Controlo integrado da Lagarta das Pastagens Mythimna unipuncta (Haworth)

II Jornadas Agronómicas Açorianas, Outubro, 1991, Ponta Delgada, Açores.No Arquipélago dos Açores, desde 1970 e com maior incidência na ilha de S. Miguel, devido ao aumento da área de pastagem, com vista ao desenvolvimento da bovinocultura, uma das espécies de Noctuídeos, Mythimna unipuncta (Haworth) (Lepidoptera, Noctuidae), assinalada na região desde 1810 por GODMAN, tornou-se num grave problema económico, estimando-se os seus prejuízos em cerça de 8% da produção anual das pastagens (TAVARES, 1989)

Identificação de regiões genômicas e genes candidatos posicionais e funcionais para características de eficiência alimentar em bovinos da raça Nelore

This thesis has been divided into three chapters for better understanding of the experiments. The first chapter refers to a brief Literature Review, with the main concepts and justifications for this work. The second chapter discusses the strategy of positional and functional candidate genes for traits of feed efficiency in Nelore cattle, and the third chapter presents a genome-wide association study for feed efficiency traits in the same population. Feed efficiency is an important production trait in beef cattle production systems. The aim of this study was to identify genes/QTLs associated with feed efficiency traits in Nelore cattle genotypes using the Illumina BeadChip BovineHD (770K) of 593 Nelore steers. The traits analyzed were: average daily weight gain (ADG), dry matter intake (DMI), feed conversion (FC), feed efficiency (FE), residual feed intake (RFI), efficiency of maintenance (EM), efficiency gain (EG), partial efficiency of growth (PEG) and relative growth rate (RGR). The first strategy discussed in this work, using candidate genes, investigated the association of Neurogenic differentiaton 1 (NEUROD1), Kv channel interacting protein 4 (KCNIP4), and Vascular endothelial growth factor C (VEGFC) genes, with production traits in the same population. Our results are in according to literature that indicate NEUROD1, KCNIP4 and VEGFC as candidate genes for feed efficiency; and this study is the first to suggest the NEUROD1 gene as a candidate for gene backfat thickness, body weigth and metabolic weight in Nelore cattle. In the genome-wide association study some QTL regions identified in this study minimally overlapped with QTL regions previously reported for feed efficiency in Bos Taurus cattle, and harbor genes with biological functions related to metabolic processes, lipid and protein metabolism, energy generation and growth. A comparison with published results indicates that different QTL and genes may be involved in the control of feed efficiency in this population of Nelore cattle. The validation of the results obtained in this work in independent populations may contribute to elucidation of the mechanisms will involved in the variation of feed consumption and specific improvement in Nelore programs.Financiadora de Estudos e ProjetosEsta tese foi dividida em três capítulos para melhor compreensão dos experimentos realizados. O primeiro capítulo refere-se a uma breve Revisão de Literatura, com os principais conceitos e justificativas para a realização deste trabalho. O segundo capítulo aborda a estratégia de genes candidatos posicionais e funcionais para características de eficiência alimentar na raça Nelore e o terceiro capítulo apresenta um estudo de associação genômica ampla para características de eficiência alimentar na mesma população. A eficiência alimentar é uma característica produtiva importante em sistemas de produção de bovinos de corte. O objetivo deste estudo foi identificar genes/QTLs associados com características de eficiência alimentar em bovinos da raça Nelore utilizando genótipos do Illumina BovineHD BeadChip (770K). As características analisadas foram: ganho de peso médio diário (GMD), consumo de matéria seca (CMS), conversão alimentar (CA), eficiência alimentar (EA), consumo alimentar residual (CAR), eficiência da mantença (EM), eficiência de ganho (EG), eficiência parcial de crescimento (EPC) e taxa de crescimento relativo (TCR). A primeira estratégia abordada neste trabalho, a de genes candidatos, investigou a associação dos genes Neurogenic differentiaton 1 (NEUROD1), Kv channel interacting protein 4 (KCNIP4), e Vascular endothelial growth factor C (VEGFC), com características produtivas nesta mesma população. Nossos resultados corroboram com resultados da literatura que indicam os genes KCNIP4 e VEGFC como genes candidatos para eficiência alimentar; e este estudo é o primeiro a sugerir o gene NEUROD1 como gene candidato para espessura de gordura subcutânea, peso médio e peso metabólico em bovinos da raça Nelore. No estudo de associação genômica, algumas regiões de QTL identificadas foram sobrepostas minimamente com regiões de QTL relatadas anteriormente para eficiência alimentar em bovinos Bos taurus, e abrigam genes com funções biológicas relacionadas com processos metabólicos, metabolismo lipídico e proteíco, geração de energia e crescimento. A comparação com os resultados publicados indicam que diferentes QTL e genes podem estar envolvidos no controle da eficiência alimentar nesta população de bovinos da raça Nelore. A validação dos resultados obtidos neste trabalho em populações independentes pode contribuir para elucidação dos mecanimos envolvidos na variação do consumo alimentar e para programas de melhoramento específicos para a raça Nelore

