Concentrates-fed lamb meat is often associated with an unfavourable lipid profile (high levels of saturated and/or n-6 polyunsaturated fatty acids; SFA and PUFA). For this reason, Spanish sheep producers from Mediterranean areas are turning to traditional grazing by ewes to obtain healthier lamb meat. The objective of this research was to determine the effects of maternal grazing on the fatty acid (FA) composition of weaned lamb meat. The ewes (Segureña breed) were allocated to two different rearing systems during pregnancy (5 months) and lactation (45 days): (i) feeding indoors on barley grain and lucerne pellets; (ii) grazing on cereal stubble, fallow land and seasonal pastures consisting of Mediterranean shrubs, herbs and trees. Two groups of 20 autumn and spring lambs were sampled. The lambs were weaned at 13.1±0.9 kg and 45.0±4.1 days age and fed on grain-based concentrates until they reached 24.8±2.1 kg live weight (light lambs slaughtered at 98.3±3.6 days of age). The FA content was determined in the intramuscular loin fat by gas chromatography using a flame ionization detector. The ewe diet did not affect the levels of the main lamb FAs (C18:1c+t, C16:0 and C18:2c), and so did not provide any additional reduction in fat saturation. Saturated fatty acids represented around 40% of total FAs determined in the meat. Ewe grazing acted as an n-3 PUFA-promoting diet, providing a lamb meat with a lower n-6/n-3 ratio. Spring lamb meat had higher proportions of n-3 PUFA (C18:3n-3, C20:5, C22:5 and C22:6) and conjugated linoleic acid (C18:2c9t11+c11t9) to the detriment of the n-6 PUFAs (C20:4, C20:2 and C22:4), while autumn lamb meat also had higher levels of C18:3n-3 and C18:3n-6, and lower level of C20:4, which points to little seasonal differences. The n-6/n-3 ratio achieved by ewe grazing fell from 8.2 to 4.1 (Spring) and from 7.6 to 5.5 (Autumn), values which are close to those recommended in human diet for good cardiovascular health. These n-6/n-3 reductions were associated with lower levels of total PUFA and C20:4n-6. Our research concluded that grazing on stubble and Mediterranean shrubland by ewes, a sustainable rearing practice involving local agro resources, contributed to obtaining weaned lamb meat with a more favourable lipid profile and so can be recommended to sheep farmers.

Several studies have been carried out to evaluate the main drivers behind biological invasions and their ecological consequences. Nevertheless, it is still extremely difficult to acquire a full understanding of the invasion process due to its high level of complexity. The problems that complicate invasion studies are low detection during the early stages of invasion, and the high survey cost of working over large, inaccessible, and rugged areas. The studies that develop efficient tools to reduce costs and time will help to control or mitigate the invaders' damaging effects. Hieracium pilosella is an aggressive invader of grasslands worldwide. The aim of this work was to conduct a regional assessment for the suitability of H. pilosella invasion in the Fuegian Steppe by combining field surveys, spatial modeling, and geographic information system tools. We recorded the invader cover in 167 sample sites and we determined the relationship between environmental variables and the probability of invasion. This was carried out by the selection of alternative generalized linear models. The best model indicates that disturbance and plant community were the main drivers to predict invasion suitability on a regional scale. Therefore, these two variables were used as main inputs to construct a regional invasion suitability map, which identifies the most critical areas for prevention, control, and further monitoring. This approach corresponds to a tool that permits us to evaluate the suitability of invasion even over large and inaccessible areas. The results especially warn about soil disturbance associated with usual management practices in Fuegian rangelands.