Buoyed up by a recent surge in grass growth I decided I wanted to see how much supplementary food I could remove from our cows’ diets, how much grass they would then eat and what milk yields could be sustained.

Determined to make things as simple as possible this summer I am running all of the milking cows in one group. However, this does mean some degree of compromise because of the following:

  • The cows currently calve all year round
  • We have parlour feeders but have to feed all cows the same amount


If we were running a block calving herd with some rather more up to date feeders in the parlour, we could target feed more accurately. So, these are two things I am looking at changing this year.

In the meantime, we cut out all buffer feed several weeks ago once I became confident we had enough grass in front of the cows (following some diligent application of the plate meter). The replacement of some good quality 1st cut, rolled wheat and a blend with just grazing and cake did us no harm at all – milk yields actually rose.

Three days ago I decided to cut the cake in half, down to 2kg per cow per day for fresh-calved and stale cows alike. My ability to assess the impact of this decision has been somewhat hampered by some really wet weather over the weekend, which means we lost the fantastic grazing conditions we were enjoying a week ago.


So, what happened?

  • One thing very quickly became apparent – cutting the cake in half put a real edge on the cows’ appetite.
  • Despite being more generous when it came to moving the electric fence, when I went to get the cows in I found it had been grazed down to residual levels I have never achieved before.
  • We lost 2 litres of milk per cow when it was really wet on Saturday.
  • Cows were waiting at the gate to come in for milking and hurried to the parlour.


What did I learn from this experience?

  • Our cows (Montbeliardes) can eat much more grass than I previously thought. I estimate they were eating 18kg of grass dry matter a day.
  • Cows can be aggressive grazers even in rough weather.
  • It is possible to achieve the kind of ‘text book’ grazing residuals I keep hearing about.
  • Heavy storms didn’t dampen the cows’ appetite but they struggled to eat enough to maintain milk yields.
  • Because we offer no buffer feeding to the cows at any time, they do not stand at the gate bawling to come inside when grazing is less than ideal – they just get on with it.
  • Biggest lesson – if you keep filling your cows up with supplementary feed they will be lazy grazers.


What will I do following this experience?

As I mentioned earlier, our calving pattern and our parlour feeding system make feeding cows at grass a difficult job – you either under feed some of the fresh calved cows or over feed the stale ones. Changing this is important but it can’t be achieved overnight.

So, right now, the aim for me is to find the tipping point at which the removal of supplementary feed I save is outweighed by the loss in milk income. We are currently at a point where the loss in milk yield is pretty much equivalent to the value of the feed saved, as illustrated below.

Feed saved 360kg (180 cows x 2kg)
Cost per tonne £250
Cost saving / day £90


Loss in milk 300 litres
Price per litre 29.5p
Loss in revenue £89


It is important to remember that the weather has contributed to the loss in milk. I am expecting the milk to recover to within 150 litres of where it was before I cut the cake back, which would mean we make a small gain. So, for now I am going to leave the cake feeding at 2kg a day and see if we can get milk yields back up to the level they were before I cut the feed back.


Further considerations

My weekend experiment was not just about playing with our cows and their food. It was really about exploring the potential of grass and, on the whole, I am pleased with what I discovered. We can get more from grass. But, there are a few other pros and cons I need to consider going forward, as follows:

  • Does the reduction in supplementary feed having any influence on health and fertility of the cows? It’s too soon to say but I did notice one or two cows became quite loose when the grass was very wet with some bubbles in their dung, which I believe is a sign of sub acute ruminal acidosis (SARA).
  • Will I drive down milk yields in the longer term? If fresh calved cows don’t peak as high, I might not get much milk form them from July onwards when grass quality declines.
  • Is this increased grass consumption helping my pasture management? At the moment grass is growing well and I believe we can continue to meet the extra demand that reducing supplementary feed has created. In addition, we are getting grass eaten down tighter and should see better regrowth.
  • How long can I maintain grass quality to ensure that it has a nutritional value at least equivalent to the cake I am feeding? I know grass quality will deteriorate from the end of this month and I will have to supplement cows in early lactation at some point to keep milk up. If we run into a dry spell I may need to buffer feed to balance demand with supply.
  • I wonder if I should perhaps offer the cows that extra kilogram of cake in the parlour on wet days, when simply eating enough grass becomes difficult. Hopefully, this small lift in feed (and subsequent removal again) wouldn’t upset them too much.


Final thoughts

As you will have worked out by now this was not a scientific experiment and I have drawn no hard and fast conclusions, but I have learned a bit more about our cows and farm. I just hope the experience I have shared here provokes a bit of thought amongst Free Range Dairy farmers who are looking to graze their cows as much as possible.

It is very clear to me that if you just turn cows out to unknown quantities of grass, feed them a little something extra just because you always have done and make no proper assessment of what grazing is actually putting in the milk tank, you will fail to make good use of the grass that grows on your farm. Doing something about it isn’t difficult – it just requires a bit of thinking time and some regular walking round your pastures.

It’s never too late to start improving your grazing management, but I am glad I set about doing that from the outset this year. I don’t know what challenges the next few months will present but I am now better placed to deal with them.

Make that Pasture Promise and remember – grazing is amazing!


Leave a Reply