Author Archives: Sandra

Calving is slowing down and spring is here.

Calving is on the downhill run for most farmers, and the focus is now on making the best of the season – which so far has been very favourable. The first southerly storm of the spring arrived a few days early – hopefully not a portent of the spring to come. Fortunately it shot through pretty quickly.

The biggest potential hiccup was off-farm in the form of the potential Botulism risk for some Fonterra products.

Out on the farm

The benign climate over August might have led you to expect that there would be absolutely no calving health issues – but like any biological process this is rarely the case.

With so much grass there has been widespread grass quality issues and some metabolic problems.

The DPSL InfoLine keeps you abreast of the technical aspects of the problems being confronted on farms.

We have been having a lot of “problem” referrals from other vets and consultants since mid-August concerning metabolic problems that are odd or difficult to resolve. One of the more common issues is down, or more often suddenly dead, cows in the milking mobs, usually after supplements have been removed because there is a lot of grass. The problem is that cows cannot eat enough grass to meet their higher production needs (especially if pre-graze covers exceed 3000-3500Kgs DM/ha) and succumb to sub-clinical or clinical ketosis, often complicated by other metabolic problems. In some cases, poor transition management has exacerbated problems. Storms will also precipitate problems in these circumstances. Vets have also mentioned a big increase in mastitis in some cases. We are not seeing these problems amongst DPSL clients in general.

This was not the year to stick to a rigid rotation planner. With seasonal pasture-growth rates much higher than usual, grass has grown to “problem” levels on some farms, especially where transition cows have not been fed and managed to maximise appetite.

This highlights that a rotation plan is a tool that needs to have prevailing and expected growth rates in the equation, and to be flexible.

A new pasture-growth forecasting tool has just been released – it will be interesting to see if DairyNZ incorporates this into the rotation planner tool.


If the sunny weather of late continues, there will be more early silage made on farms. Ensure that sufficient drying time is allowed before harvest – very low DM grass makes poor quality silage, low sugar levels may delay fermentation and high NPN levels may end up as ammonia. Turning of the grass will be essential to get adequate drying in 2-3 days and using an inoculant would be good practice.

Late-calving cows

Focus should now be on late-calving cows. With so much grass available it is easy for these girls to get too much grass, fewer acid minerals, less high energy supplement and, therefore, to be at risk of suffering from Milk Fever. It is also important to develop a successful plan for transitioning late calvers, even if they are cleaning up after the herd. Ensure you calculate the grass use accurately (it is easy for this to be substantially less or more than required), and continue to feed the supplements.

Late calving cows are a particular risk group for non-cycling and not being mated successfully in the 1st round of mating (especially if they had milk fever). This group of cows has a much higher chance of being culled for empty or late pregnancy, but has the potential to do well if fed and managed appropriately.

Every farm will have different management programmes, but consider keeping these cows in the colostrums longer, while possibly on once-a-day milking, and then entering them into the 2nd or smaller/younger herd if there is one.

Any sick cows and those cows which have been treated for metritis subsequent to metri-checks within a month of calving should also be considered for the 2nd herd. This group likewise has a higher risk of going empty.


The precautionary recall of products that had been manufactured using potentially contaminated Fonterra WPC came right out of left field on the 2nd August.

It took 2 weeks for retailers of that product to get all the potentially affected products off the shelf. Our wider afield customers were very jittery, but the next GDT bounce-back indicated that they had faith in Fonterra to put it right. It is a bit ironic that markets like Sri Lanka and Bangladesh and some of the Russian states imposed the harshest restrictions on further trade.

Fonterra has been widely criticized in the press for its handling of the situation in the absence of the CEO, who was overseas at the time. Gary Romano subsequently resigned and 2 other managers took an enforced holiday.

Quality control in the food chain

Farmers have always known they are at the start of a very long food chain, and quality starts with them. It has been expected that the rest of the chain had fewer opportunities for systemic failure due to unavoidable influences.

Subsequent to finding that the initial tests were wrong, this incident will likely result in the blame game being played out in court, but it serves as a timely reminder that quality is only as good as the weakest link. It also highlights that media management of these often technical events is a part of the quality process.

We could be similarly exposed to a significant biosecurity incursion like Foot and Mouth, or even industrial espionage.

The underlying importance of sound science has been evident throughout these events and it is to be hoped that this is recognized in the future.

