December silage and grazing management
"It's a good year to be understocked."
(contractor, talking about the weather as farmers do - it's been an exceptionally cold and wet winter and spring thus far and many farms in the area are short of feed.)
Cut just over 9 ha last week, another two paddocks sitting quiet until I decide they're ready to cut for hay - probably another fortnight.
The farm is carrying just under 3 cows/ha (jerseys and jersey cross, about 42% heifers) doing 1.4 MS per cow at present, peak day was 17 Oct at 1.64 kgMS/cow. They've been well fed right through, thanks to the low stocking rate through the cold, wet winter (ten cows were bought in July) and a very slow, late calving - 10% of the herd calved in October and my calving start date was one - two weeks later than average for the area.
They're leaving high residuals, which are topped when they get too clumpy (if large clumps are left two consecutive grazing rounds). Leaving grass behind makes for a slightly lower efficiency per hectare, but I'm happy to sacrifice a couple of MS per hectare in favour of cow welfare. The critical factor in a lower stocking rate is protecting grass quality, which in the long run impacts cow welfare.
I learned what not to do from one of my neighbours last year, while managing another prime example of what not to do. My farm last year had lots of large hungry cows on a small area, going into short grass round after round and cleaning it out like dry cows.
The farm next door had a much kinder stocking rate, and fed his cows well through the spring and early summer while the cows I managed raced around the paddock after me wanting to know where the rest of their food was.
After Christmas, it got a little dry but not too dry and my cows were going into short green grass and getting a couple of kilo silage to keep them going - and the neighbours cows were bawling their heads off and running around complaining of hunger.
They were running around in knee-length grass. So I had a closer look.
What they were standing in, was deep clumps of dead material topped with a tinge of green. Brown stalks, left behind from a previous lax grazing, and the lax grazing before, and the lax grazing before that - completely unpalatable. And the neighbour's cows, unaccustomed to grazing hard, had taken a contemptuous sniff at it and decided there was nothing here for them to eat.
Lesson learned: yes, it's great to feed the cows as much as they can handle. But keeping the grass in a growing state, and minimising the amount of unpalatable dry matter, is imperative.
It's all a matter of balance. You can get away with a lot in farming, but get that balance between feeding the cows and growing grass badly upset, and it can all turn to custard. The farm I was working on, with the fantastic grass quality, was plagued with poor health among the cattle. Top production per hectare, high profitability per hectare - put push the system too far and it's the cows that will give up. And the cows are the key to production, not the grass.
So how do I manage my farm? With the minimum of hard work :-)
The cows are on consecutive (for ease of management) 24-hr grazing (for ease, better spread of fertiliser by cows and because I think they clean the paddocks more evenly and compete less for feed on 24-hrs rather than 12hr breaks).
I aim to offer them the same amount of grass each day, resulting in a relatively consistent residual. The only way to do this is to know the paddock areas and measure the grass - so if one paddock naturally grows less, you need to give them a bit more area than normal and vice versa. With the area offered fluctuating slightly from day to day, it's important to keep track of what the actual rotation length is to ensure that you're not munching into the feed wedge faster than it's growing (or can grow before you return to the paddock). I use some 'rule of thumb' rotation lengths which of course need adjusted according to the season and calving start date (60 - 120 days through winter, 45 days going into August, 30 days reducing to 20 through September, 17 - 20 through spring and early summer out to 24 - 30 for late summer and autumn). If I'm not on those rotations, something needs to change - paddocks out for silage, silage fed out to cows, urea spread, cows fed less, paddocks topped or grazed by lower priority animals, buy cows, sell cows, milk once daily, dry off cows... whatever is possible, and appropriate to the time of year.
For maximum pasture production a number of factors have to be right - post-grazing residuals, soil, nutrients, water, protection from back grazing, temperature, light.
Some of these factors are out of the farmer's control. Grazing he can control. My aim is to put the cows in at 15 cm for most of the year, taking them out at 5 - 6 cm with as few clumps as possible. In practice, if 5 - 6 cm are left behind there will usually be clumps, so some topping is required to avoid the 'dead grass' situation described on the neighbour's farm last year (or drop paddocks out for silage to get back to a stage in the round where the cows can graze to the lower level of 5 cm).
When grass growth slows down, the cows will easily graze down to 3 - 4 cm and at this level they will leave almost no clumps provided all the grass is in a palatable condition when they go in.
I like to work on a 24/48 hour limit, although with water trough access making that difficult, I do quite often work on a maximum of four days when break feeding, or allow a semi-setstocking at times (eg, with lame cows in a close paddock). In practice this means if I open a gate to let the cows into a paddock, that gate is shut 48 hours later to spell for fourteen or twenty days depending on grazing length. In that time frame I may have put the cows back in there the following day to clean up, or given them their new paddock plus access back, or topped the paddock (and sometimes let them access back to eat the topppings), or put another group in behind them to graze the leavings.
Later than 48 hours and the paddock is shut, regardless of how much is left behind. The reasoning for this is the speed with which the grass can send up new shoots. I've been told that if the new shoots are grazed, there is a delay before the plant can send up another shoot, and this is the main reason why rotational systems (which prevent back grazing) are more efficient than set-stocking systems. Round about two days is both the time frame in which most of the grazed plants will have started to grow new shoots, and cows will start to show an interest in back grazing where they've already grazed.
Any longer than two days with the cows on a single area, and new growth is being sacrificed to cattle who think it's quite pleasant to walk along and nip off all the soft green tips that have sprung up overnight.
When the grass ahead of the cows is longer than they need to maintain the current rotation length, the decision is to increase the length of the rotation, increase grazing pressure or drop paddocks out (which increases grazing pressure on the remaining area). Too early in the year and too much grass to increase rotation length when the pre-grazing lengths started to escape (mid-November, just when rye-grass is heading into reproductive growth), I tightened the cows up to two-thirds of their daily area, toppped what they left behind and skipped six paddocks ahead of them.
It took another four paddocks dropped to return to the point where the cows could go into 1/20th of the designated grazing area and leave a residual that didn't need topped.
One of those paddocks was re-opened for lame/slow cows, seven have just been cut and are regrowing, two are bulking up for hay and the farm pasture cover has just dropped dramatically. In anticipation of the cut paddocks coming back into the rotation and good growth, the daily area allocated to the cows has slightly increased over the past couple of days.
Next year I'd hope to save the work and expense of silage by having a higher stocking rate and earlier, tighter calving, then decreasing grazing pressure after Christmas. But with a bunch of dainty Jersey yearlings expected to arrive next June it's doubtful they'll have much effect at all on increasing the liveweight per hectare - who knows, we could be cutting heaps of silage again next year.
I don't think I'd be complaining too much.
posted by nellta holdings @ 5:00 PM
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