This document summarizes research into improving the efficiency and sustainability of livestock production through plant breeding. It discusses breeding perennial ryegrass and clover varieties with increased nitrogen, phosphorus, and water use efficiency to reduce environmental impacts. The research aims to develop varieties that support higher animal performance while lowering greenhouse gas emissions and nutrient losses. New varieties with traits like high sugar content, drought tolerance, and optimized protein levels are being evaluated for their effects on feed intake, milk production, and nitrogen partitioning in livestock.