Genetic improvement and population structure of the Nelore breed in Northern Brazil

O objetivo deste trabalho foi avaliar a estrutura populacional e o progresso genético e fenotípico da raça Nelore na Região Norte do Brasil. Informações sobre o pedigree foram analisadas em animais nascidos entre 1942 e 2006. A estrutura populacional foi estimada utilizando-se o programa Endog. Dos 140.628 animais avaliados, 67,7% dos pais, 14,52% dos avós e 3,18% dos bisavós eram conhecidos. O coeficiente de parentesco médio e a endogamia foram, em geral, baixos: 0,13 e 0,20%, respectivamente. Contudo, esses parâmetros podem ter sido subestimados, já que as informações de pedigree eram incompletas. O número efetivo de fundadores foi de 370 e a variabilidade genética na população explicada pelos 10, 50 e 448 mais influentes ancestrais foi de 13,2, 28 e 50%, respectivamente. A existência de variabilidade genética indica possibilidade de aumento na produtividade por meio da seleção. Adicionalmente, estratégias de manejo para diminuir a idade ao primeiro parto e o intervalo de gerações são importantes para o melhoramento da raça.The objective of this work was to evaluate the population structure and the genetic and phenotypic progress of Nelore cattle in Northern Brazil. Pedigree information concerning animals born between 1942 and 2006 were analyzed. Population structure was performed using the Endog program. average relatedness coefficients were low: 0.2 and 0.13%, respectively. However,The effective number of founders was 370 and the genetic contribution of 10, 50 and 448 most influent ancestors explained 13.2, 28 and 50% of the genetic variability in the population, respectively. The genetic variability for growth traits and population structure demonstrates high probability of increasing productivity through selective breeding. Moreover, management strategies to reduce the currently observed age at first calving and generation intervals are important for Nelore cattle genetic improvement

INBREEDING DEPRESSION AND GENETIC VARIABILITY IN NELLORE BREED

Inbreeding depression is caused by breeding between closely relatedindividuals and can have a significant negative impact on cattle production. It can be estimated at the population level using pedigree analysis or molecular markers. Such estimations can then be used to better manage the genetic resources of herds. The objective of this study was to evaluate genetic variability and the influence of inbreeding depression on productive traits in 45 785 animals Nellore cattle (polled variety) from Brazil. Inbreeding depression was determined by fitting four regression models (linear, quadratic, exponential and Michaelis-Menten) to the errors generated by the animal model. The traits studied were weight at 205 (W205), 365 (W365) and 550 (W550) days of age. The effective number of founders (fe) and ancestors (fa) was 288 and 283, respectively, with 173 ancestors explaining 50% of the genetic variability in the population. Inbreeding depression effects were identified on all growth traits (W205, W365, and W550), demonstrating significant losses in evaluated weight means. For each 1% increase in inbreeding there was a depression of about 0.14% or 0.24 kg (W205), 0.12% or 0.29 kg (W365) and 0.09%or 0.29 kg (W550). Exponential and Michaelis-Menten models were similarly efficient predictors for all the traits (P<0.01). We conclude that Nellore cattle in Northeastern Brazil presents low genetic variation and the relationship between inbreeding and depressed productivity in this breed is not linear, with the greatest effects occurring when endogamy is above 20%. To change this scenario, it is important to use a high number of male breeders, mainly young individuals of high breeding value, and improvement of reproductive indexes of females. To achieve this goal, a traditional mating system focused on the utilization of a few (and famous) male breeders should be avoided by both farmers and technicians

Genetic improvement of Nellore cattle in the semi-arid region of northeastern Brazil

