Sustainable intensification for a larger global rice bowl.

Future rice systems must produce more grain while minimizing the negative environmental impacts. A key question is how to orient agricultural research & development (R&D) programs at national to global scales to maximize the return on investment. Here we assess yield gap and resource-use efficiency (including water, pesticides, nitrogen, labor, energy, and associated global warming potential) across 32 rice cropping systems covering half of global rice harvested area. We show that achieving high yields and high resource-use efficiencies are not conflicting goals. Most cropping systems have room for increasing yield, resource-use efficiency, or both. In aggregate, current total rice production could be increased by 32%, and excess nitrogen almost eliminated, by focusing on a relatively small number of cropping systems with either large yield gaps or poor resource-use efficiencies. This study provides essential strategic insight on yield gap and resource-use efficiency for prioritizing national and global agricultural R&D investments to ensure adequate rice supply while minimizing negative environmental impact in coming decades

Estudio de asociación de genoma completo para resistencia genética a nematodos gastrointestinales en ovinos Corriedale. [abstract].

El objetivo de este trabajo fue identificar regiones genómicas asociadas a la resistencia a NGI en ovinos Corriedale a través del estudio de asociación genómica en un solo paso (ssGWAS) del recuento de huevos por gramo en heces (HPG) utilizando 2 paneles de baja densidad y un panel comercial de mediana densidad

Cuánto mejora la precisión de la evaluación de resistencia anematodos gastrointestinales en Corriedale por inclusión deinformación molecular?. [Abstract + poster]

Los nematodos gastrointestinales (NGI) son las infecciones parasitarias ovinas más prevalentes. Una alternativa de control es la selección genética en base al recuento de huevos por gramo en heces (HPG). El objetivo de este trabajo fue evaluar el aporte de información molecular a través de la comparación de las precisiones de los valores de cría (EBV) y EBV genómicos (GEBV) de HPG y diámetro de fibra (DF) en la raza Corriedale

Genome-wide association study of parasite resistance to gastrointestinal nematodes in Corriedale sheep.

ABSTRACT.- Selection of genetically resistant animals is one alternative to reduce the negative impact of gastrointestinal nematodes (GIN) on sheep production. The aim of this study was to identify genomic regions associated with GIN resistance in Corriedale sheep by single-step genome-wide association studies (ssGWAS) using 170, 507 and 50K single nucleotide polymorphisms (SNPs). Analysis included 19,547 lambs with faecal egg counts (FEC) records, a pedigree file of 40,056 animals and 454, 711 and 383 genotypes from 170, 507 and 50K SNPs, respectively. Genomic estimated breeding values (GEBV) were obtained with single-step genomic BLUP methodology (ssGBLUP), using a univariate animal model, which included contemporary group, type of birth and age of dam as class fixed effects and age at FEC recording as covariate. The SNP effects as wells as p-values were estimated with POSTGSF90 program. Significance level was defined by a chromosome-wise False Discovery Rate of 5%. Significant genomic regions were identified in chromosomes 1, 3, 12 and 19 with the 170 SNP set, in chromosomes 7, 12 and 24 using the 507 SNP chip and only in chromosome 7 with the 50K SNP chip. Candidate genes located in these regions, using Oar_v4.0 as reference genome, were TIMP3, TLR5, LEPR and TLR9 (170 SNPs), SYNDIG1L and MGRN1 (507 SNP chip) and INO80, TLN2, TSHR and EIF2AK4 (50K SNP chip). These results validate genomic regions associated with FEC previously identified in Corriedale and other breeds and report new candidate regions for further investigation. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

SNP arrays evaluation as tools in genetic improvement in Corriedale sheep in Uruguay. [Evaluación de paneles de SNP como herramientas en la mejora genética de ovinos Corriedale en Uruguay]. [Avaliação de painéis de SNP como ferramentas em melhoramento genético de ovinos Corriedale no Uruguai].

