Dust and rats pose significant risks to both livestock and humans, and farmers must address these threats effectively, according to discussions at a symposium held by the Animal Feed Manufacturers Association (Afma) in Pretoria.
Dr Burak Ruperez, technical sales manager at Perstorp Animal Nutrition in Spain and a veterinarian specialising in monogastric animals, highlighted the growing prevalence of salmonella worldwide. Nearly 94 million cases are reported annually, 85% of which can be traced back to food, resulting in approximately 155 000 deaths each year.
Animal feed contamination originates from various sources: raw materials (fungi, fermentation, and decay), dry feed (mainly bacteria) and water (microbiological contamination). On farms, people and other hosts can also contaminate feed.
Farmers must take all possible steps to protect their feed, starting with storage after grain harvesting and continuing through to feeding the animals. Feed must be safeguarded from fungi and bacteria at all times.
Ruperez emphasised the need for a holistic approach, as no single solution works for all critical control points. This includes managing dust – salmonella can survive for over 300 days on dust particles. Significant dust is generated in feed mills, particularly in areas where raw materials are received, as well as at hammer mills, roller mills, mixers, conveyors and bagging stations.
Effective rat control
Rats must also be controlled as they are widespread. Seeing one or two rats during the day suggests there could be 400 to 1 000 rats in a facility or farm shed. Each rat weighs about 300g and consumes 10% of its body weight daily. This means 500 rats can easily eat 15kg of feed in one day.
On a poultry farm raising 10 000 broiler chickens at a time, feed consumption over a 42-day cycle totals 44 tons. In the same period, a rat infestation of 500 could consume approximately 63kg of feed – about 1.5% of the total – while contaminating ten times more feed than they eat with their droppings. Each rat dropping contains roughly 230 000 salmonella units.
Controlling animal diseases
Animal diseases have become so complex that they require a swift scientific response. Otherwise, finding solutions is far from guaranteed.
Dr David Bravo, chief scientist at the Dutch animal nutrition company Nutreco, noted that animal performance now occurs in a highly complex environment. In the past, performance depended on breeding material, nutrition, farm management, health and antibiotic-free farming. Today, additional factors such as sustainability, animal welfare, politics, protectionism and regulatory measures play a role.
“Diseases that were previously unknown are now emerging. If we don’t tackle them with scientific agility, we’ll still be talking about the same diseases in ten years,” Bravo warned.
He added that traditional research and development methods are no longer adequate for these challenges, as the problems encountered are too unpredictable.
