Effects of PUFA-Rich Dietary Strategies on Ruminants’ Mammary Gland Gene Network: A Nutrigenomics Review

Although the inclusion of polyunsaturated fatty acids (PUFAs) in ruminants’ diets appears to be a well-documented strategy to enrich milk with PUFAs, several gene networks that regulate milk synthesis and mammary gland homeostasis could be impaired. The objective of this literature review is to assess the effects of nutritional strategies focused on enriching milk with PUFAs on gene networks regulating mammary gland function and lipogenesis, as well as the impact of feed additives and bioactive compounds with prominent antioxidant potential on immune-oxidative transcriptional profiling, as a part of mammary gland homeostasis and health. The findings support the conclusion that PUFAs’ inclusion in ruminants’ diets more strongly downregulate the stearoyl-CoA desaturase (SCD) gene compared to other key genes involved in de novo fatty acid synthesis in the mammary gland. Additionally, it was revealed that seed oils rich in linoleic and linolenic acids have no such strong impact on networks that regulate lipogenic homeostasis compared to marine oils rich in eicosapentaenoic and docosahexaenoic acids. Furthermore, ample evidence supports that cows and sheep are more prone to the suppression of lipogenesis pathways compared to goats under the impact of dietary marine PUFAs. On the other hand, the inclusion of feed additives and bioactive compounds with prominent antioxidant potential in ruminants’ diets can strengthen mammary gland immune-oxidative status. Considering that PUFA’s high propensity to oxidation can induce a cascade of pro-oxidant incidences, the simultaneous supplementation of antioxidant compounds and especially polyphenols may alleviate any side effects caused by PUFA overload in the mammary gland. In conclusion, future studies should deeply investigate the effects of PUFAs on mammary gland gene networks in an effort to holistically understand their impact on both milk fat depression syndrome and homeostatic disturbance

An Overview of Poultry Greenhouse Gas Emissions in the Mediterranean Area

The growing population and income drive the rapid increase in food demand. Greece and a few other Mediterranean countries are characterized as countries with a high proportion of mountains favoring goat and sheep breeding; however, poultry breeding is also important, and production is increasing rapidly. Poultry breeding is characterized by the millions of birds reared with increased quantities and prices of feedstuffs. There is a parallel increase in greenhouse gas (GHG) emissions., since poultry production generates a significant amount of GHG. The aim of the present study was to provide an overview of poultry GHG in the Mediterranean area. Emissions’ sources and mitigation practices are presented. Future is promising given that sustainable practices are implemented

The Effect of Dietary Inclusion of Microalgae <i>Schizochytrium</i> spp. on Ewes’ Milk Quality and Oxidative Status

An unprecedented challenge for nutritionists arises during the 21st century in order to produce highly nutritious and functional food which promotes human health. Polyunsaturated fatty acids (PUFA) that are highly contained in microalgae have broadly been confirmed for preventing cardiovascular diseases and regulating immune-oxidative status. However, their optimum dietary inclusion level needs to be defined since PUFA are prone to oxidation. For this purpose, 24 cross-bred dairy ewes, were separated into four groups (n = 6) and were fed with different levels of microalgae Schizochytrium spp. [0 (CON, no microalgae), 20 (SC20), 30 (SC30) and 40 (SC40) g/ewe/day] for 60 days. The results showed that although the production parameters were not impaired, milk fat content was decreased in medium and high-level supplemented groups while protein content was suppressed only for the medium one. Concerning the fatty acids (FA) profile, the proportions of C14:0, trans C18:1, trans-11 C18:1, cis-9, trans-11 C18:2, trans-10, cis-12 C18:2, C20:5 (EPA), C22:5n-6 (DPA), C22:6n-3 (DHA), the total ω3 FA and PUFA were significantly increased, while those of C18:0, cis-9 C18:1 and C18:2n-6c were decreased in the milk of treated ewes. Additionally, in the S40 group an oxidative response was induced, observed by the increased malondialdehyde (MDA) levels in milk and blood plasma. In conclusion, the dietary inclusion of 20 g Schizochytrium spp./ewe/day, improves milks’ fatty acid profile and seems to be a promising way for producing ω3 fatty acid-enriched dairy products

Sustainable Strategies for Greenhouse Gas Emission Reduction in Small Ruminants Farming

During the previous decades, the growing demand for animal origin products has gained considerable attention. As a result, livestock breeding has faced a rapid intensification in order to fulfil market expectations. This increase in livestock production has led to a large scale of manure that is associated with many environmental impacts, such as climate change, to an increase of greenhouse gases (GHG) emissions. Livestock production is considered to generate significant amounts of GHG, mainly carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Methane and nitrous oxide are the main emissions from livestock systems. Ruminants contribute highly to total livestock emissions. In the present study, the contribution of livestock and especially of the small ruminants in GHG emissions is reviewed. Additionally, useful sustainable strategies for farming and feeding of small ruminants are highlighted. Some of the practices discussed include but are not limited to efficient manure management, the replacement of mineral fertilizers by farm manure, the improvement of feed efficiency and provision of feed supplements. Moreover, the use of food waste or agro-industrial by-products is discussed as a sustainable strategy