Why is "Stock car (rail)" trending?

Wikipedia Overview

In railroad terminology, a stock car or cattle car is a type of rolling stock used for carrying livestock to market. A traditional stock car resembles a boxcar with louvered instead of solid car sides for the purpose of providing ventilation; stock cars can be single-level for large animals such as cattle or horses, or they can have two or three levels for smaller animals such as goats, sheep, pigs, and poultry. Specialized types of stock cars have been built to haul live fish and shellfish and circus animals such as camels and elephants. Until the 1880s, when the Mather Stock Car Company and others introduced "more humane" stock cars, death rates could be quite high as the animals were hauled over long distances. Improved technology and faster shipping times have greatly reduced deaths.