Key drivers of sheep flock profitability include number of lambs reared per ewe to the ram, minimising losses and optimising the speed and efficiency with which those lambs can be finished. The talk will consider some key threats to this production and the role of trees when integrated into livestock farming. Emphasis will be placed on the effects of trees on drainage, changes of conditions underfoot and provision of shelter and therefore the potential consequences for production limiting threats such as neonatal lamb mortality, infectious lameness, mastitis and liver fluke. These challenges can compromise the absolute numbers and efficiency of lambs produced compromising profitability, health, welfare, sustainability and even future flock performance. The costs of these diseases, and the longer term threats posed, such as that of flukicide resistance, will be considered for on- going sheep and beef production.