Liver selenium analysis in cows with a fast method of neutron activation reveals deficiency areas in The Netherlands.

A total of 230, 100-g freeze-dried liver samples from the caudal lobe of cows from 13 slaughterhouses in the Netherlands were analysed by irradiating with neutrons in a high flux generator for 5 s followed by measurement of the short-lived isotope 77mSe in a rigid time sequence, under fully automated conditions. Liver Se ranged from 0.16 to 1.82 mg/kg DM and did not appear to relate to geography. 3% of the livers contained Se less than 0.25 mg/kg DM, which is considered critical for development of Se deficiency. Another 20% with less than 0.4 mg/kg DM was considered borderline Se deficiency. There was no evidence of Se toxicity. Liver Se positively correlated with liver copper, which may be obtained via feed, but not with liver zinc. It was concluded that animals at risk to Se deficiency are those not fed on concentrates, particularly heifers suffering from retained placentas at delivery. The feeding of Se fortified feeds is recommended.