Investigating Wet-Dry Rates and Protecting the Asset

“ 400 bloody wet-dry ewes at tailing…I’m not doing that again.”

Over the last couple of months I have done a number of investigations into higher than normal wet-dry rates in ewes at tailing.

With hill ewes it can be hard to determine when these scanned in-lamb ewes are losing their lambs. The main areas are:

• Disease that causes abortion (toxo, campy, hairy shakers). This includes early embryonic losses through to weak live lambs.

• Iodine, cobalt and selenium deficiency.

• Poor body condition and lack of adequate feeding of multiples in late pregnancy.

• Storms after pre-lamb shearing.

• Mob size and stocking density of twins too high.

• Lack of shelter/starvation.

• Genetics of both ewe and lamb.

Speed of delivery, lamb birth weight and lamb fat reserves are all important for getting up to get the first drink. It is interesting that “lamb smarts” are reasonably heritable also. Triplets are of course up against it on many fronts with respect to the survival stakes.

Blood testing of wet-dry ewes can assist with investigations. Below is an example of results from unvaccinated ewes with less lambs at tailing. 40% of w-d ewes have had recent infection with toxoplasma. Infection with campylobacter was evident also, with 70% showing recent exposure and shedding of the bacteria. Toxoplasma is from cat (especially kitten) faeces and campylobacter lives in the gut of ewes and shed through faeces.

Protecting your next year lamb crop

The majority of our clients now use Toxovax and Campyvax4 vaccine in first year breeding ewes to prevent abortions. It is very routine now. 100% farms have some level of toxo on the place. 83% of farms have evidence of Campylobacter in ewe flocks.

Toxovax is a single, 1 shot for life vaccine. It helps plug the gaps in ewes that have not had natural exposure. In the early days of toxovax development they demonstrated 7-9% increase in numbers of lambs weaned when flocks did not observe any abortions or perceive a problem.

Campyvax4 requires 2 shots with the minimum recommendation being sensitizer and booster shots to first year breeding ewes. Longer term protection occurs if a single campyvax booster is given in the 2nd year. If you gave hoggets a 2 shot course then as 2 tooths they will only require a campyvax booster. Farms with high challenge have seen benefits to boosting all mixed aged ewes annually.

It's Fly Time

With a combination of heat and moisture the danger zone for fly is now upon us.

If you are getting fly strike, stop and have a think about why there are struck sheep:

• Are they uncrutched and offering smelly dirty bums to interested flies?

• Lambs missed a drench?

• Could a preventative dip have been done sooner and more efficiently?

• When were they last dipped and was the dip applied correctly?

• The best and most cost-effective approach to prevent flystrike is to use a combination of strategies that keep sheep as unattractive to flies as possible.

1 No fly chemical works in dags

• Preventing sheep becoming daggy is vital.

• Have a robust worm control programme using an effective drench to reduce scouring. Don’t extend drench intervals unless you are monitoring with FEC.

• Crutch or shear to remove dags and allow the crutch to dry out.

• Grazing high tannin crops or clean pasture results in less dags.

2 Reduce fly challenge

• Keep sheep away from fly hotspots.

• Flies love sheltered conditions such as shelter belts and gullies with scrub. Move sheep to higher open ground where the temperatures are cooler, and the wind speed is higher.

• Get dead carcases down the offal hole as quickly as possible.

3 Chemical application

• Faulty application is often to blame for poor fly results following dipping

• For saturation dips to be effective the sheep must be wet to skin level along the backline, over the rump and around the crutch. Pushing large numbers of sheep quickly through the jetting race is often to blame for inadequate coverage. When the first pen of sheep has been through the jetting race, stop and part the wool at multiple sites to ensure the skin is wet.

Ewe Mastitis

I have not written too many articles on ewe mastitis, possibly because there is not a lot we can do about it when discovered. The classic signs from a distance are:

• Lame /stiff gait.

• Sitting down when other ewes grazing.

• Shelly gaunt lambs hanging around a ewe.

Closer inspection

• Udder swollen and purple/blue. Cold. Watery bloody discharge. This is black mastitis.

