
The objectives of this project were to:
1) quantify the benefits of deferred grazing
2) establish criteria to help farmers identify when deferred grazing is appropriate in their farm system.
This was achieved by comparing standard rotational grazing and deferred grazing in replicated plot studies at two sites:
- Mataiwhetu Station – a summer wet property
- Otorohaea – a summer dry property.
The deferred treatment was not grazed between mid-October and the end of summer / early autumn (depending on the farm) but was rotationally grazed after the deferred period for the remainder of the study.
Comparing the effect of standard rotational grazing and deferred grazing in a replicated split-paddock study on three sites:
- Mataiwhetu Station – a summer wet property
- Otorohaea – a summer dry property
- Pukekauri Farms – a summer wet property.
Background
‘Deferred grazing’ is a management tool used to maintain pasture quality and rejuvenate paddocks on pastoral farms. In the deferred paddocks, perennial ryegrass produces seeds, new tiller buds that form at the base of existing plants remain dormant over summer and develop into new tillers in autumn. The deferred pastures are grazed to low residuals at the end of the deferred period over one or two grazing’s (e.g. to 1500 kg DM/ha) so that the ryegrass seedlings and new ryegrass tillers have access to light. The previously deferred pastures are treated as renewed pastures and are grazed carefully with light stock for short periods.
Deferred grazing has been used by some hill country farmers in the mid Northern North Island New Zealand for more than a decade. These farmers could see benefits for both the deferred pastures and for the rest of the farm and wanted to quantify those benefits through a science-led project.
Key results
Compared to standard rotational grazing, deferred grazing improved pasture performance by increased:
- ryegrass ground cover and tiller densities
- topsoil moisture
- anaerobically minerablisable nitrogen (the amount of nitrogen potentially available for plant uptake) and reduced:
- facial eczema spore counts
- weed content.
There was reduced nutritive value in the deferred paddocks during the deferred period, but pastures rapidly recovered after the deferred period. Decline in quality of the deferred pastures was not enough to offset overall farm-scale profitability.
When compared to standard rotationally grazed pastures, the deferred pastures grew less during the deferred period but more after the deferred period, so dry matter production was similar in both over the experimental period.
FARMAX modelling carried out on one of the farm sites showed there was an 8% increase in total farm and per-hectare gross margins when 15% of the farm was deferred.
Benefit for farmers
This project provided science-based evidence for the benefits of deferred grazing compared to standard rotational grazing, on three farms in the Bay of Plenty and Northern Waikato. Information from this project has been disseminated in a handbook and a fact sheet including a checklist for farmers on how to defer paddocks.
Timeline and investment
This was a three-year study with investment by B+LNZ of $180,000 over the duration.
Outputs
Farmer events
- Farmer field days throughout the project.
Popular press articles
- Country-Wide: “Giving pastures a break”
- Ballance Grow magazine: “Deferred grazing plusses”
- New Zealand Herald: “Weighing up deferred grazing benefits”
- B+LNZ Knowledge Hub article: “Deferred grazing – a tool to build farm system resilience”
Scientific publications
- New Zealand Grasslands Association Journal : "Effects of deferred grazing during late spring and summer on pasture productivity in Waikato and Bay of Plenty hill country”
B+LNZ resources
- Handbook for farmers including decision ‘rules’ to help farmers identify when deferred grazing is appropriate in their farm system.
- B+LNZ factsheet.
Partners
This was a Ministry for Primary Industries Sustainable Farming Fund project led by AgResearch and co-funded by B+LNZ, Ballance Agri-nutrients, Bay of Plenty Regional Council with in-kind support from the Waikato Regional Council, Plant & Food Research and AgFirst.
Lead Scientist: Katherine Tozer (AgResearch).
Farmers involved: Allen Coster, Rick Burke, Jon Sherlock, Brian Thomas.
B+LNZ point of contact: Maria Shanks and Cara Brosnahan.

The aim of this study was to provide an understanding of introducing refugia into a lamb finishing operation that had a triple drench resistance issue. Refugia, introduced through lambs with susceptible parasites, was compared to the more conventional practice of quarantine drenching.
Background
Resistance of parasites, or worms, to all classes of drench is a major concern in New Zealand farming systems. Intensive finishing and hogget grazing systems are at high risk of developing triple drench resistance, as are areas on farm predominately utilised for grazing young stock.
