Providing pigs with more straw in their pens can lead to higher weight gain. Researchers found that for every extra 100 grams of straw given to pigs daily, their average daily weight gain increased by 8.1 grams. This means that pigs given 500 grams of straw per day gained 40 grams more weight on average compared to those given only 10 grams. The feed conversion ratio, however, was not affected by the amount of straw provided. The increase in weight gain is likely due to improved gut health from ingesting more straw and increased feed intake from increased stimulation of exploratory behavior. More studies are needed to confirm these findings.