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exports Ways to reduce your farm’s footprint
ENVIRONMENT FARM FOOTPRINT
Solutions to reduce farm footprint
New DairyNZ research shows farmers can identify ways to increase efficiency and reduce environmental footprint – but there will be challenges for some.
The Greenhouse Gas Partnership Farms research project worked with farmers to identify and model how their farms might reduce both nitrogen loss and greenhouse gas emissions.
“Making these gains will be the first steps as farmers work towards the Government’s 2030 climate change targets,” said DairyNZ strategy and investment leader Dr Bruce Thorrold.
For some farms, the research identified options that offered lower footprint and higher profit. For already highly efficient farms, footprint gains tended to come at a cost to profitability.
“It is more challenging for farms that are already efficient. For them, it’s about where even the smallest gains can be made. Small improvements on individual farms add up at national level.”
The dairy sector is working through a process of helping farmers know their emissions profile numbers, identify options and implement solutions.
“The Partnership Farms research highlights that to reduce footprint, all farms had to reduce total feed eaten and nitrogen surplus. The findings highlight the need for ongoing research into technology to reduce footprint without reducing feed,” said Dr Thorrold.
“These technologies are required for dairy farmers to achieve the challenging Climate Change Commission recommendations. Investment in R&D and support from the government will be crucial.”
The Partnership Farms research is part of DairyNZ’s Dairy Action for Climate Change commitment to support dairy farmers and the wider sector to address on-farm methane and nitrogen emissions longterm.
The Partnership Farms modelling was carried out for six farms in Waikato, Southland and Canterbury.
The work found a strong understanding of the farm, the people and the farm system was important at the beginning. The process involved a Whole Farm Assessment and modelling in Overseer and Farmax.
Dr Thorrold said dairy farmers are committed to playing their part in addressing climate change, alongside the rest of New Zealand, and there is a wide range of work underway on farms throughout the country to achieve this.
“It’s about doing the right thing as a sector and consumers are also increasingly demanding sustainable products.”
The next step is for DairyNZ to work more widely with farmers to start exploring their own system adaptations through its Step Change project. Step Change is helping farmers understand the options best suited to their farm and how to improve profitability and water quality and reduce greenhouse gas emissions. A series of Step Change events will start on March 10 to help farmers explore their options.
“Our regional teams are working with farmers to help them understand their starting position and then uncover the opportunities available – some of which are demonstrated through this research,” said Dr Thorrold.
Farmers interested in learning more about improving their environmental performance and profitability can find out more at dairynz.co.nz/stepchange
Case studies: See the Greenhouse Gas Partnership Farms’ case studies on the DairyNZ website at dairynz. co.nz/GHGfarms. These detail options for farms to reduce both nitrogen loss and greenhouse gas emissions, while maintaining or increasing profitability in some cases.
Step Change: Farms such as Tokoroa Pastoral, which are highly efficient, generally can only slightly reduce environmental losses without affecting profitability.
A SNAPSHOT OF ONE PARTNERSHIP FARM CASE STUDY – TOKOROA PASTORAL
Five options were modelled for the Moss family farm, Tokoroa Pastoral, in Waikato, owned by climate change ambassador George Moss and his wife Sharon. The 70-hectare farm milks 175 cows.
The modelling showed reducing replacement rate achieved a small reduction in greenhouse gases and a small gain in profit, and looked to be the best opportunity. This option relies heavily on reducing the not-in-calf rate and finding an alternative use for additional grass grown on the support block.
The modelling on Tokoroa Pastoral also showed reducing imported supplement is the option most likely to reduce GHG, but this tended to reduce profitability. When combined with a reduction in nitrogen fertiliser use, it made the largest reductions in GHG emissions, with a small drop in profitability.
George said he had taken steps to reduce emissions, including fastforwarding his genetics with sexed semen, using urease inhibitors and reducing his nitrogen surplus.
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STOCK CALVES SLIPPING
Early scans picking up pregnancy losses
Farmers who scan their cows early to see if they are pregnant have the advantage of being able to get a cow that has slipped back in calf. Karen Trebilcock reports.
During early pregnancy scans, farmers will often hear the word ‘slipping’ from the vets.
It’s describing a pregnancy that has ended, for whatever reason, and the foetus is no longer alive.
