Supplementary feeding options to alleviate the impacts of decreased water availability on dairy-farm economic performance in northern Victoria

Abstract

The anticipated effects of climate change, competing demands from the environment, industry and urban users, and changes in water policy are likely to reduce the amount and increase the variability of water allocations to dairy farmers in northern Victoria. The way two irrigated dairy farms that differed in feedbase characteristics, herd size and farm area, would operate and perform with reduced and more variable water allocations was examined over 10 years. Strategies to manage the impact of changed water availability were tested; namely, increasing milk production by feeding more supplementary feed, changing the feed system to present supplements in a partial mixed ration (PMR), and increasing milk production by using a PMR. Neither farm was profitable under medium climate change, or if the conditions that generated the low inflows of water into irrigation supply dams between 1996–97 and 2006–07 prevailed, unless changes were made to the farm system. Feeding supplements in a well formulated mixed ration have the potential to increase the efficiency of metabolisable energy use and offers the opportunity to increase feed intake and milk production. A PMR system enabled one of the farms to maintain and increase profit under medium climate change conditions; however, risk, measured as variability in profit, also increased. Under more severe reductions in water availability, neither of the farms examined was profitable over the run of years. Changes to the farm system other than feeding additional supplementary feed to increase milk production and/or using a PMR system, would be needed to counteract the effects of reduced and more variable water availability and maintain profit.