There main course of action when cold and blue is to cut the teat off to drain the poison out. Administering long acting antibiotics and some anti-inflammatory drugs may have some benefit to keeping her alive. The vet only footrot antibiotic is actually the most potent for treating ewe mastitis. I have never found cow tube treatments any use. Removal to a hospital paddock for monitoring is a good idea.

The cause has often been reported to be Staph aureus bacteria, but there are other bacteria types that can cause sheep mastitis. If you have had some causes getting laboratory culture could help tease out the risk factors of the pathogen. If you are seeing any higher rates of mastitis, joint ill or pneumonia it might be worth investigating.

Common risk factors for sheep mastitis are:

• 1 – 6 weeks into lactation. Usually higher producing multiples.

• Teat damage (chewing, cracks, scabby mouth).

• Recent cold snap.

• Mob stocking/ higher densities.

• “Dirty” paddocks. i.e. that have over hanging shaded trees, swamp areas or common dirty camp areas.

Checking udders 1 month after weaning is advised to prevent the subtle cases slipping through for another season.

Animal Welfare Guidelines

• Transporting lame sheep and cattle

Sheep, Cattle deer and pigs must be able to bear some weight on all limbs. Severe lameness can only be moved for treatment. If unsure get a Vet certificate. With lines of lame sheep a vet certificate is required.

• Dehorning

To dehorn any cattle local anaesthetic must be used. This includes calves.

To transport animals the horns must be inside the ears. Ingrown horns left unattended are an offence.

The best time to dehorn an animal is as a calf, this includes beef cattle. Using local plus debudding iron will achieve the best results. We do have a certification process to farmers to administer local anaesthetic and dehorn their own cattle. It does require an on-farm audit annually.

• Castration

Can be done with a ring up to 6 months of age, after that local anaesthetic must be used when castrating.

SMCO Poisoning

SMCO toxicity, also known as redwater or kale anaemia, is a very uncommon occurrence seen in animals grazing brassicas. SMCO (S-methyl cysteine sulphoxide) is in all brassicas in varying concentrations, especially kale. It is converted to the oxidative compound dimethyl sulphide which reacts with red blood cells and decreases haemoglobin, causing anaemia and red tinged urine. Animals must be on the toxic feed for at least one week for clinical signs to begin.

Clinical signs are weakness, diarrhea, yellow mucus membranes, poor performance, red urine and death.

SMCO concentrations increase in older plants and the flowering plant in spring. Levels are also higher on crops with high nitrogen and sulphate soil or fertilizer exposure. Ensiling affected crops does not stop the high SMCO concentration.

SMCO cannot be tested in the plant or the animal in NZ any more. Diagnosis requires proving the presence of severe anaemia and ruling out copper poisoning and bracken fern toxicity which cause similar clinical signs and anaemia. It is also important to rule out nitrate poisoning by testing suspect crops.

Once a toxic crop has been identified, ideally it would not be fed. However if toxic crops need to be utilized, animals can adapt to increased SMCO feeds to some extent with a sound transition regime over a 10 day period and feeding the toxic feed at no more than 50-60% of the diet. Very toxic crops would need to be fed at lower rates than this. If the crop needs to be fed, change breaks daily and ensure animals don’t go onto the crop empty. It takes the animal 4-8 weeks to replenish red blood cell levels so affected animals shouldn’t be stressed or run any distance during this time period. Treatment with selenium may reduce the oxidative effects of SMCO. Cows are suspected to be more susceptible to SMCO than sheep, however there are anecdotal reports of feeding known toxic crops to cows following sheep deaths without issue if they were carefully managed.

Although it is seldom reported, this winter period we have seen SMCO poisoning in sheep in the Maniototo on two farms feeding different brassica crops resulting in substantial losses and there are reports of other cases further afield. Bloat, acidosis, nitrate poisoning, scald and choke are more common and better known than SMCO toxicity, however it is important to keep it in mind when feeding brassicas to any ruminants.

Metabolic Disease around Lambing

There are two main causes of a down ewe prelamb, pregnancy toxaemia and hypocalcemia which can have similar clinical signs and can present in similar circumstances.

