A Survey of Added Vitamins and Trace Minerals in Diets Utilized in A Survey of Added Vitamins and Trace Minerals in Diets Utilized in the U.S. Swine Industry the U.S. Swine Industry

Summary 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 vitamins and trace mineral concentrations in swine diets. Respondents were asked to provide vitamin and trace mineral inclusion rates, weight ranges associated with each dietary phase, and number of sows utilizing their nutritional recommendations. Survey participants represented 4.38 million sows, or 72% of the U.S. industry. Data were compiled into 3 nursery phases (weaning to 15 lb; 15 to 25 lb; and 25 to 50 lb), 3 finishing phases (50 to 120; 120 to 220; and 220 lb to market), gilt development, gestation, lactation, and boar diets. Within each dietary phase, the vitamins and trace minerals of interest included: vitamin A, vitamin D, vitamin E, vitamin K, thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, vitamin B 12 , 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), median, minimum, maximum, 25th percentile (lowest quartile), and 75th percentile (highest quartile). In addition, all average vitamin and trace mineral concentrations within each phase of production were compared to the requirement estimates reported in the NRC. 2 The results of this survey follow similar trends observed in a previous survey in 2016. 3 Nutritionists generally supplemented vitamins and trace minerals well above the NRC (2012) requirements. However, greater variation among respondents was observed


Introduction
Vitamins and trace minerals are added to swine diets to contribute to good health, performance, and well-being of the animal.Depending on the production phase or stage, pigs require different amounts of each vitamin and trace mineral.Most commercial diets are formulated well above the NRC (2012) requirement estimates for two main reasons.First, nutritionists want to maintain a margin of safety to account for potential reductions in the bioavailability of vitamins resulting from unfavorable storage conditions or excessive storage time.Second, this is an area with traditionally little research, resulting in a lack of knowledge.Six years ago, nutritionists for 2.3 million sows were surveyed and confirmed that, in the U.S., vitamin and trace mineral concentrations are frequently higher than the NRC estimates.Additionally, the survey showed considerable variation in the levels used by different swine operations.This variation might be attributed to differences in health status, vitamin and trace mineral source, feed mill characteristics, or nutritionists' opinions as to a margin of safety.Furthermore, in 2018 there were vitamin shortages that caused some vitamin inclusion rates to be reduced.It is not clear if the resulting supplementation rates remained or were again increased after the vitamin supply became adequate.Because it has been 6 years since the last U.S. survey, and 10 since the previous NRC publication, our goal was to update the vitamin and trace mineral concentrations used, and survey a greater portion of nutritionists in the industry than in 2016.

Procedures
The survey procedures followed the same methods as Flohr et al. (2016).Nutritionists from swine production companies in the top 40 Pork Powerhouses list4 and nutrition supplier companies were contacted via email or phone from November 2021 to February 2022.
The survey aimed to identify industry levels of added vitamins and trace minerals in complete diets based on the phase of production.The phases included: 3 nursery phases (weaning to 15 lb; 15 to 25 lb; and 25 to 50 lb), 3 finishing phases (50 to 120; 120 to 220; and 220 lb to market), gilt development, gestation, lactation, and boar diets.Within each dietary phase, the vitamins and trace minerals of interest included: vitamin A, vitamin D, vitamin E, vitamin K (menadione), thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, vitamin B 12 , choline, vitamin C (ascorbic acid), carnitine, copper, iodine, iron, manganese, selenium, zinc, cobalt, and chromium.
Results were compiled and pooled to determine descriptive statistics in an Excel spreadsheet (Microsoft, Redmond, WA).Descriptive statistics used included: average, weighted average (determined by the total number of sows), median, minimum, maximum, 25th percentile (lowest quartile), and 75th percentile (highest quartile).All values were determined using Excel formula functions, including average, standard deviation (STDEV.S), median, minimum (MIN), maximum (MAX), and 25th and 75th percentiles (QUARTILE.EXC).Weighted averages were calculated using the SUMPRODUCT function of Excel, in which the participant vitamin or trace mineral concentration was multiplied by the number of sows and then divided by the total number of sows for all participants who provided added levels for that nutrient.Average vitamin and trace mineral concentrations within each phase of production were compared to NRC (2012) total dietary requirement estimates and to Flohr et al. (2016).

