Pre-mating Check List

 Create a 3-week submission rate target of >90%. Plan forward to actively achieve it. A high six-week in-calf rate with a low empty rate are impossible without it!

 Pre-mate Tail Paint – this should go on 35 days before (~18th September) the planned start of mating or a minimum of 25 days before an intended non-cycler program. Touch this up every five days.

 Monitor pre-mate cycling rates on farms with wearables compare to targets and act if falling behind. Vet Centre bench marking reports will give you an indication of where you sit compared to other local herds this season.

 Consider BSCing your herd ASAP if you have not done it already. This will help with strategic decision making. Good nutritional/energy status in your cows is key. Low second round entry covers may be putting nutritional stress on your cows in early October.

 Run light (and low rumination) cows as a separate herd at least 3-4 weeks before PSM and feed preferentially and/ or OAD milk. Farms with Halter may consider pausing collars of light cows so they can cross the virtual fence.

 Monitor daily BMT protein percentage. This should be steadily increasing from the 15-20th of September. 3.7-3.8% should be the lowest point and aim for 3.9-4.0% by early October, with a steady increase to 4.05-4.1% by start of December. A decrease at any stage in the pre-mate/mating period indicates a drop in herd level energy intakes and will impact both submission and conception rates.

 Maintain calcium supplementation in high production system farms beyond peak lactation (aim for 50g/day down the throat). Also ensure cows have a continuous supply of salt made available.

 Starchy feeds or feed additives such as grains or Rumenox, boost propionate production in the rumen, this indirectly increases blood insulin levels which stimulates earlier resumption of cycling.

 Supplements high in omega 3 fatty acids have been shown to boost pregnancy rates (through better conception and embryo survival). Full Fat Canola Meal (from Pure Oil NZ) at 200g/day achieves this. It can be incorporated into in-shed feed blends. Start 4 weeks premate and continue to 4 weeks plus into mating.

 Metricheck herd in batches. Identify with tail-paint (or Protrack) and check 10-28 days post calving. Cows previously treated should be rechecked 10-20 days later (we expect 85-90% cure rates).

 Ensure adequate trace element status – blood test herd in late September early October. Selenium, Iodine, Copper, Zinc and Vitamin B12 deficiencies can all effect reproductive performance. Soil Iodine, Zinc and Selenium are consistently low is this district. Blood Vitamin B12 levels are generally low in the months from late September to mid-November, in the lush growth period. Strategic use of vitamin B12 in late September / early October and again four weeks later anecdotally increases submission and conception rates (CR).

 Give Multimin Evolution Injection (high in Zn) three to four weeks pre-mate increases 6 WICR by 3 - 4%. (national & local trials). Marksmin is also available (this has less Zinc but has the benefit of containing B12).

 If supplementing Iodine, use 10% Stock Iodine at a rate of 50mls/100 cows/day.

 Drench lighter animals and heifers, this will give a significant reproductive boost. In the Eprinex trial involving the Lincoln Dairy Farm, treated heifers conceived on average 12.9 days earlier than untreated heifers.

 Act immediately when evidence is found of a BVD PI in the herd (through LIC BVD Bulk Milk Tank testing) - talk to your Prime vet.

 Start sourcing bulls now if using them. Ensure they are BVD blood tested BVD free (sight the lab report). Have them vaccinated if BVD exists in your herd.

 Consider Pink Eye vaccination for bulls if this has been a problem in the past. Many bulls contract it from the cows.

 Bull Requirements. A 700-cow herd using AI for 6 weeks will require 8 bulls in the herd at all times, plus 8 extras to rotate on every second day. A 700-cow herd which AI’s for just 4 weeks will require 12 bulls in the herd at all times and 12 extra to rotate.

 Consider sexed semen to speed genetic gain in the top 20-30th percentile of the BW cows in the herd (these should be 5 years old and less, early calving, with multiple pre-mate heats and in good BCS (BCS 4.5 and greater).

 Select a fertile bull team that has a positive Fertility BV of 2% or greater for longer term herd fertility improvement.

 Identify optimal AI timings if using wearable technology (based on heat activity peak) in cows being aligned to expensive semen and/or synchrony.

 Lower quartile BW cows are best allocated to beef straws. Use SGL semen from week 7 in all cows to condense calving pattern.

 Confirm your intended planned start of mating and book in your synchrony programs with Vet and AI tech now to avoid clashes.

