No document available.
Abstract :
[en] After ingestion of moulded beet pulp silage, cases of cortico-cerebral necrosis (CCN) and
mortalities have been observed in a Belgian Blue (BB) herd. Contamination with
Paecilomyces spp., a mould that produces byssochlamic acid, malformins and patulin, has
been proven. Among these toxins, patulin is known to have cancerogenic, immunosuppressive
and tremorgenic effects, but also acts on the respiratory and digestive systems.
Twenty-five days after progressive introduction of beet pulp silage into the ration of a dual
purpose BB herd, most of the animals showed diminished appetite, salivation and decreased
milk production. All 35 cows were reluctant to consume the beet pulp silage, but continued to
eat grass silage voluntarily. Seven of them showed anorexia and nervous symptoms, like head
pressing and blindness. Four animals died within 1 week after onset of neurological
symptoms. No necropsy has been performed, since legislation does not allow post-mortem
examination of the central nervous system in the field. The three survivors had been treated
successfully with thiamine (10 mg/kg, IV, TID) and recovered completely within five days.
After the beet pulp silage had been identified as causative agent, it had been removed from the
animals’ ration and no more clinical case has been observed. Four weeks later, the same beet
pulp silage has been reintroduced into the animals’ ration and provoked again diminished
appetite, salivation and a decrease in milk production in most of the animals. Clinical signs
were also suggesting lead poisoning but any contact with lead containing material could have
been excluded.
Silage was obviously moulded and analysis revealed the presence of 1.6 million CFU
Paecilomyces spp./g of silage. Although no further investigation has been made to identify the
mycotoxins, an intoxication with patulin has been suspected, since other mycotoxins produced
by these species are less toxic. Although it has not been described that CCN can be induced
by ingestion of Paecilomyces spp., it seems that there is a close relation between ingestion of
Paecilomyces-contaminated silage and observed clinical signs in this herd.
