May 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.

Plan-Mark the following dates in your diary and have an action plan at each date. This will maximise the number of matings each cow will get. 

 

COWS

Pre breeding.

If you have been heat detecting pre-breeding get the cows not yet shown heat calved 35 days checked by your vet. Otherwise put forward the cows that have had milk fever, retained afterbirths, severe mastitis, digestive issues and those with discharges to be checked by your vet. 

 

Key point: Get cows not yet shown heat calved 35 days checked by your vet.

 

1st 3 weeks of the season 20th April – 11th May

1. Tail paint all cows twice a week in normal weather e.g. Monday and Thursday.  In wet weather you will need to increase this. Clipping the hair on the rump allows the tail paint to be removed easier during mounting. 

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 

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. 

 

Key point: Act immediately if not meeting these targets as early intervention is the Key. At the end of the 3 weeks all cows calved 30 days not bred need to be examined by your vet. This will give those cows an opportunity to have 3 matings before the season ends.

 

2nd 3 weeks of the breeding season

This is the 3 weeks where the game is won or lost.  Heat mounting activity is halved.  Therefore heat detection has to be doubled in intensity compared to the 1st three weeks. Many herdowners  this spring complained of a lull in calving-Avoid the lull in 2016.

 

How do I increase my heat detection intensity?

Get a vasectomised Bull fit him with a chin ball -A male will always increase sexual activity!

Top up tail paint 2-3 times a week-avoid any lapses.

Put on scratch cards.

Check cows last thing at night in the field and be more vigilant at the morning milking.

Synchronization and fixed timed AI for those calved 30 days not shown heat.

 

Maintain Energy Intakes

Cows

It is crucial to maintain energy intakes during the breeding season and to match input with output.  In inclement weather when intakes are reduced or when grass is in short supply it is prudent to supplement in the breeding season. A medium sized cow producing 25 litres of high solids milk needs 1-3 Kg concentrate. 

 

Heifers

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; and clearly maintaining dry matter intakes during the early pregnancy period by avoiding sudden grass shortages is critical in achieving a high pregnancy rate.

 

Key point: It is crucial to maintain energy intakes during the breeding season.

 

Heat Detection Aids

Apart from tail paint, scratch cards and the vasectomised bull are excellent, and in most farms all 3 can be used.  

 

Vasectomised Bulls

A vasectomised bull is absolutely superb in detecting heifers and cows in heat. Start him off with heifers in a paddock first, as they are of similar size to himself and he will get trained easily without getting hurt. 

 

Then 4-5 weeks into the breeding season when we have 1-2 cows coming on heat daily we can introduce him to the cows. Introducing him to the cows with too many cows coming on heat each day (3+) will probably result in him getting hurt unnecessarily and then we will not have him available when needed.

 

Always fit a vasectomised bull with a chinball harness. Keep the chinball topped up regularly with chinball paint only. Shake this paint exceptionally well as it is in a heavy oil base. Change the colour every 3 weeks-red, blue or green.

 

 

It is the markings on the back of the cow that the bull makes when mounting her on standing heat that you will AI on. Note a young bull can be following a cow for 24-36 hours with some body marks, watch these carefully and then you will see when she stands the marks will be on the back.

 

 

Scratch cards

Prepare rump by brushing or combing the hair. Ensure dry, clean rump and all loose hair removed. Avoid clipping as we need hair to stick the glue to. Apply midway between the rump and the pins on a high point in the spine, apply perpendicular to the spine.

 

 

The cards come in different colours-red, green and yellow. When the heifer is on heat the card will go from a silver to colour. In cows all the silver colour will be removed, however in heifers you may just have the entire centre strip removed. With a lot of activity a lot of the colour will be removed and the card will appear white. Reapply as necessary, should last 2-3 weeks weather dependent. 

 

Maiden heifers

In week 1 of breeding you should have 1/3 of the heifers bred. If you have achieved this you know the heifers are cycling and you are picking them up. Secondly you can be very confident injecting the remaining 2/3 that is not bred with a dose of PG (e.g. Estrumate, Lutalyse, Enzaprost, Cyclix) on day 7, 8 or 9. 

 

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. The advantage of this is that all the heifers are bred in 12 days and the repeats will be together which will aid heat detection.

 

In large groups of heifers where you are letting off a bull after one AI, it is still beneficial to go in with the PG injection after 7 days. However watch for the 2-4 days the bulk of the repeats are coming and AI as well to avoid the bulls being overworked and reduced conception rates.