Humeral Fractures over Mating

As we head into October, we often see a second surge of spontaneous humeral fractures in heifers (the first period being around one week on either side of calving).

It is interesting that in affected farms it is very rare to see fractures occurring in both the peri-calving period and the pre-mate/mating period.

This would lead us to think that that nutritional intakes of calcium and phosphorus (and their ratios) in the 1-3 months before the fracture occurs may have an association.

We know that heifers that fracture in the pre-mate/mating period are generally in the top 20th percentile for production in their co-hort. It therefore makes sense that these will have the highest calcium demand, which could lead to thinning of the bones if calcium intakes are not supported.

Recent studies have shown that low liver copper values found in heifers with fractures may not be the cause of fractures but rather due to the effect of thinning bones. The body scrambles to fortify thin bones with copper containing proteins and enzymes.

Many of our diets are low in calcium and/or have a low Ca/P ratio. PKE, fodder beet, cereal grains and maize are all low, and this year we have measured some surprisingly low Ca percentages in pasture (possibly created by low pH soils).

For high producing herds the supplementation of lime flour in heifers (as well as cows), should be an essential practice until they get beyond peak lactation in November.

“We’re over half way calved, and now we have the scours”

Calf scours are often an issue in the latter part of calving, as bug levels rise in our facilities after many calves have already passed though.

You can minimise the chances of this by ...

• Maintain your excellent colostrum procedures – late season calves need a lot of immunity to counteract the extra bugs. Collect the best quality gold colostrum cleanly from the cow, and get it into your newborn calves ASAP.

• Spread calves out as extra space becomes available, avoid overcrowding with no less than 1.5msq per calf indoors , but allow more if they are staying inside for more than 2-3 weeks.

• If warm enough, get calves outside into sheltered paddocks as soon as possible.

• If you have to reuse pens that have had a lot of calves through them or have had sick calves in them already, remove any clumps of faeces from and disinfect all the solid surfaces, clean out all feed and water troughs, and either dig out bedding, or at least lay a decent thick layer of new bedding over the top.

• Keep yourselves and your calf staff smiling – positive people rear the best calves. Morning tea or other treats may be required.

Rehydrate is an electrolyte mix that our practice formulated. Its ingredient list is far superior to that offered by many other commercial preparations but at a fraction of the cost.

Top Tips to Minimise Calving Mastitis and Lower BMSCC

70-80% of all cows will calve by the end of August, so what you do to control and manage mastitis this month will have a large bearing on the rest of the season. Aim for the BMSCC in the month of August to never exceed 200,000 and average under 150,000.

• Where possible calve springers on the cleanest ground you can. Back fencing springer cows will likely result in more faecal contamination of the udder as cows are forced to sit down in a smaller area.

• Bolster immune defence at calving. Multimin given pre-calving halved the rate of clinical mastitis in a NZ trial.

• Teatspray springers daily if they are coming to the shed – this will both help to condition the teats (make them smooth and soft) and prevent new infection occurring.

• Collect calves twice daily. Studies have shown that the longer the calf stays on the cow, the greater the risk that she gets mastitis.

• Never make springer or colostrums cows run – this may result in blood in the udder and enable bacteria into the teat through leaking milk - cows may also prematurely loose the teat-sealant. Big walks coming back from the run-off close to calving are also a risk.

• Low pressure wash any dirty/muddy teats before the first milking. Dry with paper towels.

• Strip every quarter at the first milking with gloved hands and be fastidious with hand hygiene. Wash hands in between infected cows.

• During the colostrum period hand teatspray before and after cup removal. This will dramatically speed the conditioning of teats. Teatspray concentration should be not less than 1:5 in this period and should have an overall emollient concentration of 15-20%. Apply teat grease to any cows with cracks or chaps.

• On the 4th day in the colostrum mob, RMT test every cow before she exits into the milkers. Treat any clinicals immediately and retain Grade 2 and 3 cows for retesting in 48hrs. Any cows after 48hrs that remain at or increase to Grade 3/clinical should be treated.

• By being the gate keeper and stopping infected cows entering the milking herd you will set the season up for the best quality milk.