There is an opportunity to better understand drench resistance on farm. This project harnessed the power of relationships between a group of Wairarapa breeding and finishing properties, their vets and industry experts to have an in depth look at the impact lambs supplied from the group breeding properties had on a large scale finishing farm receiving their store lambs, including the development of triple drench resistance on this farm.
Key results
Know your worms. It is important to have a recent faecal egg count reduction test (FECRT) from the farm you are buying lambs from prior to arrival to your farm. By doing this, you know if you are introducing parasites that will be susceptible to drench and can introduce refugia on your farm, or drench resistant parasites that will increase the likelihood of drench resistance on your farm. In this study, the group of farmers shared their recent FECRT results and explored how their results impacted the next farm their stock traveled to. The project enabled them to reduce cost and gain efficiencies by cutting out ineffective quarantine drenches, improved the relationship between breeding and finishing farms and showed a start to reversing triple resistance status of the finishing farm involved.
Triple combination drenches may not be effective quarantine drenches. This includes for hogget grazing blocks and stock purchases. To know what quarantine drench you need, you need to know your worms.
For the introduction of refugia onto the farm the eggs must develop into infective larva, be ingested by lambs and breed. The time of the year to best achieve this and not induce clinical parasitism, or disease, needs to be considered for each farm system.
In this study, an increase in efficacy of drench was shown on the farm by both refugia and quarantine drench procedures. Testing will continue on this farm over the next 2 years to compare refugia and quarantine drench to determine if one or the other is better to reverse the effects of drench resistance over time.
Refugia can come with risks. In this study there was an unintended introduction of barber’s pole worm in the refugia trial. Barber’s pole was not detected at the initial screening but was detected in the refugia farm when tested 28 days later.
The results from this study so far suggest that both quarantine drenching and refugia can be used as management tools to reverse triple drench resistance. However, due to the short period of this project (6 months) testing will need to continue over the next 2 years to reliably confirm these results.
Benefit for farmers
This study demonstrated that by knowing the status of the parasites both on your farm and the farm you are buying stock from, you can put in place effective management strategies to reverse triple drench resistance.
Timeline and investment
This was a six-month study with investment by B+LNZ of $10,000 over the duration.
Partners
This project was carried out by Inside New Zealand Ltd, PGG Wrightson, South Wairarapa Vets and funded by B+LNZ and Silver Fern Farms.
Project leads: Renee Hogg (Inside New Zealand Ltd) and Andrew Dowling (PGG Wrightson).
Farmers involved: Wairarapa Producers Group.
B+LNZ point of contact: Will Halliday and Cara Brosnahan.

The aim of this study was to analyse existing data sets from animal health laboratories around New Zealand and from animals at slaughter via meat processing companies to see if the prevalence and distribution of facial eczema (FE) in beef cattle could be quantified.
Background
Facial eczema is a disease of concern in New Zealand known to affect sheep, cattle, goats, llama and alpaca. FE is attributed to the ingestion of a toxin (sporidesmin A) produced by strains of the fungus Pseudopithomyces chartarum which sits in the litter at the base of some pasture swords.
The damaging impacts of FE on sheep and beef farms include reduced production and income, stress on farmers and their animals, impacts on animal welfare and environmental concerns around zinc treatments. As the fungus prefers warmer temperatures, it is likely that an increase in temperatures due to climate change will increase the number and extent of FE outbreaks in New Zealand.
While it is known that FE affects beef cattle, it is unknown to what extent or where in New Zealand it mostly occurs.
Benefit for industry
Understanding the prevalence, distribution and impact this disease has in beef cattle allows an informed strategy for the resources needed for research and management.
Key results
The data showed presence of FE in beef cattle. However, due to the limitations of the data from the animal health laboratories and meat processing companies, this could not be quantified. The limitations of the data were:
- the number of animals tested/affected were not consistently recorded
- there was a lack of detail in the meat processing data on livestock type and origin available
- there was a lack of detailed data from the lab on what test was used for diagnosis and if this was consistent across the different laboratories
- it is suspected that not all farmers with suspected FE had their animals tested, so the data was not truly representative
Timeline and investment
This was a seven-month project with investment by B+LNZ of $8,000 over the duration.
B+LNZ investment: B+LNZ investment into this project is $8,000 over the duration of the project.
Partner
This project was led by Ken Geenty and funded by B+LNZ.
