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12th December, 2018

PLANNING ON ACCURATE HEAT DETECTION

An improvement in soil temperatures has brought relief to most dairy farmers as they see an opportunity to get cows outdoors by day and night. 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 maintain 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 put preventative health measures in place. These herds are faced with the stark reality of an inordinately high percentage of non-cycling subfertile cows.

Milk production has been significantly reduced in grass based spring calving herds this year. The normal peaks in the lactation curve will not be achieved in herds where a setback was imposed by non-intervention to meet the needs of cows in the dry cows and early lactation periods.

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 8 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 65% for the first 3 weeks of the breeding season. If this is the case on your farm, there is an opportunity to make a financial gain of €8750 in a 100 cow herd for the first 3 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 3 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 5% 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 4 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 90% submission rate for the first 3 weeks of the breeding season.

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

Article written by Dr. Dan Ryan for the Farming Independent 24th April 2018