Iodine in Raw and Pasteurized Milk of Dairy Cows Fed Different Amounts of Potassium Iodide

Abstract

Relation between iodine (I) intake by lactating Holstein cows and iodine concentrations in raw and pasteurized milk were investigated. Four treatment groups with eight cows assigned to each treatment were fed a basal diet containing 0.534 mg I/kg alone or supplemented with potassium iodide at 2.5, 5 or 7.5 mg/kg in 7-week period. Iodine concentrations in raw milk increased with each increase in dietary I from 162.2 ng/ml for basal diet to 534.5, 559.8 and 607.5 ng/ml when 2.5, 5 and 7.5 mg/kg was fed as potassium iodide (P < 0.05). This trend was found for blood plasma and urine iodine concentration. Iodine supplementation had no significant effect on thyroidal hormones. high-temperature short-time (HTST) pasteurization process reduced I concentration. The mean iodine content found in the milk prior to heating processing was 466.0 ± 205.0 ng/ml, whereas for the processed milk this level was 349.5 ± 172.8 ng/ml. It was concluded that iodine supplementation above of NRC recommendation (0.5 mg/kg diet DM) resulted in significant increases in iodine concentrations in milk, although the effect of heating in HTST pasteurization process on iodine concentration was not negligible.

Iodine content in milk from German cows and in human milk: new monitoring study

“…The relationship between iodine intake in lactating Holstein cows and iodine concentrations in their milk was analyzed by Norouzian [8]. The author reported that basal diet supplemented with either ~ 0.5 mg iodine per kg or with potassium iodide at 2.5, 5, or 7.5 mg/kg feed over a 7-week period increased iodine concentration of milk with each increase in dietary iodine from the basal value of 162 ng/ml to 534, 560 and 608 ng/ml, respectively.…”

“…But, iodine content in dairy products is subject to variation by a variety of factors, like leaching the soil with iodine (soil -feed -milk path), and supplementing cattle feed with iodized mineral mixtures, whieh mainly leads to higher iodine levels in the milk [8,9,10]. However, new data suggests that milk iodine response curves should not be extrapolated linearly for iodine intakes, because secretion ratio decreased at high levels of iodine supplementation [8].…”

“…On the other hand, heating processes such as pasteurization lead to a reduction of iodine concentrations in milk [8].…”

Effect of diet supplementation with Ascophyllum nodosum on cow milk composition and microbiota

“…Although the increase of iodine content in milk after feed supplementation with inorganic forms of iodine is well documented in literature (Schöne et al, 2009;Moschini et al, 2010;Norouzian, 2011), few studies (Mosulishvili et al, 2002;Antaya et al, 2015) have been carried out on the increase of iodine in cow milk after feed supplementation with algae. Brown seaweeds have the unique ability to concentrate iodine from seawater, and certain species accumulate up to 1 million fold and therefore constitute an important source of iodine (Dierick et al, 2009).…”

“…The iodine of milk and milk products represents the second-most important food source of the trace element in the European Union or in the United States (Bader et al, 2005), and its concentration in cow milk ranges between 30 and 300 μg/L (Moschini et al, 2010). Considerable interest has been displayed in the last years in supplementing the diet of lactating animals with iodide, by using fortified feeds either from inorganic (sodium iodide, potassium iodide, calcium iodate hexahydrate, and anhydrous calcium iodate) and organic sources (Moschini et al, 2010;Norouzian, 2011). In this respect, marine algal supplements are promising tools for iodine fortification, as they are relatively easy to incorporate into rations, contain protein and are consumer-friendly, considering regulatory limitations and concerns over the use of fish products in ruminant diets (Reynolds et al, 2006).…”