Industry survey of added vitamins and trace minerals in U.S. swine diets.

From November 2021 to February 2022, 37 swine nutritionists representing 29 production systems and 8 nutrition supplier companies in the United States were surveyed about added vitamin and trace mineral concentrations in swine diets. Respondents were asked to provide vitamin premix and trace mineral concentrations, inclusion rates, and weight ranges associated with feeding phases. Survey participants represented 4.38 million sows, or 72% of the U.S. industry. Data were compiled into three nursery phases (phase 1, weaning to 7 kg; phase 2, 7 to 11 kg; and phase 3, 11 to 23 kg), three finishing phases (23 to 55 kg; 55 to 100 kg; 100 kg to market), gilt development, gestation, lactation, and boar. Within each dietary phase, the vitamins and trace minerals of interest included: vitamins A, D, E, and K, thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, vitamin B12, choline, vitamin C, carnitine, copper, iodine, iron, manganese, selenium, zinc, cobalt, and chromium. Descriptive statistics used included: average, weighted average (determined by the total number of sows represented), median, minimum, maximum, 25th percentile (lowest quartile), and 75th percentile (highest quartile). In addition, all average supplementation rates for vitamins and trace minerals within each phase of production were compared to the requirement estimates reported in the NRC (2012). Nutritionists generally supplemented vitamins and trace minerals well above the NRC (2012) requirement estimates. However, great variation among respondents was observed in all vitamins and trace minerals, particularly in the fat-soluble vitamins. Also, the use of alternative sources of vitamin D [25(OH)D], E (natural, d-alpha-tocopherol), and organic or chelated minerals like copper, manganese, selenium, and zinc were being used by approximately 40% of the respondents, primarily in breeding herd and nursery diets. Understanding current supplementation practices may help develop research trials to test different vitamin and trace mineral inclusions and provide an industry benchmark of vitamin and trace mineral usage.