Pregnancy toxaemia (sleepy sickness, twin lamb disease) caused by a negative energy balance i.e., the ewe is unable to supply enough energy for her foetuses as well as meet her own demands. Affected ewes often become drowsy, stop eating, may separate themselves from the flock and if left to progress sit down and die within 2-7 days. A characteristic feature is ‘wool pull,’ where the wool plucks easily. General treatment includes providing energy either in the form of oral ketol or injectable glucalphos but often treatment can be unrewarding, and prognosis is much better if she is still eating.

Risk factors include multiple bearing ewes and severe weather events. Reduce the chance of pregnancy toxaemia by making sure adequate feed is on offer, especially for multiple bearing ewes in the last 6 weeks of pregnancy as they have the highest energy requirement. If pasture is tight, supplementary feed may be required, especially in bad weather. Minimise any time ewes are required to be off feed.

Hypocalcemia (milk fever) is a deficiency of calcium; clinical signs are usually more rapid onset than pregnancy toxaemia and once ewes are down, they usually die within 24 hours. When treated with injectable calcium, they have a rapid recovery. A response to calcium is diagnostic of the condition. Sheep in the last weeks of pregnancy and first few weeks of lambing are most at risk, especially older ewes, ewes held off feed or extreme weather reducing ewe’s feed intake.

Both pregnancy toxaemia and hypocalcemia are preventable and the key to prevention include adequate nutrition and minimal stress (e.g., yarding) in late pregnancy and early lactation.

Preventing Twisted Stomachs with Prophylactic Gastropexy

Unfortunately, twisted stomachs (GDV) are a common cause of loss of working dogs. Large breed dogs, with deep chests, especially Huntaways are much more prone to the condition than Heading Dogs and some lines of Huntaways are more at risk than others.

Warning signs a dog is developing a twisted stomach are: discomfort, panting, bloating, and reluctance to work. Sadly, many dogs develop twisted stomachs overnight and are found dead in their kennels in the morning.

Dogs with a twisted stomach require emergency surgery to untwist the stomach and ‘fix’ it back in the correct location to prevent re-occurrence.

What many people may not know is that there is a preventative solution available.

A gastropexy is a surgery where the stomach is permanently secured to the inside of the abdominal wall. After a gastropexy, a dilation of the stomach can still occur, but the life-threatening twist cannot. The surgery can be combined with de-sexing. Recovery involves 3-4 days of strict rest followed by 2 week of gentle exercise. After surgery, there may be a short period of belching as the stomach adapts to its new position but otherwise complications are uncommon.

Please ask about prophylactic gastropexy if you have an at-risk dog. In the right hands, this is a straight forward procedure that may save your dog’s life.

Scanning Hinds for Pregnancy

While we’ve had an exceptionally dry mild autumn the year is not standing still, and winter is rapidly approaching. Most stags were probably removed from the hinds in early to mid-May and the most common question I’m now getting asked is “when should I be scanning my hinds”. The answer is it depends on what information you want to get from your pregnancy test.

We’ve already scanned mobs of hinds where AI was used in late March followed by a chaser stag, this has allowed us to identify AI pregnancies and the first round of natural mating’s to the chaser stag through aging of the foetus.

To achieve the best possible outcome from scanning there are a few things to consider.

Timing of scanning. Hinds can be diagnosed pregnant from 35 days of pregnancy until around 120-130 days of pregnancy. After 120 days, the pregnancy tends to drop down into the abdomen making visualisation of the pregnancy difficult. Hinds should be scanned 35 days after the stag has been removed from the mob, this means most hinds should be scanned from early June through to early July.

Facilities. Sufficient restraint of hinds is necessary. While deer crushes are the ideal setup but with quiet hinds and an extra person to help with deer handling, swinging doors, races and small pens can all be workable options.

Permanently identify dry hinds. Dry hinds should be tagged with either a coloured fold over sheep tag or a slaughter tag, this saves a lot of confusion further down the track when aerosol marks wear off!

If you are planning to scan your hinds for pregnancy or are unsure about your facilities or the help required please talk to one of the Veterinary Centres experienced deer vets.

