There are several practical measures farmers can utilise to improve youngstock management.
Content brought to you by PGG Wrightson
Heading into the busy summer months on farm, The Country has partnered with PGG Wrightson’s animal production technical team for a three-part series of practical advice for dairy, sheep, and beef farmers across New Zealand.
Hosted by Rowena Duncum, the first episode focuses on the health and growth of young dairy and dairy-beef calves – specifically around the challenges of weaning.
In it, Duncum is joined by veterinary nutritionist Laura Pattie, who shared her experience and insights on farm management for optimal calf health.
Pattie grew up on a small dairy farm in the Bay of Plenty before becoming a veterinarian and later completing further study on animal nutrition to improve on-farm outcomes. Based in Tauranga, she covers the upper North Island and works with PGG Wrightson Field Reps to support farmers across Northland, Bay of Plenty, King Country, and Waikato.
The Challenges of Weaning Stress and Solutions
Weaning brings a high-stress period for calves, which can impact their immune systems and growth.
According to Pattie, when calves are weaned, “their stress levels may spike, leading to increased cortisol production.”
This surge in stress hormones can compromise the immune system, making young calves more vulnerable to parasites and infections like coccidiosis and yersiniosis.
Pattie highlighted the importance of rumen development, explaining, “The rumen is not fully developed at birth and needs careful management during the early rearing and weaning period.”
Feeding high-quality calf meal, especially those containing coccidiostats, can assist in developing the rumen and minimising stress-related health issues.
Pattie recommends farmers “continue feeding calf meal for at least four to six weeks after weaning, supporting calves to transition smoothly through the diet changes, supports weight gain, and reduces the risk of disease.”
Diagnosing and Managing Health Issues in Calves
When health issues arise – such as diarrhoea linked to stress or parasites – Pattie suggested that farmers should collaborate closely with their local vet for accurate diagnosis and effective treatment.
“Diarrhoea can have many underlying causes,” she said.
Lab testing of faecal samples can also help farmers – by pinpointing specific problems, such as worm infestations or bacterial infections.
Regarding faecal egg counts (FEC), Pattie explained the timing aids in achieving relevant results.
“The earliest it is recommended to conduct FEC is four to six weeks after calves have had access to grass,” she said.
“FEC are also useful to gauge worm burdens accurately and manage drench intervals.”
The State of Drench Resistance and Effective Management Strategies
Drench resistance is an increasing concern for New Zealand farmers, with intensive youngstock systems, such as dairy calf rearing and dairy bull operations being at greatest risk.
Pattie believes the challenge is growing.
“Double and triple-resistant worms are becoming more common – especially Cooperia, which can significantly hinder growth rates if not managed,” she said.
To combat this, Pattie said there are several practical measures farmers can utilise.
Listen below as Rowena Duncum speaks with Laura Pattie:
“Calibrate your drench equipment properly, weigh your calves to dose them accurately, and choose the most effective drench type.”
Pattie said oral drenches were the preferred option for younger animals, as they target parasites in the digestive system directly.
“Injectables and pour-ons can be less effective, particularly for certain parasites.”
She also believes regular drench checks post-administration are vital.
“It’s crucial to conduct these checks to ensure your drenching program is working effectively.”
Supporting Stock Growth with Trace Minerals
Pattie said trace minerals were important in calf development, with the three main trace minerals to monitor being selenium, copper, and cobalt (vitamin B12).
“These minerals are essential for bone growth, antioxidant protection, and energy metabolism,” she said.
Pattie advised farmers to monitor mineral levels through blood tests or liver biopsies.
Pasture sampling and assessing trace mineral content of the feed, is another tool to assess if the diet is meeting requirements.
“Depending on your farm system, injectable, oral, and powder supplements can help maintain proper mineral levels.”
The second podcast episode in this series will be released on November 27.