The study was conducted to analyse the effect of sheep body weight (BW) at mating, mid-pregnancy, lambing, early lactation, mid-lactation and late lactation on milk yield and patterns of milk production. Also, the effects of environmental factors such as number of lambing (NL) and type of lambing (TL) on BW and milk production were analysed. A total of 52 multiparous East Friesian ewes from an experimental flock were used. Ewes were assigned to three different groups according to their BW at each productive stage: low (LBW), moderate (MBW) and high BW (HBW). Lactations were fitted using the mechanistic model described by Pollott. Total milk yield (TMY), peak yield (PY) and time at peak yield (TPY) were also calculated. HBW ewes had consistently higher TMY (p < .001) and PY (p < .05) values, than LBW and MBW in most of productive stage measured. There was a positive linear relationship (p < .05) between TMY and BW in all-productive stage, except at mid-gestation where the relationship was quadratic. HBW ewes weighted at mid-pregnancy showed the highest values of maximum secretion parameter (p = .04) of Pollott model, which could partially explain the better milk yield of HBW ewes. A significant effect of NL on BW (p = .007) and TMY (p = .007) was observed. The BW ewe’s in pregnancy and early lactation is a useful indicator at farm level to improve the milk yield performance in dairy sheep.

Steppe ecosystems in Chilean Patagonia are located in the Andean rain shadow zones in the Aysén and Magallanes administrative regions, on the eastern slopes of the Andes along the border with Argentina, and in the north-central sector of Tierra del Fuego island. This chapter describes the distribution, climatic conditions, biodiversity, and changes in vegetation coverage of the steppe in Chile. Steppe biodiversity faces threats due to the negative impacts of multiple anthropogenic activities, particularly the development of the hydrocarbon sector, grazing pressure, wildfires, and the introduction of exotic species, as well as global climate change. Conservation of the Patagonian steppe in Chile depends both on protection within state parks or reserves and on cultural changes in the management of the unprotected area; economic uses and conservation must be integrated through sustainable management strategies. Keywords Patagonia Chile Grasslands Meadows Tussock grasses Management

In extensive livestock production, high densities may inhibit regulation processes, maintaining high levels of intraspecific competition over time. During competition, individuals typically modify their behaviours, particularly feeding and bite rates, which can therefore be used as indicators of competition. Over eight consecutive seasons, we investigated if variation in herd density, food availability, and the presence of a potential competitor, the guanaco (Lama guanicoe), was related with behavioural changes in domestic sheep in Chilean Patagonia. Focal sampling, instantaneous scan sampling, measures of bite and movement rates were used to quantify behavioural changes in domestic sheep. We found that food availability increased time spent feeding, while herd density was associated with an increase in vigilant behaviour and a decrease in bite rate, but only when food availability was low. Guanaco presence appeared to have no impact on sheep behaviour. Our results suggest that the observed behavioural changes in domestic sheep are more likely due to intraspecific competition rather than interspecific competition. Consideration of intraspecific competition where guanaco and sheep co-graze on pastures could allow management strategies to focus on herd density, according to rangeland carrying capacity.

The Magallanes region in Chilean Patagonia encompasses 13 million hectares with approximately 3.6 million used for agricultural and livestock systems. This portion is located to the east of the Andean Mountain chain in the rain shadow zone, with annual precipitation increasing along an east to west gradient from 200 to almost 1,000 mm. To fully describe sheep farming in the Magallanes region, many topics need to be addressed, including sheep production and management, existing vegetative communities, livestock-wildlife interactions, and economic diversification into agritourism and another sheep industry products. All these give shape to the story of the development of sheep farming in Magallanes, which is important at the regional and national level. Three key points are identified that together can lead to a successful future for the industry: sustainable management, human resources and the market.