What is Vitamin B12 and Why is it Important?

Cobalt/Vitamin B12 is an important mineral for grazing sheep in New Zealand. Dietary cobalt is incorporated into Vitamin B12 by microbes in the rumen, which is then absorbed by the animal and used to aid in nutritional metabolism of energy. Because of this, cobalt/B12 deficiency in growing lambs can be similar to malnutrition and lead to reduced growth rates, general ill thrift, emaciation, poor appetite and anemia.

The main source of cobalt for ruminants is from pasture/soil. Sandy coastal soils, soils with a higher pH and soils which have been used for prolonged or intensive cropping tend to have lower levels of cobalt causing deficiency in the animals grazing them. Seasons favoring fast growing lush pastures, particularly in spring, tend to be lower in available dietary cobalt.

Unweaned lambs’ main source of stored Vitamin B12 is absorbed through the placenta with less amounts available in their mother’s milk. These stores begin to deplete within 5 weeks of birth and lambs need to start producing their own B12, using pasture cobalt, as their rumen becomes functional.

Do my sheep need supplementing?

Lambs are very susceptible to cobalt related ill-thrift and if not being supplemented, B12 levels should be monitored over successive seasons if farming in a potentially cobalt deficient area. Through our Tracecheck for sheep programme we recommend monitoring:

• Autumn – liver sample x 5 works lambs (Optigrow – contact us to arrange this)

• Weaning – liver sample x 5/blood test x 10 lambs (if there are any concerns lambs could be deficient prior to weaning and are not supplemented at tailing)

Cobalt deficiency in older sheep is very uncommon, however pregnant and lactating ewes have a increased demand needed for the growing lamb. On properties with deficient soils and diagnosed deficiency in lambs, testing of B12 levels in blood of 5 x 2 tooths in the autumn prior to tupping would be the cautious approach if choosing not to blanket supplement.

Hogget Mating - Feed Planning

By this point most of you would have made the decision on whether or not to go ahead with mating your hoggets. Managed well, hogget mating has the potential to boost your flock’s overall productivity and profitability, but poorly done and it will have the opposite effect. Reaching target liveweights before and after mating is the key to successfully mating your hoggets. The heavier she is at mating, the less pressure there is on your winter feed, to reach target weights after lambing:

• 40kg/65% of mature LW is the minimum target for each animal at mating, not the mob average – this may mean only a proportion of your ewe lambs are mated in a particular year.

• Target growth rate during pregnancy: 135g/d, to gain at least 20 kg and reach a minimum of 60kg before lambing – 50kg straight after they’ve had the lamb.

• Hogget lambs may need to be weaned early so that mums reach targets of at least 60kg mated as 2-tooths.

To meet these feed requirements during pregnancy, decent pre-grazing covers of at least 1200kg DM/ha will be necessary, or forage crops can help achieve this. If feed is short reducing other stock numbers is worth considering – the extra feed required to feed 7 in-lamb hoggets (vs 7 dry hoggets) is roughly the same feed required by one pregnant mixed age ewe over winter – an efficient use of resources. Post-lambing legume-based forages consistently give the highest growth rates in both lactating hoggets and their lambs.

What about feeding lucerne before & during mating?

Phyto-estrogens found in red clover, subterranean clover and lucerne are known to cause issues with fertility and reproduction, and hoggets are more sensitive to the depression in ovulation than ewes. However, many farmers successfully flush and mate their ewes on lucerne with no issues, and in most cases the advantages of the high-quality feed will outweigh any potential decrease in fertility. Some precautions to take:

• Oestrogen levels are elevated when the crop is stressed e.g. from aphid attack, leaf spots, moisture stress, or fungal disease (warm, wet weather).

• If there is any risk that oestrogen levels in the lucerne may be elevated, ewe and hoggets can be flushed on lucerne but should be removed 2 weeks before mating and mated on pasture.

• If you have the option, flushing on lucerne, removing 2 weeks before mating then returning to the crop after mating is the safest scenario.

• It’s not foolproof, but if ewe lambs develop pronounced udders or elongated teats after grazing lucerne, take that as a sign oestrogenic compounds are being produced and the crop is not safe.

