Fertility and The Dairy Vet Flashcards
Compare these 2 lactation curves
Left – average UK heifer. Peak around 30L per day, about 60-80 days in milk and then gradually decline
Right – peak comes earlier, 40-50 days in milk and peak is higher, higher yield
So managing repro in heifers compared to cows is different
How efficiently is the farm making use of its facilities?
calving event and milk production, calving, steep rise in production and then decline
If you know herds fertility performance e.g. noticing heat, can start to imagine what would happen to a place in the herd over time and start to think about how it fits as a whole herd
What is sufficient rate?
The amount of heats they can detect
Define conception rate?
how much leads to a pregnancy
What do we use subission and conception rate for?
Can use the SR and CR to estimate the total production – can use the data to apply to other herds and work out what their output would be
What do we use to calculate the cost per “day open”?
Fertility cost calculator
£2-3.50 per day on the calving index
Why do practices need rely on fertility for their business? (3)
- Other sources of income that are getting tougher for farm vet income, e.g. TB testing as the amount vets get paid for it is getting less – puts more pressure on other stuff such as fertility
- Lay people and paraprofessionals providing services that used to be vet roles such as scanners, trimmers etc.
- Farmer also more skilled at ill cow cases and dealing with it
Can you forsee any threats to the fact vet practices rely on fertility visits? (3)
- Paraprofessionals – other people competing to deliver this
- Supermarkets and contractors
- Brexit
How can we help farmers minimise non-pregnant days in the post natal check? (5)
- ~14-28 DIM
- Check clean
- Check cycling
- Not always presented
- Commonly done 1-4 weeks after calving, want to check she is clean and cycling. Farmers don’t always present these, some farmers do their own
How can we help farmers minimise non-pregnant days when oestrus not observed? (4)
- >~21d past VWP OR had PD- and no subsequent serve
- Check for abnormal findings
- +/- Treat to reduce days to next serve
- Cows that haven’t been seen in oestrus -
How can we help farmers minimise non-pregnant days during pregnancy? (3)
- 28-60 days after serve
- Pregnant or not?
- If not then treat as ONO
Discuss this example herd
Each line is a cow, S – serve
Top cow – serve quite quickly and served every 21d until pregnant – she will only get a PD
2nd – bigger delay, might have oestrous not observed – big gap between serves
3rd – serve relatively early on, then PD –ve, then probably get presented as ONO next visit
What can we find on a fertility exam?
Both normal? (2)
And abnormal? (4)
Normal:
- Pregnant
- Non pregnant cycling
Abnormal:
- Endometritis
- Ovarian cyst
- Anoestrus
- Other
What do we do if we find a non pregnant?
can try to see where she is in cycle – often will be in luteal phase as this is majority of cycle
What is the milk prgesterone test and how does it work?
- Quick cow-side test available
- Confirms cow is/isn’t in luteal phase/pregnant
- Probably most use for confirming oestrus (low milk P4), if farmer is seeing some signs but isn’t very convinced.
If low – somewhere in oestrus cycle (red triangle on picture on slide before)
What is the bPAG test and when is it done?
Pregnany test
- Offered through milk recording companies
- 60-80d after serve
- ~£3-4/test
Is fertility testing financially viable?
- Overall net benefit in >83% herds
- ~5% herds would lose more than £10/cow/yr
- “Typical” (median) herd would gain £17/cow/yr
- REMEMBER this is just based on identifying CLs and giving PG
- Economic impact of routine fertility visits – often better off doing them than not doing them – weight up vet and drugs vs economic shortfall of not being efficient
You’re presented with a NSB (ONO) cow
- Not seen before, no previous heat recorded
- Cycling normally
- CL present
- Clean on vaginal exam
- Do you treat her with PG?
- What would you need to ask?
- How do you decide?
- Where is she relative to calving, how many days after calving?
- What is the VWP?
- Anyway she could be pregnant – do you have bull on farm? AI and not recorded?
- How many days ago was her last heat if she has had one?
- If she had heat more than 15 days ago – the next one will be in next week or so, so if you have got previous heat that is 15+ days ago, may lead to not doing anything
- Got to discuss with farmer and what the right way to approach this is
- Trading off cost of prostaglandin vs gain of cutting days until her next serve
- Economic benefit to it
- If you prostaglandin lots of cows together, lots of cows to come into heat at same time 3-4 days later
- Generally would prostaglandin almost all of the time with this sort of decision?
What do we want the cows in after the VWP?
In the first 24 days
•Any cow past 21 day mark, give her some drugs and serve 10 days alter – straggler cows brought in – quick aggressive approach. Or give the farmer another 21d to catch them and then enrol them in synch regime
You can use synchronisation to improve bringing cows in after VWP..
- Is this likely to be financially beneficial?
- What are the ethical/other considerations?
- Is the cost of the medicine in the synchronisation regime justified by the benefit they will get back by moving the late first serves to somewhere more acceptable. Will what they earn pay for the cost of the ovysnch for example?
- ? Block calvers want a very tight calving period and this is more important. If they are an organic unit, use of hormones in physiologically normal cows isn’t permitted! Ethical considerations – trading off reducing chance that cows culled early in productive life verses the cost of lots of injection for lots of cows in the herd. Potential residue concerns? Hassle factor
What else should vets be doing apart from ferility on their visit?
•Monitoring health, performance and welfare
If records are available what should we be looking at? (3)
Management records- Calving dates, drying off dates, serves, PD results, lameness & mastitis cases, other diseases, fertility exam results etc
Milk recording data- Recording dates, yield, SCC, Pr and BF
And therefore the:
Performance analysis
e.g. fertility, lameness, mastitis, production
If no data is avilable how can we monitor reproductive performance?
- Reproductive performance
- Key index is number of pregnancies per unit time (i.e. per visit) e.g. 400 cow year-round calving herd, fortnightly visits ideally aiming for 400 pregnancies/year = 400/52 = 7.7/week… so aim for ~15 at each visit
- Remember – the %PD+ (i.e. proportion of PDs presented which are positive) is mostly driven by heat detection
- Perfect heat detection means no negative PDs ever! (as they will always detect cows returning before 30d)
If you have herd that her perfect heat detection, but CR is poor, still wouldn’t have –ve PD as they would always catch the heat 21d later and you wont presented until they get to 28d for a PD – so can have PD –ve performance even if performance and CR is poor. Wouldn’t get presented with many PDs
How can we monitor “other disease” if there is no data monitoring? (4)
•Cases of mastitis in last month?
e.g. 200 cow herd, reports 10 cases last month
= ~120 cases/year = 60 cases/100 cows/year
- Can use same approach for other diseases
- Current bulk milk SCC
Beware – can manipulate which cows contribute
•Prevalence of lameness in cows seen?
But remember selection bias
What is the most common interserve interval length? (What is a good range)
- Most common interval length appears to be 22d
- 19-26d probably most appropriate normal range
Why is there a range in the interserve interval? (2)
- Cycle length not consistent within cow
- Practical implications
