Irish Independent - Farming

It’s catch-up time but heat is on to get dairy cows out

- DAN RYAN

AN improvemen­t in soil temperatur­es has brought relief to most dairy farmers as they see an opportunit­y to get cows outdoors. Yet many farmers are still faced with keeping cows indoors at night until grass covers sustain a normal grazing rotation.

Supplement­al concentrat­es with forage extenders have been the key to maintainin­g herd health on many farms where silage supplies were limited and the quality of purchased silage was poor.

However, there are many farms where low cost milk production systems did not see preventati­ve health measures put in place. These herds are faced with the stark reality of an inordinate­ly high percentage of non-cycling sub-fertile cows.

Milk production has been significan­tly reduced in grassbased spring calving herds this year.

The normal peaks in the lactation curve will not be achieved in herds where a setback was felt due to a lack of interventi­on to meet the needs of cows when they were dry and in early lactation periods.

The lower peaks in milk production potential will enable these herds to achieve compensato­ry gain with a flush in grass growth in the weeks ahead.

It is essential as a breeding programme begins that the excess highly-degradable protein in the burst of grass growth is managed from a dietary perspectiv­e. The typical scouring effect where blood ureas increase is associated with impaired reproducti­ve performanc­e.

Egg quality for cows being bred over the next eight weeks has already been decided by experience­s of the herd previously. It is essential that you optimise the opportunit­y for egg quality by minimising stressors in the herd prior to the breeding event.

Lameness, mastitis, pneumonia, restricted feed intake and quality have to be avoided.

There is a significan­t financial cost when a high submission rate is associated with a low pregnancy rate. Focus on maintainin­g herd health in an optimal state for the next 12 weeks, which will dictate your calving pattern next spring.

Heat detection will be the big challenge on farms in the immediate future. Indeed, there has been a significan­t increase of reported injuries to cows because of bulling events indoors. Cows would normally be outdoor on a full-time basis by mid-April.

As herd size has increased, detecting heats has become a bigger challenge. Farmers do not have the time nor the desire to watch cows for bulling events. It is unfortunat­e that heat detection rates are still averaging 65pc for the first three weeks of the breeding season. If this is the case on your farm, there is an opportunit­y to make a financial gain of €8,750 in a 100-cow herd for the first three weeks of the breeding season.

This should incentivis­e farmers to think “smart” about optimising the opportunit­y for cows to express signs of heat and facilitate accurate detection of these heat events.

Farmers have been inundated with new aids to improve heat detection. The greatest danger with these aids to heat detection is that they portray an ability to remove your need to spend time watching your herd for signs of heat.

To date, I have not experience­d any heat detection aid that will remove the need of farmers to spend time watching for signs of heat.

Remember, there is a financial gain of €250 for each heat event accurately detected. The danger of many detection aids is the percentage of inaccurate heat events presented and secondly, those missed heat events.

The first three weeks of a breeding season is an ideal opportunit­y to introduce proven genetics using AI. This will improve your herd profits. It will also reduce the risk of injuries to stock and teaser bulls, when 5pc of the herd will present heats on a daily basis.

Identify your problemati­c breeding cows now with a pre-breed scan. This gives you an opportunit­y to get these cows presented for AI at the beginning of your breeding programme. It will also maximise the number of opportunit­ies to get these cows in calve over a four-week breeding period.

In conclusion, minimise stressors during the breeding before your breeding season begins. Finally put in place a heat detection system which optimises the opportunit­y to achieve an accurate 90pc submission rate for the first three weeks of the breeding season.

Dr Dan Ryan is a bovine reproducti­ve physiologi­st and can be contacted at www.reprodoc.ie

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