ABSTRACT.- One control strategy for gastrointestinal nematodes (GIN) is genetic selection. This studys objective was to compare eggs per gram of feces (FEC) and fiber diameter (FD) estimated breeding values (EBV) and genomic EBV (GEBV) in Corriedale breed. Analysis included 19547 lambs with data, and 454, 711 and 383 genotypes from 170, 507 and 50K SNP chips, respectively. A univariate animal model was used for EBV and GEBV estimation, which included contemporary group, type of birth and dam age as fixed effects, and age at recording as covariate. Differential weights (?) were considered in the genomic relationship matrix (G), and the best fit models were identified using Akaikes Information Criterion (AIC), which were later used for GEBV and accuracies estimation. The use of only impacted on low density SNP chips. No differences were observed in mean accuracies for the whole population. However, in the genotyped subgroup accuracies increased by 2% with the 170 SNP chip (?=0.25), and by 5% (?=0.5) and 14% (?=0.75) with the 507 SNP chip. No differences were observed in FD EBV and GEBV mean accuracies. These results show that it is possible to increase GEBV accuracies despite the use of low-density chips -.-.-.-.-.-.-.-.-.-.-.-..-RESUMEN.- Una alternativa para el control de losnematodos gastrointestinales (NGI) es la selección genética. El objetivo de este trabajo fue comparar las precisiones de los valores de cría (EBV) y los EBV genómicos (GEBV) del recuento de huevos por gramo en heces (HPG) y diámetro de fibra (DF) en la raza Corriedale. El análisis incluyó 19547 corderos con datos fenotípicos y 454, 711 y 383 genotipados con paneles o chips de 170, 507 y 50K SNP, respectivamente. Los EBV y GEBV se estimaron con un modelo animal univariado que incluyó los efectos fijos:grupo contemporáneo, tipo de nacimiento y edad de la madre,y edad al registro como covariable. Se consideraron pesos diferenciales (?) en la matriz de relaciones genómicas, identificándose los modelos con mejor ajuste con el criterio de información de Akaike (AIC), que fueron utili-zados para la estimación de los GEBV y sus precisiones. El uso de ?solo impactó en el ajuste con paneles de baja densidad. No se encontraron diferencias en las precisiones promedio de la población total. En cambio, en el subgrupo de animales genotipados las precisiones aumentaron 2% con 170 SNP (?=0.25), y con 507 SNP 5% (?=0.5) y 14% (?=0.75). No hubo diferencias en precisiones de los EBV y los GEBV de DF. Los resultados muestran que es posible aumentar las precisiones de los GEBV aun con paneles de baja densidad. -.-.-.-.-.-.-.-.-.-.-.-..-RESUMO.- Uma alternativa para o controle de nematóidesgastrointestinais (NGI) é a seleção genética. O objetivo deste trabalho foi comparar as precisões dos valores genéticos estimados (EBV) e dos EBVs genômicos (GEBV) da contagem de ovos por grama de fezes (OPG) e diâmetro de fibra (DF) na raça Corriedale. Aanálise incluiu 19547 cordeiros com dados e 454, 711 e 383 genotipados de 170, 507 e 50K SNPs, respectivamente. Foram estimados os EBV e GEBV com um modelo animal univariado que incluiu efeitos fixos de grupo contemporâneo, tipo de nascimento e idade da mãe e idade no registro (covariável). Pesos diferenciais (?) foram considerados na matriz de relações genômicas, identificando os modelos com melhor ajuste via critério de informação de Akaike (AIC), os quais foram utilizados para estimar o GEBV e suas precisões. O uso de ?=0.75 somente impactou no ajuste com painéis de baixa densidade. Não foram encontradas diferenças na precisão média da população total. Em contraste, no subgrupo de animais genotipados as precisões aumentaram 2% com 170 SNPs (?=0.25), e com 507 SNPs 5% (?=0.5) e 14% (?=0.75). Não houve diferenças na precisão de EBV e GEBV de DF. Os resultados mostram que é possível aumentar a precisão de GEBVs mesmo que se utilizem painéis de baixa densidade

Prevalence and Factors Associated with Anthelmintic Resistance in Gastrointestinal Nematodes of Cattle: A Systematic Review and Meta-analysis.

