Improving grazing efficiency to support high productivity per cow in intensive mixed dairy systems

The world-increasing demand for food combined with the necessity to improve the resources use efficiency are fundamental reasons to investigate feeding and grazing management strategies and the development of tools with a multi-factorial approach that addresses animal behaviour, economic, and environmental sustainability. Through an analytical and modelling research approach, the objectives are (i) to study the effect of feeding strategies and environmental conditions during the supplementation period on the productive and economic performance of autumn and spring-calving dairy cows: a whole lactation study; (ii) to study the impact of the defoliation intensity on the productive performance of high-production dairy cows, the animal behaviour strategies adopted to achieve the daily herbage dry matter intake (DMI) and their relationship with pasture characteristics, and pasture productivity. Also, to quantify and study the environmental impact (methane emissions and N balance) of the grazing management; and (iii) to further develop an extant mechanistic model in order to predict DMI by integrating nutritional constraints, ingestive behaviour and sward characteristics, and methane production of dairy cows, as well as further include improvement of the prediction of nutrient availability for the host animal at rumen and lower tract level, and milk production.