This presentation aims to present and discuss methodologies used to model and integrate classical knowledge in animal nutrition, and new discoveries produced by new molecular sciences like nutrigenomics, proteomics and metabolomics. These sciences and bioinformatics are helping to expand >very quickly the knowledge of the biological systems of interest in animal nutrition. I will discuss the importance of dedicating part of our efforts to integrate current knowledge to prioritize research problems using the most adequate tools. This will help to […]

Swine and Poultry production showed enormous progress in the last few years, mainly due to the increased knowledge in genetics and nutrition. In the area of feedstuffs evaluation and nutritional requirements the improvement also was big due to the seriousness of the professionals to make high quality research in Brazil and abroad. This paper shows methodologies that can improve feedstuffs utilization more efficiently with lower costs. Procedures are described for adequate execution of growth experiments with poultry and swine. Actually, […]

This text describes a basic approach of systematization with focus on meta-analysis. It is presented the art state of the meta-analysis, recovering information of its evolution and basic methodologies for its accomplishment. In this text are described the historical antecedents of meta-analysis, the limits of the classic approaches of literature review, the conceptual bases and the objectives. It is indicated a general methodology for meta-analysis procedures. The criteria for the definition of the objectives are presented. The procedures of the […]

Feeds for pigs can be attributed different energy values according to, first, the step considered in energy utilization (DE: digestible energy, ME: metabolizable energy and NE: net energy) and, second, the method used for estimation at each step. Reference methods for evaluating DE content are based on in vivo digestibility measurements; indirect estimates of DE values are obtained from in vitro methods or prediction equations based on chemical characteristics. Methods have also been proposed for estimating urinary energy (and gas […]

The objective of this paper is to present some of the issues faced by those whose interest is to predict responses in poultry, concentrating mainly on those related to the prediction of voluntary food intake, as this should be the basis of models designed to optimise both performance and feeding programmes. The value of models designed to predict growth or reproductive performance has been improved inestimably by making food intake an output from, as opposed to an input to, such […]

This review covers methods that have been applied to study the nutrient value or quality of specific ingredients fed to dogs, cats and comparable species (i.e. foxes, minks, rats, etc.). Typically, the nutritional value or utilization of a specific ingredient is measured by total tract digestibility and has been expanded through the measurement of total nutrient balance (i.e. nitrogen or energy). However, to better understand digestion it is necessary to obtain a more accurate measurement of nutrients entering and leaving […]

During the assimilation and use of food process, the animals’ organism can develop different metabolic responses. These responses results of complex integration mechanisms, involving the neuro-endocrine systems and organs activity, were being influenced, besides the diet, for the animal species, age, physiologic condition and corporal composition. In this paper will be discussed the physiologic importance and study methods of carbohydrates post-prandial responses, as well as the physiologic alterations induced by diet electrolytic balance. Amount, chemical composition and industrial processing of […]

The development of in vitro embryo production (IVP) methodology to maximize genetic gain and animal production at lower cost is a challenge of the research and it has been studied for many years. The possibility to produce, in commercial scale, embryos from ovum pick up methodology may increase the benefits of the use of artificial insemination (AI) for its decisive role to maximize the genetic progress between generations, according to the requirements of each genetic improvement program and livestock capacity. […]

The market demands, since the end of the 1920s the market demands a technology for spermatozoa sexing that can be inserted in the industry to production of frozen semen and that has the following features: a) does not change sperm viability; b) it be compatible with freezing of spermatozoa after treatment for sexing; c) it allows the spermatozoa sexing after their thawing; d) it allows the production of various doses of sexed frozen semen per day at a compatible cost […]

Genetical genomics experiments combine information on phenotypic traits, molecular markers and gene expression to study the genetic mechanisms governing variation in complex traits. Such studies can be used, for example, to estimate heritabilities of mRNA transcript abundances, to map expression quantitative trait loci (eQTL), and to infer regulatory gene networks. Microarray experiments, however, can be extremely costly and time consuming, which may limit sample sizes and statistical power. Thus it is crucial to optimize experimental designs by carefully choosing the […]