Results and Discussion
In total, 37 U.S. swine production systems and nutrition suppliers participated in the survey totaling approximately 4,382,700 sows.Using the 2022 U.S. Department of Agriculture sow inventory estimate of 6,100,000 (USDA, 20225 ), this survey sampled approximately 72% of the U.S. swine industry.

Nursery
For nursery diets (weaning to 50 lb), fat soluble vitamins (A, D, E, and K) ranged from 4.3 to 11.8 times the NRC (2012) requirement estimates (Tables 1, 2, and 3), and on average were 99% of the values obtained by Flohr et al. (2016).A major difference was 11 of the 36 respondents used 25-hydroxyvitamin-D 3 as a source of vitamin D (Table 4).Four of the 36 producers specified natural vitamin E as the single source or a percentage of the added vitamin E. Water soluble vitamins (thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, vitamin B 12 , choline, and vitamin C) ranged from 0.7 to 12.7 times the NRC (2012) requirement estimates and on average were 110% the values obtained by Flohr et al. (2016).
For minerals, nearly all participants reported using pharmacological levels of Zn from weaning to 25 lb (Table 11), and overall mineral concentrations followed the levels observed by Flohr et al. (2016).Approximately half of the respondents reported using some sort of organic mineral source for Cu (12), Mn (11), Se (18), and Zn (9).

Finisher
For finishing (50 lb to market) diets (Tables 5, 6, and 7), fat soluble vitamins ranged from 1.9 to 8.1 times the NRC (2012) requirement estimates, and were on average 98% of the values obtained by Flohr et al. (2016).Three systems reported using 25-hydroxyvitamin-D 3 as a source of vitamin D, and 4 of the 36 producers specified natural vitamin E as the single source or as a percentage of the vitamin E. Water soluble vitamins ranged from 0.8 to 3.7 times the NRC (2012) requirement estimates and on average were 118% of the values obtained by Flohr et al. (2016).Trace minerals ranged from 1.4 to 18.8 times the NRC (2012) requirement estimates and on average were 93% of the values obtained by Flohr et al. (2016).Some respondents reported using some form of organic mineral source for Cu (6), Mn (2), Se (3), and Zn (3).

Breeding herd diets
In gestation (Table 8) and lactation (Table 9) diets, fat soluble vitamins ranged from 1.9 to 7.9 times the NRC (2012) requirement estimates, and on average were 113% of the values obtained by Flohr et al. (2016).Thirteen systems reported using 25-hydroxyvitamin-D 3 as a source of vitamin D, and 8 of the 36 producers specified natural vitamin E as the only source or as a percentage of the vitamin E. Water soluble vitamins ranged from 0.5 to 4.5 times the NRC (2012) requirement estimates and on average were 103% of the values obtained by Flohr et al. (2016)  0.9 to 3.7 times the NRC (2012) requirement estimates and on average were 104% of the values obtained by Flohr et al. (2016).Some respondents reported using a form of organic mineral source for Cu (13), Mn (13), Se (23), and Zn (12).
In gilt development diets (Table 10), fat soluble vitamins ranged from 1.7 to 7.1 times the NRC (2012) requirement estimates, and on average were 112% of the values obtained by Flohr et al. (2016).Thirteen systems reported using 25-hydroxyvitamin-D 3 as a source of vitamin D and 8 of the 36 producers specified natural vitamin E as the only source or as a percentage of the added vitamin E. Water soluble vitamins ranged from 0.4 to 4.2 times the NRC (2012) requirement estimates and on average, 103% the values obtained by Flohr et al. (2016).Trace minerals ranged from 1.2 to 4.3 times the NRC (2012) requirement estimates and on average were 108% of the values obtained by Flohr et al. (2016).Many respondents reported using a form of organic mineral source for Cu (12), Mn (11), Se (22),and Zn (11).
Boar diets (Table 11) were provided by 21 of the producers and fat soluble vitamins ranged from 2.4 to 13.6 times the NRC (2012) requirement estimates, and were on average 123% of the values obtained by Flohr et al. (2016).Eight systems reported using 25-hydroxyvitamin-D 3 as a source of vitamin D, and 5 of the 21 producers specified natural vitamin E as only source or as a percentage of the added vitamin E. Water soluble vitamins ranged from 0.4 to 4.7 times the NRC (2012) requirement estimates and on average were 103% of the values obtained by Flohr et al. (2016).Trace minerals ranged from 1 to 4.6 times the NRC (2012) requirement estimates and on average were 102% of the values obtained by Flohr et al. (2016).Many respondents reported using a form of organic mineral source for Cu (9), Mn (11), Se (17), and Zn (9).
In conclusion, this survey updated the U.S. current inclusion levels of vitamins and trace minerals in pig diets, and it can be used as an industry benchmark.Different herd health status and vitamin and trace mineral sources, and diet formulation philosophy with a margin-of-safety mindset are reflected in the variation found in vitamin and trace mineral concentrations observed in all production phases.Compared to Flohr et al. (2016), this survey captured a larger representation of the U.S. swine industry and the difference in respondents probably reflects many of the changes when comparing both surveys.In addition, comparisons to the most recent NRC (2012) requirement estimates highlight the necessity of future research to better understand vitamin and trace mineral requirements in swine diets.

