Checkline Grass Bureau - S M Hackett：靠岸缆索草局的哈克特.doc

Checkline Grass Bulletin 2010 Sample Date: 10th May to 23rd May 2010Week 3Grass EnergyThe chart shows grass energy levels compared to last year and an average year. Grass energy together with dry matter will give an indication of the value of grazed grass to dairy cows.Grass ProteinThe chart shows the average protein content of grass on each sample date. Once protein gets above 20% in the grass there is a danger of a surplus in the cow. This can lead to fertility problems if not correctly balanced. Grass Dry MatterThe chart shows the dry matter of grass on each sample date compared to last years results. As dry matter declines the cow will need to eat much more bulk in order to keep dry matter intake the same.Checkline Grass Bulletin 2010 Sample Date: 10th May to 23rd May 2010Week 3AreaDry Matter %Crude Protein %D ValueEnergy Mj/kg DMSugar %Fibre %MABLETHORPE 114.124.87411.613.532.4MABLETHOPPE 220.616.27511.821.233.0MABLETHOPPE 318.119.27411.718.733.4NEWARK16.621.87311.516.036.4MABLETHORPE 414.923.77211.3 9.440.0COLSTON BASSETT19.314.87311.519.933.8STONE19.224.97311.513.733.9HERTFORD 19.615.27111.216.841.7RIPLEY20.221.17411.716.534.0SHREWSBURY 115.224.77411.612.736.5SHREWSBURY 217.815.57612.021.736.6SHREWSBURY 321.521.67712.220.129.2STAFFORD 119.624.37411.716.331.5STAFFORD 219.015.67411.619.638.4NANTWICH18.925.67211.411.234.3LUDLOW20.922.07611.917.934.1CONGLETON20.619.37411.617.136.0WINSFORD 17.225.37411.713.135.2STOKE ON TRENT 18.120.87511.716.136.6LYDBURY16.318.17411.717.938.3Grass Bureau data 10th May to 23rd May 2010Dry MatterProteinD ValueMEEFMESugarNDFAshOAH%g/kg DM%MJ/kg DMMJ/kg DMg/kg DMg/kg DMg/kg DMg/kg DMAverage18.42087411.710.61653538951Min14.11487211.310.1942927842Max21.62567812.211.121841810363Last Yr18.22107511.710.615035392532 Weeks Ago21.120475.911.910.81863348453High Protein Fresh Grass and Milk UreaOne of the problem areas in feeding large quantities of fresh grass at this time of year is the fact that we feed large quantities of protein which is very difficult to balance up with enough fermentable dry matter.The figures in the latest BOCM PAULS Grass Bureau for the Newcastle area show that protein has virtually stayed the same as two weeks ago at 208 g/kg DM. If you are feeding the average then that can be worked with far easier than if you are producing grass with our highest test that of 25.6% protein. Average dry matter has dropped to 18.4% and the energy of the grass has decreased slightly from 11.9 to 11.7 MJ/kg DM along with a decrease in sugar level over the last two weeks from 18.6% to 16.5%.So, back to protein. How will this level of protein effect milk urea levels? Milk urea is a direct reflection of the cows blood urea and blood urea reflects the status of rumen degradable protein available for the cow.So why is it important to get milk urea at the right level? Research work over ten years ago (Kenneth Blaxter 1996 and Beltstone USA) showed that for the cow to get rid of excess rumen degradable protein required energy and that energy used up could have been used for milk production instead. So, if the milk urea is above average then this will reduce milk production. Likewise, if milk urea is below average then this will also reduce the potential from the cow.If milk urea is lower than normal on your farm this implies that rumen degradable protein supply is not in excess in the total diet. This can be due to a number of reasons, the grass you produce on your farm is lower in protein than the average detailed above, the level of fermentable carbohydrates you are feeding are higher than normal and are balancing the level of degradable protein in the diet. If you are noticing lower than normal milk urea then it also suggests that you may find it beneficial to re-assess the protein supply in the total diet and this can easily be assessed by BOCM PAULS Account Managers with the use of Dietplan the leading dairy rationing program in the country.Alternatively if milk urea is higher than normal this implies that rumen degradable protein supply is in excess in the total diet again due to a number of reasons. The grass you produce on your farm is higher in protein than the average detailed above, the level of fermentable carbohydrates are lower than normal and are not balancing the level of degradable protein