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17th February, 2019


Breeding programmes have now begun on most farms for grass based milk production systems.  The primary focus has to be accurate heat detection with a minimum of 90pc submission rate for the first three weeks of the breeding season.


We need a common sense approach to targeted heat detection rates.  Create a numerical list of cows greater than 40 days calved at the onset of your breeding programme.  Walk through your cows at grass and identify which cows could potentially be at risk of not cycling.  Cows which are lame and in poor condition score are prime examples.  Some farmers reduce the walking distance and introduce once a day milking for these at risk cows.  Prevention has to be the key when one considers that the opportunity cost of missed heats is €250.  Cows which have had either twins, difficult calvings, milk fever, displaced abomasums, lameness pre or post calving, ketosis, mastitis or retained afterbirth are all at risk of impaired resumption of heat cycles post calving.


It is essential that your animal health vaccination programme is up to date with continuous monitoring for risk of diseases such as IBR, Johnes’, Liver and Stomach Fluke.  The risk of BVD should be minimal if biosecurity measures are in place and BVD tagging of calves has resulted in no positives in the past two years.  Unfortunately, we do not have compulsory removal of BVD positive calves from farms.  This disease could be eradicated if this measure was enacted for suckler herds where profit is highly dependent on the calf.


Having created a numerical listing of cows in your herd, identify “at risk” cows for reproductive assessment by scanning.

Your vet can then address potential reproductive disorders rather than waiting four to five weeks into the breeding season.  The financial costs of missed heats far outweigh the cost of a prebreed scan.  It is worth noting that in excess of 30pc of cows with reproductive disorders cannot have same associated with previous recorded events.  Remember, the reproductive tract is an excellent biomarker of herd health which can be accurately assessed using ultrasonography.


With the emphasis placed on heat detection as a primary driver of farm profit, there has been an onslaught of heat detection aids.  However, many farmers have become dependent on the use of this technology as the primary driver of breeding cows.  You need to spend time with cows while grazing to identify cows with milk signs of heat, cows “at risk” if not showing visual standing heats and those cows requiring veterinary examination.


Dairy herd expansion has also resulted in new entrants which have had no previous experience in dairying in many instances.  Dairying requires active input seven days a week.  Technology such as robotic milking will not remove this requirement.  A client in dairy was recently asked if he could go away for a holiday having installed a robotic milker.  He responded by saying “Yes, if I could get a return flight on the same day”.  You will get both false positives and missed heats with any of the automated heat detection systems available on the market.


There is a risk of either introducing infection or causing embryonic death by inseminating cows when they are not in heat.  Automated heat detection systems are an aid to visual heat detection, whereby you spend time with the cows at opportune times on a daily basis.


Many new entrants to dairying expect a lifestyle which enables a “five day week approach to herd management”.  Technology can be an excellent aid to improved health and welfare of the dairy herd. However, you need to be an excellent stockman to reap the rewards from this potential.  Dairying now moves into an area where the consumer ultimately demands assurance of the health and welfare of cows used for food production.  It is surprising that any new entrants to the industry do not undertake a formal training course in dairy herd management.  There are responsibilities associated with the health and welfare of animals under our supervision.


It is ultimately in the best interest of the farmer to maintain optimal health of dairy stock at all stages of the production cycle.  Accurate heat detection and its associated fertility are primarily dependent on your management during the transition period described by the dry cow period and the first two weeks post calving.


Best of luck with heat detection in this AI season which is the primary driver of farm profitability.  Remember, that technology can be an excellent aid to management but will not replace good stockmanship skills.


Dr. Dan Ryan is a cow fertility expert and can be contacted at


Article written by Dr. Dan Ryan in The Farming Independent May 6th 2014.