Iodine for mating

The trace element status of ewes pretup affects:

• Ovulation rate

• Implantation and survival of embryos

• Health of the newborn lamb.

Iodine is an essential trace element required to make the thyroid hormones which control the metabolism and temperature of the ewe and is required for bone, brain and wool development of foetuses. A very iodine deficient ewe may abort in late gestation or at full term, while a live lamb deficient in iodine frequently will have an enlarged thyroid gland, and may be born small or weak and have little or no wool. These lambs are very susceptible to starvation/exposure. Farms that benefit from iodine supplementation frequently report similar scanning rates but improved lamb survivability.

Iodine deficiency may be a primary deficiency where the diet lacks iodine (eg some pastures and most winter root crops), or more commonly in NZ, a secondary deficiency, where plants producing goitrogens such as clover or brassica crops are fed which prevent the thyroid gland from utilising the iodine in the diet.

There are two main methods of supplementation:

• Oral drenches eg LSD-short acting. Given pre-tup, 8 & 4 weeks pre-lamb

• Iodised oil injections eg Flexidine. Single injection of 1.5ml 3-4 weeks pre-tup. Increases iodine status for up to 200 days, label claim is to supply sufficient iodine for one year.

Flexidine is our most popular iodine supplementation method due to its length of action and easy administration. It is usually given at the same time as CampyVax4. A 1% increase in lamb survival easily justifies the cost and time to use it.

If you miss the boat pre-tup it can be used up to two months before lambing, and at weaning.

If you’re on the fence about Flexidine or other iodine supplementation call into your local Veterinary Centre clinic and discuss your specific farming system with one of the team.

Lamb Trading Essentials

With many parts of the district a-wash with clover and surplus grass, lamb trading and fattening is being considered by more than just the seasoned experts. Below are reminders for some of the basic animal health essentials for the 30kg store-lamb.

1. Don’t bring on resistance worms: use an effective drench.

• 30kg lamb Zolvix (74c) or Startect (64c) are gold standard, but if you are using Matrix triple drench (17c) do a FEC 10 days later to check efficacy. There are plenty of triple drench resistance worms traded FOC (free-of-charge) with lambs currently….

• A drench interval of 28-30 days will not get you into trouble at this time of year. Pushing drench out passed 5 weeks can see lamb growth rates plummet. A 30 day FEC is recommended if you want to push drench intervals out. Moderate worm challenge will cost 50 – 100g per day. A high challenge will cost – everything you’ve invested sometimes!

2. Stop them from dying. Boosting lambs with Multine 5 in 1 (33c) with selenium and B12 (57c) is worth it, especially when going onto crops or changing feed. Lambs going onto lucerne will benefit from a Covexin 10 (now in 500mL packs, 75c). Every dead $120 lamb is the profit margin on another 4 lambs!

3. Keep the flies out. A squirt of Clikzin (shorter acting Clik) around the crutch (30c) or jet with 2.5l Cyrazin (35c) / Cyrazin KO (58c) or Cyrex (55c) will give ~6-8weeks protection. Not sure what the cost of messing around with melting lambs full of flies is, but its never good.

4. Don’t bring on disease. Troughing in 10% zinc sulphate will keep a lid on foot scald and early footrot. Lambs respond better to troughing than adult stock having softer feet and less complex lesions. Feet issues really do knock growth rates and can be over-looked by the trader without the mind set for dealing with it. Viral pneumonia is trickier to deal with but is one to look out for in lambs trucked over long distances (NI). I have had dealings with this last year, salvaged with a long acting shot of antibiotics – losing the ab free contract is better than losing lambs!

5. Longer term winter lambs will benefit from long acting products such as SmartShot B12, Cydectin LA and make sure they get their second shot of 5-in-1.

So for your 30kg stores put just over $2 in the budget for animal health – a very sound investment to avoid all the hassles of death, disease and disappointment.

*All dose prices are for a 30kg dose and exclude G.S.T.