B+LNZ point of contact: Cara Brosnahan.

This project investigated the following:
- the potential effect of long-acting drench products on the rumen microbiome.
This was done using 300 ewes in total that were given one of three different treatments (long-acting drench product, controlled release capsule and untreated control). The rumen microbiome of these animals was sampled three times throughout the trial
- the effect of parasites on ewe growth, Body Condition Score (BCS) and fecundity over the summer-autumn period.
This was done by assessing 300 ewes (as above) and three measures were taken:
- Ewes were weighed and their BCS were assessed at days 0, 36, 78, 182 and 320.
- Faecal samples were recovered from a sample of ewes from each treatment group at days 0, 36, 78, 182 and 320 to determine the parasite load, or worm burden.
Pregnancy status was determined by scanning. During lambing, all dead lambs were collected, and weaning lambs weighed.
Background
Long-acting drench products can have activity against organisms other than parasites, for example fungi and bacteria. The effects of long-acting drench products on the microbes within the rumen (rumen microbiome) are largely unknown and may influence such things as animal performance and production of green-house gases.
Long-acting drench products are administered as a pre-lambing treatment of ewes by about 80% of sheep farmers in New Zealand. Pre-lamb drenching is done as farmers expect that by treating ewes, both ewes and their lambs will be heavier at weaning and ewes will be in better condition. In particular, it is widely believed by farmers and veterinarians that poor condition in ewes (low BCS) is caused by parasites and that by focusing drench treatments on these animals, it will result in significant production gains.
Key results
- Farmers may not be making money from pre-lamb drenching every year.
- If resistant parasites are already on your farm, then using long acting anthelmintics will make the issue worse.
- To improve profitability, considering ways of improving lamb drop and lamb survival is likely to be more important than drenching.
- There was a change in the rumen microbiome of drenched vs undrenched animals. This was the first study to investigate the influence of long-acting anthelmintics on the rumen microbiome and it provided baseline information for future studies to build upon. Future studies are needed to understand what the observed changes in the microbiome of the treated animals in this study may mean for ewe performance as well as methane production.
Benefit to farmers
This study suggested that a financial benefit resulting from the administration of these long-acting drench products pre-mating is unlikely.
These results are consistent with earlier studies which indicate that 1) parasites are not a major cause of low BCS in ewes on New Zealand farms and 2) studies showing that the production responses to the use of long-acting drench products are, to an extent, temporary and tend to decline or even disappear completely after the products have expired.
Timeline and investment
This was a 32-month project. B+LNZ investment was $190,000 for the duration of the project.
Outputs
Popular press
- B+LNZ media release: Do ewes really need a pre-lamb drench?
- B+LNZ e-diaries: The value of long-acting drench treatments again under the spotlight
Scientific manuscripts
- New Zealand Journal of Agricultural Research: "Production responses in adult ewes to long-acting anthelmintic treatment pre-mating: relationship with body condition score"
- Scientific reports: “Anthelmintic compounds with long-acting, broad-spectra of activity impact the rumen microbial communities of grazing sheep”.
Partners
This work was led by AgResearch and co-funded by AgResearch and B+LNZ with in-kind support from Pāmu.
Lead Scientist: Dave Leathwick.
B+LNZ point of contact: Suzanne Keeling.

This project measured the concentrations of ivermectin (a macrocyclic lactone) reaching target cattle tissues (abomasum and small intestine) and the target parasites (Ostertagia and Cooperia) when given to cattle orally, by injection or pour-on.
Background
While it is known that different routes of drench administration can result in variable efficacy against some parasite species it is not understood why this occurs or why different organs appear different. Despite evidence that pour-on administration is the least effective and most likely to select for resistant parasites, these products are the most common for the cattle market in New Zealand today. Solid evidence explaining why one route of administration is better or worse than others is required to understand if a change on-farm is required.
Current data indicates that in cattle, oral drenches are more effective than injections or pour-ons and this is probably because orals deliver a higher concentration of active ingredients to the target parasites in the gut.
Despite this information, most cattle farmers continue to use pour-ons because of their ease of application. This almost certainly results in failure to properly control Cooperia (with an associated production loss) and the likely promotion of drench resistance in Ostertagia.