ABSTRACT. The semi-arid region of Brazil represents approximately 57% of the northeastern territory. The main economic activity in this region is agriculture and livestock, in most cases, using traditional technologies. However, there is little published information currently available on cattle-raising in this part of Brazil. The objective of this study was to estimate genetic parameters and trends for productive and reproductive traits of Nellore cattle raised in semi-arid region of northeastern Brazil. Data were collected on weight-adjusted at 205 (W205), 365 (W365) and 550 (W550) days of life, age at first calving (AFC), calving interval (CI) and scrotal circumference (SC) at 550 days of life of cattle born between 1965 and 2011. Estimates of covariance and variance were obtained through univariate analysis using a Gibbs sampler. The estimated coefficients of heritability (mode) were 0.27 (W205), 0.36 (W365) and 0.39 (W550), 0.37 (SC), 0.22 (AFC) and 0.03 (CI). Little or no gain from selection is apparent in the genetic trend analysis over the 45 years of the study. However, environmental improvement has allowed phenotypic progress in growth traits and age at first age calving. Keywords: age at first calving, genetic progress, genetic parameters, heritability. Melhoramento genético de bovinos Nelore na região semi-árida do nordeste do Brasil RESUMO. A região semiárida do Brasil representa aproximadamente 57% do território nordestino. A principal atividade econômica da região é a agricultura e pecuária e, na maioria dos casos, utilizando tecnologias tradicionais. No entanto, há poucas informações publicadas, sobre a criação de bovinos nesta parte do Brasil. O objetivo deste estudo foi estimar parâmetros e tendências genéticas para características produtivas e reprodutivas de bovinos Nelore criados na região semiárida do nordeste do Brasil. Foram coletados dados ajustados aos 205 (P205), 365 (P365) e 550 (P550) dias de vida, idade ao primeiro parto (IPP), intervalo entre partos (IP) e perímetro escrotal (PE) aos 550 dias de idade em bovinos nascidos entre 1965 e 2011. As estimativas de variância e covariância foram obtidas por meio de análise univariada usando um amostrador de Gibbs. Os coeficientes estimados de hereditariedade (moda) foram de 0,27 (P205), 0,36 (P365) e 0,39 (P550), 0,37 (PE), 0,22 (IPP) e 0,03 (IP). Pouco ou nenhum ganho de seleção foi encontrado na análise de tendência genética ao longo dos 45 anos do estudo. No entanto, a melhoria do ambiente permitiu progresso fenotípico das características de crescimento e idade ao primeiro parto. Palavras-chave: idade ao primeiro parto, progresso genético, parâmetros genéticos, herdabilidade

PROPOSTA METODOLÓGICA PARA PADRONIZAÇÃO DOS ESTUDOS DE ATITUDES EM COMUNIDADES ADJACENTES ÀS UNIDADES DE CONSERVAÇÃO DE PROTEÇÃO INTEGRAL NO BRASIL

A eficácia em alcançar objetivos de conservação é considerada um dos maiores desafios para a gestão de áreas protegidas. No Brasil, as unidades de conservação (UCs) de proteção integral têm um papel fundamental para conservação da biodiversidade, porém, persistem os conflitos sociais. Estes são frequentemente associados a comportamentos individuais que podem comprometer os objetivos de conservação (caça, desmatamento, etc.), resultando em crimes ambientais locais nas UCs que demandam recursos da gestão que poderiam ser investidos em outros programas e ações preventivas e de manejo. Assim, é essencial compreender melhor os fatores que moldam os comportamentos dos membros das comunidades adjacentes às UCs, pois são os principais atores do território protegido. Sendo as atitudes determinantes importantes de comportamentos individuais, o estudo destas em relação às UCs pode ter um papel crucial na gestão, constituindo ferramenta para, por exemplo: (i) avaliar a concordância entre os valores de criação da UC e os das comunidades; (ii) apoiar a implementação e monitoramento de estratégias de mudança social em relação à conservação da biodiversidade; (iii) mitigar conflitos locais; (iv) fornecer indicadores para monitorar a efetividade de ações/programas de conservação e conscientização nas comunidades; e (v) contribuir para o manejo das zonas de amortecimento. Neste artigo propomos um método baseado em pesquisa socioambiental para padronizar o estudo de atitudes em comunidades adjacentes às UCs, com ênfase nas de proteção integral. O método conta com três etapas principais: (1) preparação do questionário para estudo das atitudes baseado num modelo geral elaborado a partir da revisão de literatura; (2) desenvolvimento de um protocolo de aplicação do questionário; e (3) aplicação nas comunidades do entorno de uma unidade de conservação. Neste estudo, a formulação genérica será apresentada junto à experiência de aplicação no Parque Nacional do Catimbau (PE). Os resultados do estudo de caso evidenciaram a posição das comunidades sobre o Parque e delinearam padrões comportamentais. Por exemplo, pessoas mais jovens mostraram-se mais positivas em relação ao Parque e os agricultores mais favoráveis ao uso dos recursos naturais (madeira, lenha seca, caça). Baseado nestes dados, uma maior inclusão da sociedade em atividades diretamente relacionadas à conservação (monitoramento de espécies invasoras, zoneamento participativo, etc.) e o desenvolvimento de programas de sensibilização e educação foram sugeridos aos gestores da UC para aproximar as comunidades e as pessoas que se mostraram menos positivas com relação ao Parque

TRY plant trait database – enhanced coverage and open access

Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

The Functional Biogeography of Leaves of the Amazonian Rainforest

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