Case Study: Weaning Management
Emily Stretch, Stretch Enterprises, Kojonup WA
Author correspondence: emilystretch@hotmail.com
Context
We run between 12 000 and 18 000 merino sheep in any given year. Generally, our breeding ewe flock is 5000 head. We join our maiden ewes at 1.5 years of age. We have a finer wool genetic base with slower body growth than maternal and crossbred sheep. We let our sheep grow out on a gradual rising plane; we don’t need our sheep to push a really high growth rate as we don’t join ewe lambs. The wethers are kept on the farm for a few years to give us flexibility in tight winters, or extremely wet winters, being the first sold when Feed on Offer (FOO) is low. The rest of the flock consists of bought wethers, weaners, and hoggets. Our cropping system ranges from 1,200 hectares (when running 18 000 sheep) to 1800 hectares (when running 12 000 sheep). We join in mid-February and lamb from mid-July to the end of August. We aim to wean anywhere from 20 October to 10 November. We generally start harvest around the 1 December, give or take a week, and like to have the weaners settled by then so that we can focus on harvesting.
Weaning in a nutshell
We wean an approximate 3700 lambs onto one of two paddock types; standing oat fodder, or kikuyu, clover and ryegrass. We leave around one ‘leader-ewe’ to every 100 lambs weaned (or enough ewes to make up a full bale of wool at weaner shearing in April). The weaners get their booster vaccination, a drench (if required after a worm egg count), and Clik to protect from flies. The standing oat crops create an ecosystem where flies can thrive; the wind doesn’t always penetrate the oats to dry the weaners off.
Our ideal weaning scenario:
We settle the weaners for 1-2 days with hay and water in the sheep yards or small holding paddocks with secure fences. We then drive them gently out to their kikuyu paddock (our preference) or standing oat paddock (if a kikuyu paddock is not established on that part of the farm). We move them ALL to the water point in that paddock and hold them there until they start to drift off and graze. We have dams in almost every paddock; if we were working with troughs we would hold them for longer on the water point to ensure that everything has had a drink. We then leave them alone until the next morning, in which time they will undoubtedly walk the length of the entire fence. We check on them at 8-9am, about when adults would typically walk to water points. Regardless of the leader-ewes’ ability to do their job, some weaners are always separate from the mob; there will be a group standing in full sun, or one with its head caught in a fence, or one cast against a log. We bring all the animals back to the watering point, let them drink and then shift them to shade in the morning. In the afternoon we pick them up from shade at 3-4 pm, take them to the watering point and then let them graze. We do this every day for the first week. Then we check once a day for the second week, once every two days for the third week, and finally tapering off into a weekly check that tends to coincide with a supplementary feed. In standing oats, this job is far more intensive as the oats act as a natural barrier that they don’t want to walk through. They also have trouble seeing each other, which means they bunch into little pockets instead of a big mob.
Our feed supplementation strategy is based on metabolisable energy (ME) requirements (available via the LTEM: Lifetime Ewe Management app and DPIRD’s Supplementary Feeding and Feed Budgeting for Sheep). We make sure that we have lupins on hand for increased protein intake, as well as harvested oats for the autumn period when available roughage is limited. We budget on feeding from December to mid-June for the weaners and mid-January to mid-June for the adult flock. On a basic level, we make sure weaners have a feed ration with 15% protein and more than 10 megajoules (MJ) of energy per day. Oats alone don’t meet the protein requirement, so we supplement with lupins. The lupins also help increase the ME eaten with a smaller volume of feed ingested.
The general rules for our weaner rations are:
- Allow for rumen adaptation to the oats for the first three to four weeks.
- Start supplementary feeding lupins in a trail to introduce them to the feed @ 50g/head/day.
- Increase the feed rate by 25g/head/day every two weeks. This is variable depending on feed available in the paddock.
- Once they are accustomed to the grain and the feed being brought into the paddock, we use a spreader at a 4-6m width and broadcast the lupins through the oats. This encourages them to pick up the oat grains off the ground as well.
Standing oat fodder
Why do we do it?
- We don’t strive for a massive growth rate, just a steady one.
- We’re busy harvesting from December to mid-January.
