The importance of grass in the diet.
Let us compare the MDF with another dairy farm. At the moment, our litre production is lower than target, but milk solids per cow is on target, because the fat and protein test are up. Litres are less relevant, when talking about milk production, especially as the milk company we supply no longer charges for each litre (there is a small litre charged by Dairy Food Safety Victoria). Our stocking rate is lower and therefore grass intake per cow is higher. The other farm is feeding more grain to compensate for grass, but the MDF’s milk solids/cow, margin/cow and farm feed margin are still higher.
This result illustrates the importance of maximum grass in the diet. Now, although the MDF has more grass available to each cow, we are by no means running the perfect farm. Let’s highlight some factors below that you can check on your own farm.
At the MDF, paddock 20 is part grazed. Soil moisture is now perfect. 1.5 kg of N element per hectare was applied, but the N response looks weak. Pdk 20 is fairly flat, with heavier soil and overgrown spinner cuts, so is prone to water logging, by rain or irrigation. Spinner cuts on flood irrigation were first used in the 80’s in Northern Victoria. There are two video links on the MDF website, and one on the Dairy Australia website, explaining spinner cut theory and use on the farm.
The ungrazed bit of paddock 20 is half strongly seedheading PRG, and half leafy PRG. Any tiller that was in existence, even as a miniscule bud, during winter, i.e. was “winterised”, cannot be stopped from seedheading in Spring, unless eaten or topped, and killed. The leafy clumps are producing a lot of new tillers. The seedhead clumps are taller, but it is their quality, not their tallness, making them difficult to graze off. Even so, all parts of the paddock are being grazed hard, the leafy clumps down to 3 cm, the seed head clumps down to 10 cm. This is a sure sign the cows are hungry, or that they would eat more if more grass quantity and quality was available.
Cows can be “hungry” at any level of feeding. Hunger, or drive to eat, can be used to eat out seed heads, but at the cost of reducing intake. It is important to maintain current intake level, to maintain or lift milk production, and to avoid too much body condition loss. Feed is then used more efficiently, to get more MS from each tonne of food. Also, a herd that has a high intake demand is more likely to eat more grass into the future. The two most powerful drivers of the feed margin, high grass consumption per ha and high kg MS produced per tonne of food, need to be maintained.
So, the cows would eat more if offered more. A ten-day shorter grazing rotation would offer more grass today, but less in the future. A shorter rotation would make little difference to the seed head clumps and would significantly reduce quantity in the leafy clumps. Maybe only this paddock is a poor grower compared to the rest of the farm, so one less feed in this paddock would mean more grass for the cows today, but that feed must be found somewhere else to maintain the overall rotation.
A topping of paddock 20 at the previous grazing (late October) would have removed a large proportion of the seed heads when they were rising, but still short and not so obvious, and more quality leaf would be on offer now. Late October was a very effective time to top paddocks. More grain supplement is probably justified but that would not stop the cows looking for more grass. More likely, some high quality forage supplement is the answer. Purchased silage can be poor quality and expensive because often there is only 250 kg DM in a bale. Vetch hay can be pricy, but is a good choice as it has high dry matter and more often high quality.
If your cows are grazing hard at the moment, or paddocks are looking heavily in seed-head, note these conditions and try to change them for next spring. Preparation is the key for the spring and summer rotation.
| FEED MARGIN PERFORMANCE | MDF TEN DAYS AGO | MDF THIS TEN DAYS | ANOTHER MID FARM | Units |
| Ten days to date: | 20-Nov-20 | 30-Nov-20 | 30-Nov-20 | |
| Milker graze area | 71 | 73 | 65 | Ha |
| Milkers | 295 | 293 | 310 | Head |
| Stocking rate | 4.2 | 4.0 | 4.8 | cows/ha |
| Average graze rest time | 30 | 30 | 30 | Days |
| Estm’d pasture consmp’n | 49 | 49 | 46 | kg DM/ha/day |
| Pasture consum’d per cow | 11.8 | 12.1 | 9.6 | kg DM/cow/day |
| Pasture growing spend | $3.85 | $3.85 | $3.90 | $/ha/day |
| Estm’d pasture price | $78 | $79 | $86 | $/T DM |
| Conc (incl additives)supp fed/cow | 6.3 | 5.9 | 7.2 | kg DM/cow/day |
| Conc (incl additives)supp avg price | $353 | $353 | $392 | $/T DM |
| Hay/silage supp fed/cow | 0.0 | 0.0 | 0.0 | kg DM/cow/day |
| Hay/silage supp price | $/T DM | |||
| Feed Conversion Efficiency | 112 | 111 | 106 | kg MS/tonne DM |
| Total feed intake/cow | 18.0 | 17.8 | 16.5 | kg DM/cow/day |
| NDF Fibre in diet | 32.9% | 33.3% | 27.4% | % NDF |
| Litres/cow | 27.3 | 27.2 | 25.2 | l/cow/day |
| Fat test | 4.21% | 4.13% | 3.70% | % |
| Protein test | 3.24% | 3.23% | 3.33% | % |
| Milk Solids per cow | 2.03 | 2.00 | 1.77 | kg/cow/day |
| Milk price (less levies)/kg MS | $5.68 | $5.68 | $5.75 | $/kg MS |
| Milk price (less levies)/litre | $0.42 | $0.42 | $0.40 | $ per litre |
| Milk income/cow | $11.51 | $11.38 | $10.20 | $/cow/day |
| All feed cost/cow | $3.15 | $3.03 | $3.64 | $/cow/day |
| Margin over all Feed/cow | $8.36 | $8.35 | $6.56 | $/cow/day |
| MOAF /ha /day | $34.74 | $33.53 | $31.27 | $/ha/day |
| Farm MOAF per DAY | $2,467 | $2,448 | $2,033 | $/day |