Grass growth rates have continued to decline over the past week, decreasing 5kg from 59kg DM/ha last week to 54 kg DM/ha this week. Grass quality, however, has improved slightly with an average metabolisable energy (ME) of 11.7 MJ/kg DM, up 0.2 MJ/kg DM compared to last week. This is on par with the six year average, and 0.5MJ greater than the same week last year. Crude protein has remained static at 21.6%.
Milk from grazing has also remained steady at M+ 12.9 litres but with falling grass growth rates we can expect this to start to fall as less fresh grazing becomes available and rotations lengthen.
In response to the high temperature and humidity levels experienced this past week, heat stress has been a major problem on livestock farms. Cows respond to heat stress in several ways, however the main consequence is reduced feed intakes.
This compromises the cows’ health and performance significantly with evidence of a 20% reduction in milk yield for cows under severe heat stress as experienced this week. Cows that have little time to adapt to increased temperatures are at the highest risk of becoming heat stressed, showing signs of increased respiratory rate, lethargy and standing with heads bowed.
Preventative measures to reduce heat stress include:
- 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 25th July 2016