- It’s a simple way to make sure that the animals have their base ration of feed.
- When managed correctly, they pick up little to no worms, which increases their chances of consistent growth rates.
- The weaners are in confined areas for checking.
- The adults can get the most out of the stubbles which our weaners tend to lose weight on as they walk a long way to pick up a smaller amount of grain.
- Fodder crops are clean of grass seeds (when managed correctly through winter).
- It often looks expensive on paper, but the simplicity of the management system while we are busy elsewhere is hard to measure.
How do we grow it?
We grow these paddocks as if they were commercial oat crops to achieve the most grain and biomass yield possible. If we didn’t have fodder paddocks, we would be harvesting grain or buying grain in to feed them.
We make sure that we have at least one paddock of oats on each block of land to make weaning simple. We try to seed 100 hectares for the weaners in small paddocks or areas of paddocks that oats thrive on and where canola and other cereals don’t. These paddocks may also have grass issues and they generally become pasture the following year, so any regrowth oats or grasses aren’t an issue. They can be tough to manage if they need to go into crop the next year due to stubble retention. Running adult sheep over them after the weaner mob helps to smash the stubble down and make sure all of the grains are picked up off the ground.
We manage our fodder paddocks the same as our cropping program. They get a full knockdown spray, seeded at 100kg/ha, fertiliser down the tube at 100kg/ha. We spray and spread as normal throughout the season, with an added selenium chip spread with the first urea pass. Historically we know that our soils are deficient in selenium. We try to use a shorter variety of oats like Mitika as the weaners stand a chance of seeing over it. All of our soil testing, tissue testing, and liming happens as normal within our rotation. These aren’t sacrificial paddocks; we make them work hard so that the weaners can benefit from them.
How do we manage it?
At haying off the oat fodder paddocks get a hay cut or harvest run around the fences and to the water point from multiple directions. These paths give weaners access routes to follow to water, and space to walk the fence without pushing on it. It also gives us a safe place to drive or ride through the paddock with less fire risk from vehicle exhausts. It also helps when you push weaners into the paddock for the first time as they don’t hit a wall of oats and stop moving. If the paddock is larger than 30 hectares we look at putting in a temporary fence so they don’t trample the whole paddock walking kilometres to water.
The fodder paddocks are hayed off naturally and weaners are drenched onto these paddocks at this time. We could spray-top to move this forward for a weaning timeline but haven’t needed to so far. On the blocks where we have kikuyu paddocks established, the weaners head there first which enables an earlier weaning. Our weaner drenching management plan for the fodder crops is that we don’t leave any refugia animals to ensure optimal growth for all. After the weaners have moved off that fodder paddock we run an undrenched mob of adults over the paddock to dilute the worm population to minimise breeding drench resistant worms. Alternatively, we can leave the leader ewes undrenched and monitor closely with egg counts especially if there is summer rain.
Weaners are stocked at 25 DSE/ha to 50 DSE/ha, with a maximum mob size of 1000 head. Calculating the grain production alone, a 30ha paddock of oats yielding an average of 3t/ha has 90 000kg of oats available. From feed tests, this 90 000kg of oats equates to a total of 963 000 MJ of energy, which gives 1000 weaners nearly 100 days of grazing that started at a bodyweight of 30kg and are maintaining a 50g growth rate per day. The table below gives some guidelines on daily energy requirements for medium-frame weaner sheep on different growth rates.
Then there is the biomass of the oat itself. Our weaners graze the whole Mitika plant which lengthens the time frame for grazing. However, we do our feed budgeting on the grain portion alone to ensure that we have adequate feed reserves. The lupin supplement for protein also prolongs the length of grazing as they don’t have to eat the oats at that rate to meet their ME requirement.
Paddocks are monitored from mid-January onwards for numbers of grain per square foot to ascertain when the animals need to shift to their next fodder paddock, or when to increase their supplementation with an oat ration as well. If the paddock gets too bare, we shift them onto a pasture base or different stubble to minimise erosion.
NB. Insurance on standing fodder can be a grey area and needs defining with your insurance agent. Also keep in mind, animals in standing fodder are in a high fire risk environment.
