Variation in the hog barn is becoming an increasing topic of interest in the pork industry. Variation within the barn is a cost to the producer as it reduces barn utilization and causes a loss of revenue market. Variation can be the result of many causes, but most often fits into the categories of genetics or environment. Birth weights, weaning weight, litter of origin, gender and the parity of the dam all genetically affect the individual pig. Ideally, negative environmental impacts would all be eliminated. However, this is not usually the case. The producers goal should be to minimize negative environmental impacts by ensuring access to resources such as feed and water and minimizing exposure to pathogens. Statistically, variation can be defined in many ways. Most commonly, variation is measured as the standard deviation or coefficient of variation. The more dispersed the weights of the pigs, the larger the standard deviation. Certain management practises can be employed to reduce variation; however, this depends on the existing coefficient of variation. One suggestion to manage variation is to house barrows and gilts separately since barrows tend to eat more feed than gilts and reach market weight 5-7 days sooner.