Grazing early in the springtime can have many positive effects on the cow, farm and farmer because of DMI and cost savings, and for environmental and mental reasons as well, writes Bernard Stack, InTouch feeding specialist, Alltech Ireland.
The focus should be on the dry matter intake (DMI) of the animal, as cows try to match their intake with their ever-increasing milk production. Measurement is key. Knowing how much grass is available and its quality is essential in developing a corresponding supplementation programme. Teagasc and the industry have done a lot of work in the promotion of grass measuring and management techniques, yielding much success, but there is still a cohort of farms that see it as too much of a ‘chore’, even in the face of it being a profitable process.
For those not measuring, it is time to step back and answer the following questions:
1. How much grass will my cow eat today?
2. What is the total DMI requirement of my cow?
3. What is the amount of supplementation I need to give?
If you don’t know the answer to these three questions, then more than likely your herd is under unnecessary pressure. The increasing stocking rate on many farms over the past few years has not been followed with an adjustment in paddock sizes, and so our traditional reasons for placing a ‘strip’ wire or allocating the same paddock for a day means the animals are now consuming less grass. Measuring the grass cover of the paddock that the cows are entering is the first step in this process.
The objective here should be to capitalise on this high-dry-matter and high-protein grass down to 4cm, which will set a good platform for the quality of the second and third rounds of grass. To achieve this, the farm needs to have 60 per cent of the total area grazed by mid-March and 100 per cent grazed by the end of the first week in April.
Dividing your milk yield by 1.5 should give you an approximate DMI for your animals, taking note of the top 20 per cent of your herd, which should then allow the determination of the amount of supplement required. While a logical option might be to eliminate supplementary feed to increase appetites at grass, any shortfalls will need to be filled. Supplementary feed should focus on quantity before quality, and the following diets and concentrate levels should be in place with the arrival of fresh cows:
• No-grass diet – 0.33kg of concentrate per litre of milk;
• Grass-by-day diet – 0.22kg of concentrate per litre of milk; and
• Full-grass diet – 0.11kg of concentrate per litre of milk.
These concentrate levels are based on silage with a dry matter digestibility (DMD) of 65 and serve as a guide rather than a definite level. Diets should be focused on the best-quality concentrates and forages available, and grass silage should be minimised as much as possible, but it must be reinstated when cows come back inside and you find yourself increasing concentrate levels above the limits outlined. The supplementary diets should naturally balance the protein, fibre and energy levels of the grass with lower, less degradable or controlled-release protein sources, effective-type fibre and starch to complement the sugar in grass. Naturally, we do not live in a perfect world, and so this grazing must be completed in the presence of changing weather and grazing conditions. We need to be mindful to avoid serious poaching of the ground. There are many ways to minimise this, including the use of back fencing, using good roadways or even field track, and having multiple entry points in a paddock with central water facilities. If it’s not possible to graze, having the best quality ingredients available to minimise the ‘step back’ is advisable.
If grass budgeting is not done on your farm, take the first step by measuring what is in the next paddock first.