Trace elements are commonly responsible for nutritional problems that affect growth, milk production or fertility. Further complicating matters, some minerals interact with others, reducing supply. The table below shows the averages for grass silage for 2012 and 2013, there are a number of minerals worth discussing. It’s also worth bearing in mind that these figures are simply year to year averages and will not reflect deficiencies on individual farms.

2012 & 2013 Grass Silage Mineral Averages
2012 2013 % Difference
Calcium % 0.53 0.54 -1.88
Phosphorus% 0.29 0.30 3.45
Magnesium % 0.16 0.16 0.00
Sodium % 0.21 0.21 0.00
Potassium % 2.24 2.47 10.27
Sulphur % 0.18 0.20 11.11
Chloride % 0.9 1.02 13.33
Iron mg/kg 361.5 290.01 -19.77
Manganese mg/kg 89.3 81.54 -8.69
Cobalt mg/kg 0.24 0.21 -12.5
Zinc mg/kg 26.2 26.57 -1.41
Selenium mg/kg 0.054 0.054 0.00
Aluminium mg/kg 264.9 242.75 8.36
Lead mg/kg 0.92 0.76 -17.39
Molybdenum mg/kg 1.5 1.66 10.67
Copper mg/kg 6.3 7.6 20.63

Although copper levels are up for 2013, so too are molybdenum and sulphur which will tie up copper supply. Iron too will interact with copper which although down in 2013 is still at high levels on some farms.

Selenium levels show no improvement in 2013 from last year. Signs of selenium deficiency include reduced growth rate and high embryonic mortality between three and four weeks after conception. The incidence of retained cleansings in dairy cows is also linked to selenium deficiency.

Potassium averages are higher for 2013, however, high potassium interferes with magnesium absorption, so may contribute to grass staggers this autumn. As cattle will hopefully be out at grass for longer this season, this issue is worth tackling.

Improved sulphur levels this year will enable rumen microbes to efficiently utilize forages more effectively, so animals will make better use of home-grown forage.

Ask your rep or ring the office to find out more about our: –
• Dalesman Tri-mag buckets
• Dalesman Cattle fertility plus
• Cattle general health minerals
• And much more!