The MDF is currently on 60 days rest and growing 2.8 leaves in this time, certainly not three. Rotation shortening is on everyone’s mind now, as the herd size builds and needs more feed. For the last 20 years, September has needed an average rest time of 42 days to get to three leaves. At three leaves, if you have applied N, the grass may sometimes be too tall to allow the cows to graze it down to a reasonable residue. It may be best to restrict growth and avoid tall grass, by not aiming for three leaves regrown. Keep in mind that the ryegrass seed-heads do not start arriving until mid-October. The weedy grasses, like poa and foxtail, will definitely have seed-heads before that time, but who has these weeds in their pasture? The point is, shortening the grazing rotation too early may feed the growing herd now, but could easily cause a severe feed pinch in a few weeks time. It is important to strike the right rotation length throughout August and September to feed the cows as much as possible, without over or under grazing and negatively affecting future rounds.
If rest times are a little long, tall grass can be difficult to graze out well. Firstly, there can be simply too much grass on offer, and secondly, the cows need to make too many passes over the grass and too many bites into the sward. A sign that “passes” are a problem is the strip under the electric fence that is always grazed out very well. This yellow strip always shows where the fence was (photo on website). The only thing different from the rest of the paddock, which is not grazed out as well, is that the cows do not soil and compress this strip before it is grazed. Grass soiling and compression by the cows is a major cause of lowered grass intake and grass utilisation.
To balance grass/fibre intake, the MDF feeds grain, assuming that with a ration balanced for fibre, there is very little grain substitution of pasture, and, if some of the grain goes onto the back of the cows, well and good. The point is that the response to grain is not always 67 grams of milk solids per kg DM of grain, which is the underlying assumption of the “Milk price: Grain price ratio of 1.5” rule.
Care is needed when choosing ratios or indicators to strive for. Note that the other MID farm, is performing much better than the MDF, with a much higher feed margin. But the other farm has a much higher “feed cost $/kg MS” and much lower “proportion of grazed grass in diet”. Sometimes it is suggested that these two latter indicators, should be lower and higher respectively, to achieve success.
| FEED MARGIN PERFORMANCE | MDF TEN DAYS AGO | MDF THIS TEN DAYS | ANOTHER MID FARM | Units |
| Ten days to date: | 30-Jul-20 | 10-Aug-20 | 10-Aug-20 | |
| Milker graze area | 55 | 52 | 120 | Ha |
| Milkers | 109 | 129 | 330 | Head |
| Stocking rate | 2.0 | 2.5 | 2.8 | cows/ha |
| Average graze rest time | 46 | 60 | 45 | Days |
| Estm’d pasture consmp’n | 17 | 20 | 23 | kg DM/ha/day |
| Pasture consum’d per cow | 8.4 | 8.0 | 8.3 | kg DM/cow/day |
| Pasture growing spend | $2.28 | $2.28 | $2.23 | $/ha/day |
| Estm’d pasture price | $137 | $115 | $98 | $/T DM |
| Conc (incl additives)supp fed/cow | 6.3 | 5.0 | 8.6 | kg DM/cow/day |
| Conc (incl additives)supp avg price | $370 | $370 | $482 | $/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 | 95 | 96 | 113 | kg MS/tonne DM |
| Total feed intake/cow | 14.5 | 12.8 | 16.9 | kg DM/cow/day |
| NDF Fibre in diet | 30.6% | 31.5% | 26.3% | % NDF |
| Litres/cow | 16.7 | 15.5 | 25.5 | l/cow/day |
| Fat test | 4.41% | 4.05% | 3.72% | % |
| Protein test | 3.93% | 3.92% | 3.79% | % |
| Milk Solids per cow | 1.39 | 1.24 | 1.92 | kg/cow/day |
| Milk price (less levies)/kg MS | $6.60 | $5.79 | $5.81 | $/kg MS |
| Milk price (less levies)/litre | $0.55 | $0.46 | $0.44 | $ per litre |
| Milk income/cow | $9.18 | $7.17 | $11.14 | $/cow/day |
| All feed cost/cow | $3.48 | $2.75 | $5.29 | $/cow/day |
| Margin over all Feed/cow | $5.70 | $4.42 | $5.85 | $/cow/day |
| MOAF /ha /day | $11.30 | $10.97 | $16.08 | $/ha/day |
| Farm MOAF per DAY | $622 | $570 | $1,929 | $/day |
| Feed cost $/kg MS | $2.50 | $2.22 | $2.76 | $/ kg MS |
| Proportion of grazed grass in diet | 58% | 62% | 49% | % |