Kikuyu paddocks
Why do we do it?
- Kikuyu paddocks tend to hold together sandier soil profiles and reduce erosion in wind and rain events.
- Acts as a summer feed base while providing a vitamin E boost.
- Grows in areas where we struggle to keep other species persisting.
- Once it’s established it is easier to keep clover and rye persisting through it in winter due to reduced soil profile damage in summer.
- We don’t seed paddocks every year; our last paddock was around 10 years ago. We are looking to establish some more in the next two years because we now understand how to utilise these paddocks in our soil and livestock systems.
How do we grow it?
Kikuyu paddocks have been established with similar timing and systems to normal pasture seeding. We use our normal seeding gear and sow during autumn or spring when it’s warmer. The paddocks require prior manipulation/spray control to allow the kikuyu to get established. This year we have seeded a problem area to oats which gives us the knockdown and broadleaf control through winter. We will then spray it out and graze or cut it for silage in spring. After that, we should have a clean paddock for kikuyu establishment.
These paddocks do require careful grazing. Livestock will pull the rhizomes straight out of the ground if they are allowed to graze it too early or to the ground. We graze to a golf ball height with sheep and a cricket ball height with cattle. While it’s being established, keep sheep, kangaroos, rabbits and any other animals off the paddock.
During winter we can graze the paddocks as per normal. As long as there are good growing conditions, the winter pasture tends to grow above the kikuyu meaning the animals can’t overgraze it. This also keeps the kikuyu from getting rank or thatching. We lock these paddocks up in late August to allow the winter feed base to bulk up and to minimise the worm burden. As temperatures warm up, the kikuyu begins to grow up through the winter feed base. When we wean onto it they get a mixture of clover, rye and green grass to build up their vitamin E bank.
We haven’t needed to reseed kikuyu in the paddocks that have established well. Kangaroos are a significant issue for getting these paddocks going and keeping them persisting. We will need to maintain a reseeding schedule for the clover and rye in these paddocks as the weaners deplete the seed bank each year. For this purpose, a disc seeder is used during autumn over the kikuyu to replenish clover and ryegrass seed numbers.
How do we manage it?
Weaners go out onto these paddocks anywhere from 20 September to 10 November. Depending on the year the annual pastures can be green at this time or haying off. Quite often we won’t drench weaners onto these paddocks. We monitor their worm burden with egg counts before weaning. If they are over 75-100 eggs per gram, we drench them onto the paddock to keep them growing well. If they are under this threshold, we monitor them closely and potentially just drench the light or weedy animals at weaning. When the weaners come off the kikuyu paddock and head for standing oats, they get a drench. The oat paddock is worm free. If the weaners don’t take worms in, they’ll stay healthy for longer. We don’t always drench onto the kikuyu paddock as we know they’ll be getting one in 3-6 weeks. These paddocks have a solid pasture height which reduces worm egg intake as well, however these paddocks may have worms the whole way through summer due to the persistent green feed.
If it rains during summer, we will bring the weaners back to the kikuyu paddocks every 6-8 weeks to bring their vitamin E levels back up. If there’s no growth in the paddock and grazing would be detrimental, we’ll look at using a vitamin E drench or grain treatment instead. Once they have been back on the green feed, we monitor for worms closely by using faecal egg counts.
Other management techniques
- Training feeds with multiple grains – before weaning, we introduce the feed cart to the mob. We use the ewes to teach the lambs to come to the feed cart and to pick up grain from a trail. We feed them at least twice with oats and twice with lupins to start some rumen adaptation. The rumen adjustment period after weaning can temporarily reduce growth rates, so we start that adjustment before they have the additional stress of weaning.
- Yard, trough and shed training – at lamb marking and weaning we introduce the lambs to as many different things as possible while they have their mothers to teach them. It makes life easier for them and us over their lifespan.
- We also allow our sheep to exit or calmly walk through high stress areas such as drenching races or truck load out areas.
The fodder crops and kikuyu pastures have worked extremely well in our enterprise. Feed budgets and worm thresholds will vary depending on your flock, breed, climate and many other factors. It is important to do your research based on your animals and enterprise!