The average grass growth rate has declined this week to 51kg DM/ha/day, down 8kg DM/ha/day from last week. With declining growth rates it is important to monitor grass supply carefully to identify potential deficits as early as possible. If grass growth continues to fall below 50kg DM/ha/day it will be important to adjust the rotation length accordingly, with a target of 22-23 days for a growth rate of 40 – 50kg DM/ha/day.
The potential grass DM intake and Milk Yield From Grazing have remained static in comparison to last week at 9.9 kg of DM and 6.3 litres respectively. With reducing grass growth it is important that the milk yield from grazing is not overestimated and consequently cows underfed. A loss of 0.5 of a body condition score at this time will result in a potential milk yield loss of 2 litres per head per day in the first 3 months of winter, as feed energy is used to replenish body condition.
Crude protein levels have also continued to decline this week to 19.1%, this is below the 2015 average of 21.6% and 6 year average of 22.74%. Coupled with declining grass growth it will be important to ensure that supplementation level and energy and protein content are balanced accordingly.
Looking forward to next week and the hotter weather forecast it is also important that strategies are considered early to reduce possible heat stress. Possible preventative measures include:
- Increase energy density (e.g. megalac)
- Water troughs no further than 250 metres away from cows
- Feeding fresh feed during cooler times of the day (between 8pm and 8am)
- Grazing cows in fields with sufficient shading areas during high risk times of day
- Spray cooling cows with water in collecting yards, in combination with assisted airflow (fans)
Summary by Steve Brown, Report Supplied by Trouw Nutrition
Download Full Report: Grass Watch Report 15th August 2016