Tannins in Ruminant Nutrition: Impact on Animal Performance and Quality of Edible Products

Tannins are widespread throughout the plant kingdom, occurring as hydrolysable and condensed tannins and at different levels in several animal feeding sources. Recent years have seen an increasing interest in the use of tannin-rich plants and plant extracts in ruminant diets for improving the quality of their edible products. Some results show that this strategy is effective in improving the fatty acid profile of meat and milk, increasing the level of health-beneficial fatty acids as well as enhancing the oxidative stability of the products. However, the use of tannin-rich feed in animal diets requires great care, due to its possible detrimental effects on animal performance and induction of metabolic disorders. Although promising, the results of studies on the effects of tannins on animal performance and quality of their products are still controversial, probably depending on type and chemical structure of tannins, amount ingested, composition of diet, and species of animal. In this chapter, the current knowledge regarding the effect of dietary tannins on animal performance and the quality of their products (meat and milk), particularly on the fatty acid profile, oxidative stability, and organoleptic properties, is reviewed. The tannin chemistry diversity and its occurrence in ruminant diets, as well as its beneficial and adverse effects on ruminants, will be briefly reviewed, and aspects related to oral cavity physiology, saliva production/composition, and postingestive effects will also be discussed.

Between the centre and the margins: Services location, economic (re)structuring and quality of life in metropolitan periurban areas.

This paper aims to discuss the specificities of the role of services in the economic structuring and in the social liveliness and attractiveness of periurban areas. Drawing upon on the result of an empirical work developed in 5 different parishes of Lisbon Metropolitan area, which represent five categories of periurban spaces previously identified, it is analysed the role of services in these “in-between” territories and the way they are important in the spatial economic structuring of these areas and in the quality of life and well-being of their inhabitants and users. A tentative typology for framing the analysis of the role of services on periurban metropolitan spaces is suggested and some policy implications are pointed out.