June 16, 2005
Immunity related diseases in pigs - new challenges in Asia
New challenges caused by diseases affecting the immune system of pigs have been addressed at meetings in China, Taiwan and the Philippines, in early June 2005. The meetings focused on two major causes of reduced immunity in pigs: Postweaning Multisystemic Wasting Syndrome (PMWS) and mycotoxins. In total, more than 700 people came to attend these meetings and the long time spent on each occasion during the"questions and answers"session clearly showed their keen interest in these subjects.
Dr François Madec, vice-director of one of the veterinary research laboratories of the French Agency for Food Safety and Head of the epidemiology research unit, is one of a handful of experts on PMWS in the world.
In his presentation, Dr Madec described the symptoms of PMWS that appear to be due to a virus (PCV2, porcine circovirus type 2) involved in the pathogenic process through an impact on the immune system. On the other hand, directly or indirectly, other pathogens and the environment the pigs are given play an important role in triggering PCV2 action, he explained. PCV2 is widely spread and it can be found, without any sign of disease, in a vast proportion of farms.
Studies conducted by Dr Madec and his team have shown that certain farm practices would increase the risk of observing the clinical expression. They relate to herd management, hygiene and husbandry, including prophylaxes schemes.
Dr Madec observed that emergence of the syndrome in main pig producing countries (often nearly at the same time), is an indication that something wrong has occurred in our way of raising pigs in recent years. He then described a list of management changes that may be required on affected farms. There was an interesting exchange with the audience on how these recommendations could be applicable and tailored to each unit. Also, practical points to help prevention in affected farms were displayed and discussed.
In the second part of the meeting, Mathieu Cortyl from Impextraco Singapore, presented the interaction between mycotoxins and immunity. Although it was postulated for a long time that mycotoxins affect immunity, scientific evidence was still lacking. But recent research has, for example, revealed that mycotoxins such as aflatoxin, ochratoxin or fumonisins reduce resistance of piglets to pathogenic bacteria such as E. coli or salmonella. There is also now clear evidence that mycotoxins play a role in vaccination failure.
Mathieu Cortyl insisted that even if prevention is very important to avoid problems related to mycotoxins, it is almost impossible to ensure the feed will not be contaminated. He therefore presented different strategies that have been successfully implemented. These different feed additives belong to the Power-Protexion™ Range, a fully complementary and synergistic range of feed ingredients, each of them reinforcing the others for efficient and safer meat production. Since there is not a single solution against the different mycotoxins, IMPEXTRACO has developed ELITOX®, a feed additive combining different strategies. ELITOX® is based on toxin-degrading enzymes, toxin-binding natural biopolymers, and toxin binders of mineral origin. Also, natural extracts and vitamins are used to reduce the stress-related symptoms, he explained.
The data obtained on large scale farms show that with ELITOX® it is possible to improve reproduction performances of sows. Their piglets are healthier and grow faster, which means a better return for the producer. Mathieu Cortyl also explained that acidifiers such as ACIDAL® or substances that promote the natural defence of the organism, such as ECOCELL®, a prebiotic based on Mannan Oligo Saccharides (MOS) and beta-glucans extracted from purified yeast cell walls, enriched with Fructo Oligo Saccharides (FOS), could be helpful.
The meeting was held in Guangzhou and coordinated by Impextraco, Hua Tian Long, the Guangdong Pig Industry Association, Guangdong Agriculture Department and Guangdong Academy of Agriculture Science of Veterinary Medicine Institute. There were more than 450 delegates attending the meeting, some coming from as far as Beijing. The welcome speeches were presented by Mr. Luo Dao Xu, President of Guangdong Pig Industry Association, Mr. Luo Jian Min from Guangdong Agriculture Department and Professor Wang Gui Ping, Director of Guangdong Academy of Agriculture Science of Veterinary Medicine Institute. Professor Song from Guangdong Academy of Agriculture Science of Veterinary Medicine Institute, made a presentation about the situation of PMWS in China. Later, Dr Zhao Yun from the Institute of Veterinary Drug Control in Beijing gave a talk about classical swine fever.
The meeting was held at the Taiwan Livestock Research Institute in Tainan and coordinated by Impextraco and Go Far. After the welcome speech by Dr. Yu-Shin Cheng from Taiwan Livestock Research Institute, the first presentation was made by Professor Wei-Cheng Lee from the Graduate Institute of Veterinary Pathology,
College of Veterinary Medicine, National Chung Hsing University. Professor Lee is one of the experts on swine diseases related with immunosuppression in Taiwan. His main fields of research are swine diseases, veterinary pathology and cellular immunology. He is also involved in immunopathology.
Professor Wei-Cheng Lee discussed the current situation of different diseases, including PMWS, in Taiwan. He had a practical approach to explain how they affect farms and presented some possible solutions.
The meeting was held at the New World Hotel in Manila, and was coordinated by Impextraco, Nuevo Milenio and De La Salle University. Focusing on the current status of PMWS in the Philippines, Dr. Romeo Sanchez, Assistant Professor of the Department of Veterinary Paraclinical Sciences, College of Veterinary Medicine, University of the Philippines Los Banos, reviewed the general characteristics of the disease. He made a presentation about clinical and epidemiological aspects, pathology, diagnosis and control of PMWS, illustrating his speech with different examples observed in the Philippines. The closing speech was performed by brother Armin A. Luistro, President of De La Salle System. He welcomed this first and highly successful interaction between De La Salle University and the industry.
Left to right: Dr. Zhao Yun, Prof. Song, Dr. Madec, Left to right: Prof. Lee, Dr. Madec and Mr. Mathieu
Mr Mathieu Cortyl and Dr. Liang Cha Cortyl