Amanda d’Ávila Carvalho

Meta-análise em pesquisas científicas: enfoque em metodologias

ABSTRACT - This text describes a basic approach of systematization with focus on meta-analysis. It ispresented the art state of the meta-analysis, recovering information of its evolution and basic methodologies for itsaccomplishment. In this text are described the historical antecedents of meta-analysis, the limits of the classicapproaches of literature review, the conceptual bases and the objectives. It is indicated a general methodology formeta-analysis procedures. The criteria for the definition of the objectives are presented. The procedures of thesystematization and management of bibliographical data base selected to meta-analytic studies are described(selection, code, data filtration). The most common analysis (graph, adjustments) are presented, the choice of thestatistical model (a qualitative explanatory factor, a qualitative or quantitative effect), the interference factors andthe post-analytic procedures (residual variations, heterogeneity among results). In conclusion, this text shows thatmeta-analysis is better than traditional methods of literature review for esteeming with more precision the treatmentseffects adjusting it’s for the experimental heterogeneity. However, the meta-analysis requires discipline in thesystematization and analysis of the research results.

Digestibilidade de dietas e balanços metabólicos de suínos alimentados com dietas contendo aflatoxinas

An experiment was conducted in order to investigate the digestibility of diets and metabolic balances of piglets fed diets containing 800ug kg-1 of aflatoxins. This study used eight with littermate barrows whith an average initial weight of 13kg, housed in metabolic cages in a semi-acclimatized environment. A completely randomized experimental design was used, with two treatments (control diet and control + 800ug kg-1 of aflatoxins) and four replications, with the animal as the experimental unit. The digestibility coefficients of dry matter, protein and gross energy were not affected (P>0.05) by the addition of 800ug kg-1 of aflatoxins in the diet. The gross energy metabolization was 6% (P 0.05) by the addition of aflatoxins in the diet. Energy losses in urine increased (P<0.05) 52% in the pigs fed diets containing aflatoxins. The presence of an aflatoxin level of 800ug kg-1 in the diet did not affect the digestibility, but it altered the protein and energy metabolism of weaned piglets.

Digestibilidade aparente de dietas e metabolismo de frangos de corte alimentados com dietas contendo soja integral processada

Foi realizado um experimento para avaliar a digestibilidade aparente de dietas e o metabolismo de frangos de corte alimentados com dietas contendo soja integral (SI) processada a vacuo (SIvac) ou a vapor (SIvap). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos (dieta controle - DC; DC com substituicao isometrica de 40% de SIvac ou SIvap; dieta com SIvac e dieta com SIvap). Os tratamentos com substituicao isometrica avaliaram a digestibilidade das sojas processadas; os demais, a digestibilidade de dietas contendo ou nao soja processada (controle). A ingestao de N foi 23 e 20% menor (P 0,05) pelas dietas. A excrecao de energia foi 19 e 22% menor (P 0,05) para a soja integral processada a vacuo ou a vapor. A soja processada a vacuo ou a vapor e uma alternativa ao farelo de soja e ao oleo vegetal em dietas para frangos de corte.

Modelagem da ingestão, retenção e excreção de nitrogênio e fósforo pela suinocultura brasileira

A static, empirical and determinist model of ingestion, retention and excretion of N and P was developed for the Brazilian pig production. The general principles were: technological systems (ST), animal categories, N and P in the diets, and digestive and metabolic efficiencies of N and P. The model integrates three aggregation levels, being constituted by ten compartments (ingestion, gastrointestinal contents, retention, and excretions of P and N), 300 sub-compartments (50 related to ST and 250 to animal categories). The ST was defined by the number of slaughter animals/sow/year. The flows of N and P among compartments and temporary relations were the same as literature data. The simulated N ingestion and retention were of 193 and 46 thousand t, respectively. The simulated N excretion by fecal and urinary was 37 and 110 thousand t, respectively. Approximately 58% of N ingestion, 77% of N retention and 52% of N excretion were observed in the high ST. The simulated P ingestion and retention were of 46 and 11 thousand t, respectively. The simulated P fecal and urinary excretion was of 29 and 6 thousand t, respectively. This model is adequate to simulate N and P flows for systems of high and medium technologies of the Brazilian pig production.

Processamento da soja integral e uso em dietas para suínos: digestibilidade e metabolismo

An experiment was carried out to evaluate the full-fat soybean (FFS) processed by vacuum (FFSvac) or by steam (FFSstm), by means of digestibility and metabolism of pigs. A completely randomized experimental design was used, with five treatments (control diet, diet with FFSvac, diet with FFSstm, 40% FFSvac + 60% control diet, 40% FFSstm + 60% control diet) and four replications each, being the animal the experimental unit. The digestibility coefficients of gross energy were 4% and 3% lower for the diets with replacement of soybean meal by FFSvac or FFSstm, respectively. The replacement of soybean meal by FFSvac or FFSstm did not influence the digestion and the metabolism of nitrogen of the pigs. For FFS, the content of digestible protein and energy were 10.4 and 4.0% higher with vacuum processing. The diet digestibility and energy metabolism are similar in pigs fed with diets containing FFSvac or FFSstm. For pigs fed with diets containing FFSvac or FFSstm, the diet digestibility and nitrogen metabolism are not different. The vacuum processing improves the digestible contents of protein and energy of full-fat soybean.

