Fish meal
Fish meal is a product obtained by processing whole fish or fish waste. Fish meal typically contains high concentration of crude protein, adequate balance of amino acids, and presence of omega-3 fatty acids (NRC, 2012). The inclusion of fish meal in swine diets enhances palatability and usually increases feed intake. However, the quality of fish meal may vary considerably depending on the species of fish, freshness of raw materials, and processing method (Kim and Easter, 2001; Jones et al., 2018). Fish solubles, which is a concentrate from the fish meal processing and rich in B vitamins and minerals, is generally found at 8-15% in fish meal but its level is not associated with fish meal quality (Jones et al., 2018).