 Plan to start mating in maiden heifers 5 – 7 days earlier than the herd. If using synchrony there are plenty of options for doing this. Changes to the heifer CIDR synchrony program last year saw an average conception rate of 67% over 21 farms.

 Submit early calving (August) eligible non-cyclers for treatment 9 to 1 day before PSM. Later calving (September) non-cyclers should be treated by day 10 to 11 into mating.

 Check drafting gates and wearable tech systems are running smoothly well before PSM.

 Book in a Reproductive Consult with your vet to identify and prioritise required improvements based on last season’s performance. We have access to a new custom repro analysis report from LIC. These take 5 days to generate once ordered.

What to do with those High SCC cows? Identify and make a plan

The BMSCC target by the end of August should be below 150,000 and holding steady or declining. When it is high or lifting there is cause to take action to protect the milk quality for the remainder of the season.

Start with checking the basics. Is the plant operating within the optimal range settings. If in doubt Hamish, Mat (Oamaru), or Ewan (Waimate) can visit during milking to do a dynamic machine check and at the same time trouble shoot for other apparent issues.

By late September/start October many herds will be doing their first herd test for the season. There is an opportunity here to review the ISSC results and order LIC’s Mastitis Multiplex PCR test on the high cell count individuals. This identifies 3 of the most common mastitis pathogens including Staph aureus as well as a gene for penicillin resistance. Testing must be pre-booked but there is no commitment to test until our vets have reviewed the herd test results and recommend cows for testing. The cost is $19/cow submitted.

Identification of cows carrying Staph at the start of the season can be managed (run in the last herd or set on draft and milked last). By doing this you will limit the spread of this hard-to-treat infection and protect your uninfected cows.

As a reminder though, while you wait for your first herd test – we also have in clinic quadratic plate cultures with an AI plate reader with a rapid turnaround on results.

Milk Fever Prevention – There is no set recipe

The causes of milk fever are multifactorial. Having a good understanding of what these risks are on your farm and in your herd, can enable a sensible preventative plan to be put in place.

• Cows of 6 years and greater are at much greater risk.

• Fat cows. Risk of milk fever increases by 40% as cows shift from BCS 5.0 to 5.5.

• Bone calcium stores/reserves from the previous lactation and dry period. High production cows from the previous lactation that were not calcium supplemented, then spent a winter on e.g. fodder beet will likely have low calcium bone reserves.

• Energy intakes of springers – more energy drives more colostrum, more colostrum more calcium draw.

• High DCAD diets – these create a metabolic alkalosis in the cow. In a high pH environment inside a cow, the cells necessary for releasing bone calcium reduce their activity.

• High calcium diets as a springer will switch off the Parathyroid gland (PT). This gland regulates blood calcium by triggering increased bone calcium resorption, increased intestinal absorption and reduced kidney calcium excretion when blood calcium levels fall. Ideally, we want an activated PT gland at both before and after calving.

• High dietary potassium will increase the DCAD but it also has a direct competitive effect with the absorption of both calcium and magnesium.

• Low magnesium diet will make the PT gland less responsive, whereas excessive magnesium diets can compete with calcium. It is important to provide ‘just enough’.

Preventative strategies

1. In cows with good bone calcium stores/reserves as a result of plentiful supplementation in the previous lactation and dry period, a good preventative strategy would involve the following components:

• A low calcium springer diet (under 0.4% for 10-14 days)

• A low DCAD diet (aim below 200 units). Maize is good, as well as high doses of anionic salts (must be for 10-14 days).

• With a low DCAD diet success can be measured by a lowering of urinary pH (<6.5 but >5.5). It is easy to collect urine from springer cows and test them with cheap electronic pH meters. Normal cow urine is about pH 8.0 when on pasture only.

• Modest magnesium supplementation (blood Mg of 0.75-1.1)

• Plenty of fibre (hay straw)

2. In cows with poor bone calcium reserves, there is little benefit from using low DCAD diets (and or springer transition minerals) and/or restricting calcium intake as a springer. This is because those two strategies are attempting to promote release of bone calcium. This may be of limited use if there is reduced available calcium in the bone. Consider the following:

• Although it seems counter intuitive if springer cows are offered a very high calcium intake (think 400g/day of limeflour), the cow is no longer reliant on her bone supply or kidney retention. Her dietary intake saturates all needs.

• For this method to work cows MUST have a consistent daily supplement routine – i.e. you can not afford to miss a day! It is imperative that you discuss this strategy with your Prime Vet before undertaking it.

