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Papers by Alan Cruz

Journal of Animal Science

Fiber diameter is the main selection objective and criterion in alpaca breeding programs, but it ... more Fiber diameter is the main selection objective and criterion in alpaca breeding programs, but it can vary across anatomic regions of the animal. As fiber diameter is usually registered from a unique sample from the mid side of the body, fiber diameter variability within fleece is never addressed and phenotypic and genetic differences may exist for fleece uniformity in alpaca populations. The objective of this work was to estimate the genetic parameters of fleece uniformity in an alpaca population. Fiber diameters measured in three different locations were used as repeated records of the same animal and studied for fitting a model that considers heterogeneous the residual variance of the model. Also, the logarithm of the standard deviation of the three measures was used as a measure of the fleece variability. Estimate of the additive genetic variance of the environmental variability was 0.43±0.14, enough high to suggest the existence of wide room to select for fleece uniformity. Gene...

Revista de Investigaciones Veterinarias del Perú

Los registros genealógicos y productivos son el pilar importante dentro de los programas de mejor... more Los registros genealógicos y productivos son el pilar importante dentro de los programas de mejora genética y genómica, donde la diversidad de datos que pueden colectarse debe ser sistematizada y relacionada, para llevar un análisis estadístico adecuado considerando todos los factores que influencian a las variables. Por otro lado, las propuestas actuales no contemplan el registro total de la población, tanto de registros genealógicos como productivos, además que no existe un software que permita sistematizar, ordenar y proveer información objetiva y medible en forma ordenada dentro del manejo de los camélidos domésticos. Por ello se planteó la construcción de un aplicativo informático que permita el recojo de los registros genealógicos y productivos de toda la población tanto de alpacas como de llamas dentro de los rebaños. Como resultado se construyó el aplicativo informático denominado “Pacokipu” y “Llamakipu” para alpacas y llamas, respectivamente, los cuales fueron construidos ...

Revista de Iniciação à Docência

O presente artigo tem como objetivo analisar as concepções dos estudantes, da Universidade Region... more O presente artigo tem como objetivo analisar as concepções dos estudantes, da Universidade Regional do Cariri – Urca/Unidade Descentralizada de Missão Velha-Ceará sobre Educação Ambiental. A pesquisa do tipo exploratória, descritiva e de natureza quali-quantitativa foi desenvolvida com os acadêmicos do 5º e 9º semestres do curso de licenciatura em Ciências Biológicas da Urca. Para isso, utilizou-se de um questionário semiestruturado, contendo cinco questões subjetivas e seis objetivas. A análise dos dados evidenciou que os estudantes compreendem a Educação Ambiental como sendo uma mudança de postura do homem com a natureza, sendo assim, justificam a importância de adotar hábitos conscientes, comportamentos e valores que promovam a qualidade de vida para todos(as). Conclui-se que as discussões e os debates sobre a Educação Ambiental ocorreram de forma significativa, elucidando a importância para temática. Sendo assim, emerge a necessidade de ampliar o dialogar com a comunidade escola...

Revista Peruana de Biología

En alpacas los fenotipos del color de vellón tienen diferentes terminologías que induce a una con... more En alpacas los fenotipos del color de vellón tienen diferentes terminologías que induce a una confusión dentro del color marrón y sus tonalidades, el que requiere de una mejor descripción y cuantificación. En consecuencia los objetivos del estudio fueron cuantificar el color de fibra e identificar los PNSs informativos del gen MC1R (receptor 1 de melanocortina) en alpacas marrones y negras. Un fenotipo vicuña (n=14) y cuatro fenotipos de alpacas (n=79), marrón claro, marrón oscuro, marrón-negro y negro fueron evaluados por colorimetría. El vellón de vicuña mostró mayor luminosidad (47.74) e intensidad de color (24.33) respecto a las alpacas marrones. Los valores obtenidos de CIE L*a*b* (luminosidad e intensidad) sugieren valores bajos en alpacas eumelánicas y altos en alpacas feomelánicas. En vicuña y alpaca la secuencia codificante del gen MC1R tiene un solo exón de 954 pb, las vicuñas no mostraron la deleción (c.224_227del). Sin embargo, esta deleción se ha observado en los tres f...