“Actual conception rates, sperm fertilising egg, can be as high as 90% in cows but losses can occur at any stage, particularly early on, so that we end up with our 60% target,” said vet Jason Darwen of Clutha Vets.
A pregnancy could be detected from about 28 days by manual palpation or ultrasound scanning.
“At 35 days we’re looking for something that is about a centimetre long from crown to rump if it was stretched out and we’re looking for a heartbeat to confirm it’s alive.
“At that stage it is just a very quick flutter,” he said.
“Unfortunately, some of these early detected pregnancies will not survive, and we consider it normal to lose up to 5% of pregnancies diagnosed between 28 and 42 days (four to six weeks), so we always recommend rechecking these cows at a later stage.”
He said if a herd was not scanned early, the cows would eventually show up as late or empty, and the farmer would never know that the cow had been in calf and slipped.
“Some of these cows may show up with long return intervals between services with no explanation.”
Farmers started doing early pregnancy scans at least 15 years ago and for about 5% of Clutha Vets’ dairy farmers it was now routine.
“The original reason was to pick up phantom pregnancies – cows that had been mated and had not come back on heat but were not pregnant. We have the option of treating these cows with appropriate hormonal interventions at this stage.”
Cows that were recorded as having been mated but did not have a viable pregnancy at scanning could be given a PG (prostaglandin) injection if they have a corpus luteum (CL) on the ovary. This may bring them back on heat in a few days.
“It means the farmer can do something quickly and hopefully get the cow back in calf,” Jason said.
“For farmers who only scan after mating is finished it’s too late for them to do anything if there is a high empty rate.
“If they scan early they can leave the bull in or keep going with AB. For some clients it can be better to have late calving cows than empty ones.”
Allan Bote, farm manager at Braeburn Dairies at Clydevale in Otago for the past six years, has done early pregnancy scanning since the farm owner, Mark Shore, decided to go no-bull five years ago. They used to mate for 15 to 16 weeks using a combination of AB and natural mating but now use AB for 11 weeks only.
“We had to adapt when they phased out inductions,” Allan said.
Planned start of calving is August 3 with all of the 800 to 850 cows milking by the
Braeburn Farms manager Allan Bote talks to vet Jason Darwen about early pregnancy scanning of the herd.
Right: A scan of a pregnant dairy cow 40 days following conception.
end of October. They do an early scan eight weeks after the start of mating and this year decided to use AB for another week, until January 17, after the early scan showed not enough cows were in calf.
A final scan to find empties for culling is done six weeks after the end of mating and, if Allan has seen cows riding that scanned as pregnant at the end of the season, he will do a final one in May.
The farm uses Friesian straws for its replacements and finishes with beef breeds Speckle Park and Stabilizer instead of short gestation dairy because it wants to avoid putting calves on the bobby truck.
Jason said the number of slipping pregnancies (dead foetuses) at Braeburn was not unusual, and no particular reason has been found there for calves slipping.
With few farms doing early pregnancy scans, and with farms doing them at different stages of pregnancy, it was difficult to benchmark calves slipping between farms and from one season to the next.
“Certainly if there are an unusual number on a farm we’d go looking for causes,” he said.
“BVD can cause early embryonic loss, but the vast majority of our herds, including Braeburn, are regularly monitored for BVD using bulk milk testing.
“We do get the odd hiccup with BVD in the district. A lot of the herds haven’t had any exposure for years so any introduction has a significant effect.”
Salmonella, M. bovis, and other pathogens could also cause cows to lose a pregnancy, he said.
“Macrocarpa and mouldy balage will do it as well, but that usually happens in late pregnancy.
“If cows are not stressed, if they are healthy and happy and well fed, then you are doing everything right. A few early pregnancies slipping is just part of mating.”
Allan said the herd was fed grain daily throughout the season on the rotary platform while milking to smooth out grass quality and quantity issues during mating and early pregnancy.
“One of the hardest things is you’re mating at the time of the year when the weather here can be very changeable,” Allan said.
“It means grass quality is very changeable too.”
Jason said it was unlikely that a farmer would notice an early foetus slipping.
“In those early stages it’s smaller than a grape, so the only way to detect it is by doing early scans.”
As a PG shot would abort a foetus, care was always taken to make sure the cow was not pregnant before it was used.
“It’s a very thorough process. If we scan a cow empty we always do a manual check as well before using PG.
