Grasslands have to be considered not only as a mean for providing foods for domestic herbivore but also as an important biome of terrestrial biosphere. This function of grasslands as an active component of our environment requires specific studies on the role and impact of this ecosystem on soil erosion and soil quality, quality and quantity of water resources, atmosphere composition and greenhouse gas emission or sequestration, biodiversity dynamics at different scales from field plot to landscape. All these functions […]

The suitable evaluation of nutritional value of forages depends on the adoption of appropriate methodologies. Forage quality is highly dependent of fermentation products, in case of silage, and the losses of soluble compounds and microorganisms activity in the case of hay. The theme “Methodological advances in evaluation of preserved forage quality” at the 44th Annual Meeting of Brazilian Society of Animal Science has as main goals to highlight the more useful and particular methodological procedures for conserved forages and additional […]

Grasslands are being replaced by urbanization and more profitable agricultural activities around the world. Producers may be faced with land constraints and need to consider intensification of the remaining grasslands as a means of maintaining overall production on a decreasing land resource. However, intensification of the grazing system is usually associated with greater nutrient inputs, including those from commercial fertilizers and supplement fed to animals. Excessive loading of nutrients in intensive grazing systems via fertilizer and animal wastes can cause […]

Methodological advances are usually a direct consequence of conceptual and technical advances. In the case of animal intake on pasture, recent conceptual advances regarding the process of searching and apprehension of the forage by the ruminant provide insight regarding the importance of the basic unit of intake, the bite, and the importance of processes limiting intake that occur before the forage reaches the rumen. Applying a reductionist approach to the grazing process, along with its spatial-temporal hierarchy, brought a new […]

Finite mixture models are helpful for uncovering heterogeneity due to hidden structure; for example, unknown major genes. The first part of this article gives examples and reviews quantitative genetics issues of continuous characters having a finite mixture of Gaussian components. The partition of variance in a mixture, the covariance between relatives under the supposition of an additive genetic model and the offspring-parent regression are derived. Formulae for assessing the effect of mass selection operating on a mixture are given. Expressions […]

Microarray technology allows monitoring thousands of genes simultaneously in a specific tissue of an organism, in different developmental stages or environmental conditions. Microarrays are very common in functional genomics experiments with both animals and plant species, and they have been increasingly used also in different areas of livestock research, such as growth and metabolism, reproduction, immune response to diseases and parasites, response to non-infectious stress factors (such as dietary restriction, exposure to toxic elements and other unfavorable environmental conditions) as […]

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 […]

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 […]

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. […]

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 […]