Carryover of aflatoxin from feed to milk in dairy cows with low or high somatic cell counts

Abstract

Aflatoxin M1 (AFM1) residues in milk are regulated in many parts of the world and can cost dairy farmers significantly due to lost milk sales. Additionally, due to the carcinogenicity of this compound contaminated milk can be a major public health concern. Thirty-four lactating dairy cows were utilised to investigate the relationship between somatic cell counts (SCC), milk yield and conversion of dietary aflatoxin B1 (AFB1) into milk AFM1 (carryover (CO)). The AFM1 in milk increased as soon as the first milking after animal ingestion with a pattern of increment up to the observed plateau (between 7th and 12th days of AFB1 ingestion). There was a significant (P , 0.01) effect of the milk yield whereas no effect could be attributed to the SCC levels or to the milk yield 3 SCC interaction. Similarly, the main effect of milk yield was also observed (P , 0.01) on the total amount of AFM1 excreted during the ingestion period. Although the plasma concentration of gamma-glutamyl transferase was significantly affected by aflatoxin administration, levels of this liver enzyme were within the normal range for lactating dairy cows. The current data suggest that milk yield is the major factor affecting the total excretion of AFM1 and that SCC as an indicator of mammary gland permeability was not related to an increase in AFM1 CO.

Ability ofLactobacillus rhamnosusGAF01 to remove AFM1in vitroand to counteract AFM1immunotoxicityin vivo

“…AFB 1 quickly appears in cows (as AFM 1 metabolite in blood after just 15 min (Moschini et al, 2006) and in milk at the first milking (Diaz et al, 2004;Masoero et al, 2007) after ingestion of aflatoxin-contaminated feed. We recently demonstrated that, in Beja province (Tunisia), milk and milk by-products were contaminated with high levels of AFM 1 (3-4-fold above the permitted dose) (Abbès et al, 2012).…”

Effects of two different blends of naturally mycotoxin-contaminated maize meal on growth and metabolic profile in replacement heifers

“…The Aspergillus mycotoxin aflatoxin B 1 (AFB 1 ) is of great interest for the dairy farmer because it contaminates feeds, which are commonly fed to lactating cows (Sweeney and Dobson, 1998). The AFB 1 is metabolized by the cow and excreted as its derivative aflatoxin M 1 (AFM 1 ) into the milk (Masoero et al, 2007). The EU regulation is extremely severe about the contamination with aflatoxins in the diets of lactating cattle, with a threshold of 0.005 ppm; instead, diets for growing cattle can contain up to 0.020 ppm (European Commission, 2003).…”

Determination of Aflatoxin Levels of Feeds Used in Dairy Cow Farms and Their Effects on Blood Parameters and Milk Aflatoxin Levels in Hatay Province

“…In a metaanalysis of transition rates, Pettersson (29) found that the CO rate of AFB1 to milk was between 0.18- that milk yield is the major factor affecting the AFM1 excretion. Thus, higher milk yield results in higher AFM1 excretion (8,14,15 A seasonal effect of aflatoxin M1 concentration has been reported in some studies, in which it was observed a higher concentration of AFM1 in cold seasons than in hot seasons because farmers tend to use higher amounts of compound feeds in winter (34). In other words, animals consume less concentrated feeds in summer because they also graze on pasture.…”

“…In order to protect the consumer from the harmful effects of aflatoxin, the maximum level of AFM1 in milk and milk products is restricted by many governments, as is the level of AFB1 in feedstuffs (7). The defined maximum limit is 0.5 µg/kg in the USA and 0.05 µg/kg in the European Union, Africa, Asia and Latin America (8,9).…”

“…However, milk yield may have a large effect on the AFM1 excretion (8,13). High-yielding dairy cows could show high excretion rates up to 6%.…”