June 2015 Fertility and Breeding Notes

Doreen Corridan MVB MRCVS PhD 

Munster Cattle Breeding



1. Ensure enough bull power, this is crucial for compact calving, 1 young bull needed per 15-20 empty females. Our female numbers are increasing and our stock bull numbers have not increased accordingly.
2. Check his easy of calving index. In AI we are finding that for maiden heifers you need less than 2% difficult calving figure and for cows 4% or less. The reliability is lower is stock bulls and to be sure you need to try them out in cows in their first year for security.
3. Buy him/them two months in advance of when needed, to allow for acclimatisation and disease testing.
4. Bulls are very susceptible to stress and sudden nutritional changes.
5. Footbath him/them on arrival to avoid introduction of Mortellora and pair him with another animal.
6. Vaccinate him/them with whatever the herd is being vaccinated for.
7. Get him/them fertility tested by your vet.
8. Monitor him/them throughout the breeding season. Young bulls need to be fed during the breeding season.
Maiden heifers calving ease sires.
It is crucial to use easy calving sires on maiden heifers to maximise their reproductive and production performance and to allow them remain in the herd. 
The genomic calving figure is not as reliable as the fertility and production figures and should not be used in selecting bulls suitable for heifers.  Only use bulls with an actual calving survey and where the reliability is over 90% and less than 2% calving difficulty e.g. bulls like OCP, SLP, HDJ and CFF. More bulls will come available when ICBF will have analysed the 2015 calving’s. The Angus bull KYA is 99% reliable with a calving figure of 0.9%.
Key point: Use easy calving sires on maiden heifers.  For AI this means bulls of 90% reliability and less than 2% calving difficulty.
Maiden heifers
1. Vaccinations
Complete all vaccinations prior to breeding season; BVD and Lepto are licensed to be administered together.
2. Live Weight and Body Condition Score-the two factors influencing heifers coming into heat and their subsequent conception rates.
Ensure heifers are 330Kg+ and their BCS is 3.0-3.25 at mating.  Heifers over 400Kg can have reduced conception rates.
Poor silage and 2Kg of concentrate can limit weight gain to only 0.3Kg/day! On the following regime heifers can gain 1Kg per day:
■ Heifers on target/Grass Scarce need 2 Kg of concentrate 
■ Heifers on target/Grass Plentiful grass should be sufficient 
■ Heifers below target/Grass Scarce need 3-4Kg of concentrate
■ Heifers below target/Grass Plentiful need 2 Kg of concentrate
Avoid holding back light heifers for 3 weeks, breed them and work with them throughout the year to maximise their gain each month.
It has been demonstrated that  a short-term (two-week) reduction in energy intake during or after AI severely reduces embryo survival rate in heifers. Maintain dry matter intakes during the early pregnancy period, by avoiding sudden grass shortages, is critical in achieving a high pregnancy rate.
3. Heat Detection Aids
A vasectomised bull is absolutely superb in detecting heifers in heat. The next best system is scratch cards see section on heat detection.
Best heat detection aids for heifers
4. System for heifers to maximise the number in calf in 4 weeks.
-Get heifers used to coming into the yard each day. Feeding them 1Kg of concentrate each day in yard is a great encouragement to get them in easily. Each morning after milking get them into the yard, do your heat check, AI what is on heat and replace any cards that need to be replaced or top up the chin ball.
I. If you begin on Mon 20th April, get all the heifers into the yard and apply scratch cards. The day needs to be dry, watch the forecast- it may be necessary to apply the cards the previous week if there is a wet forecast. AI each day what is on heat and remove the used scratch cards.
II. By Mon 27th April you should have 1/3 of the heifers bred, if you have not a 1/3 bred either the heifers are not cycling or your heat detection needs improvement. 
III. The 2/3 that is not bred should receive a dose of PG (e.g. Estrumate, Lutalyse) on Mon 27th or Tues 28th or Wed 29th. Plan ahead as the injected heifers will be on heat 48-72 hours later, so ensure that you are available for heat detection and drafting.
IV. Breed the heifers at detected heat; by 4th May all heifers should be bred once. Now we have two choices either pick up repeats or let them off with a stock bull. 
Cows-Planning for the 2015 breeding season
Pre Breeding 1-20th April
1. Ensure all vaccinations are completed
2. Ensure cows adequately fed and the intake matches the output. 
Cows need to be adequately supplemented in difficult grazing conditions and where yields are over 20-25 litres.
3. Tail paint all cows or put on a scratch card on 1st April. Read the tail paint or scratch card on the 20th April prior to the breeding season.
Tail paint is an excellent heat detection aid for mature cows
4. 20th April cows not detected in heat need to be drafted out and treated by your vet. If you have not done a pre breeding check pull out the following cows for examination-difficult calving’s, retained afterbirths, milk fever, ketosis, severe mastitis, visible dirty discharges and those without any scuff marks from being in heat. This treatment will give these cows an opportunity of an extra heat to go incalf.
First 3 weeks of the season 20th April – 11 th May
1. Tail paint all cows twice a week in normal weather-Monday and Thursday.  In wet weather you will need to increase this.
2. Herd size will determine the level of mounting and the ease of heat detection
4-5 cows on heat/day each cow has 50 mounts tail paint and reading at both milking’s 
2-3 cows on heat/day each cow has 25 mounts tail paint and reading at both milking’s with a heat check last thing each night 
1 cow on heat/day each cow has 15 mounts need a vasectomised bull or scratch cards.
3. Targets
30% of your cows bred at end of week 1 the 20-26th April,
60% of your cows bred at end of week 2 the 27 April -3rd May
90% of your cows bred at the end of week 3 the 4th -10th May. 
Act immediately if not meeting these targets as early intervention is the Key. 
Herd Health
Are you experiencing less than optimum fertility or milk solids production? Join the Dairygold bulk milk testing programme now. IBR, Lepto, Neospora, Salmonella, Liver Fluke, Lungworm, Stomac worm etc. Get results that may help you with the 2015 breeding programme. Call Patrick Kelly 022 43228.

