The longest winter ever - the plan to optimise herd performance in a milder May
From the cow's point of view, we must consider how much grass she can eat in a day, and what the quality of that grass is like, writes ruminant nutritionist Biran Reidy.
We are now moving into the month of May and our Irish weather continues to play up, I've heard a couple of clients saying it feels like the longest winter ever on my latest round of visits.
Over the last few weeks, we have continued to see a considerable amount of rainfall and this has given rise to many challenges for grassland management.
Already, we as a country, have supplied less milk than we had this time last year. The wet weather and poor grass growth have caused energy and dry matter intakes to be depressed and if energy doesn’t go in it cant end up in the tank.
Are they still getting first-round grass weeks after it should have been eaten?
The weather affects the cow's ability to maximise grass intake, and we must figure out how to take account of this when complementing the intakes achieved from grass on any given day and be prepared to adjust accordingly.
When grass is in good supply, many farmers will be tempted to reduce or even stop supplementary feeding. This can bring short-term improvements in margins.
The cows will continue to milk satisfactorily, and any small reductions in milk yield are generally accepted on the basis that margin per cow will be increasing due to the use of cheaper feed (pasture).
However, some of these short-term gains may be hiding longer-term losses in performance. Initially, the cow may continue to milk well, but this could often be at the expense of increased body tissue loss.
In the best grazing conditions possible, when feeding no supplementary feed, grass intake is unlikely to exceed 18kg/day.
There are however many situations when grazed pasture will not support more than 14kg DM intake/day, when grass quality, grass cover and weather are taken into account. In recent days I have tested second-round covers of 1,600-1,700 kg at 14.5% Dry Matter, meaning that over 120 kg of fresh grass must be consumed to reach 18kg of dry matter.
Consider the above in the context of the last few weeks. For many, an early application of Nitrogen where it was possible to do so had a very poor response. Growth was poor due to the weather as it was so wet and harsh. Excellent grazing conditions in February, quickly turned to little or no grazing for a lot of March. As a result, most are only recently finishing the 1st round as I mentioned above. This has resulted in cows grazing grass which is not ideal for milk and solid production as it is stemmy and lower in energy and leaf content than we would like.
Decisions need to be made quickly, where possible, to skip paddocks and wrap or pit them.
As mentioned above, milk supply is down in 2023 so far.
If cows are milking below their potential, then they are under pressure. Cows are bred to milk, and even if they do not consume sufficient nutrients, they will in most cases deplete their body reserves in order to try and maintain production.
If you are feeding the same level of concentrates to your cows at grass this year (with poorer grass quality) as you did in previous years and milk yield is lower than expected then cows are likely to be under a bit of pressure.
Milk protein is under pressure around the country this year, indicating that cows are deficient in energy intake. This will have a subsequent effect on cow condition and fertility.
Look and listen to your cows. If solids are dropping, then energy intake is insufficient. This may be due to grass being too strong and of poorer quality or due to underfeeding of supplementation at grass.
It may, however, be due to the too-rapid throughput of grass through the cow’s digestive system. In order for cows to maximize their production from grass it needs to remain in the rumen long enough to be thoroughly digested. Keep an eye on dung consistency.
Remember that for a cow to function efficiently, she must maximize cud chewing activity in order to process her feed into milk.
If she eats material which is soft or of small particle size then what will she chew on? The addition of some straw to the cows as a Grazing supplement will supply this much-needed physically effective fibre.
On the issue of excessive protein supply, it must be borne in mind that during the spring and summer months, grass will rarely be below 23-24% protein and may reach as high as 32%.
Excessive protein intake has also been linked with embryo death. Grass for grazing in a typical 17 to 21-day rotation can only use one unit of Nitrogen a day. Any extra units are an unnecessary cost and detrimental to the cow.
Unfortunately, I have received several customers wanting my opinion on the physical quality of the nuts/pellets they are feeding in the parlour.
I have seen a lot of very dusty and not fit-for-purpose nuts/pellets causing low intakes of concentrates and causing respiratory issues in herds. Complementing grass under pressure with unpalatable concentrates is a big issue at any stage of lactation but particularly so when in the middle of breeding.
The weather has had an extremely adverse effect on dairy and beef farms so far in 2023. Not alone is production down, but silage quality will inevitably also be affected.
With regard to production and cow performance, it is worth remembering that if you bred a cow to milk, then you need to manage and feed her accordingly.
A poor growing season or poor weather should not be solely to blame for poor production and below-average fertility.
- Brian Reidy is an independent ruminant nutritionist at Premier Farm Nutrition.
