L. A. Josahkian

ORCID: 0000-0001-9609-8142
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About
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Research Areas
  • Genetic and phenotypic traits in livestock
  • Animal Genetics and Reproduction
  • Effects of Environmental Stressors on Livestock
  • Genetic Mapping and Diversity in Plants and Animals
  • Livestock and Poultry Management
  • Aquaculture Nutrition and Growth
  • Livestock Management and Performance Improvement
  • Rural Development and Agriculture
  • Genetics and Plant Breeding
  • Meat and Animal Product Quality
  • Animal Nutrition and Physiology
  • Agricultural and Food Sciences
  • Silkworms and Sericulture Research
  • Animal Behavior and Welfare Studies
  • Agriculture and Rural Development Research
  • Reproductive Physiology in Livestock
  • Sustainable Agricultural Systems Analysis
  • Cancer-related molecular mechanisms research
  • Fish biology, ecology, and behavior
  • Agriculture Sustainability and Environmental Impact
  • Forest Insect Ecology and Management
  • Milk Quality and Mastitis in Dairy Cows
  • Gut microbiota and health
  • Growth Hormone and Insulin-like Growth Factors
  • Forest Ecology and Biodiversity Studies

Fundação André Tosello
2022-2024

Universidade de Brasília
2021

Instituto Federal Catarinense
2021

Weatherford College
2021

Universidade Federal de Viçosa
2020

Universidade de Uberaba
2000-2016

Summary Zebu breeds play an important role in cattle production systems Brazil. To assess the genetic variability from animals Herd Books of Nelore, Gir and Guzerat breeds, generation intervals, inbreeding, effective population size parameters gene origin (effective number founders, ancestors founder genomes) were calculated using pedigree records 1938 to 1998. Breed subdivision was quantified by Wright’s F ‐statistics. Calculations separately carried out for consecutive 4‐year intervals...

10.1111/j.1439-0388.2008.00767.x article EN Journal of Animal Breeding and Genetics 2009-03-15

The productivity of herds may be negatively affected by inbreeding depression, and it is important to know how intense this effect on the livestock performance. We performed a comprehensive analysis involving five Zebu breeds reared in Brazil estimate depression productive reproductive traits. Inbreeding was estimated for 13 traits including individual rate as linear covariate standard genetic evaluation models. For all almost (no observed gestation length), performance animals compromised...

10.1111/jbg.12219 article EN Journal of Animal Breeding and Genetics 2016-05-19

Descreveu-se a estrutura da população do rebanho Tabapuã registrado no Brasil. Foram geradas estatísticas descritivas distribuição número de progênies e estimados o intervalo gerações, F, efetivo fundadores, ancestrais genomas remanescentes, além tamanho população, usando registro genealógico animais nascidos entre 1971-1998. Entre 1994 1998 foram registrados 37.778 animais, 18.736 machos 19.042 fêmeas, pertencentes 136 criadores. As médias dos intervalos gerações estimadas para os períodos...

10.1590/s0102-09352002000600009 article PT cc-by Arquivo Brasileiro de Medicina Veterinária e Zootecnia 2002-12-01

The study reported here evaluated genotype × environment interaction in individual performance and progeny tests beef cattle. Genetic parameters for final weight (FW), ADG, scrotal circumference (SC) of 33,013 Nellore young bulls tested on pasture or feedlots were analyzed. posterior means (and highest density interval with 90% samples [HPD90]) heritability traits measured pasture-raised feedlot-raised animals 0.44 (HPD90 = 0.40 to 0.48) 0.50 0.43 0.56) FW, 0.26 0.23 0.29) 0.20 0.32) 0.53...

10.2527/jas.2014-7983 article EN Journal of Animal Science 2015-01-01

The aim of this study was to estimate genetic parameters for 305-day cumulative milk yield and components, growth, reproductive traits in Guzerá cattle.The evaluated were first-lactation yields (kg) (MY305), fat (FY305), protein (PY305), lactose (LY305), total solids (SY305); age at first calving (AFC) days; adjusted scrotal perimeter (cm) the ages 365 (SP365) 450 (SP450) body weight 210 (W210), (W365), (W450) days. (co)variance components estimated using restricted maximum likelihood method...

10.5713/ab.21.0458 article EN cc-by Animal Bioscience 2022-01-04

Descreveu-se a estrutura populacional da raça Nelore Mocho utilizando dados do registro genealógico de animais nascidos entre 1969 e 1998. O banco foi separado em quatro períodos 1979-1983, 1984-1988, 1989-1993 1994-1998. Calcularam-se as estatísticas descritivas número criadores, reprodutores reprodutrizes. A endogamia total aumentou 0,55% para 0,98%, esperada sob acasalamento ao acaso 0,11% 0,56% devido à subdivisão permaneceu constante, redor 0,45%, indicando que genética é próxima zero...

10.1590/s0102-09352002000500008 article PT cc-by Arquivo Brasileiro de Medicina Veterinária e Zootecnia 2002-10-01

O objetivo deste trabalho foi descrever a estrutura da população do rebanho Gir Mocho registrado no Brasil. Foram geradas estatísticas descritivas distribuição número de progênies, estimados o intervalo gerações e tamanho efetivo população, usando registro genealógico animais nascidos entre 1976-1998. Os intervalos médios para os períodos (1979-1983, 1984-1988, 1989-1993 1994-1998) foram, respectivamente, 4,5; 6,05; 7,17 9,14 anos. tamanhos efetivos nos quatro 3, 22, 63 70.