Goats - No Kidding

Sheep dominate the fibre industry worldwide, however goats produce two of the warmest and most luxurious fibres-cashmere and mohair. With New Zealand farmers looking for new ways to diversify, the goat fibre industry is a growing field with farmers from Marlborough to Wyndham venturing into goat fibre production, meaning fine fibre can be produced across the country, not limited to Merino suited areas.

Goats fit into many farming systems from beef finishing to extensive sheep properties. They’re browsers, meaning they like to eat what is often considered unproductive pastoral areas where sheep typically would not thrive. For some farms up to 10% extra stock units can be added as goats without reducing sheep or cattle numbers. Apart from high fibre returns, they can help control pasture weeds and scrub, improve clover cover and pasture utilisation by capital stock allowing faster growth rates. They can provide a valuable source of parasite refugia for sheep.

Cashmere production is highly heritable meaning crossing a feral doe and a cashmere buck is likely to produce a pure white cashmere kid (F1) that will shear close to 16 microns and 200-400g of fibre annuallyincredible genetic improvement in one generation. From here the yield and micron will improve over the generations.

Selective breeding means goats are hardier than they were when first farmed in the 1980s, and we know a lot more about their health issues and management. Internal parasites, lice, trace element and feet concerns all apply and can be managed. Dagging and crutching aren’t required and bearings and flystrike are very rare. The drenching schedule is similar to sheep, with kids regularly drenched and does/ bucks done once or twice yearly. Goats travel longer distances each day than sheep and move in mobs so lower stocking rates are preferred. Goat meat has no sex, age or carcase finish specifications and the schedule is fairly stable. Cull fibre goats can be processed at several meatworks.

A wide variety of farms can have profitable low input doe and wether flocks as part of their integrated cattle and sheep management plan. Your local vet can help discuss care and animal health planning for goats and work them into your overall farm plan.

Parasites and Protein

Young growing lambs have a high demand for protein: for body maintenance, lean tissue and wool growth and a healthy immune system. Going into summer, worm burdens can place an additional protein demand on lambs, often coinciding with declining pasture quality, legumes making up a lower proportion of the sward, weaning, or a reduction in milk intake as ewe production drops.

A worm burden affects the lamb by:

• reducing appetite, limiting the total intake the lambs are achieving

• direct damage to the gut lining resulting in reduced protein uptake

• additional losses as the gut ‘leaks’ protein.

If lambs are already on a marginally adequate diet (low protein, low available energy or overall lack of feed), then the effect of the parasite burden can significantly reduce feed intake and growth rates over this critical period. Immunity will also suffer, and lambs will be less able to resist a parasite burden or infection (e.g. pneumonia).

Smaller lambs have the highest protein demand, and will be most affected by a heavy parasite burden. Lambs under 35kg should be a priority group for access to any higher quality feed available such as chicory, herbs or brassicas. These feeds have the added advantage of tending to have lower levels of larval contamination than grass dominant pasture. It is the daily ingestion and development of larvae within the lamb that cause the majority of production losses. In a 1982 study, it was shown that undrenched lambs grazed on low contamination pastures grew faster than lambs that were drenched regularly on high contamination pastures.

Depending on the season and available pasture, lambs may already be on the back foot as ewe’s milk production drops and pasture that is available may not have adequate legume content. It is therefore important to maintain good parasite control as to not add additional stress to the growing lambs, and where possible, prioritise feeding cleaner higher quality feeds such as brassicas or herb and legume-based pastures.

Scabby Mouth - an "Orf-ful" Disease

Scabby mouth, orf, contagious pustular dermatitis, whatever you call it – it’s time to think about this contagious disease as we head into tailing.

Cause - Scabby mouth is caused by an orf virus. It is extremely contagious and will infect people. Some flocks have a 90% infection rate, though this disease mostly affects young lambs.

Signs – Typically crusty, pus filled lesions (pustules) develop around the mouth, over the face, ears and around the hooves. Although lesions are temporary and usually self-resolve, it can result in decreases in growth potential due to reduced feed intake.

