Janice recently attended the TotalDairy Conference 2016 in Gloucestershire and here are some snippets of information on the latest developments:
Sub Acute Ruminal Acidosis (SARA)
- Rumen pH is a poor predictor of acidosis in individual cows.
- Volatile fatty acids Valerate and Propionate are much better markers, but not currently available to farmers.
- On average 10% cows are subclinically acidotic at any one time.
- Lush pastures, clovers, WCC and maize silage are all risk factors.
- Avoid rapid changes in feed – the rumen bugs take 10-14 days to adapt to a new diet – be patient.
Improving Immune Function in Dairy Cows
- For many minerals feeding too much is as bad as feeding not enough.
- Vitamin E, selenium and copper are the most important for the immune system as they are anti oxidants.
- We may need to review levels, especially in cows that have no access to grazed grass.
- Cows with inadequate Selenium usually have high SCCs, high levels of clinical mastitis, severe mastitis cases that last a long time.
- Target blood selenium levels are 0.16 – 0.18
- Plasma levels of vitamin E drop sharply around the time of calving. There is evidence to say that supplementation levels should be increased in the 2 weeks prior to calving – but longer than this it can actually make things worse. Difficult to do this in practise.
- Copper – only supplement if deficiency/lock up has been confirmed on your farm.
Milk Fat Depression
- There is a seasonal pattern of milk fat and protein that happens worldwide – in UK they are high in winter and low in summer – day length related.
- Focus not on % but on kg fat produced (unless your milk contract penalises hard).
- Diet is only 1 factor – remember the others which are breed, milk yield, stage of lactation, disease, grazing or TMR, stocking density/gut fill.
- In diet formulation, consider unsaturated fats, fermentable carbohydrates, effective fibre intake, rumen available nitrogen, rumen buffering, presentation of feed and water quality.
- Management factors to consider with low butterfat issues:
- Is the diet being fed the same as the one formulated?
- Are the cows eating the quantity of food estimated?
- Is the TMR evenly distributed along the feed barrier?
- Is the TMR being pushed up regularly so the cows can reach?
Is there always food in front of the cows?
- Are the cows sorting the mix?
- Are the knives in the wagon still sharp?
- Are you over filling the wagon?
- Is the mix over processed?
Good Herd Stockmanship
- Cattle that become agitated when being weighed have lower weight gains.
- Cows gave 5% more milk yield after stockmen were trained to handle cattle quietly.
- Signs of fear and stress in an animal are:
- Tail swishing – speed increases as fear increases
- Head held up to look around
- Sweating with little exertion
- Skin quivering
- Showing whites of eyes
- Ear radar – ears point towards the thing they are concerned about.
- Acclimatise animals to handling and anything they are likely to come into contact with – tractors, machinery, variation of staff, parlour, handling area.
- Cows need to feel safe on their feet – look at all areas on the farm where cows slip/fall and reduce risk.
- It is very important that an animals 1st experience with a new place/piece of equipment/person is a good one.
- Cattle do not forget bars slammed on their heads in a head yoke!
- airy cows that approach people rather than move away have lower SCCs.
- The person who AI’s cattle should not do painful or frightening procedures to the animal if possible.
- Try to do all the nasty procedures in one place (and not the place you AI !).
- Don’t inject cows in the parlour.
- Heavy boned cattle are calmer than fined boned cattle.
- Cattle with a spiral whorl above the eyes are more likely to become fearful and agitated.
- New things are attractive to animals if they are allowed to voluntarily approach.
- We should try to minimise fear in the milking parlour as much as possible – so why do we inject cows during milking?
Good Handling Facility tips
- Ensure there is plenty of light – cows hate dark areas.
- Ensure flooring is sound and non slip.
- Remove distractions – have solid sides to races so that animals cannot see other animals/vehicles on other side.
- Ensure there are no shadows/shafts of light falling across the race within buildings – cows panic when they see them.
- The diameter of the teat orifice increases with age – which is why older cows are more prone to picking up infections.
- Many cases of mastitis are subclinical for a long period before they become clinical. Must focus more on identifying subclinical infections.
- One case of mastitis increases the risk of a future case by 5 times – even in subsequent lactations.
- Work was presented showing that very few clinical cases are acquired during the dry period – it is normally at the point of calving and the first 7 days after! Hence the importance of transition and fresh cow management.
Click for more information on Dairy Herd Mastitis
Selective clinical mastitis treatments
- If you don’t foremilk you will miss 50% of mastitis cases!
- Clinical mastitis detection is based on recognising the signs of inflammation of the udder not on the presence of infection.
- Cannot identify type of mastitis based on symptoms alone – must do bacteriology.
- Some farms are now doing bacteriology on farm to identify mastitis pathogens prior to treatment.
- Up to 40% clinical cases are not growing anything – the bacteria has gone and all that is left is the cow’s inflammatory response the bug has triggered – so no need to give antibiotics in this scenario.
- Around 17% of cases are opportunistic organisms that are antibiotic resistant – so no point in treating these either.