“When you are scanning you’re never 100% sure you are seeing all of the uterus.”
He said sometimes they would find a dead foetus in one horn of the uterus, but a viable one in the other.
He said scanning did not cause pregnancy losses. Ultrasound was widely used across a wide range of species, including humans.
However, inseminating a pregnant cow could cause an abortion so farmers picking cows for AI later in the mating season needed to make sure they were genuinely on heat.
“We don’t just look at the tail paint,” Allan said. “We look at all of the data we have on the cow, such as when she was last inseminated, and we look for other signs of riding such as rub marks.
“If it’s been wet or there are trees in the paddock the cows could have rubbed against we are very careful, and we redo the tail paint every week so it is always fresh.”
Early pregnancy scanning also improves detection of twins and occasionally triplets.
Of the 400 cows scanned eight weeks after mating started at Braeburn this season, there were 16 sets of twins.
“We can’t sex a foetus until it is 60 days old so we have no idea if they will be freemartins,” Jason said.
VETS VOICE ULTRASOUND
Modern ultrasound
Left: Ultrasound shows fluid in the chest of a heifer with severe pneumonia. Fluid is black, and the diaphragm is seen as a grey band. dollars. Middle: Modern cattle ultrasound units are lightweight and portable, meaning they can be used more readily onfarm. Below: A section of small intestine in a cow, which is blocked with gravel.
Words by: Lisa Whitfield
to make a definitive diagnosis, deciding whether surgery is warranted, and assisting ultrasound saved the farm a lot of money
Most farmers are accustomed with giving a prognosis. on treatments that would not have saved to the sight of the vet For cattle with internal problems, the heifer and it allowed us to end her putting on their ultrasound ultrasound gives us a window into suffering much sooner. gear to do pregnancy the cow to provide more information, So how does ultrasound work? The diagnosis at this time of the year. without having to make an incision. A transducer contains crystals that emit Modern ultrasound units are lightweight, few years ago, I was asked to examine a ultrasound waves into the body. The waves ergonomically designed machines cow that was off her feed and off milk are bounced back by whatever they hit, that allow the user to move about during spring. After the clinical and depending on how solid the object is, freely and work quickly and examination, everything pointed either more or fewer waves are bounced comfortably for a few hours at clearly towards a problem in her back to the transducer. A computer a time. abdomen, but it was unclear organises the signal to create an image,
Did you know that whether she needed surgery with more dense objects appearing whiter, ultrasound can be used for or not. Ultrasound was used to and less dense objects appearing blacker. more than just pregnancy examine her abdomen, which For example, bones are very solid and diagnosis in cattle? showed that there was a blockage reflect almost all of the ultrasound waves,
With the ability to see more Lisa Whitfield or a twist, and it allowed us to see while soft tissues such as muscle appear as than 20cm deep through the skin that surgery was necessary to save a variety of greys, and fluids such as urine and into the cow, the latest ultrasound the cow. We went ahead with surgery and are black. units can be used to examine the internal when we opened her up, we found a 20cm Ultrasound can provide useful organs quite readily. From viewing the long piece of intestine that was completely information to assist a vet in making heart and lungs in the chest, to the liver, blocked with gravel. The blockage was able clinical decisions for cases. Performing stomachs and intestines in the abdomen, to be cleared, and the cow recovered, got an ultrasound exam can improve the there are many organs that can be assessed in-calf, and went on to have a productive outcome for a sick cow significantly, for problems. season. whether through improved treatment
In a sick cow, a thorough clinical exam is In another case, a dairy heifer presented plans, or allowing the decision to be made the fundamental process that vets perform to me with signs of pneumonia. The signs to euthanise. to identify abnormalities. Once all of her were bad, but not enough to say she was Talk to your vet about what they can problems have been identified, a diagnosis not saveable. We performed ultrasound offer in this area – not everyone will carry can be made, or often, a list of potential on her chest to help decide whether to an ultrasound unit around in the truck diagnoses is made. Ultrasound can provide go ahead with treatment. The ultrasound with them, but most will have a portable additional information by giving the vet showed she had a huge build-up of fluid unit available that can do the job. an extra visual assessment of internal around her lungs, and the prognosis was structures, which can be useful in decision unfortunately grim. In this case euthanasia making around the case, including helping was best choice for her. The use of • Lisa Whitfield is a Manawatu-based production animal veterinarian.
