Grass quality and quantity key

The relationship between quantity and quality of grass on Irish farms and farm profit cannot be under-estimated. This is according to Eva Lewis, Teagasc researcher based in Moorepark who was speaking at the first session of the Irish Grassland Association dairy conference this morning.

“As grass utilisation increases, net profit increases. The research is telling us that we need to maximise grass in diet and nutrition, and the way we can do that is by growing more grass on our farms,” she said.

Lewis also outlined the latest cutting-edge grass research at Moorepark.

“When we measure the OMD (organic matter digestibility) in the quality of the grass, we can measure the energy in that grass. Grass that is high quality, has a high OMD, that grass will have a high energy content. When grass is very highly digestible, it tends to have lower fibre content, so it is less filling. So in the animal’s rumen she can actually eat more. Then correspondingly if you have poor-quality grass, low OMD grass, that has lower energy, it has more fibre, it is more bulkier and it takes up more room in the rumen and they can actually eat less of it.”

She referred to an example of the implications of this.

“Take for example a standard cow producing 24 litres of milk, 1.7 kilos of milk solids. We have done out the calculations. That animal has to take in 15.8 ufls of energy in order to produce that milk. If we take grass of high quality it takes 15.2 kilos of that grass to give that animal enough energy to produce that milk.

We can then calculate how much that animal can potentially eat and that comes out at 17.8 kilos, so we see that the animal can potentially eat more than she needs. So she needs to consume enough grass for her energy requirements to produce that milk.

She continued: “If we take a much lower, poorer-quality grass, the cow now needs to eat 16.5 kilos of that particular grass. She can potentially eat 16.8 kilos so she is just on the brink. She is just barely able to eat enough of that grass of that quality to produce that milk.  If we step up the milk production, if we go up to 28 litres, two kilos of milk solids, take that high-quality grass, she needs to eat 16.8 kilos of dry matter grass, potentially she can eat 18.3 kilos, clearly eat enough to produce that milk and everything is fine.

“But take that animal, offer her a poor quality grass, she needs to eat 18.3 kilos of that grass, she can only eat 17.2 kilos, so clearly she cannot eat enough of that grass to produce the milk that we want her to produce. What this shows is the quality of grass on your farm is extremely important to the milk production that you can actually achieve.”

The dairy nutrition researcher also spoke on the importance of protein percentage and its relationship with grass quality.

“Every year in Teagasc Moorepark our national survey shows in the mid-season period we see a drop in protein and that drop is costly for you and for the processor. A number of years ago, a study was carried out by Teagasc Moorepark to find the factors associated with that. What it found was that one of the factors associated with the protein percentage, was grass quality. It found that the higher quality of the grass, the higher digestibility of grass, the higher milk protein percentage. We now need to focus on producing tonnes of grass and we need to focus on producing tonnes of high-quality grass.”

Also speaking at the first session of the Irish Grassland Association conference was Abigail Ryan of Teagasc. She spoke on getting the balance right between grass quality and quantity, and referred to two research farms under way, farms in Waterford and Kilkenny.

“How do we know we are getting the balance right? The fundamentals of dairy farm are cash, cow fertility, grass production and milk solids production. So if all of these are going right for you, then you are getting the balance right between quality and quantity.”  In terms of its research on grass growth rate average  specifically, the researchers here found that over a three-year period across 12 counties is only 35 kilos per day for April.

Ryan also noted that soil fertility is also one of the key issues with growing more grass “None of Greenfield farms or grassroots that I have worked with, have enough Nitrogen, Phosphorus, or Potassium to grow the maximum amount of grass. In the spring on high-stocked farms as growth rates are normally lower you need to get at least 50 per cent of the annual Nitrogen application out by 1 April.”

In addition, south west Wexford farmer John Curtis outlined his own dairy farm experience. “You have to be on top of your job. The more grass I can grow the less painful,” he stated matter-of-factly.

Curtis has a significant proportion of his farm leased. He said: “We have a 52ha farm of this 42ha is leased at a cost of 18,000 per year. This helps to focus the mind there is no room for complacency. You have to be on top of your job. The more grass I can grow the less painful the lease is for me.”

In his presentation Curtis noted that: “It takes time to get your farm performing to its potential. It’s easy to find yourself in an intensively stocked situation even though you’re not intensively stocked. Simply because you’re not growing enough grass and you’re buying a lot of feed.”

He highlighted that: “We measure silage, we measure meal, we have diet feeders with clocks on them, we go to an awful lot of trouble for a couple of months during the winter. But we have no time at all on measuring the cheapest thing, ‘the grass’ which we are feeding for nine months of the year.”

“Measuring grass has contributed greatly to profit on our farm, especially with land leased,” he stressed.

Curtis plans to milk 100 cows in 2015 on his milking platform of 28ha. He said: “I need to grow 15 tonnes dry matter per ha for 100 cows. One tonne extra of dry matter for me over the whole farm would be 52 tonnes. That would feed 11 cows fully for the year.”

 More reports to follow from the Irish Grassland dairy conference. 

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