Published: 02 Mar 2022 | Last Updated: 02 Mar 2022 11:45:59

New research from the Royal Veterinary College (RVC), has shown that repeated needle use increases the required puncture force which could lead to increased pain experienced by piglets. This research provides critical data supporting the recommendations of changing needles between litters (12 piglets), crucial for protecting piglet welfare.

Close ups of needles

More than 8.9 million pigs are reared for slaughter in the UK each year, with indoor pig production accounting for approximately 60% of the industry. The majority of indoor born piglets require an iron injection in the first few days following birth to prevent iron deficiency. This is known as anaemia, a condition that can reduce growth rates and increase disease susceptibility and mortality.

The reuse of needles between animals is common in livestock farming.  However, without regular needle changes, the force needed to administer the injection increases and may cause pain and distress for the piglet.

In conducting this study, the research team, led by undergraduate veterinary student, Kathryn Owen, and supported by Dr Nicola Blackie, Senior Lecturer in Production Animal Science; and Dr Troy Gibson, Associate Professor in Animal Welfare Science, examined the force required to puncture the skin of a piglet cadaver for the first time, 12th time, 36th time and 100th time, mimicking reuse of needles.

The RVC researchers then also viewed the needles under scanning electron microscopy to assess the damage caused to needles over repeat usage. They found that the puncture forces increased after 36 uses and the electron microscopy imaging showed visible damage to the needle tip after only 12 uses. 

As part of the research, the team also sent a survey to a sample of UK pig farmers asking about their iron injection practices. From the 31 respondents, 81% of farms reported needle reuse. Of these, only 39% changed the needle between litters or earlier if damaged, and 23% changed the needle when it felt blunt or damaged, after each injection session or when changing the bottle of iron solution.

This vital research provides essential data to support the recommendation that needles should be changed between litters of piglets or more often. It will also help to inform and change the advice veterinarians give to clients and their own practices when reusing needles

Kathryn Owen, the lead researcher on this paper and undergraduate veterinary student at RVC, said:

“Needle reuse increases the force required to puncture the skin, this indicates blunting which could cause pain and distress of piglets”

“Electron microscopy shows that after 12 injections the needle tip is visibly blunted.”

Notes to Editors

The study was funded by the Animal Welfare Foundation.

The full study can be viewed here:

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About the RVC

  • The Royal Veterinary College (RVC) is the UK's largest and longest established independent veterinary school and is a Member Institution of the University of London.
  • It is one of the few veterinary schools in the world that hold accreditations from the RCVS in the UK (with reciprocal recognition from the AVBC for Australasia, the VCI for Ireland and the SAVC for South Africa), the EAEVE in the EU, and the AVMA in the USA and Canada.
  • The RVC is ranked as the top veterinary school in the world in line with the QS World University Rankings by subject, 2021.
  • The RVC offers undergraduate and postgraduate programmes in veterinary medicine, veterinary nursing and biological sciences.  
  • In 2017, the RVC received a Gold award from the Teaching Excellence Framework (TEF) – the highest rating a university can receive.
  • A research led institution with 79% of its research rated as internationally excellent or world class in the Research Excellence Framework 2014.
  • The RVC provides animal owners and the veterinary profession with access to expert veterinary care and advice through its teaching hospitals and first opinion practices in London and Hertfordshire.

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