• Use anti-inflammatories (Metacam is best) in cows with significant udder swelling (hard, red, painful), in infected quarters. It is the inflammation that causes a quarter to become light. Early anti-inflammatory treatment in conjunction with antibiotics will give the best results.

• Make sure that all staff are fastidious about hygiene before inserting an intramammary into the teat end. The teat end must be cleaned just the same as you would when teat-sealing a cow to ensure no extra bugs are introduced into the udder. Teatspray after insertion.

• Ensure colostrum cows are not over-milked – cups should be on no longer than 9 minutes.

• Monitor your cows’ teats after cup removal – are they excessively swollen, do they feel thick and meaty? This may indicate either an excessive milking time, too high vacuum, a mismatch of inflation to teat size or faulty pulsation.

• Make sure all your staff know the MRS T rules – Mark, Record, Separate and then Treat.

The Cows had a Breakout on Fodder Beet – What do I do??

In early June, we see many cases of acidosis on fodder beet, because of either breakouts or overallocation.

Often the first clinical signs of acidosis are not seen until 10-12 hours after the breakout and new cases may continue to appear for up to 24 hours. This is because rumen fermentation and the systemic effects of the rumen acid load on the cow are progressive.

Early clinical signs may start with a cow looking wobbly, grinding her teeth, a distended gut and a lack of interest in food (sometimes you will also see long strings of mucous from the vagina). Being proactive before they get to this stage serves a far better outcome.

The most important thing to do when there is a suspected overallocation or breakout is to act quickly. Get the whole herd off the crop immediately, provide them with as much long fibre as possible – e.g. hay, straw or bailage and/or long rank grass. This will encourage cudding and the circulation of pH buffering saliva in the rumen. This will slow down the rate of fermentation and help prevent the rumen moving into a pH free-fall.

Fine-chop silage, will not be as effective as the particle lengths are too short and the pH is lower (we want to lift rumen pH). Dust the baleage and/or pasture heavily with limeflour – work on 300-400g/cow. This will provide calcium to prevent secondary milk fever and will also help buffer the rumen.

If cows are found already down (e.g. the breakout occurred the night before), triage them by giving IV calcium (use Calpro375).

Providing additional phosphate in these cases is of zero value. Less severely affected cows, if they just have a secondary hypocalcaemia, will get up immediately, move off and eat.

Cows which are unresponsive to calcium treatment, are depressed, have a distended abdomen, sunken eyes and grinding teeth have a poor prognosis. Cows which are still modestly bright but cannot stand after IV calcium (or those that are standing but look sickly), should get stomach tubed with Selekt Antacid mix (just mix with 5L of water), be given a 3-day course of high penicillin (to treat rumen ulcers) and a dose of Metacam (to reduce toxaemic effects).

Moderate to severely affected animals are best to spend the remainder of winter on grass, while the rest of the herd can be returned to the crop the next day at 2/3rds of the previous allocation before rebuilding them.

Turning Off the Tap

May has arrived so cows will start to be dried off. Regardless of what products you are using they will work best if they are applied correctly to cows that are well dried down and have a low milk volume (< 10 litres at final milking)

• A well dried off udder will retain a high concentration of dry cow antibiotic in the udder tissue/residual milk and is less likely to lose internal teat sealant.

• A poorly dried off udder will have high risk of losing teat sealant, delayed teat plug formation and will end up with lower dry cow antibiotic concentration in the udder tissue due to systemic re-absorption.

For cows currently producing > 1.5kg MS/day it can be challenging to shut down milk production. Reducing both the energy and protein component of the diet will have the greatest effect.

7 days out from dry off

• Drive production down to 1.0kgMS/day.

• Requires 150MJME/day (~12-13kgDM) with <16% CP.

• Stop in shed feeding of concentrates.

3 days out from dry off

• A big focus should be on abruptly cutting back high protein fresh grass while keeping the cows’ content and full. Use ad lib straw for additional gut fill and udder hygiene.

• Consider going backwards on your round into paddocks which have been recently grazed rather than giving the herd a very small break of grass.

• Aim for little to no production by dry-off.

• Requires 90MJME/day pre and 80MJME post.

• This is ~9-8kgDM, with 12% CP.