Farm Ireland
Independent.ie

Tuesday 24 October 2017

Wet conditions causing grazing problems

Denis Minogue

The unsettled weather conditions have challenged many farmers over the last few months, including the Derrypatrick herd at Grange. From May 14, cows and calves were grazing the silage area (closed since April 10).

With the breeding season under way, it was essential that cows and calves remained at pasture. On May 14, the yearling heifers and bulls were housed due to a combination of inadequate grass supply and very poor grazing conditions.

Until then, average daily gain at pasture was 1.05kg and 1.43kg for heifers and bulls respectively (Table 1). Grass growth during April and May (<30 kg DM/ha/day) equalled the lowest recorded since regular measurements began at Grange about 20 years ago.

Th rate is insufficient for the Derrypatrick unit, which requires around 70kg DM/ha/ day to meet feed demand.

Pasture covers on a notable portion of the silage area were also quite low (1,700kg DM/ha), despite being closed for over a month. Wet soil conditions on a lot of the silage meant post-grazing heights were raised and cows and calves were moved through paddocks at a quicker rate to prevent damage to pasture.

In total, approximately 30pc of our silage area was grazed before returning to the grazing platform. In late May, once weather and ground conditions improved, post-grazing heights of 4.5cm were reached with relative ease.

Since the end of May, sporadic downpours coupled with wet soil conditions have required close monitoring to prevent any heavy damage to pasture. We grew grass at approximately 80kg DM/ha/day last week. However, it is proving difficult to maintain post-grazing residuals at 4.5cm as a result of variable weather conditions.

The other main problem facing the herd is maintaining grass quality. The feed supply will ultimately determine any silage removal (baled silage). However, any paddocks showing distinct signs of heading will be made a priority for this treatment.

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Topping post-grazing or the removal of some paddocks as surplus grass are two strategies to deal with this issue.

Neglecting these paddocks (by not grazing well or not topping) will limit animal performance later.

Silage was harvested on June 5, five days later than expected. It was necessary to delay the harvesting date as grass yields were low due to poor grass growth.

On visual inspection, there are only two full pits of silage, compared to almost three last year. We are hopeful that opportunistic silage, removed as surplus grass from the grazing area, will help replenish most of the feed required for next winter.

Post-weaning performance 2012

While housed (May 14), heifers were offered high digestibility (72pc DMD) grass silage ad-libitum plus 1.5kg of concentrate/head daily. They were returned to pasture on May 24. The yearling bulls, due to be housed around late June, as per the production system operated, were kept indoors.

They were adapted over 20 days to a barley-based concentrate diet offered ad-libitum (87pc barley, 6pc soya, 6pc molasses and 1pc minerals, plus 5kg fresh silage/head/day).

This means that the indoor finishing period for the yearling bulls will be extended by 20-30 days.

Management details to 11/06/12

• Average farm grass cover is approximately 926kg DM/ha, giving a total of 17 days grazing ahead. The growth rate over the last seven days is estimated at 83kg DM/ha/day.

• The overall farm stocking rate is 2.8LU/ha, which includes 99 cows and calves, 45 heifers, 60 bulls and 25 replacements (including five stock bulls).

• The stocking rate on the grazing platform at present is 4.04LU/ha, which includes a total of 99 cows and calves, 45 yearling heifers and some 25 replacements (including five stock bulls).

• Yearling bulls are currently being offered concentrate ad-libitum plus 5kg of silage per head per day.

• Soil conditions for grazing are currently variable. Sporadic rainfall over recent weeks has hindered post-grazing heights. Monitoring soil conditions will allow you to determine the rate at which stock should be moved through paddocks.

Denis Minogue manages the Derrypatrick research herd at Teagasc Grange. Email: denis.minogue@teagasc.ie

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