Key programme results
Route of administration is likely to influence the exposure of ivermectin for different parasite species:
- for most parasite species (e.g. Cooperia species), oral administration of ivermectin will deliver the highest exposure of parasites to the drug
- for Ostertagia ostertagi, administration of ivermectin by injection is likely to be the preferred option for achieving maximum drug exposure.
Ivermectin concentrations were highest in the small intestine following oral administration.
Benefit to farmers/industry
This knowledge provides farmers and veterinarians with scientific evidence on the type of administration of drench that is most effective in cattle and that the most effective administration may differ depending on the parasite targeted. Changes to the most effective way of administering drench will help reduce the likelihood of drench resistance and improve productivity.
Outputs
Scientific publication
- International Journal for Parasitology: Drugs and Drug Resistance Route of administration influences the concentration of ivermectin reaching nematode parasites in the gastrointestinal tract of cattle
Presentations
- Two B+LNZ field days.
Timeline and investment
This was a 20-month project. B+LNZ investment was $95,000 over the duration of the project.
Partners
This work was led by AgResearch and co-funded by B+LNZ and AgResearch.
Lead scientists: Dave Leathwick and Tania Waghorn.
B+LNZ point of contact: Suzanne Keeling.

The aim of this project was to develop an udder scoring system associated with udder health, lamb survival and lamb growth rates and can accurately be used by farmers.
To do this, the following was investigated:
- recognise and describe the range of udder and teat defects found in commercially-farmed ewes
- factors associated with clinical and subclinical mastitis in ewes
- the impact of udder and teat defects and udder health on lamb survival and pre-weaning live weight gain.
Background
Lambing percentages in New Zealand have increased over the past twenty years, putting increased emphasis on ewe udder health to enhance lamb survival and maximise pre-weaning growth rates.
Many farmers indicate that they examine the udders of their ewes and make culling decisions based on this. However, there is sparse information available, and therefore guidance, on what farmers should be examining and the impacts of various udder characteristics on lamb performance.
Without this knowledge, farmers may fail to cull ewes who will not rear lambs successfully or whose lambs will display poor growth rates. Conversely, they may incorrectly cull ‘sound’ ewes.
Key programme results
Udder scores can be used to determine culling decisions or identify ewes whose lambs had greater odds of failure to survive weaning.
Udder palpation, udder symmetry and clinical mastitis scores during lactation were associated with lamb growth rates.
Benefit to farmers
This project provided information and resources to more accurately assess ewe udder health and make sound culling decisions.
Lambs that are born to ewes with udder defects will have a reduced chance of survival and the lambs that do survive grow an average of 25g less per day than lambs whose dams had normal udders so for long term productivity, understanding udder defects is hugely important.
Outputs
Six presentations
- Six to farmer and industry audiences.
Popular press articles
- B+LNZ website: “Udder issues limiting production”
- B+LNZ website: “Examining ewes’ udders to identify possible problems” video
- B+LNZ scene and herd podcast: “More and better lambs, just by checking ewes’ udders”
- B+LNZ factsheet: "Examining ewe udders"
- Webinar: “Why check ewe udders”
- The Journal: “Longevity and wastage in New Zealand commercial ewe flocks – a significant cost”
- Rural News: “Check ewes’ udders after weaning – study”
- Rural News: "Reducing ewe deaths could save $28m annually"
Scientific publications
- New Zealand Society of Animal Production
- New Zealand Veterinary Journal: "Associations between lamb growth to weaning and dam udder and teat scores"
- New Zealand Veterinary Journal: "Investigating associations between lamb survival to weaning and dam udder teat scores"
- New Zealand Society of Animal Production: “Investigation into udder characteristics, mastitis and milk production in crossbred sheep”
Timeline and investment
This was a four-year project. B+LNZ investment was $345,000 over the duration of the project.
Partners
This work was led by Massey University and funded by B+LNZ, Massey University, the C. Alma Baker Trust and Lincoln University.
Lead Scientist: Anne Riddler.
B+LNZ point of contact: Suzanne Keeling.

Previous research has shown that sowing a catch crop can reduce nitrate leaching losses by as much as 40%, as well as improving nitrogen use efficiency and farmers’ profitability. This project aimed to upscale this previous applied research into working winter crop rotations in Canterbury and Southland and adapt it to the various soil and climatic conditions.
Background
The use of catch crops is recognised as a potential tool to help reduce farmers’ nitrate leaching losses but without good guidelines, the successful adoption of such technology is likely to be disorganised with variable outcomes.