10.1590/s1516-35982001000800004 article PT cc-by Revista Brasileira de Zootecnia 2001-12-01

O objetivo deste trabalho foi determinar parâmetros genéticos do peso desde o nascimento até 730 dias de idade na raça Indubrasil. Registros (82.481) 20.890 animais aos foram utilizados. Os determinados por meio regressão aleatória. Amostras da distribuição a posteriori dos interesse obtidas com amostrador Gibbs. Polinômios Legendre ou segmentados utilizados para modelar trajetória média crescimento. efeitos genético aditivo direto e ambiente permanente modelados polinômios Legendre. Um...

10.1590/s0100-204x2014000800003 article PT cc-by Pesquisa Agropecuária Brasileira 2014-08-01

O polimorfismo do gene hormônio de crescimento bovino (bGH) foi estudado em 211 bovinos machos da raça Nelore, puros origem (PO), a fim observar as freqüências genotípicas e alélicas, possível associação com característica peso. Para alcançar este objetivo, foram considerados os pesos ao nascer, à desmama mensais dos 10 aos 16 meses idade, calculados ganhos peso nascimento meses. Foi coletado sangue para extração DNA análise sítios polimórficos (RFLP) oriundos digestão endonucleases Msp I...

10.1590/s1516-35982000000500016 article PT cc-by Revista Brasileira de Zootecnia 2000-10-01

O objetivo deste trabalho foi descrever a estrutura genética da raça Sindi no Brasil, utilizando dados do registro genealógico de animais nascidos entre 1955 e 1998. banco separado nos seguintes períodos: 1979-1983, 1984-1988, 1989-1993 1994-1998. A endogamia total aumentou 0,38 para 10,13%; esperada sob acasalamento ao acaso, 0,07 5,65%; atribuída à subdivisão populacional, 0,30 4,74%, considerando os períodos inicial final, indicando existência na Sindi. tamanho efetivo populacional...

10.1590/s1516-35982004000400005 article PT cc-by Revista Brasileira de Zootecnia 2004-08-01

O objetivo deste trabalho foi descrever a estrutura da população do rebanho Sindi registrado no Brasil. Foram geradas estatísticas descritivas distribuição número de progênies, estimados o intervalo gerações e tamanho efetivo população, usando registro genealógico animais nascidos entre 1955-1998. médio calculado para arquivo completo 7,65 anos período 1994-1998 7,96 anos. Os tamanhos efetivos nos quatro períodos (1979-83, 1984-88, 1989-93 1994-98) foram, respectivamente, 501, 26, 20 19.

10.1590/s1516-35982001000800005 article PT cc-by Revista Brasileira de Zootecnia 2001-12-01

The polymorphism of the bovine growth hormone gene (bGH) was studied in 211 Nellore pure breed males for association with reproductive traits. Scrotal circumference and testosterone concentrations were collected monthly from 10 until 16 months age. Additionally, testicular rates calculated. DNA amplified by PCR digested using Msp I Hae III restriction enzymes. Every presented two alleles. predominant alleles D (0.85) F (0.98), respectively, genotype EE - bGH/Hae missing. Significant...

10.1590/s1516-89132002000300007 article EN cc-by-nc Brazilian Archives of Biology and Technology 2002-09-01

The environment is vital to the agricultural sector since it can cause adversities throughout entire productive chain. This study evaluated geographical distribution of zebu breeds in Brazil and correlated their occurrence with environmental variables human development index. Herds purebred cattle (Bos indicus) were classified as beef, dairy, dual-purpose breeds, all spatialized ArcGIS program. Environmental (precipitation, temperature, relative humidity index) index (HDI) examined. We...

10.1590/1678-992x-2022-0008 article EN cc-by Scientia Agricola 2022-10-17

<title>Abstract</title> The fecal microbiome is emerging as an essential component of the gut microbiota and host metabolism, whereas in cattle, characterization still needed. Recent evidence indicates that small RNAs, such miRNAs, may be isolated from feces involved host–microbe interactions. In this study, samples were collected rectal ampulla Nelore bulls phenotypic divergent for residual feed intake (RFI). miRNA sequencing 16S rRNA gene (V3-V4 region) performed to reveal associations...

10.21203/rs.3.rs-4744784/v1 preprint EN cc-by Research Square (Research Square) 2024-08-09

Records of 17,141 Nellore cattle participating in championships, born from 1994-2009, were used to estimate genetic parameters between animal rank evaluated weaning 36 months age as repeated traits, and growth, fertility, carcass at 365 days single traits.Two traits defined for championships: value 1 was attributed animals ranked 1st 3rd place within the category, 0 assigned remaining (TOP3).Value 5th category (TOP5).The (co)variance components estimated based on Bayesian inference under a...

10.4238/2014.july.25.28 article EN Genetics and Molecular Research 2014-01-01

Abstract This study aimed to investigate the feasibility of genomic prediction for productive and reproductive traits in Guzerá cattle using single-step BLUP (ssGBLUP). Evaluations included 305-day cumulative yields (first lactation, kg) milk, lactose, protein, fat, total solids; adjusted body weight (kg) at ages 450 days, 365 210 days; age first calving (in days), from a database containing 197,283 measurements males females born between 1954 2018. The pedigree 433,823 animals spanning up...

10.21203/rs.3.rs-2061251/v1 preprint EN cc-by Research Square (Research Square) 2022-09-22

Abstract The aim of this study was to evaluate the geographical distribution zebu breeds in Brazil and correlate their occurrence with environmental variables human development indicator. herds purebred cattle were classified as beef (Brahman, Polled Brahman, Nelore, Nelore Tabapuã), dairy (Gir Gir), dual-purpose (Guzerá, Indubrasil, Sindhi Sindhi), all being spatialized ArcGIS program. Variables examined included statistical analysis logistic regression.The lower states Northeast compared...

10.21203/rs.3.rs-787879/v1 preprint EN cc-by Research Square (Research Square) 2021-10-18
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