Positive interactions Various interactions can be considered either positive or neutral. Neutral interactions are considered positive because, in conjunction with positive interactions, they contribute to an overall non-negative relationship between a stock-person and the stock. Pigs are often fearful of fast movements. When entering a pen, it is good practice for a stock-person to enter with slow and deliberate movements. These minimize fear and therefore reduce stress. Pigs are very curious animals. Allowing the pigs to approach and smell whilst patting or resting a hand on the pig's back are examples of positive behavior. Pigs also respond positively to verbal interaction. Minimizing fear of humans allow handlers to perform husbandry practices in a safer and more efficient manner. By reducing stress, stock are made more comfortable to feed when near handlers, resulting in increased productivity. Impacts on sow breeding Hogs raised in confinement systems tend to produce 23.5 piglets per year. Between 2013 and 2016, sow death rates nearly doubled in the United States, from 5.8 to 10.2 percent. 25 to 50 percent of deaths were caused by prolapse. Other probable causes of death include vitamin deficiency, mycotoxins in feed, high density diets or abdominal issues. Iowa's Pork Industry Center collects mortality data in collaboration with the National Pork Board to collect data from over 400,000 sows from 16 U.S. states. The farms range in size and facility types. Increasing death rates are a profit concern to the industry, so money is invested into research to find solutions. Genetic manipulation Pigs were originally bred to rapidly gain weight and backfat in the late 1980s. In a more fat-conscious modern day America, pigs are now being bred to have less back fat and produce more offspring, which pushes the sow's body too far and is deemed one of the causes of the current prolapse epidemic. Researchers and veterinarians are seeking ways to positively impact the health of the hogs and benefit the hog business without taking much from the economy. Terminology Pigs are extensively farmed, and therefore the terminology is well developed: Pig, hog, or swine, the species as a whole, or any member of it. The singular of "swine" is the same as the plural. Shoat (or shote), piglet, or (where the species is called "hog") pig, unweaned young pig, or any immature pig Sucker, a pig between birth and weaning Weaner, a young pig recently separated from the sow