This project was a farmer-led initiative to develop and demonstrate the use of catch crops in winter forage grazing rotations to lower the nitrate leaching footprint. Using catch crops successfully not only reduces nitrate leaching losses but increases nitrogen use efficiency and feed production on farm.
For more information about this project visit: https://www.lincolnagritech.co.nz/capabilities/capabilities-and-projects/catch-crops/
Key results
- The introduction of catch crops into winter forage rotations can be both a practical and an economically viable farm management tool to help reduce nitrogen loss from winter forage grazing systems.
- Timely sowing (as early as possible) with the appropriate winter-active species is important to make the most effective use of these catch crops.
- High sowing rate are needed to get good nitrogen uptake, fast canopy closure and to produce a high yielding crop.
Benefit for farmers
This project established a practice of sowing winter catch crops as a normal part of winter forage management and demonstrated effective alternatives to farmers that lower nitrate leaching losses after winter forage grazing.
Timeline and investment
This was a three-year project with investment by B+LNZ of $30,000 over the duration.
Outputs
Farmer events
- Three field days throughout the programme
Popular press articles
- Sarah's Country – “The benefits of using catch crops”
- Rural News – “Hardy catch crops may reduce nitrate leaching by 40%”
- Rural News – “Aiming to improve farmers' profit and environment”
- NZ Dairy Exporter – “Catch the Flow”
- Rural Contractor – “Field Trials Reinforce Value of Catch Crops After Winter Grazing”
- Rural Contractor – “Dairy Farmer's Spader Takes Star Role In Catch Crops Trial”
- Catch Crops interview on RNZ, listen in at 1.54'
- B+LNZ “Catch crops prove a valuable environmental tool”
Scientific publications and conference proceedings
- FLRC Conference, “New tillage technology to improve catch crop outcomes in Southland”
Resources
Partners
This is a Ministry for Primary Industries Sustainable Farming Fund project led by Lincoln Agritech and co-funded by MPI, B+LNZ, Ballance Agri-Nutrients, Ravensdown, Agricom, Luisetti Seeds with in-kind support from Craigmore Farms, Dairy Holdings, DairyNZ, Foundation for Arable Research (FAR), South Island Dairy Development Centre (SIDDC), Irrigo Centre Ltd, and Lincoln University’s Centre for Soil and Environmental Research.
Lead Scientist: Peter Carey (Lincoln Agritech).
Farmers involved: Bruce Taylor, John van Vliet, Gary McGregor, Shaun Wilson, Andrew Gorman, Clint Jordan, Simon Kelly, Chris Giles.
B+LNZ point of contact: Suzanne Keeling and Cara Brosnahan.

The aim of this project was to evaluate different ways of communication for their reach, impact and associated behaviour change. Parasite management is important for every livestock farmer and this topic was used to help evaluate five different communication methods.
The project used:
- analytics to assess the reach of the material
- models to predict the impact of this parasite campaign
- online surveys taken by participants immediately after viewing the material
- online surveys taken by participants approximately 2-3 months later to assess if learnings from these communication methods was adopted.
Background
Drench resistance is an increasing issue in New Zealand. Farmers need to have access to the most up to date information so informed decisions can be made for parasite management with the aim of preventing or reversing drench resistance on their farms. To do this, the information needs to be communicated effectively and have the desired impact.
A variety of communication channels were used to provide information to farmers:
- A podcast with farmers at various stages of their drench resistance journey.
- Wormwise drench poster.
- Wormwise workshops/e-learning module.
- An animated video on understanding parasites and anthelmintic resistance.
Each of these channels of communication were evaluated for reach and impact on farmer knowledge, attitude, skills, aspirations and behaviour change. They were benchmarked against other B+LNZ comms messages. Additionally, the success of each communication method was compared to each other.
Key results
- 251 farmers and 17 vets completed the initial survey and 29 farmers completed the follow up survey.
- The podcast was the best performing resource with almost 2,000 downloads.
- Farmers and vets noted that it was good to hear current farmers experiences rather than just theory from scientists.
- Farmers recognised the need for multiple channels of communication that are targeted at various levels of knowledge.
- 75% of people surveyed and who had viewed the resources planned to review or change their parasite management practices in the next 12 months.
- Engaging with the resources appeared to increase farmer confidence.
Benefit for farmers
The benefits for farmers of this project were:
- Parasite management communicated in new and different ways with the aim of reaching a large audience.