A systematic review and meta-analysis was conducted with the aim to measure the prevalence of anthelmintic resistance (AR) in cattle gastrointestinal nematodes (GIN) and potential management factors associated with development of such resistance. A search algorithm was constructed and a comprehensive search of the primaryliterature was conducted in: CAB abstracts (1990-2016), Medline (1860-2016), Agricola (1924-2016) and Lilacs (1985-2016). Prevalence estimates were combined through meta-analysis (MA) using the logit prevalence and between-study heterogeneity was quantified. Twenty-nine publications (5 cross-sectional studies; 14 prevalencesurveys and 10 field trials) were included in this review. Random effects MA resulted in an overall AR prevalence of 72.0% (95% CI=58.4% to 80.0%). However, a high heterogeneity was observed (I2=55.9%). From studies reporting the nematode genera involved in the AR, Cooperia spp were present in 91.7% of the studies (n=24); Ostertagia sp. in 44.5% (n=22); Haemonchus sp. in 47.8% (n=23); Trichostrongylus sp. in 36.4% (n=22) and Oesophagostomum spp. in 23.8% (n=21). The included cross sectional studies suggested that frequency of treatments, age of cattle and type of management were potential management factors associated with AR in bovine GINs. However, more detailed studies are necessary to fully evaluate management guidelines for implementation of sustainable GIN control strategies

Breeding for sheep parasite resistance in extensive production systems: from phenotype to genotype. IAEA-CN-281-181.

Worldwide, gastrointestinal parasites (GIP) generate numerous productive and economic losses in sheep production and Uruguay does not escape to this problem. Due to the aggravating situation of anthelmintic resistance to all drugs available in the market, the use of non-chemical alternative strategies is essential to address the problem of GIP

Situación actual de la resistencia a las drogas antihelmínticas en ovinos en Uruguay.

En los sistemas productores de ovinos en Uruguay, así como en otras partes del mundo, los parásitos gastrointestinales han sido y continúan siendo causantes de importantes pérdidas productivas y económicas. Como ha sido descrito en otras oportunidades, el uso de las drogas de síntesis química como único método de control, ha llevado al desarrollo de parásitos resistentes

Prevalence and Factors Associated with Anthelmintic Resistance in Gastrointestinal Nematodes of Cattle: A Systematic Review and Meta-analysis.

A systematic review and meta-analysis was conducted with the aim to measure the prevalence of anthelmintic resistance (AR) in cattle gastrointestinal nematodes (GIN) and potential management factors associated with development of such resistance. A search algorithm was constructed and a comprehensive search of the primary literature was conducted in: CAB abstracts (1990-2016), Medline (1860-2016), Agricola (1924-2016) and Lilacs (1985-2016). Prevalence estimates were combined through meta-analysis (MA) using the logit prevalence and between-study heterogeneity was quantified. Twenty-nine publications (5 cross-sectional studies; 14 prevalence surveys and 10 field trials) were included in this review. Random effects MA resulted in an overall AR prevalence of 72.0% (95% CI=58.4% to 80.0%). However, a high heterogeneity was observed (I2=55.9%). From studies reporting the nematode genera involved in the AR, Cooperia spp were present in 91.7% of the studies (n=24); Ostertagia sp. in 44.5% (n=22); Haemonchus sp. in 47.8% (n=23); Trichostrongylus sp. in 36.4% (n=22) and Oesophagostomum spp. in 23.8% (n=21). The included cross sectional studies suggested that frequency of treatments, age of cattle and type of management were potential management factors associated with AR in bovine GINs. However, more detailed studies are necessary to fully evaluate management guidelines for implementation of sustainable GIN control strategies.Made available in DSpace on 2019-01-25T23:53:55Z (GMT). No. of bitstreams: 1 PrevalenceFactorsAssociatedAnthelmintic.pdf: 577609 bytes, checksum: 131875183d08ec6c2fa0bf420e1d6590 (MD5) Previous issue date: 2019-01-25bitstream/item/191333/1/PrevalenceFactorsAssociatedAnthelmintic.pd

Asignación de parentesco y detección de superfecundación heteropaternal en ovinos Merino Australiano mediante paneles de SNP.

El objetivo del presente trabajo fue asignar las paternidades para la generación 2020 del Núcleo Ultrafino Glencoe (NUG) y determinar la frecuencia de superfecundación heteropanernal mediante la genotipificación con paneles de SNP de mediana densidad (≈50K)