Maintenance feed requirements are closely related to bodyweight and increase as bodyweight increases.
Maintenance feed requirements also increase slightly in cold winter conditions – see Graph 1.
This ewe (and lambs to weaning) consumed about 630kg drymatter (DM)/year – about 400kg DM is required for maintenance (64%) based on Farmax modelling.
Compromises may be required with heifer grazing
Dairy heifer grazing is great for cashflow, and shows solid gross margins of about 22c/kg DM. However, gross marginal analysis does not account for the cost quality or timing of feed requirements.
It also does not account for how well that enterprise fits into the whole farm system.
Dairy farmers are becoming more demanding in their expectations, not only of total weight gain, but when it is being put on. This will mean there are reduced opportunities to use heifer growth rates to buffer feed supply and competing requirements of other classes of stock.
Specific issues
Heifer feed requirements do not match pasture growth well in most New Zealand districts.
Requirements are high in February, March, and April when feed should be accumulated for winter, or used to increase mating weights of ewe hoggets and ewes.
Feed requirements from winter to spring only increase by about 40%, while feed supply may lift tenfold.
Heifers require high-quality feed throughout the year – DairyNZ refers to diets of 11 megajoules of metabolisable energy.
At these requirements dairy heifers are competing directly with the most profitable classes of stock on a drystock farm – finishing animals, replacements and lactating ewes, hinds, and cows.
Dairy heifers often compromise the profitability of existing enterprises by competing for feed at critical times.
Rather than putting the best feed into grazers should effort be put into improving the productivity from existing enterprises?
Whatever enterprise is chosen it’s likely more productive and profitable farms will result when a greater amount of feed, and of higher quality, is grown.
• Wayne Allan is a registered consultant for Allan Agricultural Consulting, based in Christchurch. It is acknowledged that for the sake of clarity some of the analysis in this article may be overly simplistic. However, this is not considered to greatly influence the trends and relativities of any enterprise.
