Eltham Vet
Eltham Vet Services is a 10-vet practice that has served the farms and family pets of Central and South Taranaki with distinction since 1937. For your pet’s healthcare & your peace of mind contact or visit us.
This is the first issue of the newsletter since the start of the millennium where Al hasn’t graced us with an opening introduction. It is left up to me to fill the role from now on, hopefully I don’t disappoint, however I do warn those cricket tragics out there you will find very few cricket references from now on.
Those of you who have rung through to the office in the last few weeks may have heard a familiar voice on the other end as we have welcomed back Alex Rowlands from maternity leave to the reception staff. We are very excited to have her back on board, even if she comes with the obligatory daycare virus every other week.
In this issue you will also find the Dry Cow Consult form as we prepare for the end of another season. It’s amazing how quickly drying off creeps up on people. The VCNZ (vet council) are beginning to crack down on unwarranted use of whole herd dry cow so for those of you wanting to treat your whole herd there will likely be a few more hoops to jump through to do so. You will find more information in the article below.
As well as increased compliance around dry cow antibiotic therapy, we are also seeing more required for your annual farm review with the introduction of farm efficiency parameters. To include the Fonterra Insight Report into your Annual Farm Review (or Animal Health Plan) we will require you to renew our access to your Farmsource account.
That is why along with this newsletter and dry cow form you will find both the Minda/CRV and Farmsource permission forms, regardless of whether you think you have signed them before, please sign and return them to the front office to save us from having to chase you up for them again and again. It’s as simple as ticking a box on a piece of paper!
As we were about to go to print with this newsletter we received the sad news about the passing of Dennis Jacobsen. He was a valued member of Eltham Vets for many years and a favorite client of the staff who will remember him for his cheery attitude and the love he had for his cows. Our thoughts are with Carl and the rest of his family through this tough time.
Leon Christensen
With the increasing pressure being placed on reducing antibiotic usage in the food industry we are constantly having to refine our prescribing practices with whole herd dry cow antibiotic therapy (DCAT) under real pressure.
It is no longer ok to keep relying on whole herd DCAT as a bandaid to make up for other shortcomings in mastitis management. In order to be prescribed whole herd DCAT you must show you have made a plan for how to improve udder health and reduce dependency on antibiotics and that you are following through with it.
We are taking a practical approach to reducing dry cow usage and our recommendations are around relying on proper dry off techniques and teatsealants as this gives better protection at calving etc but whole herd dry cow will still be a useful tool for those farms who require it.
Herd testing and bulk tank SCC records are required for us to be able to fulfil our legal obligations in regards to a prescription consult. Please sign the forms at the clinic to give us 3rd party permission or print off your records and bring in with your dry cow form.
Drycow forms need to be returned AT LEAST one week before you require your drycow to give us time to undergo a proper consult.
Thank you for your consideration.
Weighing systems and weigh scales are essential for good heifer management. Poor growth in calves has long lasting effects and can result in poor reproduction and production in the 1st and 2nd years of lactation. It can be hard to make up for poor weight gains as heifers get closer to mature age so maximising weight gains before the animals 1st winter will help ensure dairy heifers are hitting target weights at calving. Regular weighing can help achieve targets. Good practice for weighing is a minimum of every 12 weeks and younger heifers can benefit from monthly weighs because the necessary growth rates are a higher percentage of body weight at a young age. If heifers fall behind weight early, it can be difficult to get them back on track. To achieve target weights heifers should double their weight in the first 3 months of life and double it again over the next 7 months. Regular weighing can help with early disease identification as a drop in weights or weight gain can be the earliest indication that disease is affecting your young stock. Weaner stock can be affected by a number of diseases including thiamine deficiency, facial eczema, intestinal or lung worms, pasturella, yersinia, CUS and BVD.
Knowing calf weights is important for an accurate worm prevention drench program. Some drenches have minimum weights and should not be used in smaller calves as they can be toxic. Drenches should be dosed to the highest weight of the animal in the mob. Mobs with large variation in weights should be divided into smaller mobs by size to avoid overdosing smaller calves.
If you need help weighing your calves, we have scales for hire. We can also send a veterinary technician who can come out and assist with weighing and recording to make the job as stress free as possible. Vaccination and drenching can also be done at weighing. If you are concerned about your animals growth rates or weights or there are signs or scours, poor coats or coughing please contact the clinic to talk with a vet.
If you think its hot, then your cows think it is VERY HOT! Cows work best at a temperature of around 15-16 degrees which is much lower that what we are currently experiencing.
Heat stress is defined as a disruption to thermoregulation and the earliest sign we see in cows is an increase in respiratory rate. Cows transfer heat to moisture in their lungs and breathe out heated water vapour. Sweating is not an efficient mode of cooling in the cow as they don’t have many sweat glands. The amount of heat stress depends on a huge variety of factors, such as exposure to sunlight, wind strength, water quantity and quality, genetics, size, skin colour, level of milk production, feed quality and composition, animal density and the list goes on.
Cows will avoid fibrous feeds if they can, preferring feeds such as turnips, chicory and clovers. Dry matter intake can be reduced by up to 25% as cows will know the fibrous feeds increase heat production in the rumen and this is compounded by a reduced appetite. Processing this heat comes at a further expense, requiring the cows to divert energy away from making milk to expel excess heat and induced inflammation. This can mean heat stressed animals have a reduced immune response, and hence are more prone to infections including mastitis.