- Communication methods evaluated so future messages can get to farmers in the most useful way to support practice change on farm and invest wisely in communication.
Timeline and investment
This was a 6-month project completed in September 2021. B+LNZ investment was $45,000 over the duration of the project.
Outputs
- Animated video
- Podcast
- Drench poster
- Report – available on request, please contact research@beeflambnz.com
Partners
This project was funded by B+LNZ and partnered with Scarlatti.
Farmers involved: The Farmer Research Advisory Group (FRAG).
B+LNZ point of contact: Cara Brosnahan.
DEFINITIONS OF SOME TERMS USED IN THE RESOURCE MATERIAL
Drench resistance
Internal parasites, or worms, that are not killed by a correctly applied dose of drench are called drench resistant parasites. These resistant parasites then breed and pass their resistant genes onto their offspring. Over time this leads to an increase in the numbers of drench resistant parasites on your farm.
To know if you have drench resistant parasites, and what drench families the parasites are resistant to, you need to do a faecal egg count reduction test (FECRT).
FEC
Faecal egg count, or FEC, is a tool to understand the parasite burden in your animal at any one point in time. A FEC involves collecting fresh dung, sending it to a lab or vet where the dung is treated and the eggs are extracted and counted using a microscope. The FEC is good at showing how many parasites are present, especially in young animals, but not what type of parasites are present.
Drench check
A FEC can also be known as a ‘drench check’ and should be carried out 10 days after drenching at least twice a year to confirm your drench and drench protocol is working. If eggs are present in a drench check there could be resistant parasites on the farm.
Larval culture
A FEC can be cultured (the eggs hatched) by a lab to see what different types of parasites are present in your animals. A larval culture is conducted as part of a FECRT and maybe a drench check.
FECRT
A faecal egg count reduction test, or FECRT, is a test to understand the effectiveness of the drench you are using and to know the drench resistance status of your farm. A FECRT should be performed every 2- 3 years (or more frequently if you suspect a problem) and involves the following:
1. Collect a fresh faecal sample just prior to drench (pooled from approx. 10 animals)
Send away for testing to see:
- how many eggs are present
- what kinds of parasites are present.
2. Drench groups of animals with all drench families wanting to be tested (e.g. BZ, levamisole, a triple combination)
3. Collect fresh faecal samples from each drenched animal 7-10 days later
Send away for testing to see:
- how many eggs are present
- what kinds of parasites are present.
An effective drench will be killing at least 95% of the parasites present. If you think you have a drench resistance issue, follow up with your vet for advice.
Refugia
Refugia is the practice of leaving some parasites in ‘refuge’ from drench. The aim of refugia is to dilute out the parasites resistant to drench with parasites susceptible to drench. This can be done in many ways, for example:
- leaving a portion of the mob undrenched.
- not drenching your adult ewes unless there is a demonstrated need to
- Not drenching young stock at intervals less than 28 days and, if appropriate, extending the drench intervals of young stock (Note, careful and regular monitoring of FEC is required when extending drench intervals past 28 days).
Drench families
Drenches are divided into several ‘chemical family’ groups that each have a different way of acting to kill the parasites.
These families are:
Family | Common names | Chemical actives | Examples of NZ products* |
Macrocyclic lactones | ML’s
Mectins |
Abamectin
Ivermectin Moxidectin Doramectin Eprinomectin |
Cydectin
Clomax oral Eprinex PO Exodus Genesis |
Benzimidazole | White drenches
BZ’s |
Albendazole
Fenbendazole Oxfendazole |
Bomatak C
Oxfen C Hi-mineral |
Levamisole | Clear drenches
LV’s |
Levamisole | Gold drench for Cattle & Sheep |
Amino-acetonitrile derivative | AD | Monepantel | Zolvix plus (also includes Abamectin) |
Spiroindole | SI | Derquantel | Startect (also includes Abamectin) |
*B+LNZ does not endorse specific brands, these are presented here as examples only.