Concentrados de alta fibra em dietas para a terminação de novilhas Nelore

O estudo foi conduzido para avaliar o efeito de duas proporções de concentrado, 70 e 80%, com duas fontes energéticas, milho e farelo de gérmen de milho, e volumoso à base de silagem de milho, sob o consumo de nutrientes, desempenho, características de carcaça, não componentes de carcaça e qualidade da carne de 28 novilhas Nelore confinadas, com aproximadamente 14 meses de idade e peso corporal médio de 200 kg, objetivando o abate. O delineamento experimental utilizado foi o inteiramente casualizado segundo esquema fatorial 2 x 2 ( 2 proporções de concentrado x 2 fontes energéticas) totalizando 4 tratamentos e 7 repetições, sendo as médias comparadas pelo teste de Tukey a 5%. Não houve interação da proporção de concentrado x fonte energética da dieta sobre o consumo de MS. Houve efeito significativo da interação proporção de concentrado x fonte energética da dieta para os consumos de proteína bruta (PB) e fibra em detergente neutro (FDN), sendo que a maior proporção de concentrado, associada ao milho, possibilitou maior consumo diário de PB (1,17 kg/dia) e FDN (4,05 kg/dia). Observou-se valor médio de consumo de fibra em detergente ácido superior para as dietas com 80% de concentrado, tanto para a dieta com milho quanto com farelo de gérmen de milho. Houve efeito significativo da fonte energética da dieta sobre o peso final dos animais, sendo que os animais alimentados com as dietas contendo milho apresentaram valor médio de peso final (326,14 kg) superior aos alimentados com as dietas contendo farelo de gérmen de milho (292,07 kg). A associação de altas proporções de concentrado, com milho como fonte energética, proporciona resultados satisfatórios de ganho em peso e desempenho de novilhas Nelore, já a substituição total do milho pelo farelo de gérmen de milho, associado à altas proporções de concentrado ricos em fibra...The objective of this study was to evaluate the effect of two proportions of concentrate, 70 and 80%, with two energy sources, corn and corn germ meal, and roughage basis of corn silage on the intake of nutrients, performance, characteristics of a carcass, non components of carcass and meat quality of confined 28 Nellore heifers. The experimental design was a completely randomized design in factorial scheme 2 x 2 (2 proportions of concentrate x 2 energy sources) 4 replications and 7 treatments, and the averages has been compared by Tukey 5% test.. There was no interaction proportion of concentrate x energy source on the intake of dry matter. There was a significant effect of interaction proportion of concentrate x energy source intake for crude protein (CP) and neutral detergent fiber (NDF), suggesting that a higher proportion of concentrate, with the corn, allowed greater intake of CP (1.17 kg / day) and NDF (4,05 kg / day). It was observed average intake of acid detergent fiber than for diets with 80% concentrate, with both the diet with corn as the corn germ meal. There was a significant effect of dietary energy source on the final weight of animals, and the animals fed the diets with corn had average final weight (326.14 kg), above the fed with diets with corn germ meal (292.07 kg). The association of high proportions of concentrate with corn as an energy source, provided satisfactory results in performance of Nellore heifers, since the replacement of the corn germ meal, associated with high proportions of concentrate rich in fiber, not was recommended for young Nellore heifers. There was a significant effect the energy source of the diet on the weight of empty body, and the animals that received the diets with corn showed the average value of empty body weight (309.44 kg) than the diets of with corn germ meal (276.42 kg). The carcass yield, the thickness... (Complete abstract click electronic access below)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Consumo e digestibilidade em ovinos alimentados com grãos e subprodutos da canola Intake and digestibility of sheep fed grains and by-products of canola

