THIS IS apropos of the news report ‘Over 900 milch animals fall sick in Landhi’ (Oct 10). According to the report, the animals fell sick after consuming cottonseed cakes.
It is suspected that cottonseed cakes were polluted by pesticides. Hard facts may be different and need to be considered carefully, because cottonseed cakes have long been considered a popular and economic protein concentrate for animal feeding.
These cakes have some natural limiting factors that must be considered for safe use. Major among these factors are protein and fibre levels, quality and the gossypol content. Gossypol is a polyphenolic yellow pigment found naturally throughout the cotton plants. In the seed, gossypol is found in small pigment glands. When the seed kernels are flaked and heated as part of the oil extraction process, these small glands are ruptured and the gossypol is released.
Some of the gossypol will bind with components in the seeds which cause the poisoning in animals.
Gossypol poisoning, which is usually subacute to chronic, cumulative, and sometimes insidious, follows consumption of cottonseed cakes or cottonseed products that contain excess free gossypol. It is of most concern in domestic livestock.
The signs and symptoms of the disease may relate to effects of toxicity on the cardiac, hepatic, renal, reproductive and metabolic disorders. Prolonged exposure may cause acute heart failure. Adult dairy cattle may show weakness, depression, anorexia, oedema of the brisket, and dyspnoea, diarrhoea, and also have gastroenteritis, haemoglobinuria, and reproductive problems. Gossypol poisoning can merely be identified by animal nutritionist or well experienced veterinarian.
Diagnosis is based on a history of dietary exposure to cottonseed cakes or cottonseed products, signs, especially sudden death or chronic dyspnoea, in the farm and no response to antibiotic therapy and the presence of significant concentrations of free gossypol in the diet. Analyses of dietary components for free gossypol must be correlated with history, clinical signs, and post-mortem findings.
There is no effective treatment. Adsorbents such as activated charcoal and saline cathartics can be used in less chronic cases.
If gossypol toxicity is suspected, all cottonseed products should be removed from the feed immediately. However, severely affected animals may still die up to two weeks later.
Recovery depends primarily on the extent of toxic cardiopathy. Animal feed should be supplemented with lysine, methionine, and fat-soluble vitamins. A high intake of protein, calcium hydroxide, or iron salts appears to be protective in cattle. Cattle should also be given 40 per cent of dry-matter intake from a forage source. Iron supplement must be ensured.
Habib Hyder Laghari, Canada @Dawn