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.
With December just around the corner, another year has gone by in a blur. I have survived my first year at the helm of Eltham Vets, with the dual role as vet and CEO, I have had to juggle pretending to know how to do two jobs instead of one this year which has been a challenge. Luckily for me, the rest of the team here at Eltham Vets has dug in and done all the hard work in adjusting to life without Al and Joan.
It’s been an interesting year at home and abroad; with farm income streams improving and interest rates on the decline, people appear more positive about the next 12 months. Let’s hope certain incoming president’s planned tariffs and other international policies don’t put a stop to these improvements or start another world war!
To thank all our clients for keeping us in work over the last 12 months we have our farmers BBQ coming up in a couple of weeks and our Christmas ‘turkey’ giveaway. Yes, that’s right, due to demand (mainly by our Chairman Mr. Phil Muir) the turkeys are back. However, as not all our farmers want a turkey, we also have the option of bacon and chocolates instead. These will all be arriving in clinic first thing next month and it will be on a first come, first served basis while stocks last. So, if you qualify for our Christmas giveaway (you will be notified by text) get in early to secure your Christmas day lunch on us.
On the subject of Christmas, the clinic will be shut on Friday the 27th of December this year to give staff a much-needed extended break over this time. We will still have our on-call vet to manage any of your emergency needs over this period but otherwise we will be back to work on Monday the 30th. We will be reminding you all of this closer to the time.
Thanks for your support and a fantastic year of working alongside you and your animals.
Wishing you all a Merry Christmas and a happy New Year.
Regards
Leon
Do you have enough bulls? Do the Maths!
After a long tiring calving, then having to be constantly on your game during AB, many people look forward to when they can put the bulls out so that they can take a bit of a breather. Getting your bull numbers and bull management right is something we shouldn’t take lightly, however. For most herds the bulls will still need to get a considerable percentage of the cows in-calf. Not having enough bulls (or not managing them correctly) risks you getting a nasty shock at pregnancy testing time with a high empty rate. So, lets do the math. People usually do AB for the first six weeks of mating. The NZ average 6 week in-calf rate is 65%, so on average we expect bulls to get 35% of the herd pregnant. The average herd size for our farms is around 300 cows. So, 35% of 300 is 105 cows that need to get pregnant via the bulls. The recommended ratio of bulls to empty cows is 1 per 30 with a MINIMUM of TWO bulls in with the herd at any one time. This minimum is to reduce the risk of infertile or sub-fertile bulls being in with the herd (ie they may be shooting blanks, unable to mount, or have issues serving cows). 105 empty cows divided by 30 is four bulls in with the herd at all times (105/30 is actually 3.5 but we should always round bull numbers up). We need to rotate and rest bulls every 24 to 48 hours to keep them fertile and interested in doing the job. Therefore, we need to double the recommended ratio of bulls so that we have a “half resting half working” set up. So, this herd will need two teams of four bulls, eight bulls in total. This may seem like a lot and the cost of getting this number of bulls in may be high but it works out a lot cheaper than a high empty rate because the bulls didn’t do the job. You may AI for longer or shorter than 6 weeks or your 6 week in calf rate may be better or worse than the NZ average so do your own math. Talking to people about their repro plan it is common for them to be running considerably lower bull numbers than is recommended. People sometimes get away with running less bulls but it is a risky gamble. On the flip side we often hear people saying they think it was the bulls that let their mating down and was the cause of their high empty rate. The fertility focus report has good measures of your historical 6 week in calf rates (which you can use to work out how many bulls you need as above) as well as how well your bulls actually performed and whether they truly were the cause of your less-than-ideal empty rate (if you have one!). We can help you look through this and work it out together if need be. Finally, you should aim to have bulls on farm and set in their teams at least 2 months before they are needed. This allows them time to sort out their hierarchy so that they are not spending time fighting when they should be getting cows pregnant. We want them to be lovers not fighters by the time they are put in with the herd.
Calving Cup Winners
With calving over we can announce our winners of the 2024 calving cup. Johanna took out the cup on 81 points, followed by Jack with 72 points. Hannah ended up taking out the 3rd place on 55 points.
