PHYTOMILK

Effects of Se supplementation on milk quality

Research plan

A survey will be conducted in Eastern Finland in cooperation with the local ProAgria and local organic farms. In the beginning of year 2008 tank milk samples will be collected from 50 organic farms (25 practicing certified organic animal production and 25 farms practising only organic field farming). Representative samples of silage and concentrate mixture will be taken from each farm. Number of cows and average daily milk yield will be recorded. Farmers will be interviewed for their current feeding and Se and vitamin supplementation.

Improved Se situation

All farmers will be introduced to Se yeast. Twenty voluntary farms will switch to Se yeast supplementation (3 mg Se/cow) for 4 weeks. Tank milk samples will be collected in the end of experimental period.

Milk samples were collected from participated farms in the spring 2008.

Progress of work

Background

In January 2008 milks samples were collected from 45 organic farms (22 practicing certified organic animal production and 23 farms practising only organic field farming). The number of farms was reduced from 50 (orginal plan) to 45 farms since long distance between voluntary organic milk farms. Farmers were interviewed about their current feeding practises. Milk basic quality, selenium, vitamin and fatty acid contents have been analyzed.

Some results

Milk Se concentration of the farms practising certified organic animal production and farms practising only organic field farming has been imroved since 2006, when the last survey about Se concentration of organic milk in Eastern Finland was performed.

Improved situation

In feeding experiment, experiment model was converted to 3 x 3 Latin square: three treatments (Organic selenium as selenized yeast, Mineral selenium as sodium selenite, Organic selenium + mineral selenium) x three periods of 28 days with 15 farms (5 farms in each treatment, pooled by milk yield, number of cows and housing system). RehuRaisio provided the experimental mineral feeds. In each supplement the content of selenium was the same (20 mg / kg). The daily amount of the supplement was adjusted to cow’s daily milk yield thus daily selenium intake was approximately 3 mg per day. Feeding experiment was performed between 6.2. – 29.4.2008.

Some results

Milk basic quality, selenium, vitamin and fatty acid contents have been analyzed. Tentative results have been reported in some journals of the field, and directly to the participating farms. In selenized yeast treatment milk Se concentration was twice as high than in mineral selenium treatment. When the mixture of these two Se sources was used, Se concentration was nearly the same than with selenised yeast merely.

Link to a press release (in Finnish)