StettlerLocal.com September 15, 2021, contributed by Yaremcio Ag Consulting, Ltd.
The use of net wrap is becoming more popular for many reasons. Bales made with net wrap tend to shed rain better than those made with twine. It has been reported that bales stored outdoors unprotected from the weather can have 8% less shrink or dry matter loss over the first year of storage when they are made with net wrap compared to twine.
Unfortunately, there are potential downsides when net wrap bales are used to feed or bed cattle. In the June 5th, 2014 edition of the Western Producer, an article written by Dr. John Campbell from the Western College of Veterinary Medicine, discusses potential problems and hazards of cows consuming net wrap and twine.
Dr. Campbell indicates that the deaths occurred on a well-managed farm. The cows that died were in good condition and close to calving. No symptoms of ill health were noted prior to the sudden deaths.
The dead cows appeared to have very large rumens. The post-mortem found that the rumen was full of feed and a “large mass of bale net wrap that appeared to have obstructed the outflow of the rumen.” Dr. Campbell surmises that the pressure from a full rumen and the cow being near calving resulted in severe pressure being put on the lungs, restricting the ability to breathe and the animals suffocating to death.
In this case, the bales were delivered to the feeding area by bale processor. The processor did not tear apart the net wrap adequately to allow the plastic to flow through the cows’ digestive system.
This situation was severe with dead animals being present. The “less severe” cases where the twine or net wrap is trapped in the rumen can potentially reduce voluntary feed intake. This can occur without any problems being observed. In a cold hard winter, cow body condition can drop. Was the drop due to the weather or was it partly due to the cows not able to eat as much feed as normal because of plastic taking up space in the rumen?
Removing twine and net wrap is recommended. Take the extra time to prevent problems.
Barry Yaremcio
Ruminant Nutritionist