Worm/parasite types
See page 14 of the Wormwise handbook for details on all parasites. Below is a list of the most common internal parasites present in New Zealand livestock:
Parasite | Common name | Main facts |
Haemonchus contortus | Barber’s pole |
|
Ostertagia (Teladorsagia) circumcincta | Brown stomach worm |
|
Trichostrongylus | Trichs |
|
Nematodirus | Thin-necked intestinal worm |
|
Ostertagia osertagi | Medium stomach worm |
|
Cooperia
|
Parasitic roundworm |
|
Quarantine treatment
Quarantine treatment is used to make sure any stock coming onto your property do not carry resistant worms with them. A quarantine drench should contain one of the new actives, monepantel or derquantel as well as another drench family, for example a macrocyclic lactone (e.g. abamectin). It should not be the same drench as you use for regular drenching. These animals should then stay off pasture for at least 24 hours either in yards if feasible or be put out onto dirty pasture you know contains parasites.
Knockout drench
Knockout drench is when you substitute a routine drench with a drench containing monepantel or derquantel (the same drench as you would use during a quarantine drench). It is important this is given at the right time to be most effective on your property – generally late summer/early autumn to prevent an autumn larval peak of resistant parasites on pasture. The purpose of a knockout drench is to remove any parasites that survived your ‘normal’ drench treatment.
Exit drench
Exit drench is a drench (usually a triple combination, or a drench containing monepantel or derquantel) given to an animal treated with a long-acting drench or capsule after the protection period has finished. The purpose of this drench is to kill parasites that have survived a long-acting drench or capsule treatment

The overall project objective was to define the role of helicropping in crop establishment and pasture renewal including:
• methodology
• where best undertaken
• identification of risks (particularly at grazing)
• risk mitigation (catch crop, cover crops, sediment bunds and runoff barriers).
The project harnesses learnings from existing knowledge gained by the industry (particularly farmers already successfully helicropping) as well as developing new scientific methods around measuring the effectiveness of buffers and mitigations.
Background
Helicropping is a process-driven application of recently available technologies that enable helicopters to be used for precision application of herbicides, fertiliser and seed to hill country to establish crops and renew pastures.
For more information on this project, see the Ballance website.
Key results
The main findings from this project showed that helicropping can be undertaken and utilised in a way that minimises environment risks.
Note that a helicopter is not necessary for a helicrop. The process can be followed using wheeled equipment.
• To successfully helicrop and establish a crop or pasture with no tillage, it needs to be done correctly with a clearly defined process. Planning is key.
• It is recommended that a helicrop be established on flat or rolling topography (not on steep terrain).
• Pasture renovation can be undertaken by helicropping on steep terrain but not the cropping phase of the process.
• Heli-cropping is competitive with tillage for establishing a crop with less risk of soil loss.
Benefit for farmers
This project has provided insights from farmers using this technology on-farm and has determined key factors that need to be considered for the successful application of helicropping.
B+LNZ investment
This was a three-year project with investment by B+LNZ of $105,000 over the duration.
Outputs
Farmer events
Five field days throughout the project.
Popular press articles
- Rural Contractor and large scale farmer magazine – “Helicropping – from ‘spray and pray’ to aerial no-tillage”.
- Rural Contractor – “Taupo farmer says helicropping as good as direct drilling”.
- The Journal – “Helicropping – aerial no-tillage cropping to protect soils”.
- Rural News – “Helicropping could take off”.
Scientific publications and conference proceedings
- NZGA Hill Country Symposium – “Hill country cropping with no land based equipment”.
- NZGA Conference Proceedings – “Helicropping – early adopters experiences”.
- Agronomy Society of NZ – “Helicropping – the role of nitrogen and phosphorus in forage cropping with aerial no-tillage”.
Resources
- Maungahau Farm case study
- Webinar series:
• Heli-cropping handbook – contact Ballance for your hard copy.
• Ballance factsheet (PDF, 1.3MB).
Partners
This is a Ministry for Primary Industries Sustainable Farming Fund project led by Ballance Agri-nutrients (Suzanne Young and Ian Tarbotton) and co-funded by MPI, Ballance Agri-nutrients, B+LNZ, Agricom, PGGW Seeds, Bay of Plenty Regional Council, AgFirst and NuFarm.
Lead Scientists: Karen Mueller (Landcare Research), Bruce Willoughby (independent scientist), Murray Lane (Ballance Agrinutrients), Graeme Hull (Scopix LtD).
Farmers involved: The sustainable helicropping group.
B+LNZ point of contact: Jason Griffin and Cara Brosnahan.

This project aimed to understand how to better manage tagasaste (commonly known as tree lucerne) on-farm in the Hawkes’ Bay region and Taupō. Field trials were carried out at three sites to assess the following:
- Seed germination and establishment of tagasaste.