Techniques to combat heat stress include supplying ample fresh water and provision of shade (natural or artificial). Cows may increase their water intake by 50% during heat stress, which compensates for losses from increased respiration rates and sweating. Good access to water immediately after milking is crucial. Sprinklers in cowsheds can be effective but it must be heavy droplets, so it wets and drops off the cow, taking heat with it. It is most effective when combined with fans or natural breezes. Sprinkling cows lightly, with poor air flow can worsen heat stress by causing a hot and humid environment. Severe heat stress can be managed by hosing cows with cold water and ideally increasing airflow around them to help increase evaporative cooling. Stomach tubing cold water can also help. Milking times, ration density, breed selection (Jerseys and Brown Swiss are more heat tolerant) and mineral supplementation are also important factors to mitigate heat stress and can be discussed in more detail at your Annual Farm Review.
I have started hearing the question ‘Have you guys started spore counting yet?’ when out on farm, so it’s about time for us to give you our annual spiel. Most of you will be familiar with Facial Eczema but here’s a quick recap;
Facial eczema is a disease caused by a toxin that is produced by a fungus. These fungi grow in dead plant material at the base of pasture. Warm and wet conditions allow the fungi to grow and so we see facial eczema in mid to late summer and autumn. When the spores produced by the fungus are ingested, a toxin the spores produce causes damage to the liver as well as causing sensitivity to sunlight and sunburn, especially on unpigmented white skin.
The disease can have devastating effects on cow health, production and future reproduction. There is no treatment available which means prevention is essential. Facial eczema is prevented by dosing animals with zinc which binds the toxin and reduces its toxicity to the liver, and/or by spraying pastures with fungicides to kill the fungus before spores can be produced.
Knowing when to implement your prevention plan is important because it is a costly exercise if you get it wrong. You will all be aware we do regional spore counting, however these are only a snapshot of the area and can’t be relied on specifically for your farm and grazing system, if you are concerned about your farm or an area of the farm we recommend doing spore counts on your property. Its $20 per sample and gives you exact info on what is happening on your property. High risk areas include paddocks shaded from the sun and wind as they are ideal areas for fungus growth and spore production as they are more likely to be warm and damp.
Because prevention is so important, it is essential that you are doing it right. If your zinc level is too low, you will not get any protection from the zinc and if it’s too high zinc can be toxic. Trial work done in 2014 showed that around 70 percent of cattle did not have enough zinc to protect against facial eczema. Treating via water alone tends to be ineffective.
Therefore to prevent Facial eczema you need to know how much zinc your cows are getting. Testing your cows once you have started supplementing zinc is the only way to know if you are giving the right amount. This is as simple as bleeding 10 mixed age cows 2 weeks after you have started your full rate of zinc supplementation. Testing costs around $12 a cow so it is very cost-effective way to make sure you are doing everything you can to avoid facial eczema in your herd.
If you have any further questions or are keen to have your cows zinc tested, then please don’t hesitate to give us a call.
Imagine you scan (or get your milk test results or see how many cows are coming up empty on your collar program) and your empty rate is higher than you’d like. What do you do? Time and again we hear people say something like “we always used to get less than 10% empty but now we’re always up around ….%, what’s happened?” or “we got heaps of bulls in this year but it hasn’t made any difference” or “I THINK it must be the heifers, maybe I should put them on once-a-day for mating”.
Just recently I was out scanning a herd and the farmer, being a little disappointed with his empty rate, asked if he should put his heifers on once-a-day around mating next season. The first question to ask is, how well did his heifers perform this season and in previous seasons? His pregnancy rate in the herd overall (the lower line) vs heifers (higher line) is below. It was a similar picture previous seasons also.
This graph is from MINDA. You can see clearly that his heifers got in calf very well, better than the whole herd average. Based on this it would make absolutely no sense to put his heifers on once-a-day next mating.
Another common comment is about bull mating. People often wonder whether the bulls let them down, or on the flip side, whether they should have done less AB mating and had the bulls out for longer. One farm I scanned recently felt like they had a good AB mating but their bulls weren’t very active. We can check the fertility focus report to see how well the bulls performed. Here is an example.
“Performance after week 6” is saying, given the number of cows you got in calf in the first 6 weeks, how many cows would we expect a well-managed, fertile bull team to get in calf? For this farm the fertility focus report expected that with a good bull team this farm would end up with a 15% not-in-calf rate, and it ended up with a 15% not-in-calf rate, so that tells us the bulls performed as expected and are not something to focus on to improve the overall reproduction in this herd.
A final example is one that comes up quite often. A farm may have hit its three-week submission rate target of 90% and in fact may have had good submission rates all the way through the AB period, but despite this they end up with a disappointing empty rate. So, what happened? Looking into their mating information we can check their conception rate.
If submission rate is high but conception rate is low that means either cows were cycling and being identified as on-heat accurately but were not holding the pregnancies OR the heat detection was not accurate and semen was being put into cows when they are not really on heat. We can check this by looking at a return service interval analysis.
In this example the farm had good submission rates but a disappointing empty rate as above. Their conception rate was low and you can see that they had a lot of short returns. Only a small number of cows (around 13%) will have a true short cycle so having considerably more than this indicates that semen is being put into cows when they are not really on-heat. This will falsely elevate submission rates but you obviously aren’t going to get cows in calf putting semen into cows when they aren’t on heat.
It is well worth making some time to sit down with one of the vets and go through all this in a repro review if you’re disappointed with your empty rate. Otherwise, where do you start to try and improve things? You could very easily be barking up the wrong tree and waste time and money trying to fix the wrong stuff.
Eltham Vet Services is a 10-vet practice that has served the farms and family pets of Central and South Taranaki with distinction since 1937. For your pet’s healthcare & your peace of mind contact or visit us.
