activity in recent years but requires new alternative sources of feed to be sustainable over time. The objective of this research was to determine the apparent digestibility coefficient (ADC) of dry matter (DM), organic matter (OM), crude protein (CP) and digestible energy (DE) of kañiwa (Chenopodium pallidicaule Aellen), kiwicha (Amaranthus caudatus L), quinoa (Chenopodium quinoa Willd), beans (Phaseolus vulgaris L.), sacha inchi, (Plukenetia volubilis L) and jumbo squid (Dosidicus gigas) meal in juvenile rainbow trout. The experimental diets were composed of a 70% basal diet and 30% of any raw materials. The ADC was determined by the indirect method using insoluble ash as a non-digestible marker. Jumbo squid, sacha inchi and quinoa showed the highest values of ADC (%) of DM (84.5, 73.5 and 69.7), OM (89.1, 78.4 and 72.9), CP (93.2, 98.0 and 90.3), and DE (4.57, 4.15 and 2.95 Mcal/kg DM), respectively. The ADC values for kañiwa, kiwicha and bean were significantly lower. In conclusion, quinoa meal and jumbo squid meal have an acceptable digestibility but sacha inchi meal is a potential alternative for rainbow trout feeding in the future

Use of machine learning approaches for body weight prediction in Peruvian Corriedale Sheep

The goal of this study was to predict the body weight of Corriedale ewes using machine learning (ML) algorithms. Fourteen body measurements (BM) and six different machine learning models were used. Body weight (BW) and BM: wither height (WH), rump height (RH), thoracic perimeter (TP), abdominal perimeter (AP), foreshank length (FSL), fore-shank width (FSW), fore-shank perimeter (FSP), tail width (TW), tail perimeter (TPe), hip width (HW), loin width (LWi), shoulder width (SW), forelimb length (FL), and body length (BL), were collected from 100 Corriedale ewes between 1.5 and 2 years old from the Illpa Experimental Centre of the National University of Altiplano in Peru. The machine learning algorithms used to estimate body weight were Support Vector Machines for Regression (SVMR), Classification and Regression Trees (CART), Random Forest (RF), Model Average Neural Networks (MANN), Multivariate Adaptive Regression Splines (MARS) and eXtreme Gradient Boosting (XGBoost). The performance of the models was evaluated by the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE). Highly correlated predictors (r ≥ 075) were removed from the dataset. The remaining predictors were then subjected to variable selection procedures using the Boruta algorithm. Boruta results confirmed the importance of TP, LWi, BL, FSL, SW and HW as predictors of ewe weight. The ML models were then trained on those selected predictors. RF had the highest R2 values and lowest values of MAE, RMSE, and MAPE. In conclusion, the RF algorithm can be recommended for accurately estimating BW from body measurements of Corriedale sheep