- Forage production and nutritive value of tagasaste.
- Weed risk assessment for tagastaste.
- Production of grass and legume pasture species grown in pasture-tagasaste systems.
Background
There is huge potential growth for the sheep and beef sector on hill country in New Zealand. Around 6 million ha of hill country is too steep to cultivate but represents 54% of the land area on which sheep and beef farming is undertaken in New Zealand, adding over $4 billion per annuum of export revenue to our economy.
East Coast farmers are concerned about the fragility of their soil and the challenges of adverse events. Their topsoil is critical to their business and its erosion and loss represents a huge reduction in the resilience of the landscape and productive potential. The depleted soil is more prone to drought, more easily invaded by woody weeds, and represents a significant loss of stored carbon from the landscape.
Soils need more than just pasture to hold them in place, but forestry is not always the best option. A potential solution is the use of shrubby vegetation e.g. Tagasaste, as a soil stabiliser as well as a stock feed. Tagasaste is a hardy nitrogen fixer with high protein foliage suitable for sheep and cattle that thrives on steep, erosion-prone, north-facing hill country. Tagasaste is suitable for both the dry shady slopes and sunny slopes, and the six-week lag time between production from the two aspects means there is the potential for two springs’ worth of stock feed. Additionally, Tagasaste provides shade and shelter to support animal welfare.
For more information on this project visit: https://www.sustainablehillcountrynz.com/
Key results
Nutrition from tagasaste
- Trees in Hawke’s Bay produced ~2.7 edible dry matter per tree per year with lowest production in autumn.
- The amount of metabolisable energy was 9.4 – 10.7 Mj/kg DM – equivalent to that of perennial ryegrass during summer and autumn.
- Crude protein varied from 17% to 23% when measured over three years.
- Neutral digestible fibre ranged from 32% to 43% when measured over three years.
- Mean concentration of macro and micro-elements in tagasaste (except phosphorous) exceeded those recommended for an adequate intake for sheep and cattle.
Growing tagasaste
- Similar germination rates were observed when seeds were placed in boiling water vs when they were nicked and put in hot tap water.
- Establishing tagasaste in resident pastures in summer-wet hill country is unlikely to be successful from sowing seed.
- Removing 20% off the top of the tagasaste was sufficient to increased edible dry matter.
Understory pasture
- Cocksfoot was the most successful understory pasture compared with other grasses.
- Lotus was the most successful understory legume compared with other legumes trialed.
Benefits of tagasaste
- Direct benefits of establishing tagasaste on hill country are estimated at $149.60/ha/yr.
- Other benefits of tagasaste include shelter, shade, soil conservation, soil improvement and biodiversity.
Benefit for farmers
This project shared practical experience on how to establish and manage tagasaste on hill country and has produced a handbook for guidelines on how to do this.
Timeline and investment
This was a three-year project completed in October 2021. B+LNZ’s investment is $165,000 over the duration of the project.
Year 1 and 2 (2018/19 and 2019/20) involved the establishment and management of tagasaste, sowing companion plants within the tagasaste-pasture systems and monitoring of tagasaste-pasture systems.
Year 3 (2020/21) focused on case studies to inform other farmers what was found.
Outputs
Farmer events
- Three field days throughout the project
Popular press articles
- Wairoa Star – “Exciting results revealed in sustainable hill country trial”.
- RNZ National interview – “Talking about tree lucerne”.
Scientific publications
- Frontiers in Sustainable Food Systems: “Vegetation options for increasing resilience in pastoral hill country”.
Resources
- Tagasaste handbook.
- Project reports.
- Factsheet (PDF, 770 KB).
Partners
This is a Ministry for Primary Industries Sustainable Farming Fund project led by the Hawke’s Bay Regional Council (Peter Manson) with co-funding from MPI, B+LNZ and Ballance Agri-nutrients and in-kind support from Federated Farmers, Greater Wellington Regional Council and Waikato Regional Council.
Lead Scientists: Katherine Tozer (AgResearch), Grant Douglas (GBD Science), Ian Tarbotton (Ballance Agri-nutrients)
Farmers involved: Greg Hart, Nick Broad, Doug Avery, Dave Read, Luke Read.
B+LNZ point of contact: Mark Harris and Cara Brosnahan.