Objetivou-se avaliar a inclusão de 8% de grãos e subprodutos da canola (farelo ou torta) nas dietas sobre o consumo e a digestibilidade. Seis ovinos machos não-castrados da raça Santa Inês (210 e 240 dias de idade e peso corporal de 44,8 + 4,2kg) receberam dietas contendo 40% de feno de capim Tifton e 60% de concentrado composto por milho em grão, farelo de soja, mistura mineral, além de canola em grão integral, farelo de canola e torta de canola, que constituíram os três tratamentos. Não houve diferença (P&gt;0,05) para o consumo de matéria seca (MS), matéria orgânica (MO), extrato etéreo (EE), energia bruta (EB), fibra em detergente neutro (FDN), carboidratos totais (CT) e carboidratos não-fibrosos (CNF) entre as dietas experimentais, no ensaio de digestibilidade. Não houve efeito (P&gt;0,05) de tratamento para a digestibilidade de MS, MO, EE, PB, EB, FDN, CT e CNF. Recomenda-se incluir até 8% de grãos e subprodutos da canola (farelo ou torta) na dieta de ovinos.<br>The effect of feeding 8% of grains and byproducts (meal or cake) of canola on intake and digestibility was evaluated. Six non castrated Santa Ines sheep (from 210 to 240 days old and body weight of 44.8 + 4.2kg) were fed diets composed by 40% of Tifton hay and 60% of concentrate based on corn grain, soybean meal, whole grain canola, canola meal, canola cake and mineral mixture. No differences on the intakes of dry matter (DM), organic matter (OM), ether extract (EE), gross energy (GE), neutral detergent fiber (NDF), total carbohydrates (TC) and non fiber carbohydrate (NFC) were observed among treatments, in the digestibility trial. No treatment effect on the digestibilities of DM, OM, EE, CP, GE, NDF, TC and NFC was observed. It is recommended to include up to 8% of grains and byproducts (meal or cake) of canola in the sheep diet

Iron Content Affects Lipogenic Gene Expression in the Muscle of Nelore Beef Cattle

<div><p>Iron (Fe) is an essential mineral for metabolism and plays a central role in a range of biochemical processes. Therefore, this study aimed to identify differentially expressed (DE) genes and metabolic pathways in <i>Longissimus dorsi</i> (LD) muscle from cattle with divergent iron content, as well as to investigate the likely role of these DE genes in biological processes underlying beef quality parameters. Samples for RNA extraction for sequencing and iron, copper, manganese, and zinc determination were collected from LD muscles at slaughter. Eight Nelore steers, with extreme genomic estimated breeding values for iron content (Fe-GEBV), were selected from a reference population of 373 animals. From the 49 annotated DE genes (FDR<0.05) found between the two groups, 18 were up-regulated and 31 down-regulated for the animals in the low Fe-GEBV group. The functional enrichment analyses identified several biological processes, such as lipid transport and metabolism, and cell growth. Lipid metabolism was the main pathway observed in the analysis of metabolic and canonical signaling pathways for the genes identified as DE, including the genes <i>FASN</i>, <i>FABP4</i>, and <i>THRSP</i>, which are functional candidates for beef quality, suggesting reduced lipogenic activities with lower iron content. Our results indicate metabolic pathways that are partially influenced by iron, contributing to a better understanding of its participation in skeletal muscle physiology.</p></div

Significantly down-regulated genes identified in the Nelore steers <i>Longissimus dorsi</i> muscle with low genomic breeding value compared to animals with high genomic breeding value for iron content.

<p>Significantly down-regulated genes identified in the Nelore steers <i>Longissimus dorsi</i> muscle with low genomic breeding value compared to animals with high genomic breeding value for iron content.</p

Cell development and a differentiation-related network of differentially expressed genes between high and low iron content in the Nelore steers <i>Longissimus dorsi</i> muscle.

<p>Genes presented in green and red are down- and up-regulated in the LowFe group, respectively. Color intensity refers to fold change estimates. Dotted arrows represent indirect interactions, and colors orange, blue, gray, and yellow denote activation, inhibition, unpredicted effect, and inconsistent effect, respectively. Reprinted from [QIAGEN’s Ingenuity^® Pathways Analysis] under a CC BY license, with permission from QIAGEN Silicon Valley, original copyright [200–2015 QIAGEN].</p

Lipid metabolism related network of differentially expressed genes between high and low iron content in the Nelore steers <i>Longissimus dorsi</i> muscle.

<p>Genes in green and red are down- and up-regulated in the LowFe group, respectively. Color intensity refers to fold change estimates. Dotted arrows represent indirect interactions, and orange, blue, gray, and yellow colors denote activation, inhibition, unpredicted effect, and inconsistent effect, respectively. Reprinted from [QIAGEN’s Ingenuity^® Pathways Analysis] under a CC BY license, with permission from QIAGEN Silicon Valley, original copyright [200–2015 QIAGEN].</p

Ranking of the biological processes based on the terms of Gene Ontology (GO-Slim) for the differentially expressed genes identified in Nelore steers with high and low genomic breeding value for iron content in the <i>Longissimus dorsi</i> muscle.

<p>The bar represents each category of the biological process. The number of genes per category is indicated above the bar.</p