Forage for Knowledge

Average cover should not include paddocks set aside for silage. Average cover is a measurement of grazeable paddocks and available to cows, so that we can plan from growth and demand that we don’t run short of grass or have too much. If you include paddocks set for silage, it distorts the numbers and makes the average cover meaningless.

May is a time for big growth rates. The average cover and entry covers change quickly, so don’t get caught chasing entry covers with these accelerating away from you.

This time of year, entry covers should be 2700–2800 kg DM/ha with the sward green from the top to the bottom. This matters because 1% reduction in grass digestibility has a resultant reduction in milk solids yield by 1–2%. This can mean a loss of 15–20 kg milk solids by mid-season.

There has been a lot of discussion recently with clients and discussion groups about how dry it is. On the face of it most of the sampling farms do not seem to be affected by dry soils yet. Otherwise, the growth rates stated would not be achievable. But of course, there is a variation in soil types and their ability to hold water.

My advice is to dig a hole and check your soil moisture. If it’s just dry dust in the root zone, don’t apply nitrogen. Prilled nitrogen of all types needs moisture to go into solution to be taken up by the roots.

If you have moisture in the root zone and watery slurry/dirty water, apply fertiliser with dirty water after to get it into the soil. If you have limited dirty water, prioritise your best paddocks to get the best response. Some discussion around dew but it is not really enough to do the job, and the halfway house is apply 50% of the rate.

Looking at the BBC long-range forecast, there seems to be scattered showers this weekend and some potentially the following week. The end of May looks to be slightly wetter at times. This is an opportunity to get some nitrogen on, especially if your soils have moisture in the root zone. The rain will then wash fertiliser into the soil and the roots will be able to take up the nitrogen which will help leaf size and growth and dry matter on your platform. I do not think it is time to panic about the dry weather. Just react quickly when you do get some rain, however light it may be. If in doubt, talk to a FACTS-registered adviser.

With the start of breeding approaching for spring herds there is an opportunity to help recovery in any late calvers.

To help them recover post-calving, milk them in the herd once a day and serve at the first signs of bulling, potentially with something cheap as early serves will have a lower conception rate. Having said that, I have had numerous clients who have followed this approach to gain days on the late calvers and have quoted to me conception in the low 30’s% to low 40’s%. This is not a great conception rate but those that do hold do gain plenty of days.

Autumn calvers will be drying off soon so you should begin planning for calving. What is colostrum quality like? Do your cow’s milk as well as you expect post-calving?

In the last three weeks pre-calving energy in the diet should be 11 ME and crude protein 14–16% in the diet. Don’t forget about body condition. Aim to calve at body condition score 3–3.25. Too thin or too fat will have negative effects and too fat arguably greater negative effects. Most autumn calving cows don’t calve too thin, but some are too fat.

For spring calving cows now at the start of breeding, you would expect the lowest body condition – 2.5/2.75. However, on a rising plane of nutrition of quality grass and now at peak intake or approaching peak intake. Average cover management is essential to realise the potential.