Lame Cow Management Reminder
This season we have noticed an increase in the number of lame cow calls. Lameness is a key animal welfare concern, as well as resulting in significant productivity losses. Researchers have placed the cost anywhere between $200 and $450/case depending on the severity, recovery time, lactation stage and pay-out. Simply speaking, lame cows eat less, and therefore produce less and have a poorer reproductive performance compared to a healthy cow. Prevention is an important part of managing a herd lameness issue. This starts at the paddock, where allowing cows time and space to walk home to the shed allows them to look for stones and place their feet accordingly. At yard entry it is important to limit stones on the concrete. When yarded, cows need enough space for the cows to reshuffle and move. Having the backing gate too tight doesn’t allow cows space to move and puts pressure on them to twist and creates white line disease. Also, other aspects such as milkers entering the yard from the pit causes cows to walk backwards and twist to get away, which allows their white line to open up and cause lameness. Treating these lame cows promptly will reduce their pain as well as preventing further damage such as joint infections. It will also reduce the costs due to production and reproductive loss and reduce recovery time. The core principles of treatment involve picking up the foot, identifying the cause, and removing any underrun hoof where bacteria like to live and exposing these bugs to the air which kills them. Very few cases require antibiotics. The most common lameness presentations on a dairy farm can be fixed with a knife, a hoof block and anti-inflammatory. Hoof blocks are an essential tool to allow the cow to walk normally and reduce pain. This works by putting a block on the healthy hoof to raise the affected hoof off the ground to reduce pain and pinching. This can be paired with an anti-inflammatory (Ketomax is good as it has no milk withhold) for pain relief and to reduce inflammation. Milking lame cows once a day and keeping them close to the shed helps reduce their distance walking and time spent on hard surfaces which will reduce recovery time. Bulls also get lame; this has a big impact on their reproductive performance. Sore feet affect a bull’s ability to mount cows and the pain means they graze less. These stressors reduce the bull’s sperm count, making them sub fertile for 4-6weeks. This means lame bulls are unfit for purpose; don't expect lame bulls to get cows in calf effectively. Preventing lameness in bulls by training them to stay off the yard, or by leaving them in the paddock reduces the chance of them getting lame so this is a very important part of effective bull management. Early treatment and rest will help lame bulls to recover faster.
Calf Vaccinations
Calves need quite a number of vaccinations and it can be confusing about what needs doing and when. Clostridial diseases - This family of bacteria cause a lot of different diseases, with sudden death a common outcome. The most common disease affecting calves is blackleg. Symptoms are calves found dead with swollen legs/gassy, blown up skin. Vaccinations are 5 in 1, Coglavax or Covexin. Vaccinations can start as early as 2 weeks of age, depending on which vaccination you are using and should be started by the time the calves are 2 months old with the second injection given 4-6 weeks later.
Leptospirosis - Lepto bacteria cause infection resulting in fever, loss of appetite, conjunctivitis, abortions, mastitis, loss of milk production, and jaundice. Humans can become infected and experience severe flu-like symptoms. Calves can be infected as early as 4 weeks old and can become carriers. Vaccinations (Lepto-4-way which contains the pacifica strain, the most common strain found in human infections) should be given sometime between 1-2 months of age with a booster given 4 weeks later. To match the calves up with the herd and heifers that are normally done before the high risk period begins in autumn, calves may need an extra booster in autumn (March-May). Lepto vaccine must be given by a vet.
BVD - Bovine Viral Diarrhoea virus can cause immune suppression resulting in increased rates of other diseases and poor growth rates in calves. Vaccinations can be given from 4 months and boosted 4 weeks - 6 months later. We use 2 different vaccinations, Bovillis BVD and Hipprabovis (which contains IBR and vaccine).
IBR -Infectious Bovine Rhinotracheitis (IBR) is caused by infection with Bovine Herpesvirus. Once infected an animal remains infected for life, and can shed virus on multiple occasions, especially when the animal is under stress. This exposes more cattle to infection. IBR infection in cattle can cause runny eyes, nasal discharge, coughing and difficulty breathing. IBR vaccination is useful when high levels are present in a herd (lots of snotty animals), but will mean animals will not be able to be exported to China. Vaccinations should start at 3-4 months and be boosted 3-4 weeks later.
Salmonella - Salmonella bacteria can cause infections in cows resulting in a sudden drop in milk production, loss of appetite, diarrhoea, and fever. In severe cases, it can cause death. Calves can also become infected and may have a high temperature, reduced appetite, and smelly, watery diarrhoea. Vaccinations in calves where the herd has been diagnosed with Salmonella cases should be done as early as 2 weeks of age, with the second shot given 4 weeks later and then a booster vaccination given in the autumn. In herds where vaccination is being given as a preventative the calves should receive their 1st shot in the autumn and be boosted 4 weeks later.