3. Some herds will just sit in the middle ground with risk. In this situation we need to place a ‘bob each way’. Things to consider:

• Place on low DCAD/low K pastures (i.e DCAD less than 500 units)

• Supplement magnesium with a baseline through water. MgSO4 is a bit more preferred to MgCl. Dose at 70g/cow/day.

• Limit grass intakes to springer to ~3-5kgDM/day

• Ensure cows are not fed more than 120MJME/day in springers

• Fed plenty of long fibre (i.e. straw or hay)

• Feed springers cows ‘Springer Transition’ mix ~300g/day. Also consider Gypsum (CaSO4) at ~200-250grams/day.

• Feed colostrum cows ad-lib ‘Colostrum cow’ mix.

• Identify high risk cows for a calcium bolus immediately postcalving (>6yrs, >BCS 5.0)

• Shift breaks in springers at about 5am (i.e. before the coldest part of the night). Give springers at least 2 feeding opportunities in a day.

• Pause collars on freshly calved Halter cows

• As soon as calved get onto high dose (~400g/day) of limeflour for first four days and then reduce to 200g/day for up to six weeks.

Contact your Prime Vet for more details or your TM for products mentioned in this article.

Spontaneous Humeral Fractures in Heifers

Humeral fractures (upper front leg) in heifers are no laughing matter. Every year we have many farms affected in this practice, sometimes losing up to 10% of their heifer line. We see two peak periods of these fractures. The first, +/- one week of calving and the second coinciding with peak lactation (we have found heifers that break legs at peak lactation are in the top 10% producers at the first herd test).

We know that the bones of these heifers have osteoporosis (thinned), and this is likely due to excessive mineral loss in late gestation and peak lactation. Heifers that are in a surplus dietary calcium status will not need to mobilise bone calcium. If dietary limeflour is supplied in excess of requirements through the last month of pregnancy and also the early lactation period (up to mid-November) at about 100g/heifer day. Avoid providing heifers high dose anionic salts (mag sulphates and mag chlorides) as these may enhance the release of bone minerals.

These heifers also have a high copper consumption, so it is important to support this with good supplement levels going into the winter.

Brassica Feeding over the Dry Period – The Good, the Bad and the Ugly

Next to fodder beet, brassicas (rape, kale, turnips and swedes), are the other mainstay of the winter diet. It helps to understand some of their properties to get the best from them.

The Good

• In kale, the upper 2/3rd of the plant has quite good ME – being about 12.5MJ. The lower part of the plant (the stalk) will be lower and is only about 7ME close to the ground. The overall ME is about 11-11.5MJ/kgDM. The ME of all other brassicas are closer to 12MJME.

• Generally speaking, brassicas have good levels of crude protein for a dry cow – 14-18%. This makes it quite a good crop to finish the winter on if you have had cows on a low crude protein fodder beet through the early part of the dry period.

• Kale/Rape have high levels of calcium – about 3 times what is in grass and 9 times what is in fodder beet bulbs. This makes it handy for replenishing bone stores in dairy cows.

• A tall grazing face can form good shelter for cows if being grazed in a southern direction.

The Bad

• Kale crops often have bad utilisation in bad weather – it can be as low as 50%. Make sure you allow for this.

• Best practice is to work on 80% utilisation in good conditions. If it is higher than this, cows are probably being underfed. Make sure you factor this in on your daily allocation.

• All brassicas are low in effective fibre (and yes that includes those chewy looking stalks). This is the reason that as a minimum 25% of the diet needs to have a long fibre source – e.g. straw, hay or baleage.

• Animals often ingest quite a bit of mud while on crop – this will deplete copper stores. Selenium is also consumed/depleted soaking up ‘free radicals’ created by a high content of poly-unsaturated fatty acids.

• Swedes can be quite hard, making it tough for calves and heifers to eat. It can tend to be lower in crude protein as well.

The Ugly

• The lack of effective fibre and if fed frozen can make cattle prone to frost bloat (a free gas bloat). The cold temperature shocks the rumen disabling the ability to belch. Wait for the frost to come off before feeding.

• Brassicas will bind up Iodine which can result in still births in calves – particularly out of heifers. Dosing a trough with stock iodine on a daily basis in the last month of gestation may reduce this risk.

• Nitrate poisoning is a real danger - particularly in rape followed next by kale. Its most likely to occur after periods of cold, low light conditions, where leaf loss has occurred from previous breakouts, and when animals go onto a frozen crop with an empty belly.

• Like fodder beet, swedes can cause acidosis. A transition period is also important.