Transmission – Transmission occurs through contact between susceptible animals (including people) and the virus which lives within the scabs from infected animals. It is important to wear gloves and wash your hands while handling animals infected with scabby mouth. Skin trauma aids infection, which is why lesions are seen mostly around the mouth and feet. The virus can live for many months within the scab material. Its broken down by water and UV light, but survives well under the shelter of covered yards or woolsheds, and this is where infection may persist on your farm.

Treatment – Treatment isn’t always necessary as lesions can self-resolve, unless pustules become infected. Topical or injectable antibiotics (such as Intracillin LA) could be used in this case.

Prevention - Vaccination is the most effective prevention for scabby mouth infection. We vaccinate with a live viral vaccine, meaning that the animals are infected with a still live virus, in a controlled way. Avoid contact between yourself and the vaccine. It is not necessary to vaccinate if you do not have scabby mouth on your property. There are two live vaccination options available:

• Phenax Classic. 150 dose pen-style applicator.

• Scabigauard 250 dose bottles mounted in gun applicator.

Both require the skin to be broken and dye vaccine applied to the scratch area.

One line is enough. Keep product chilled between use.

Lamb Tailing

As most of you are aware it has become a law that farmers need to leave a stumpy bit behind when tailing now. This has been a “best practice guideline” for 4 years, the consultation was done in 2016. Many of the meat works report on it, and most Western European countries have decided it has to be this way…so (as usual) we end up following to keep the peace. The evidence of any meaningful or useful reason for this change is sketchy at best, but we will get used to it. Most tailing contractors have been compliant for a number of seasons now.

Minimum standard for tail length came into effect May 2021. $500 fines will be issued if 2021 born animals are non-compliant.

The tail MUST be no shorter than the distal end of the caudal fold. 1

Another way of stating it is:

No shorter than the third palpable joint

Or… The tail shall be docked with sufficient length to cover the vulva of a ewe, and the equivalent length in rams. 2

1 Beef and lamb Fact Sheet July 2020. minimum standards and best practice guidelines please refer to Animal Welfare (Painful Husbandry Procedures) Code of Welfare available from MPI Tel: 0800 008 333 or www.mpi.govt.nz/protection-and-response/animal-welfare/codes-of-welfare/

2 RWS Tail Docking Standard Operating Procedure. Publication Date: August 13, 2020

Pre Lamb Clostridial Boosters

Which vaccine? We stock clostridial vaccine that has been rigorously tested, reliable and has good science and technical support behind it. Results:

Multine 5 in 1 works. It has Prefringens D that is the main cause of pulpy kidney (plus tetanus and 3 others) It has been shown to have a higher antibody peak than other 5 in 1 vaccine. We take the view that more antibodies are better and covers variables of lambing date from vaccination and amount of colostrum ingested by lambs. It also comes with B12 and Selenised.

Covexin 10 in 1 is favoured when the clostridial risk is greater and for stud stock. The risk is higher for ewes and lambs when grazing legume dominant or high sugar feeds. For example lucerne and fodder beet. Covexin 10 has been shown to have excellent antibody levels and superior to other 8 in 1 vaccines.

Optimal time for clostridial booster is 2-4 weeks pre-lamb, that is when the udder is obviously developing.

Nilvax is a clostridial vaccine with levamisole drench which can be given earlier than 4 weeks.

Hind Scanning

The dry conditions through summer and autumn have had an impact on scanning percentages.

Mobs of hinds with low average body condition score have had a higher rate of dries, but it is not always the thin hinds who are dry. The value of scanning is highlighted in these situations. Getting rid of dry hinds in the current environment is a frustration, but at least if you know who they are you can prioritise feed and animal health inputs into the pregnant ones.

Yearling pregnancy rates have been down on many farms. These girls are so much more sensitive to a feed pinch at mating, even if they were above target weight when the stag went out.

On some farms there are more late-fawning hinds than normal. Identifying these and fawning them as a separate mob or quitting them is a great idea. This makes management of the earlies much more flexible in late spring as you can start opening gates or quietly moving mobs without worrying about mismothering of new fawns.

Iodine Supplementation

Iodine is an important trace element required by the growing foetus for metabolic function, brain development, lung development and wool growth. These factors contribute to making deficient newborn lambs weak and very susceptible to cold and stress.