Animals, 2021

Improving textile characteristics is the main objective of alpaca breeding. A recently developed ... more Improving textile characteristics is the main objective of alpaca breeding. A recently developed SNP chip for alpacas could potentially be used to implement genomic selection and accelerate genetic progress. Therefore, this study aimed to compare the increase in prediction accuracy of three important fiber traits: fiber diameter (FD), standard deviation of fiber diameter (SD), and percentage of medullation (PM) in Huacaya alpacas. The data contains a total pedigree of 12,431 animals, 24,169 records for FD and SD, and 8386 records for PM and 60,624 SNP markers for each of the 431 genotyped animals of the Pacomarca Genetic Center. Prediction accuracy of breeding values was compared between a classical BLUP and a single-step Genomic BLUP (ssGBLUP). Deregressed phenotypes were predicted. The accuracies of the genetic and genomic values were calculated using the correlation between the predicted breeding values and the deregressed values of 100 randomly selected animals from the genotype...

Animal, 2021

Addressing the improvement of the textile characteristics is currently required in natural color ... more Addressing the improvement of the textile characteristics is currently required in natural color production of alpaca fiber. This study analyses the possibility of implementing a genetic improvement program aiming to reduce the fiber diameter and the percentage of medullation in natural colors under the incomplete definition of the natural colors of alpaca fiber. The study considers color determination analysis in three separate steps. The first step aimed at finding the values of lightness (L*), red/green axis (a*), yellow/blue axis (b*) of three-dimensional space of color and chroma (C*ab), tone (h*ab) and color difference (ΔE) with mathematical models for the description of the coat color. The second analysis is aimed at estimating genetic parameters of color traits and their correlation with fiber traits (fiber diameter, standard deviations and percentage of medullation - PM). The third step was to determine the potential selection criteria of breeding animals based on the parameters provided by a three-dimensional space values regarding the coat color assignment in alpacas. The colorimetric data were taken using a Chroma meter device analyzing 3 008 records from Huacaya type alpacas, collected between 2018 and 2019. In the first objective of the study, the color traits were subjected to a principal component analysis. The analysis of variance components and the estimation of genetic parameters were carried out using a restricted maximum likelihood procedure. The discriminant analysis was used for the correct assignment of the coat color. The principal component analysis results showed that the L*, a*, b*, h*ab and ΔE values can be grouped into two Principal Components (PC) to describe the color, where the L* value is mainly distributed in PC2, b* is distributed in PC1, while a* is distributed in both components. The heritabilities found were 0.144, 0.128, 0.151, 0.104 and 0.152 for L*, a*, b*, PC1 and PC2. The relevant genetic correlations were between L*-PM (-0.557) and b*-PM (-0.622). The discriminant analysis showed a high percentage of correct assignment in white (99.15%) and black (99.19%) coat colors for Huacaya type alpacas, while for the intermediate colors, the accuracy was lower. The three analyses showed that there is no pure natural color, but a range of color variation. It is better to use the values of the three-dimensional space and within them, the values of L* and b* are potential selection criteria to be included in a genetic improvement program.

Brazilian Journal of Development, 2020

A prática do Learning Spaces: construindo uma proposta sobre o paisagimo para o ensino de ciência... more A prática do Learning Spaces: construindo uma proposta sobre o paisagimo para o ensino de ciências e biologia The practice of the Learning Spaces: building a proposal on the landscapes for the teaching of sciences and biology

Reproduction in Domestic Animals, 2020

Pacomarca is an experimental ranch founded by the Inca group to act as a selection nucleus from w... more Pacomarca is an experimental ranch founded by the Inca group to act as a selection nucleus from which genetic improvement of alpaca fibre can be spread throughout the rural communities in the Peruvian Altiplano (Morante et al., 2009). Research at the farm in the last decades has importantly collaborated to increase the useful knowledge for breeding programmes, starting by the determination the most economically important selection objective and confirming that mean fibre of a staple would be the best criterion of selection for the goal of increasing the textile value of the animals (Gutiérrez, Goyache, Burgos, & Cervantes, 2009). These traits have

