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Assured Nutrition

for ruminants

Dairy Herd Phosphorus Status Not Impaired By Reductions In Dietary Phosphorus

For further details please contact our technical team.

Based on evidence suggesting that we had been significantly over feeding Phosphorus for some time there has been an industry wide move over the last five years towards reducing dietary phosphorus levels in UK dairy rations. However not all nutritionists were entirely convinced by the evidence and were concerned that Phosphorus status of herds would be affected. Premier Nutrition has received some information reported by the Dairy Herd Health and Productivity Service (DHHPS) at Edinburgh University that should provide welcome relief to concerned nutritionists. The results are shown in the table below.

Date Total Number of Cows Tested Number of Results <1.4mmol/l % Low Results
01/11/2005 – 31/10/2006 7767 515 6.63
01/11/2006 – 31/10/2007 7535 4936.54
01/11/2007 – 31/10/2008 9134 533 5.84
01/11/2008 – 31/10/2009 8823 346 3.92
01/11/2009 – 31/10/2010 9345 329 3.52

The table above is a summary of blood phosphate results from metabolic profile tests that the University have carried out over the last 5 years. The 2nd column is the number of individual cow tests run, the 3rd column is number of these individual cow tests below 1.4 mmol/l (which is the lower threshold indicating poor Phosphorus status or deficiency) and the last column is this value as a percentage of total results.

It is apparent that during the first couple of years there was not much change with around 6.4% of cows having low phosphate results, however the number and % of cows with low phosphate results has gone down in the last few years. It is important to note that almost all of these low phosphate results are due to individual cow intake issues and NOT a lack of phosphorus in the diet. Dr Macrae of DHHPS also suggests that the bulk of poor Phosphorus status cases are attributable to cows within the first 20-30 days post calving, something we have expressed our concerns over recently. These results give support to the trend in dietary Phosphorus reductions but indicate that special consideration should be given to cows within the first month post calving.