Answer:
It blocked cattle trails, making it difficult to get cattle to market.
Step-by-step explanation:
The barbed wire served the farmer and ranchers as it enabled them to secure their property and cattle in vast open areas. The barbed wire changed the appearance of the Great Plains and the West. It allowed farmers to fence their property in a better way.
One of the effects of barbed wire had was that it blocked cattle trails which make cowboys and vaquero take cattle to market as they have to find different routes to reach markets.