Iodine deficiency can occur due to a low level of iodine in soils/plants but more commonly is due to ingestion of compounds which block the uptake of iodine from the diet. These compounds (called Thiocyanate goitrogens) are found in most Brassica species such as kales and many New Zealand cultivars of clover also contain the compound. Kale and swede bulbs also contain low overall levels of iodine.

South Canterbury and parts of Otago are known to have naturally low levels of iodine in soils and last year we did see some clinical cases of iodine deficiency in newborn lambs in the Waimate district.

Clinical goitre is the classic sign of Iodine deficiency, however less obvious signs may be occurring and could be resulting in a lower lamb survivability. Often this is put down to poor weather at lambing but low iodine could be a contributing factor.

It is important to note that iodine is a requirement for the developing foetus during the last half of gestation.

Testing for iodine deficiency can be difficult. The best test is to collect and freeze 10-15 slinks/dead lambs at birth, this allows us to dissect and weigh thyroid glands to give idea if levels during pregnancy were adequate and guide decisions for the upcoming season.

Supplementation should be undertaken if:

• Feeding brassica crops

• Goitre has been recorded previously on farm

• Significant increase in thyroid:bodyweight ratios previously

• Moderate thyroid:bodyweight ratios and iodine deficiency has been noted in the district.

Supplementation options:

As iodine is required for the growing foetus during the last half of gestation, supplementation should be done before and/or during this time. There also can be some positive effects on oestrus behaviour in ewes.

Flexidine:

• An oil based slow release injection of iodine.

• Ideally given a month before mating. This will provide adequate levels for the ewe at mating and coverage for the growing foetus well through lambing.

• If this timing is missed, then can give a half dose at scanning time to provide protection to the foetus.

• Give prior to putting onto goitrogenic crops.

LSD (Livestock Survival Drench):

• An oral supplement given through a drench gun.

• Contains iodine and Vitamin D (some evidence to show may reduce milk fever and bearings), E, A. Also low levels of selenium.

• Can be mixed with drenches to be used on the day.

• Ideally given 3 doses. Prior to mating, at scanning and prior to lambing.

• If not given prior to mating then giving doses at scanning and prior to lambing will provide supplementation for the growing foetus.

If you would like to discuss iodine supplementation or testing then please contact one of us at the Veterinary Centre. If in doubt, collect and freeze some slinks for us to look at this year!

Hogget Mating - A Flexible Option

Careful consideration should be given to whether to go ahead with mating all, or part of, your hogget flock each year. It should be seen as a flexible tool to achieve higher production in good years, but keeping in mind that long term detrimental effects can occur if hoggets are not up to weight or not fed adequately.

While there can be some big advantages:

• Production of a ‘bonus’ lamb in their first year of life

• Provides an early screening tool of potentially more fertile animals

• A higher lifetime performance if fed correctly

• Reduced generation interval if selecting hogget lambs as replacements

• Higher profits

There can also be some major disadvantages:

In particular relating to if hoggets are underweight at breeding or if they are not fed appropriately after mating

- Increased feed requirements

• Potential for reduced 2th liveweight and reduced longevity in the herd if hard done by

• Increased number of rams/teasers

• Increased workload

Currently in NZ about 30-35% of hoggets are mated each year achieving an average lambing percentage of 60%. This is with a huge range from 20-140%+.

Some key things to consider are:

-MINIMUM live weights of 40Kg and BCS of 2.5 should be the target at ram in date.

-Additional feed requirements will need to be accounted for, both for the growing hoggets and additional lambs.

-Monitoring of live weights should be done throughout pregnancy period. Total live weight gains of 130-150g/day throughout pregnancy are required to ensure performance of the dam and their lambs are not affected.

• Stock numbers should be adjusted accordingly. The extra feed required by 4 mated hoggets is equivalent to the feed eaten by 1 ewe in a year.

• Teaser rams are a great tool to increase hoggets mated and condense the lambing spread.

• Ram ratios of 1:75-100 or lower should be used, particularly if teaser rams are used.

If things are looking tight this year on your farm or hoggets are not up to weights, consider either not mating, or only mating a portion of them.