Maximising Milk Production in Early Spring
Favourable conditions in July have given us the opportunity to utilise more winter pasture than usual. On all but the lightest country, we normally anticipate pasture growth to exceed requirements sometime in early September. However, this year, it could well be 2 to 4 weeks earlier. Growth rates over 30kg per hectare have been measured already and with marginal losses due to pugging, there are many farms now being able to continue feeding 12-15kg of pasture per cow daily.<P>To maximise pasture intake, cows need to be able to leave a post grazing residual of 1600-1800kg dry matter. Typically cows will have just started to give the clumps around dung patches a hair cut at this level. If cows have the opportunity to eat the 12-15kg we have available, they will obviously produce more milk. Many farmers will have been on a slow rotation (over 30 days) to ensure surviving a wet August. It is now feasible to speed this up to 20 days or less and offer cows more than they can consume. In the event of heavy rainfall this rotation can be slowed again.
The amount of concentrate feeding will be dependent upon expected and previous production level and the inherent ability of pasture growth on the farm. Nitrogen used in early spring will grow feed at well below $100 per tonne so unless this feed is not able to be utilised it will always be an option ahead of grain. If soil fertility is high and significant autumn fertiliser has been applied, it may well be feasible to apply only nitrogen as the spring fertiliser. As long as soil fertility levels are monitored, this will not cause long term detriment to soil fertility.
Urea at 100kg per hectare will boost pasture growth for 4-6 weeks by up to 20kg per hectare per day. Pasture Booster at 200kg per hectare will supply a similar nitrogen application with seven units of P and 26 units of K. The ideal time to apply these spring fertilisers is at the start of the spring growth which on most farms will be mid to late August.
Click here to view the rest of the 1999 August newsletter.