Our biosecurity and food safety are dependent to some degree on government departments. However, as our government performs its roles with “managed risk” and fewer government controls in business, it is even more important for all dairy product processors to have a robust and tested risk management response running alongside its quality systems.

The many reviews underway at present will be interesting reading when they are released. We hope they will serve as guides in “how we could have done better”.

The opinions expressed herein are those of DPSL and we are not responsible for any actions you take or resultant consequences of actions taken based on the information provided in this communication.

Alltech Review August.

We acknowledge the support of Alltech NZ in the preparation of this update.

Too Much Winter Grass?

For most of us, it is hard to remember that this is still winter. Spring calving farmers now know why autumn calving herds find calving so much easier – dry warm weather and no mud!

Too much winter grass – ketotic cows

However, the unusually high growth rates of June and July and going into August in many parts of the country mean average pasture covers at PSC were, and are still, high, with not enough mouths at maximum appetite to cope. This is causing some big dilemmas on farms and the results in some cases are starting to show up as ketotic cows in the face of supposedly plenty of grass.

Problems for lactating cows

Pasture-based dairying is always a compromise between what is best for the cow, best for the pasture and best for the long-term productivity of the farm. Traditionally in New Zealand, it is the cow that has been most compromised, especially at calving and in early lactation, as too much attention is focused on pasture quality and control. The 21st century cow does not cope well with this – if you cut her off at the knees before she has recovered from the metabolic and hormonal changes of calving and before she has had the opportunity to develop best appetite and intake, there are big downstream costs. Too much condition loss, poorer reproductive lactation length and lactational persistency included; clinical and sub-clinical ketosis may exist on top of the above.

We also know that at some stage we need to have control of pasture growth to maximise quality going into peak lactation and summer, so as to maximise mid-lactation production.

To meet these two goals, we recommend that the cow comes first through calving, so from 1st July, August into September. Worry about achieving maximum gut fill in a healthy cow with optimum appetite, not necessarily about achieving post-grazing residuals of 1500-1600 Kgs DM / ha! From late September through December pasture management is critical, but by then, if you have looked after the fresh cow, she will have the appetite to eat more (and not care what it is!) and weather conditions will tend to favour pregraze mowing to both increase cow intake and get even control without waste and without having already stuffed cow performance for the rest of the season.

At the moment, too many early lactation cows are being forced to eat into the base of overlong pasture which is actually not helping their long term goals of total performance, health and reproduction. This keeps rotation lengths long and slow, which means even more poor quality grass is developing ahead. And much of this is especially poor quality at the base. Having seen some of the lowest pasture sugar levels we have ever recorded this autumn, we are now seeing exceptionally low ME levels in grass that looks o.k. at a glance. Hamilton’s record cloudy July certainly hasn’t helped in the Waikato but overall NDF levels are high, digestibility and energy low. Grass is tough. It is hard for cows to actually collect as much as they need to meet their energy needs especially at this stage of lactation, anyway and this is made worse if they have to eat the really poor quality stuff at the base. This type of management also has the untoward result of actually delaying the development of maximum appetite and exacerbating the rate and degree of body condition loss, hence the high potential for clinical and sub-clinical ketosis. This is further worsened if cows are not being fed enough supplement. If cows are cleaning out the bins and trailers you need to be giving them more! With an apparent pasture surplus, this can be difficult to get your head around, but you cannot change how the early lactation cow is designed, and you cannot achieve higher bite rate or bite size just by wishing for it to happen!

The best option at the moment – don’t get too concerned about pasture grazing residuals with milkers. There is plenty of time to sort this out without compromising the rest of the season! The number one priority is to make sure they are full and fully fed.

Practise two tier grazing. The leafiest stuff on the top is all that is ideal for milkers and the colostrums. Put them through the paddock first, grazing down to around 2000 only, and then follow with the remaining dry cows and springers while you still have them! This means that calving cows can get a much bigger area which is better for them and they get less problematic N and K in their diet. There is no excuse for any cows overgrazing at the moment on most farms. In some cases, some early cropping or early silage harvesting may be needed but there is still a long way to go. We have the opportunity to fully feed early lactation milkers and develop high intakes, but it will not happen if they are on limited pasture area grazing non-milk-producing, stalky, low-energy, tough grass, especially if not getting adequate low volume, energy-dense supplements as a complement.