A recent Beef + Lamb New Zealand workshop highlighted the value of a growing a range of pasture plants with the aim of having a constant supply of quality feed throughout the year.
Amongst the pasture plants Agricom agronomist Greg Dunshea talked about at the workshop were cocksfoot, tall fescue, diploid perennial, tetraploid perennial, hybrid and Italian ryegrasses and prairie grass.
While older stock can eat and perform relatively well on any of these grasses, cocksfoot and old tall fescue pastures are generally not ideal for young stock such as R1 cattle and lambs, although much depends on management and the amount of clover and companion species in the sward.
“Well managed pastures of tall fescue for lambs or cocksfoot for R1 cattle are great options, it’s when management slips and pasture quality declines that issues start to arise”
There is typically a trade-off between dry matter production over a period of time and perenniality. Hybrid ryegrass for example will grow a lot of feed over 3–4 years, but has a more defined lifespan and is relatively less suited to tough conditions. In the case of cocksfoot, which is a hardy perennial, it is slower to establish than ryegrass but produces more feed during times of moisture stress than any of the ryegrasses.
“In tough sites, when the pressure comes on, it is those persistent species that produce more feed.”
Cocksfoot can be sown in a ryegrass-based mix and the plant may only become apparent years after planting during a dry spell when other species are struggling. Cocksfoot is a good option for helping build pasture resilience, particularly in dryland environments.
Italian ryegrass will produce a lot of feed over 18-24 months, with high growth rates in the shoulders of summer and over winter. As Italian ryegrass ages, pastures will naturally thin and farmers looking for a 3 year option should consider the use of Italian ryegrass with an endophyte such as AR128.
Italian and hybrid ryegrasses can be particularly useful in the late winter, early spring period, due to relatively higher growth rates than the likes of perennial ryegrass.
While hybrid ryegrasses can be sown in a mix with perennial ryegrasses, Greg cautions against using Italian ryegrasses in a mix.
Italian ryegrasses go to seed in early summer, and generally have a wider seeding window than perennial ryegrass, so would reduce the overall feed quality of the mixed pasture.
While tall fescue slows down in autumn and is relatively dormant over winter, it's spring growth is exceptional, making it a great option for summer/autumn dry locations where the majority of pasture growth occurs in the spring.
“It will just keep growing, it’s unstoppable.”
Greg says it is particularly useful for stock coming off winter forage crops and lambing ewes, as it can be set-stocked early and will just keep growing, irrespective of soil temperatures.
“It’s driven by day length rather than temperature, so be prepared to get onto it in spring.”
While tall fescue is valuable in spring, ideally it should be eased up on in autumn to allow itself to recharge its root reserves and set up tillers for the following spring.
“Don’t overthink it, you don’t need to spell it like Lucerne, just don’t graze it to the boards in the autumn. If you do, it’s not the end of the world, you will just reduce how much your fescue fires in the spring”
Sowing plans and the power of the heading date.
When putting together a planting plan, Allister Moorhead, Agricom’s Product Development Manager recommends farmers start by considering their stock classes, stock numbers, the demands of these classes and the area of the farm they are grazing. The logistics of the business also need to be taken into account when deciding where to grow what forage.
He also urges farmers to understand the heading dates of their pasture species so they know when pasture quality will decline in different paddocks.
All pasture plants have a heading date relative to Nui ryegrass (approximately late October/early November). Plants with an earlier heading date will have strong early season production, while those with late heading dates will remain vegetative for longer heading into summer.
He suggests farmers use their farm map and note the heading date of the predominant pasture species. They will then know exactly when and where they will lose pasture quality.
“It is then completely and utterly predictable -to about five days- when you are going to lose pasture quality. Weaponise this on your farm plan as it’s very predictable when this reproductive development is going to happen.”
The aim for a farm system is to have a good balance of heading dates from mid-October through until mid December.
Focus on early heading species for late winter and spring production and later heading grasses to boost production after mid-October.
In dryland environments, it is important to focus on early season production to try and utilise spring moisture and maximise pre-weaning growth rates – and in the case of lambs – maximise the weaning draft.
While diverse pastures have advantages, Allister says seed mixes need to be based on “powerful” plants sown at high enough rates to dominate the pasture. Small, token amounts of seed lead to small plant populations and where there is space, reversion with weed species happens very quickly.
Have you got the balls?
Golf, hockey or tennis balls can be a used to give a rough guide to pasture covers, other tools include the bands on red band gumboots, sward sticks (free from B+LNZ), pasture metres and satellite readings (the latter three being the most accurate).
If a thrown golf ball can be seen in a sward, then there will be insufficient feed to meet stock demand. Calibrating whatever ball is used against actual sward measurements, makes monitoring pastures quick and easy.
Cattle and sheep have a cost in terms of how many bites they can take per day to consume feed for maintenance and production. The less energy required to find the forage and to eat each mouthful the better.
Ease of harvest is critical for driving livestock performance. Lower pasture covers result in less forage being harvested per bite and a larger grazing area to provide that forage. Comparatively, higher pasture covers result in higher amounts of forage being harvested per bite, and animals needing to harvest a smaller area.
Pasture longevity
Management factors such as over-grazing and pugging and pests such as stem weevil and grassgrub impact pasture longevity. Allister says “while ryegrass thrives on hard grazing and treading, particularly in winter – as long as it is spelled and allowed to recover for a reasonable period of time. It doesn’t like pugging, nor does it do well in very hot summer temperatures.”
Weeds grasses are inevitable and Allister urges farmers to try and ensure paddock are free of green weed grasses at establishment.
“Seed banks are real, so you can’t avoid them, but you can try and hold them off for as long as possible. Allowing weeds to strike and doing a final glyphosate spray before drilling is a cheap and effective way to control those weeds”
Once a new pasture is established, the aim is to keep it in the “new grass” phase for as long as possible. Allister says this is often two years, but management and fertility help to keep the new grass phase of a paddock going into a third or even fourth year.
“Try and make that vigour last as long as possible to maximise the return on investment.”