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Respondents who added the nutrient to the diet from the 4,245,700 sows surveyed.Reported values are on a complete-feed basis.
2 Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.
Respondents who added the nutrient to the diet from the 4,382,700 sows surveyed.Reported values are on a complete-feed basis.
2 Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.

Swine Day 2022
Kansas State University Agricultural Experiment Station and Cooperative Extension Service Respondents who added the nutrient to the diet from the 4,370,100 sows surveyed.Reported values are on a complete-feed basis.
2 Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient. from . Trace minerals ranged

Table 1 .
Added vitamin and trace mineral concentrations in phase 1 nursery diets (weaning to 15 lb) Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 2 .
Added vitamin and trace mineral concentrations in phase 2 nursery diets (15 to 25 lb) 1Respondents who added the nutrient to the diet from the 4,245,700 sows surveyed.Reported values are on a complete-feed basis.2Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.3 National Research Council.2012.Nutrient Requirements of Swine: Eleventh Revised Edition.Washington, DC: The National Academies Press.https://doi.org/10.17226/13298.Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 3 .
Added vitamin and trace mineral concentrations in phase 3 nursery diets (25 to 50 lb) 1Respondents who added the nutrient to the diet from the 4,245,700 sows surveyed.Reported values are on a complete-feed basis.2Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.National Research Council.2012.Nutrient Requirements of Swine: Eleventh Revised Edition.Washington, DC: The National Academies Press.https://doi.org/10.17226/13298.Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 4 .
Percentage of participants using alternative vitamin and trace mineral sources 1Percentage of producers and nutrition suppliers that supplement partial or complete trace mineral concentrations from organic or chelated sources.Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 5 .
Added vitamin and trace mineral concentrations in early-finishing diets (50 to 120 lb) 1Respondents who added the nutrient to the diet from the 4,382,700 sows surveyed.Reported values are on a complete-feed basis.2Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.3National Research Council.2012.Nutrient Requirements of Swine: Eleventh Revised Edition.Washington, DC: The National Academies Press.https://doi.org/10.17226/13298.Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 6 .
Added vitamin and trace mineral concentrations in mid-finishing diets (120 to 220 lb) 1Respondents who added the nutrient to the diet from the 4,382,700 sows surveyed.Reported values are on a complete-feed basis.2Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient.National Research Council.2012.Nutrient Requirements of Swine: Eleventh Revised Edition.Washington, DC: The National Academies Press.https://doi.org/10.17226/13298.Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 7 .
Added vitamin and trace mineral concentrations in late-finishing diets (220 lb to market)

Table 8 .
Added vitamin and trace mineral concentrations in gestation dietsSum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient 2Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 9 .
Added vitamin and trace mineral concentrations in lactation diets

Table 10 .
Added vitamin and trace mineral concentrations in gilt development dietsRespondents who added the nutrient to the diet from the 4,182,600 sows surveyed.Reported values are on a complete-feed basis.Sum of the products of the inclusion level multiplied by the size of the production (# of sows), divided by the total number of sows from the participants who provided added levels for that nutrient 3 National Research Council.2012.Nutrient Requirements of Swine: Eleventh Revised Edition.Washington, DC: The National Academies Press.https://doi.org/10.17226/13298.
1 2 Kansas State University Agricultural Experiment Station and Cooperative Extension Service

Table 11 .
Added vitamin and trace mineral concentrations in boar diets