- Only 15% mastitis cases are severe (and usually E Coli or Klebsiella) therefore there is no immendiate medical emergency on the whole.
- If clinical mastitis is identified and cow is sick, a milk sample is taken for bacteriology and she is treated immediately (although antibiotic therapy may be changed 12 hours later when the organism has been identified)
- If clinical mastitis is identified and the cow shows no other signs, then a milk sample is taken and she is treated with uddermint only until the bacteriology result is through.
- Milk samples need to be taken very carefully – the most important step in the process.
- The milk is cultured on a microbiology plate in an on farm incubator.
- 12 hours later the result is read and the cow treated accordingly.
- This allows you to select the most appropriate drug (if required) and not waste antibiotics on cases where no bacteria is present.
- It is normal for the milk to stay abnormal for 4-6 days after mastitis has been identified. Do not start another antibiotic treatment during this time.
- PCR testing of mastitis is not great as you cannot distinguish between live bacteria of the bodies of dead ones – but they do tell you what infection the cow had.
- Practises in the USA that had significant impact on SCC were wearing gloves, milk recording, using CMT tests & clinical mastitis records and flaming udders.
- Find infected cows – treat them or eat them!
Emerging Mastitis Pathogens - Mycoplasma
Mycoplasma is becoming more of a problem with 15% bulk tank results in USA are positive. What does Mycoplasma do to cows?
- Mycoplasma causes runny noses, mastitis (can lead to a big drop in milk), lameness, joint infections, ear infections (calves often tilt head or are off balance).
- Can be spread from cow to cow and via the milk to calves (unless you pasteurise it).
- Bulk tank testing can give you false negatives as shedding patterns are quite variable.
- Culling and/or segregation is the only way to tackle it.
Klebsiella mastitis is also becoming more common and is associated with wood products normally (sawdust/shavings), but can be found in recycled sand too. 30% of klebsiella infections remain subclinical for over 100 days – so need to look at environment and also management during milking in respect of spreading infection to other cows. Klebsiella mastitis doesn’t respond well to most antibiotics. If treating use one with a gram negative spectrum.
Prototheca is an algae not a bacteria, and is found around water.
- Look out for algae on water troughs, spoiled feed, wet areas around yards/housing, flood wash slurry systems.
- No antibiotic treatments are effective.
- Assume it will spread to other cows and manage accordingly.
- Dry up wet areas.
- Don’t warm teat sealants in water before injection
- Have an excellent milking routine.
Predicting Disease on Dry Cow Behaviour
- Cow behaviour in the 2-3 weeks prior to calving can predict within 80% accuracy:
- Milk FeverMetritis
- They are measuring many aspects of cow behaviour and identifying which ones signal problems in cows.
- Need to measure a cows behaviour relative to her cohorts in the same group, as building design/management will impact on cow behaviour too and need to take this out of the equation.
- Calving time can be predicted accurately from lying/walking time and rumination. But if cows spend much more time standing it is an accurate predictor of a difficult calving.
A cow likely to get ketosis will stand for longer, visit the feed trough less often and stand there for less time a week before calving. Visits to the trough is as good a measure as dry matter intake for this condition.
- Cows likely to get metritis will spend less time at the feed trough, more time standing, but will take fewer steps than her peers.
- A cow likely to get a DA will visit the feed trough less, will take fewer steps and will have increased lying time.
- A cow likely to get milk fever will have fewer visits to the feed trough, will spend less time there, will take more steps and have increased standing time, but when she is lying down will tend to turn over from side to side.
- A cow likely to get/have mastitis will have increased lying time, but will tend to swap sides on a regular basis (presumably due to discomfort in the udder).
- These systems are being developed using collars as in the rumination monitoring systems, with an additional receiver system at the feed trough that measures number of visits and time spent at the feed face.
- A computer/smartphone will receive information to alert to issues as per rumination monitoring systems.
- Work is being done on improving the predictions, but 80% is pretty good.
- If we can predict which cows are going to get pre/post calving issues before they calve then we can treat them appropriately to reduce the risk.
Watch This Space! THE NEXT GENERATION OF RUMINATION/HEALTH MONITORING IS ON ITS WAY!
Fertility in Dairy Cows
- Measuring heat detection is easy and important.
- Monitor returns to service - with good heat detection over 50% of your returns to service should occur between 18-24 days after the previous service. However, may need to tweak this as 19-26 days appears to be the more normal range now, and older cows have longer cycles so need to consider this.
- First service submission rate is also easy to check.Write a list of eligible cows (passed their earliest service date) on day one, cross them off as they are served, and 26 days later calculate the proportion of cows that have been served. In an all year round calving herd you should achieve 80%. In a block calving herd you need to achieve 90%.
- Can measure conception rate – the number of services it takes to get a cow pregnant – but don’t just count the services from the PD+ cows!!
- Can measure 21 day preg rate – the proportion of eligible cows getting pregnant every 21 days – need computer programme to do it.
- Target pregnancy rate of over 20% for year round calving herds and over 40% for block calving herds.
- Need to record all services and all PD+