Tom Ward
Amid the difficulties caused by floods in Southland two weeks ago, those who live on the east coast of the South Island were pleased to get 20-30mm of rain. To be fair some us were just pleased to get respite from high temperatures, but for those on the land the moisture should be a real help. That moisture, on one farm I looked at mid week, penetrated 12cm.
However, summer is far from over, and February could still be brutal. In South Canterbury, some dryland farms are very short, and these farms, even with very good moisture conditions through February and March, will still be playing catchup in April.
There is simply not enough leaf area to allow the pasture to grow fast. Contrast that with many of the unirrigated winter crops which, with good leaf area, have continued to grow well even through the dry January we have just had. Even though they may have been sown in December, and especially if the ground was sprayed off in the spring to create a summer fallow to conserve soil moisture, these paddocks have grown well. The key point here is leaf area. An example of what intercepting all the sunlight can do, comes from the apple industry. Most apple orchard structures allow about 60% of light to be intercepted; with 85-90% of light intercepted yield would increase 100%.
My point is farmers need to de-stock (and possibly supplement) earlier. Some have moved away from breeding stock to give greater flexibility over summer.
Another observation of over grazed pastures is that the root systems are too shallow, a sign of poor species unable to access soil moisture. These poor species have dominated due to earlier overstocking in droughts killing the pastures species which produce the quantities of stock feed needed to sustain a viable farm system. Deeper rooting grasses like cocksfoot and tall fescue, and legumes like red clover, sub clover and lucerne, can access deeper soil moisture, growing substantial amounts of feed in early to mid-summer. They do however need good grazing management.
FEEDING SUPPLEMENT
If short of grass, you should have started supplement feeding by now, and it goes without saying all de-stocking options have been exercised.
Costs of typical supplements suited to feeding to ewes in South Canterbury are:
Grass balage 30c/kgDM, assume 10 MJME/kg DM, 3c/MJME.
Barley grain $400/tonne delivered ex stock firm, assume 12.5 MJME/kgDM, 3c/MJME.
Another source of supplement is grazing off, which would be difficult to obtain, however there are cropping farmers buying lambs already, because they have irrigated feed set aside for use before crops have been harvested.
Applying urea is probably not an option yet. However another good wetting later in the month could see a very good response, about 14c/kg DM.
If you are considering feeding ewes barley grain there are some issues to consider:
- Animals will need access to good quality water.
- Barley is low in fibre so roughage is also necessary. Good quality hay may be sufficient, however for significant liveweight gains quality balage or silage with a minimum ME of 10 is preferable.
- Feed the barley in a line, starting with 50g/ewe/day. To avoid gorging, keep the line short enough initially so that those animals that like the grain do not have the opportunity to go back for a second feed. Lengthen the line as the shy feeders get into the grain. As part of this training process, it would help if some of the 2-tooth ewes were fed a small amount of grain.
- Expect to waste 10% of the feed.
- The maximum that can be safely fed is a moot point with some professionals not going beyond 200 g/ewe/day. My view is 500-600 g/ewe/day, if introduced carefully, and monitored properly can be safely fed.
The point here is that tupping is only six to seven weeks away. If you have ewes that require a 0.5-1 body condition score (BCS) gain in that time, that is a 5-9kg liveweight gain. Breaking it down further, the ewes will need an average total increase of 7kg liveweight, or 140 grams/ewe/day over 50 days, which would require 17 MJME/ewe/day for a ewe weighing 55kg.
The feed requirements, assuming you have little spare grass, would be:
Feed available:
Barley MJME 12.5/kgDM
Balage MJME 10/kgDM
Daily feed required:
Silage 1kgDM 10 MJME
Barley 600g 7 MJME
Total 17 MJME
It will take at least two weeks to get the sheep to a 500-600g/day barley feeding level so you will have your work cut out to get the liveweight gains you want before tupping.
This also highlights the need to be very clear with your farming systems. If your farm is regularly summer dry, my suggestions are:
- Wean on ewe BCS 3.0-3.5 – it is cheaper to maintain BCS than to put it on.
- Look to sell lambs at the same time each year – the earlier the better, and when there is still good feed levels and feed quality.
- In a good season make silage if you can – store it for a dry summer.
A feed budget is very important. If you are hit by drought, you need, in addition to getting through it, to be clear on how you will recover when the weather breaks. And you need to know what your pasture cover needs to be at May 1, (ie early winter).
So when the drought breaks I suggest you will continue feeding supplement while the farm recovers, keeping the ewes on as long a rotation as possible; this is the most profitable time for feeding supplement.
- Tom Ward is an Ashburton-based farm consultant
