Because cultivation-based approaches to assess rumen microbiology assess only the minority of microbial groups and can miss opportunities to assess important functions, molecular-based approaches have flourished in microbial ecology and have been adapted to the rumen. Current approaches are described herein, specifically for a robust adaptation to nutrition studies or future opportunities. These included automated profiling techniques, density gradient gel electrophoresis, and future adaption of microarray or high-throughput sequencing technologies. Based on current knowledge, a more holistic approach is needed […]

In this review article we present an overall summary of the role that high-grain/low forage diets have on rumen composition of microbiota and how changes in the diet affect the release of bacterial cell wall components that are toxic to the host. One of these toxic compounds is lipopolysaccharide or endotoxin, a component of the outer membrane of all Gram-negative bacteria. Moreover, data are provided that support the concept that endotoxin translocates into the blood circulation and show that rumen […]

The knowledge of the importance of nutrition on animal reproduction is well known for producers and researchers for a long time. However, contemporary studies have brought new perspectives and further details of this relationship, allowing fine-tuning of diets handling in order to increase production and reproduction in ruminants. Nevertheless, especially in high-producing dairy cows, there are still serious multifactorial fertility problems, with a heavy nutritional involvement. In contrast, addition of certain ingredients to the diet, such as fat rich in […]

Healthy animals normally eat sufficient food to satisfy their energy requirements. It is one of the jobs of the nutritionist to ensure that all other nutrient needs have been met when animals stop eating because they have met their energy needs. While dogs and cats are members of the biological order Carnivora, scientific observation and research support that differences in their metabolism and nutritional requirements exist. However, the goal in feeding both species is the same; to optimize the health […]

The aim of the review is to show the major scientific advances achieved in the animal reproduction area and how they can affect the productive and reproductive performance of cattle in Brazil. The knowledge about the mechanisms involved in the reproductive physiology control, in endocrine, cellular and molecular level allowed the development of reproductive biotechnologies. Among these the TAI has been used in large scale, with some advantages such as the multiplication of genetically superior animals, increasing on birth rate […]

This paper reviews the technical bases of in vitro embryo production in small ruminants with special attention to the results obtained by our group in Northeastern Brazil. The laparoscopic oocyte recovery in hormonally treated live animals indicates a promising future for the application of this technique to genetic improvement program. New molecular biology tools should provide information to improve the efficiency of in vitro maturation. Furthers efforts have to be made to improve the oocyte maturation and to standardize the […]

Reproductive capacity is controlled by a large number of factors such as season, social interactions and metabolic status. However, the influence of emotional reactivity on reproductive success has not been intensively investigated in farm animals. In this review, we define emotion reactivity and the expression of its inter individual variability named temperament. We briefly describe our protocol to measure temperament in sheep and discuss the heritability of temperament traits. Using the results obtained from our flock of sheep selected for […]

The industry has made available in the market a series of substances (nutraceuticals) which intent would be to optimize the use of nutrients in some metabolic paths, influencing positively reproductive performance in animals. However, the response to the use of nutraceuticals varies according to the animal. As the organism is highly complex and in order to achieve a perfect activity of the hypothalamic-pituitary-gonadal axis, an ideal interaction in molecular basis is needed, where the nutraceuticals can have their direct action. […]

Fertility of dairy cattle is generally decreasing. Overall estrus detection efficiency in lactating dairy cattle is low, as expression of estrus is often compromised. Consequently, undetected estrus, low AI-submission rates, and long inter-breeding intervals are the main contributors to poor reproductive efficiency. Although failure to become pregnant is the most common reason for culling dairy cattle, pregnancy rates could be improved by increasing the AI-submission rate through increased estrus detection efficiency, timed insemination (Timed-AI), or timed embryo transfer (Timed-ET). In […]

The nutritional and production costs associated with the development of a competent immune response against nematode parasites is described, based on data from sheep. Anorexia and changes in metabolism are considered to be driven by the host immune response itself and the question is raised about the wisdom of seeking to strengthen immune responses by genetic selection. Several phases of the immune response are identified with different implications for loss of productivity and opportunity for moderation of immune responses and […]