Effects on milk production associated with consumption of decorticated extracted groundnut meal contaminated with aflatoxin
Jones, M.G.; Ewart, J.M.
Veterinary Record 105(21): 492-493
1979
ISSN/ISBN: 0042-4900 PMID: 538880 Document Number: 148546
Friesian cows were given a complete diet including decorticated extracted groundnut oilmeal 7% of dry matter. About 60% of the 140 cows calved between mid-October and early December. In early January milk yield was 76% of normal and the cows were in poor condition. The groundnut meal was examined microscopically; there was no contamination with other seeds, counts of moulds at 25 deg and 37 deg C were low and actinomycetes were not found at 60 deg . In 2 samples of groundnut meal the aflatoxin B1 was 0.75 and 0.62, B2 0.04 and 0.03, G1 0.06 and 0.05 and G2 0.01 mg/kg groundnut meal. Concentration of B1 was about 0.02 mg/kg complete feed, double the maximum recommended in UK for dairy cows and equivalent to 0.05 mg/kg DM. The groundnut meal was not given after January 14th, diarrhoea stopped after 3 to 4 days and cows started to eat more. During the next 5 to 8 days production of milk increased rapidly. Cows calving after January 14th gave the expected maximum milk yields but yields of the cows which calved earlier did not recover fully. By March 8th the body condition of cows was greatly improved. A production problem in a herd of 140 Friesian cows with av. lactation yield of 5650 l is described. Offering ad lib. a complete diet with extracted groundnut meal at 7% DM resulted in scouring and reduced feed intakes. Herd milk production was 83% of the predicted level and declined to 76% between early Dec. and mid Jan. Aflatoxin B1 at 0.62 and 0.75 mg/kg was found in samples of the groundnut meal. During the 5-8 days after removal of the groundnut meal milk production increased and then levelled out below the predicted yield.