Livestock Science, 2019

A total of 14,378 records of fiber diameter (FD) and its standard deviation (SD) from Huacaya alp... more A total of 14,378 records of fiber diameter (FD) and its standard deviation (SD) from Huacaya alpaca recorded between 2001 and 2017 at Pacomarca genetic center were used in this study. These records were analyzed by a repeatability (RM), multitrait (MT) and random regression (RRM) models. The heritability (h 2) estimates were 0.263 and 0.368 for FD and SD respectively under a RM model; these ranged from 0.653 to 0.742 for FD and 0.627 to 0.764 for SD under MT and from 0.561 to 0.614 for FD and 0.556 to 0.702 for SD under RRM. The MT and RRM show a pattern of increase in variances and heritability as age increases for SD and till 6 years of age for FD, while the genetic correlation (rg) decrease for both traits between 1 and 5 years of ages. The breeding value for the three models show a linear relationship for FD and SD across age at shearing, meaning that any of these models can be used in the selection process. The results of this study shows that during this period of time a highly favorable selection response was obtained for fiber quality in Huacaya alpaca using RM, however the use of the RRM approach can offer more valuable information, particularly in the persistence of the genetic merit of the animals at 5 years respect to 1 years old at shearing. More research is needed on the use and relationship between persistence and others economical traits in alpaca.

Revista de Investigaciones Veterinarias del Perú, 2019

El objetivo del estudio fue evaluar la variabilidad fenotípica del porcentaje de fibras meduladas... more El objetivo del estudio fue evaluar la variabilidad fenotípica del porcentaje de fibras meduladas de alpacas Huacaya, así como calcular la correlación fenotípica entre el diámetro medio de fibra (DMF) y el porcentaje de medulación total (PM). Se tomaron muestras de fibra de 36 alpacas Huacaya (machos entre 0.4 y 10.4 años) para determinar el DMF y el PM con el microscopio de proyección. El tipo de médula de las fibras fue considerada como no medulada, fragmentada, discontinua, continua y fuertemente medulada. Se observó una alta variabilidad fenotípica del PM entre alpacas y dentro de las muestras. El promedio ± desviación estándar del PM y DMF fue 32.56 ± 18.30% y 17.58 ± 2.52 µm para fibras no meduladas; 29.29 ± 11.67% y 21.49 ± 2.39 µm para fibras con medulación fragmentada; 14.01 ± 10.14% y 24.04 ± 2.40 µm para fibras con medulación discontinua; 23.90 ± 13.01% y 28.04 ± 3.10 µm para fibras con medulación continua; y 0.59 ± 0.44% y 50.85 ± 9.86 µm para fibras fuertemente medulada...

Animal, 2018

The alpaca fiber diameter (FD) varies from 18 to 36 μm, being the finer fiber categories highly a... more The alpaca fiber diameter (FD) varies from 18 to 36 μm, being the finer fiber categories highly appreciated. However, the alpaca fiber presents some limitations in the textile industry due to the high incidence of fiber medullation and diameter variability, both reduces the comfort feeling of the garments. Decreasing or even removing medullation could be a possible selection objective in alpaca breeding programs for increasing economic value of the alpaca fiber. Therefore, the present work aimed to estimate genetic parameters regarding medullation traits, as well as the genetic correlations with other economical important traits, to be able to select the appropriate criteria to reduce or remove medullation on alpaca fiber and help to reduce the prickle factor in the garments. The data was collected from 2000 to 2017 and belonged to the Pacomarca experimental farm. There were 3698 medullation records corresponding to 1869 Huacaya and 414 Suri genetic types. The fiber samples were tak...

