Grazing Management Plans improve pasture selection by cattle and forage quality in sub-alpine and alpine grasslands

Abstract

Over the last decades, the reduction of manpower for herd management has led to an increase of continuous grazing systems (CGS) in the Italian Alps, which allow cattle to roam freely. Under CGS, due to high selectivity, livestock exploit grasslands unevenly, over- and under-using specific areas at the same time with negative effects on their conservation. To counteract these effects, a specific policy and management tool (i.e. Grazing Management Plan) has been implemented by Piedmont Region since 2010. The Grazing Management Plans are based on the implementation of rotational grazing systems (RGS), with animal stocking rate adjusted to balance it with grassland carrying capacity. A case study was conducted on alpine summer pastures to test the 5-year effects produced by the implementation of a Grazing Management Plan in grasslands formerly managed under several years of CGS on 1) the selection for different vegetation communities by cattle, 2) the abundance of oligo-, meso-, and eutrophic plant species (defined according to Landolt N indicator value), and 3) forage yield, quality, and palatability. A total of 193 vegetation surveys were carried out in 2011 and repeated in 2016. Cows were tracked yearly with Global Positioning System collars to assess their grazing selectivity, and forage Pastoral Value (PV) was computed to evaluate forage yield, quality, and palatability. Five years after RGS implementation, cow selectivity significantly decreased and the preference for the different vegetation communities was more balanced than under CGS. The abundance of meso- and eutrophic species increased, whereas oligotrophic ones decreased. Moreover, the abundance of moderately to highly palatable plant species increased, whereas non-palatable plant species decreased, with a consequent significant enhancement of the PV. Our findings indicate that the implementation of Grazing Management Plans can be considered a sustainable and effective management tool for improving pasture selection by cattle and forage quality in mountain pastures.