1st June 2015 Breeding is 10th March 2016 Calving


3rd 3 weeks of the Breeding season

For those who began breeding on the 20th April, we are now in the 3rd 3 week period. This is the March calving period.  The objective is to maximise the number of cows calving in March and avoid April calvers in 2016.


Increase Intensity of Heat Detection

As you have fewer cows coming into heat now, there will be less mounts for each cow on heat. Therefore you need to increase the intensity of heat detection:

A Vasectomised bull is excellent for this job right now

Keep tail paint and scratch cards topped up.


More vigilant at milking for tail paint gone or scratch cards scratched.

Check cows last thing at night.

Use records to focus more when repeats are due.

Scan cows to focus on those not yet pregnant.

Synchronisation and fixed time AI for those not yet bred calved 35 days and those empty at scanning.


Key point: To compensate for fewer cows in heat and less mounts, step up your heat detection.

This is an excellent programme for those cows calved 35 days not bred and for those scanned empty. It is far superior to just letting off with the bull and hoping for the best. It is extremely cost effective the average cost of the programme is €30 approx., the benefit is time gained. Each 3 week gain in the breeding season is estimated to be worth €230. 


The key points are

Cows need to be clean and in a rising plane of nutrition

The dates and times must be followed carefully-note the PM injection on day 9.

High fertile semen and an experienced technician are required for maximum results.


High Fertility and Short Gestation Sires

The use of AI sires that are in the top 1% of their breed for gestation length will reduce down the number of days pregnant and result in cows calving on time or before time. Sires that have been shown to be superior in semen fertility and are above average in ensuring cows go in-calf will also maximise the number calving in March. The following are the shortest gestation bulls with the highest semen fertility that are available from the Munster stud. It is important to note calving difficulty as cows that have had difficult calving’s will take longer to go incalf that those with uneventful calving’s.

Key point: Using short gestation bulls with low calving difficulty will help you reduce your average calving interval


Maiden Heifers 2014 born

Watching for repeats is the key if you are continuing to use AI. Scratch cards and a vasectomised bull are superb for detecting repeats. When a number of them are served more than 30 days, it helps to get them scanned and then to concentrate on the heifers that are empty. The empty heifers can be ran with the herd of milking cows, making it easier to detect them as you have just one bunch to concentrate on.


If you have synchronised your heifers and now have a stock bull with them ensure you have fertile bulls and an adequate ratio. The period in which the repeats are due from the synchronisation it is worth watching for repeats and if the bulls are overworked, AI for 2-3 days as well.


Bull Fertility

In all cases 

Lame or injured bulls need to be rested and replaced

Monitor his performance - chin ball is useful here

If you are using a bull in his first season the following is important

Get him fertility tested by your vet

Ensure he can actually serve prior to allowing him to run with cows or heifers

Mate him to females a similar size or smaller than himself

Feed him during the breeding season and prevent weight loss in excess of 50-80Kg

Have a ratio of 1:15 empty females


If you are using a bull in his second or subsequent season the following is important

Work out his conception rate from the previous year- there are a lot of sub fertile bulls on farm.

Have a ratio of 1:20-25 females

If running multiple bulls rotate them 24 hour on and 24 hour off for maximum performance

In their 24 hour off period they need to be fed and rested away from females


2015 Born Heifers 

Monitor growth rates in your 2015 heifer calves now either by weighing scales or weigh band. Calves should be gaining a minimum of 20Kg per month, early February born heifer calves will weigh 120Kg now. Younger heifer calves born in March and lighter heifer calves will benefit from being grouped and fed separately. Feeding these calves 1-2 Kg of concentrates a day in addition to grass will increase growth rates, depending on grass availability and quality. Many herdowners cannot group calves at housing appropriately, so group them now at grass and have a more even group at housing.


Discuss with your local Dairygold representative/vet an appropriate parasite control programme for your 2015 calves. Fresh dung samples submitted to the laboratory within 48 hours of sampling gives a good indication of the worm burden. Calves start to ingest gut worm as soon as they begin grazing. Lungworm infections are less predictable than gut worm, initial signs are slight cough on exercise to severe coughing. Take steps now to prevent resistance developing on your farm:

Regular monitoring and appropriate treatment-avoid under dosing.


There is a tendency to overuse Ivermectins as they are cheap and convenient, rotate with the white drenches and levamisole products.


It is now recommended that animals are held on the ‘dirty’ pasture for a period of 48 hours post dosing prior to moving to ‘clean’ pastures. 



These calves should have received their Clostridia vaccines by now either Covexin 10 or Tribovax 10, both these newer vaccines contain the sordellii strain not covered by the older Covexin 8 or Tribovax T.  Two doses are required to complete the primary course given 4-6 weeks apart. As with all vaccines, it needs to be stored in a fridge 2-8 0C, administered on a dry day with clean needles, syringes and hands, and adhere to the time between both doses.


Key point: Ensure your 2015 heifers aren’t being held back by parasites or in danger from Clostridia-have an appropriate parasite control and vaccination programme in place on your farm.