Timeline example for calves born July/August
1-2 months old. October - 1st Clostridial + 1st Lepto
2-3 months old. November - 2nd Clostridial +2nd Lepto
4 months old. December/January - 1st BVD+/-IBR
5 months old. January/February - 2nd BVD+/- IBR
7 months old. March/April -1st Salmonella
8 months old. April/May - 2nd Salmonella +/- Lepto booster
Salmonella Vaccine
There were 5 confirmed outbreaks of Salmonella in dairy herds in our area this spring and 2 confirmed outbreaks in herds last year. This is becoming a more common disease in Taranaki and can have a profound effect on your animals. Salmonella causes a smelly, watery diarrhoea and a sick animal with a high temperature, reduced appetite and low production. Without treatment death rates can be high. Generally more than one animal is affected, and cows can become sick over a period of weeks. It can also lead to abortions and can affect all stock classes, calves can be especially hard hit. It is a zoonotic bacteria meaning humans can catch it. Cows can carry the bacteria without clinical signs and at times of stress, like calving, start shedding into the environment affecting other cows and putting you and your staff at risk. There is a vaccination which can be given to prevent Salmonella infection. Salvexin is a 2ml dose given under the skin and costs between $1.70-$2 inc GST. It can be added to your RVM (can be given by the farmer). Vaccination may cause a transient rise in temperature and associated loss of production. To prevent Salmonella the vaccine should be given in autumn and can be given at the same time as most other vaccinations. If you decide to vaccinate, the 1st season all classes of stock will require 2 vaccinations. In the years following the heifers and the herd will need a annual booster and calves should be done twice, 4 weeks apart in the autumn. Please contact the clinic for more information or discuss with your vet to make a plan and get Salvexin added to your RVM.
Poisonous Plants
There are many commonly occurring plants that cause toxicity in animals (and humans!), some which you may already know, and others that may surprise you. With a few of these popping up now we are approaching summer, it’s a good idea to find out what these plants are and what they do so you might be able to spot signs of toxicity early on.
Fox glove
Toxic agent: Digitoxin
Animals affected: All
Signs of toxicity: Slow, strong heartbeat, bounding pulse, vomiting, diarrhoea, collapse, sudden death.
Treatment: Unfortunately there is none, only symptomatic and supportive.
Chance of recovery: Low, depends on severity
Fat hen
Toxic agent: Oxalates
Animals affected: All grazing animals, particularly cattle.
Signs of toxicity: Down wobbly cows, milk fever! (the oxalates binds to calcium causing hypocalcaemia). Normally will have multiple in the herd at the same time.
Treatment: Calcium bag into vein (same as milk fever).
Chance of recovery: Fair to good, depending on how soon treatment is started.
Hemlock
Toxic agent: Pyridine and piperidine alkaloids.
Animals affected: All grazing animals, particularly cattle.
Signs of toxicity: hypersalivation, difficulty swallowing, diarrhoea, fever, bloat, muscle weakness, trembling and seizures, death. Treatment: Unfortunately there is none, only symptomatic and supportive.
Chance of recovery: Low to moderate depending on amount ingested.
Ragwort
Toxic agent: Pyrrolizidine alkaloids
Animals affected: All grazing animals, however cattle and horses are affected more.
Signs of toxicity: Liver damage, weight loss, decreased milk production, stumbling, depression and death.
Treatment: Unfortunately there is none, only symptomatic and supportive.
Chance of recovery: May survive initial insult, but long term liver damage may cause premature death.
Rhododendron
Toxic agent: Andromedotoxin
Animals affected: Cattle, sheep, horse, goats.
Signs of toxicity: Vomiting, excessive salivation, diarrhoea, difficulty breathing, frothing at mouth, seizures and collapse. Treatment: Unfortunately there is none, only symptomatic and supportive.
Chance of recovery: Low to moderate depending on amount ingested.
How often do you change your liners?
Teat cup liners are like tyres, they wear out and need to be replaced. And like worn tyres, worn liners are dangerous.
The condition and maintenance of liners is critical in mastitis control and efficient milking. As they age, liners gradually lose their elasticity. They take longer to open, and they close less crisply. Milking time increases and with it the potential for teat damage.
The surface of the liner is the only part of the milking plant in contact with the cow. As liners age their interior surface becomes rough and pitted. Long before you can feel this roughness with your finger, microscopic damage leaves pits and cracks which are hard to clean and provide a safe haven for mastitis bugs. Staphylococcus aureus, in particular, spreads from cow to cow through the plant. Staph. infections are notoriously hard to cure and many infected cows continue to be high SCC and shed Staph. bugs in their milk. Worn liners make it easy for these bugs to spread to other cows in your herd.
So, how often should you change your liners? As often as the manufacturer recommends! This is usually after 2,500 milkings for rubber liners and 10,000 milkings for silicone liners.
