One of the advantages we have in Ireland is the ability to produce milk off grazed grass. The lower costs involved should enable Irish dairy farmers to produce milk profitably, especially so in times of low milk prices.

When the weather behaves as it should, maximum grass availability should match peak milk yields in May/June.

This year down here on the south Cork coast, the seasons are after somersaulting, with dry warm weather in April/May being followed by cold, dark wet weather in late May/ June.

The change in weather has resulted in grass of greater variability than would otherwise be the case. The more challenging weather conditions highlight specific issues that may need closer attention for grazing dairy cows.

Energy deficiency

Less sunshine and heat means less energy in grass. While cows may compensate for this by eating more grass, neither the dry matter intake (DMI) nor the energy density of this wetter grass is comparable to grass that was available only a few weeks ago.

As a consequence, many of our clients are feeding higher level of concentrate rations than anticipated. More clients would seem to be adding supplementary ration feeding over the last number of years and continue to feed it during some of the traditional summer months.

Magnesium deficiency

In some places, there has been rapid grass growth, oftentimes as a delayed response to earlier nitrogenous fertiliser application. This grass, combined with cold nights, has led to an increase in the incidence of call-outs to cases of grass tetany.

I have treated more cases in the last week than in the previous three months. Feeding increased levels of cal-mag ration and/ or pasture dusting is strongly recommended.

Fibre deficiency:

There have been several instances of pica reported to the practice over the course of the last few weeks. This is where cows eat stones on the road or root at ditches for earth, etc. Pica may be an indication of several things: phosphorous deficiency, salt imbalance or it may be an indication that the diet may be lacking in fibre.

A lot of grazing pastures consist of homogenous grasses which are well fenced off and in these circumstances, cows may not have access to adequate fibre. Having baled silage/straw available would be recommended, as well as mineral supplementation where indicated.

Lungworm:

The good weather in April and May helped the proliferation of lungworm, with some cases seen in early turned-out calves. Lungworm can also act as a trigger for virus activation in cattle. The inclement weather may also chill such cattle, making them more prone to respiratory disease and pneumonia in particular.