No matter what weather forcasting service you look at the message appears to be the same - bright with sunny spells during the day with cold frosty conditions by night. Good for grazing conditions and utilisation but bad for growth.
So, now that you know the forecast for the next week or so, how are you going to plan your feeding regime for the next two weeks. Simple questions must be answered - what is your farm cover at the moment and what percentage of the farm has been grazed in relation to your rotation plan.
On the former point of farm cover estimation, it is clear that farmers are underestimating the amount of grass in the paddocks. Remember, heavy cover with alot of dead material, dry to touch will have a dry matter of up to 28% or even more. Green leafy material dry to touch will have a dry matter of approximately 23%, and both reducing further if wet to touch. When cutting and weighing during a farm walk be sure to adjust the DM% accordingly. The evidence of high dry matter of the grass is also bourne by the fact that cows are taking longer than expected to finish in paddocks - a true sign that the cover was under-estimated.
By now most farms have grazed off the heavy "carry-over" covers from last November. Their grazing has led to a considerable drop in average farm cover in most farms with many <400kgDM/ha. Below this level, action must be taken to prevent further significant drop in grass supply. A grass budget allows you to predict the trend in farm cover through the Spring. Our problem for the next two weeks is that predicted growths in the budget are generally on 4kgDM/ha/day fo rthe coming week and only 8kgDM/ha/day for the following week. If farm cover is already at a low level <350 kgDM/ha, then action must be taken to prevent a further drop by dropping grass demand in cover over the next two weeks. In most cases this is manifested by day grazings only allowing approximately 4-5 kgDm of grass with the remainder of intake of approximately 5 kg concentrate and 2-3 kgDM silage.
High levels of dead material in the sward do not effect he crude protein level of the sward but does dilute the the energy intake per kgDM. Therefore the concentrate type off choice is important - preferably 16-18% crude protein and dominated by starch/grain based energy source as opposed to a pulp based grain energy source. This allows for a readily available energy source in the rumen for rumen microbes to work.
I have not be a strong advocate of a rotation planner in the past on farms which were measuring and budgeting weekly. But due to the grass deficits on farms the emphasis changes towards maintaining farm cover at an acceptable level and still grazing the farm to prepare for the second rotation in April. Therefore a rotation plan is a must. However be careful. At the start of the grazing year in early February most rotation plans were developed between the start of grazing and an expected end of the 1st rotation on the 1st April. This was ok if subsequent growths through February were normal. However this was not the case. The first grazed paddocks remain at 100-200kgDM/ha and with only 25 days to 1st of April with a suggested average growth of circa 16kgDM/ha over this period - then these first grazed paddocks will only be at 500-600kgDM/ha pre-grazing yield. However if the first rotation is extended to 10-12th April then these first grazed paddocks have longer to accumulate yield for the start of the 2nd rotation. Accordingly, the rotation planner now needs to be re-set to facilitate the first rotation to end on circa 12th April, or later on wet slow growing farms.
Probably the most common question in the past week relates to the application of Nitrogen in these cold soil temperatures. Scientific evidence has clearly shown that grass does not respond to nitrogen application unless soil temperatures are greater than 6 degrees and preferably 7+. To date soil temperatures have remained well below this level hence why most farmers who have already spread nitrogen have seen a minimal response. However, just before I began to write this piece (at 5pm), I checked the soil temperature outside which read 8.4 degrees. This clearly indicates a distinct increase in soil temperatures to justify further application of nitrogen. There is anecdotal evidence to suggest that Urea spread in January is no longer available, so be prepared to re-apply once soil temperature rise in your area.
Final point...on a positive note, the weather conditions are extremely conducive for goo grazing and clean-out of paddocks which sets up the farm nicely for subsequent grazings. I have just returned from a discussion group farm walk where we stopped to discuss the residual grass left in a paddock after grazing 5 days ago. The feeling of the group was that, given that there was no growth, the best thing to do was to leave out the dry cows to graze it off. However when they got down on their hands and knees and examined the residual it was clear that there was growth since it was grazed with approximatley 2cm of new leafy material above the grazing point. If this new leaf was to be removed now with the dry cows, then the plant does not have reserves to push up another new leaf - the outcome is that the paddock will take way too long to recover for the 2nd rotation. Bottom line - if dry cows are required to "clean-out" a paddock, do so immediately after the milking cows before the new leaf is up.