Example: 40 aside herringbone milking 400 cows TAD with rubber liners.
Each cluster milks 10 cows/milking x 2/day = 20 milkings/day.
2,500 milkings/20 = 125 days. The liners should be changed every 125 days, or every 4 months.
Of course this herd doesn’t milk 400 cows from the first day of milking and progressively dries off light cows in autumn. PSC is August 5th so for practical purposes I would recommend their liners be changed at Christmas, easy to remember. Are your liners overdue for replacement?
Dairy Cow Premating Blood Analysis
Eltham vets sampled 442 cows for premating bloods during spring from 45 farms. There is variation in what each vet decides to test based on history, stage of lactation or planning around supplementation. A summary of our results is listed here.
Magnesium - At a farm level 2 out of 3 farms visited had at least 1 cow with low serum magnesium and 70/442 cows (16%) tested were low. 33/442 cows (7.5%) tested were high in serum magnesium.
B12 - 18% of cows sampled for serum B12 tested low (27/150).
Copper - 442 cows were tested for serum copper and 12 tested low (2.7%). None tested high.
Selenium - The average cow serum selenium was 642nmol/L. Please note, there is huge variation between vets, vet clinics, nutritionists, and academics on what is the cut off is for “adequate” or “deficient”. There is a difference between what is considered adequate for high producing dairy cows and the reference ranges for clinical disease. Using the cut-off 750nmol/L, 63% or 276/442 cows tested were below this limit. 1 cow tested deficient using the laboratory cut off point of 140nmol/L.
Iodine - 18 farms tested pooled serum iodine. 50% of farms tested adequate with no extra supplementation advised.
B-OH - 335 cows were tested for B-OH as a proxy for energy status. 9% of cows were elevated above the cut off of 1mmol/L (33/335 cows) but only 11 of these cows tested >1.2mmol/L which is often considered clinically significant.
We emphasise that premating blood results reflect each farm and each season and often fluctuate, meaning it is advised to test annually. A common comment in the office this season was ‘low mags and low selenium’s’ with advice centering around extra supplementation options. Late winter/early spring produced higher than normal growth rates, high utilization and lowered feed wastage meaning more DMI per cow, reflected in less ketotic cows. On the flip side, high grass quality can seemingly reduce serum B12- likely a result of faster gut transit times and higher utilization of the sugar/starch pathway. If you are not using iodine teat sprays you may have a requirement for added iodine. Serum coppers were stable but we will still highly recommend testing of cull cow livers in autumn to ensure reserves prior to winter are adequate.
Early Scanning Non- Returning CIDR Cows to identify 'Phantom Cows'
Phantom cows are animals which have been through a CIDR program and not cycled in the 5 weeks post insemination giving the impression they are in-calf when in fact they are non-pregnant. There is a risk that following insemination, cows treated in a CIDR program may return to being non-cycling. If not picked up early these cows generally show up empty at final pregnancy testing time. Early pregnancy scanning of non-returned cows at 5 weeks following insemination allows the early detection of these animals allowing them to be proactively managed, whether that be with a prostaglandin injection or running another CIDR round. This approach maximizes the chances of successful pregnancies within the herd, ultimately boosting overall productivity. Call the clinic to book your phantom cow scanning visit today.
Calf & Heifer Management
Growing your heifers well is key to getting the most out of your herd. Well grown dairy heifers have significantly increased milk production and improved reproduction compared with less well grown herd mates.
Figures from LIC show that in NZ heifers are about 5-6% below liveweight targets. There is approximately a 2kgMS production loss per year for every 1% behind target liveweight at 22 months old. So a group of heifers being 5% behind target equates to a 10kgMS loss per 2-year-old in the herd.
For a 300 cow herd with a 20% replacement rate that is around $5400 lost in milk production (at a $9 payout) and this repeats for every year that the heifers are 5% behind target. This doesn’t include losses due to poor reproductive performance or increased health issues which will also be significant. Growth rates seem to suffer particularly in the 1st and 2nd winters. It is hard to improve growth rates in the 2nd winter so the most practical course of action is to ensure heifers are reared well and are above targets in the first 6 months of life.
Options to help maximise liveweights/growth rates in calves are:
Liveweight targets for heifers are: 30% of mature liveweight at 3months, 60% of mature liveweight at 6 months and 90% of mature liveweight at 22 months (just before their first calving). If you need help setting up a young stock management plan including drenching and trace mineral supplementation, give us a call at the clinic. We also have scales we can hire out if you don’t have any. Taking the time to weigh them is worth the time and energy. Just call the clinic to arrange.
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.
