Complementary forages - integration at a whole farm level

A relatively simple, low input and low cost pasture feedbase represents a high proportion of the Australian and New Zealand Dairy industries and these factors enable this type of production system to remain internationally competitive. However, a key limitation of these pasture based dairy systems is periodic differences between herd intake requirements and dry matter (DM) production, caused by strong seasonality and high inter-annual variation in feed supply. This disparity can be moderated somewhat through the strategic management of the herd through altering calving dates and stocking rates, and the feedbase by conserving excess forage and irrigating to smooth seasonal forage availability. Australasian dairy systems are experiencing emerging market and environmental challenges which amongst other things include increased competition for land and water resources, decreasing terms of trade, adaption to a changing and variable climate, an increasing environmental focus to improve nutrient and water use efficiency, and to lower the greenhouse gas emissions intensity of milk production. The integration of complementary forages has long been viewed as a means to manipulate the home grown feed supply, to improve the nutritive value and DM intake of the diet, and to increase the efficiency of inputs utilised. Only recently has integrating complementary forages at the whole farm system level received significant attention and investment for examining their potential benefit. Recent whole of farm research undertaken in both Australia and New Zealand has highlighted the importance of understanding the challenges of the current feedbase and level of complementarity that is required to improve profit, manage risk and/or alleviate/mitigate against adverse outcomes. This paper reviews the most recent systems level research into complementary forages, discusses approaches to modelling their integration at the whole farm and highlights the potential of complementary forages to address the major challenges currently facing pasture based dairy systems.