Small Ruminant Research, 2018

The aim of this research was to estimate for the first time the heritability and genetic relation... more The aim of this research was to estimate for the first time the heritability and genetic relationship between medullation and fiber diameter in each fiber by itself. A total of 21,600 fibers from 36 samples from white fleeces, 600 fibers each sample, from males between 0.4 and 10.4 years old from Pacomarca experimental farm (Inca Group, Puno, Peru) were tested using projection microscope (PM). The individual fiber diameter (FD) and the category of medullation (CM) was recorded in each fiber. CM of each fiber was assigned to one of the five categories established in the literature. The percentage of medullated fiber ranged from 12.33% to 91.67% per sample. The correlation between OFDA 100 ® medullation percentage and PM measurements was 0.79. The statistical model used for estimation of genetic parameters for CM and FD included the age as a linear and quadratic covariate as systematic effect, and the additive genetic and the permanent environmental as random effects. The pedigree that served to predict genetic values was very robust and strong, allowing obtaining reliable and significant parameters. Univariate and bivariate models were used to estimate heritability for CM and DF, as well as its genetic correlation. Different models considering CM as continuous or categorical trait were tested. The highest heritability estimate for CM was 0.36 ± 0.13 obtained using a bivariate continuous model. Using the same model, the heritability estimate for FD was 0.35 ± 0.15 and the genetic correlation between CM and FD was 0.93 ± 0.12. These results implied that selection against medullated fiber is feasible while at the same time reducing the FD in alpacas. Since measurement of CM per fiber sample was time-consuming, PM measured by OFDA 100 ® would be useful as an indicator to reduce the number of medullated fiber in alpaca fleeces.

Livestock Science, 2017

A study was conducted to know the influence of the pregnancy and lactation states on the fiber pe... more A study was conducted to know the influence of the pregnancy and lactation states on the fiber performance in alpacas at Pacomarca experimental farm in the Peruvian highlands. Records obtained from the regular performance recording software of the farm were used, gathering 8648 records of 1541 females and 366 males of Huacaya ecotype, and 2410 records of 374 females and 132 males of Suri ecotype, registered from 2001 to 2015 and belonging to animals of three or more years. A mixed linear model for fiber diameter, standard deviation and coefficient of variation fitted the physiological state with five categories (milking, pregnant, milking and pregnant, open females and males) as an effect jointly with others such as year of recording, age from 3 to 9 or more years old and coat color. Huacaya and Suri ecotypes were independently analyzed. All the effects included in the model appeared as highly significant, being the paired differences less significant in Suri because of the lower number of records. Lactation physiological state appeared as an important effect affecting fiber performance, explaining a difference of 1.2 and 1.0 µm of differences in respectively Huacaya and Suri pregnant females, while pregnancy appeared with a much less relevant influence. Other factors greatly influenced the fiber diameter. Thus, age had a very important effect increasing 3.71 µm from 3 to 9 years of age in huacaya and 4.52 µm en Suri. A difference of 3.09 µm in huacaya and 5.93 µm in Suri was found between dark and white coat colored alpacas. These results recommend modifying the genetic evaluation model by fitting the physiological state of females to increase the accuracy of the breeding values used to select animals in the breeding scheme of the farm.

Animal, 2016

The aim of this study was to estimate the genetic parameters for preweaning traits and their rela... more The aim of this study was to estimate the genetic parameters for preweaning traits and their relationship with reproductive, productive and morphological traits in alpacas. The data were collected from 2001 to 2015 in the Pacomarca experimental farm. The data set contained data from 4330 females and 3788 males corresponding to 6396 and 1722 animals for Huacaya and Suri variants, respectively. The number of records for Huacaya and Suri variants were 5494 and 1461 for birth weight (BW), 5429 and 1431 for birth withers height (BH), 3320 and 896 for both weaning weight (WW) and average daily gain (DG) from birth to weaning, 3317 and 896 for weaning withers height (WH), and 5514 and 1474 for survival to weaning. The reproductive traits analyzed were age at first calving and calving interval. The fiber traits were fiber diameter (FD), standard deviation of FD (SD), comfort factor and coefficient of variation of FD and the morphological traits studied were density, crimp in Huacaya and loc...