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 on needle reuse provides critical data supporting the recommendations of changing needles between litters (12 piglets), which is crucial for protecting piglet welfare.
More than 8.9 million pigs are reared for slaughter in the UK each year, with indoor pig production accounting for approximately 60 percent 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 percent of farms reported needle reuse in piglets. Of these, only 39 percent changed the needle between litters or earlier if damaged and 23 percent 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.”