Relação do zinco e cobre plasmáticos com componentes nutricionais e desempenho de leitões: uma meta-análise

A meta-analysis was carried out to study the relationship among plasma Zn and Cu with diet nutrients and piglets weight gain. Eighteen publications were considered in the database. The intake of CP, lysine, Ca, P, Cu and Zn was considered as variable in the analysis. Regression analyses were used through mixed models. Plasma Zn was affected by P and Zn intake as well as Cu plasma. P intake and plasma Cu affected negatively plasmatic Zn. The regression analysis showed that for each gram of total P intake/kg BW0.6 there was reduction in 0.043 mg/L of plasmatic Zn. Plasma Cu was affected by Ca, P, Cu and Zn intake. Ca and Zn intake affected negatively plasma Cu. Weight gain was affected by CP, Ca, lysine and Cu intake as well as plasma Zn. A negative effect of Zn intake on Cu metabolism was observed; however plasma Zn had a positive effect on piglets weight gain. This meta-analysis study identified some factors of dietary origin, as P and Ca, which influence negatively the absorption and the metabolism of Zn and Cu in weanling pigs.

Características de carcaças de suínos alimentados do desmame ao abate em comedouro de acesso único equipado ou não com bebedouro

This study was carried out to evaluate the carcass characteristics of pigs fed from weaning to slaughter in single space feeders equipped or not with drinker. Ninety-six animals (48 barrows and 48 females) with 90kg live weight were distributed in a factorial design (two feeder types – no drinker; conjugated with drinker; and two sexes). The carcasses were evaluated by the Brazilian Method of Carcasses Classification and by the Dissection Method. The meat yield was 3.7% higher (P<0.05) in animals fed in dry feeders and 2.6% slower (P<0.05) in barrows. The carcass yield was not affected by the feeder type, but was 1.3% higher (P<0.05) in barrows. The loin muscle area was not affected by the feeder type and sex. The fat area was 8.8% higher (P<0.05) in the animals fed in wet feeders and 16.8% in barrows. The backfat thickness was 11.0% higher (P<0.05) in the animals fed in wet feeders and 11.2% in barrows. The relation meat/fat was 10.9% higher (P<0.05) in animals fed in dry feeders and 21.6% in females. The ham weight was not affected by feeder type, but it was 5.9% higher (P<0.05) in barrows. Feeding pigs from weaning to slaughter in wet feeders reduce lean and increase fat in carcass.

Modelagem da ingestão, retenção e excreção de nitrogênio e fósforo pela suinocultura gaúcha

A static, empirical and determinist model of ingestion, retention and excretion of Nitrogen (N) and Phosphorus (P) was developed for the pig production at Rio Grande do Sul state, Brazil. The general principles were: technological systems (ST), animal categories, N and P in diets, and digestive and metabolic efficiencies of N and P. The model integrates three aggregation levels, being constituted by ten compartments (ingestion, gut fill, retention, and excretions of P and N), 300 sub-compartments (50 related to ST and 250 to animal categories). The ST was defined by number of slaughter animals per sow per year. The flows of N and P between compartments and temporary relationships followed literature data. Simulated N ingestion and retention was 34 and 8 thousand tons, respectively. Simulated N excretion by fecal and urinary ways was 6 and 18 thousand tons, respectively. Approximately 90% of N ingestion, 98% of N retention and 85% of N excretion were observed in the medium and high ST. Simulated ingestion and retention of P was 8 and 2 thousand tons, respectively. Simulate P excretion by fecal and urinary ways was 5 and 1 thousand tons, respectively. This model is able to simulate N and P flows in high and medium technological systems of pig production at Rio Grande do Sul state, Brazil.

Digestibilidade aparente da dieta e balanço do nitrogênio em suínos de diferentes grupos genéticos com ou sem restrição alimentar

An experiment was carried out to evaluate the digestion and metabolism of different genotypes pigs fed with or without restriction. Twenty-four barrows of three commercial genotypes were used, with 47.95kg initial body weight, housed in metabolic cages maintained in semi-acclimatized atmosphere. A 3 x 2 factorial design was used (3 commercial genotypes – Agroceres, Dalland, Embrapa, with or without feed restriction), with four replications each, being the animal the experimental unit. The genotypes and feed restriction did not influence (P>0.05) dry matter digestibility, crude protein, ether extract and metabolizable energy. On the nitrogen balance, restriction feed decrease (P<0.05) 20% urinary excretion, 17% fecal losses and 19% retention. The commercial genotypes studied have similar digestibility, metabolization energy and nitrogen balance. Restriction feed at 20% level did not affect nutrient digestibility and energy metabolization.