The hidden danger in pastures for livestock
Net wrap is an effect method for binding forages, and it significantly reduces harvest and storage losses compared to regular twine. According to a forage binding study conducted by South Dakota State University (SDSU), net wrap was the most preferred method of forage binding (67%) compared to twine (26%) or both (6%), depending on the crop harvested or livestock being fed.
To save time and labor, some producers will not remove the net wrap or twine to save time prior to feeding livestock. The SDSU forage survey reported that 54% of producers removed net wrap and twine when feeding bales whole, but only 11% removed it when grinding up bales.
Whether by accident or simply out of boredom, livestock can consume some of this net wrap or twine, which in cattle, accumulates in the rumen. The buildup of this plastic twine in the rumen can result in cattle weight loss, diarrhea and other symptoms similar to hardware or Johne’s disease.
Rumen microbes do not digest plastic net wrap or biodegradable twine. Sisal twine does get digested but at a much slower rate compared to hay. Cattle can accumulate a softball size mass of sisal twine or net wrap in the rumen that can measure up to 3 feet in length when stretched out.
Research by North Dakota State University (NDSU) has shown that the rumen microbes do not digest plastic net wrap or biodegradable twine. In another NDSU study, steers were fed net wrap in a ration until 14 days prior to harvest to determine if the material would pass through the digestive system. After 14 days the research showed there was still a significant amount left in the rumen.
Even when grinding up net wrapped bales and reducing the particle size of the wrap compared to feeding intact, health issues can still occur. Failing to remove net wrap completely may affect rumen function and capacity of the cattle when fed long-term. Due to differences in diet and the amount of baled forages consumed, mature cows are likely to be more at risk than feedlot cattle. There is no treatment for the buildup in the system, so prevention is the key to avoiding health issues.
Prevention means removing twine and net wrap from fed bales and removing before adding to a tub grinder and picking up net wrap when found in pastures and along the roadside. Calves are some of the worst culprits because they like to chew on everything and everything has to go in their mouth. You may never be able to get all of it picked up but try making it more difficult for the cattle to find. It does not take a large clump to start causing problems, but any amount can cause a blockage.
Some signs to watch for:
• A cow that is slowly wasting away for no reason and she is not sick or running a fever.
• A cow with unexplained diarrhea
• A cow that has energy until she doesn’t.
• A cow that quits eating
• A cow with no manure that is not bloating.
• A cow may or may not bloat with a blockage but won’t be passing a regular amount of manure.
A cow that has a rumen full of net wrap will never be filled with hay which reduces feed efficiency. Even though ingesting small pieces will not kill them, after several years of this kind of buildup, there will start to be problems. If a producer suspects their cattle are having health issues from ingesting foreign material such as net wrap, they should contact their large-animal veterinarian immediately.
