As we are heading for fall, the weather here in Montana is fluctuating dramatically. One day, we will be close to 100 degrees and then the next we drop down to the low 60s. These dramatic changes are hard on the ponies but can be devastating to them if I have them on grass. This is because the hot days and the extremely cool nights = high sugar and starch in the stressed grass.
One thing that has worked in our favor this summer is the fact that we have been drowning in smoke. The smoke has blocked the sun, keeping the sugars and starches lower. BUT recently our nighttime temperatures have started dropping below 50 degrees meaning the sugars aren't being used at night any longer. So any sugar and starch that has built up during the day, is staying in the grass.
This brings me to the safest time of day to allow our ponies to graze --> early morning, from 4am until around 10am. Putting our ponies out during the night is not a safe practice as the evening is when the grass has the HIGHEST amount of sugar and starch.
Dr. Getty wrote a wonderful article about fall founder: NSC and ACTH - Double Trouble in the Fall!
I'll share a few more articles I have read about sugars and starches in fall grass below:
The moral of this story? Grazing in the fall is risky. Especially as temperatures rise and fall dramatically. Feeding (TESTED!) hay is the best practice for those easy keeper ponies at this time of year. Management is key to keeping our ponies healthy and sound.