Profitable pork production is determined by a magnitude of parameters. Not
always is the lowest cost or highest performance operations the most profitable.
Factors such as management, genetics, hygiene and nutrition have all changed
dramatically over the past few decades, however, as in all technologies, opportunities
for improvement still exist. From a nutritional perspective, great strides
have been made in the fields of amino acid, energy and vitamin research. However,
trace mineral research, utilizing our highly productive animals, in many cases
is lacking and the nutritional requirements we are following to feed our animals
today are often decades old. Ask yourself “Are our pigs today the same
as they were 20 years ago?” The answer is no. Unfortunately, the trace
mineral requirements we are using to feed our advanced genetics are in many
cases based on research that is 20 years old (NRC, 1998). As an example of
advancements made in research, both at the university and commercial levels,
let’s consider the essential nutrient selenium.
While originally considered a toxic substance, selenium is now known to be
an essential nutrient that promotes a healthy immune system and acts as a key
element in the antioxidant system (Surai, 2006). By definition, trace minerals
are supplied in very small quantities and in the case of selenium the maximum
level allowed in rations is 0.3 ppm. Today’s advanced genetics, large
scale production units and demanding financial requirements have elevated the
need for our pigs to have an improved health status and greater ability to
fight off disease. Maximizing the animals natural defense mechanisms will result
in optimal performance and costs. Selenium plays a key role in the maintenance
of good health, and research is beginning to differentiate between forms of
selenium. Recent findings show that the organic form of selenium, as found
in Se enriched yeast, provides not only improved animal performance but reduced
costs as well.
Preliminary research on performance differences between Se-yeast (Sel-Plex®,
Alltech®) and inorganic selenium (sodium selenite) sources was conducted
at Iowa State University in the mid 1990’s (Mahan and Kim, 1996). This
research showed that Se-yeast was more effective in increasing selenium reserves
in the body, transferring selenium to the fetus, at birth and at weaning. During
times of stress, the body’s requirement for antioxidants increases (Fortier
and Matte, 2005) and, since birth and weaning are extremely stressful periods
in a pig’s life, the use of an ingredient such as Se-yeast may be beneficial
during gestation and lactation to enhance the storage of this essential nutrient.
Essential dietary nutrients, such as selenium, are to be provided in the animal’s
diet on a daily basis for the maintenance of good health. However, during times
of stress feed intake is often reduced for prolonged periods of time, thus
reducing the intake of these essential nutrients. Utilizing ingredients such
as Se-yeast that are proven to increase tissue stores of selenium (Mahan and
Parrett, 1996; Mahan and Kim, 1996; Mahan et.al., 1999) for later utilization
in the antioxidant protection system may be warranted.
Normal metabolism within any animal produces toxic by-products (oxygen free
radicals). These free radicals require a strong antioxidant protection system
to neutralize them, or severe damage will occur to the tissues leading to reduced
performance or even death. Think of it as an engine. Small, low horsepower
engines produce less exhaust than do large, high performance engines. The swine
genetics of today are high performance engines, utilizing optimal diets (fuel)
to grow, reproduce and convert feed efficiently in to the pork you produce.
However, this “high performance engine” also produces more exhaust
(oxygen free radicals) that require an advanced antioxidant protection system
to neutralize productive disorders such as low viability in piglets, reduced
growth rate, prolonged farrowing interval, increased stillbirths, lower disease
resistance, Mulberry Heart disease and lower reproductive performance may occur
(Jacques, 2001). Ever wonder why, in your production units, the fastest growing,
highest intake, best pig in the pens quietly lies down and dies? Apparently
nothing was wrong with the pig except it is now dead. While many diseases could
be the culprit, so too could be a borderline selenium deficiency that limited
the animals natural defense mechanisms (antioxidant protection system) from “mopping
up” the excess “exhaust” (oxygen free radicals).
Considering the metabolic events occurring in our pigs on a daily basis and
the fact that a more metabolically active animal places higher demands on its
antioxidant protection system was investigated recently by Canadian researchers.
This study investigated the effect of Se-yeast compared to inorganic selenium
on the antioxidant protection system in the ovary and eventually the embryos.
The results of this experiment showed that Se-yeast, not sodium selenite, was
the only source of selenium that was able to cope with the high oxidative pressures
seen in the ovary (Fortier and Matte, 2005). The researcher then concluded
that in hyperprolific-type sows Se-yeast would be critical for the efficient
transfer of selenium to the embryos and in the subsequent development in early
gestation (Fortier and Matte, 2005). Another way Se-yeast is proving to be
the selenium supplementation of choice for swine rations.
Considering all the research finds on the positive effects of Se-yeast on
swine performance, researchers in Iowa decided to put Se-yeast to the test
under commercial conditions. They conducted a 2 part experiment, involving
over 1,650 sows, to evaluate the impact of Se-yeast on sow reproductive performance
(Lampe et.al., 2005a, b, Gourley et.al., 2006). The results were clear. Under
commercial conditions, today’s highly prolific sows weaned more pigs
(0.22 pigs/litter weaned, 0.15 pigs/litter reduced pre-wean mortality) when
Se-yeast was used as the sole source of selenium supplementation compared to
inorganic selenium (Hooge, 2006). The economic impact of this improvement in
reproductive performance is significant. Hooge, 2006 reported a return on investment
of 7:1 when Se-yeast was used in place of inorganic selenium to supplement
sow rations. Further calculations show that when Se-yeast is used in place
of inorganic selenium and, considering these production improvements, sow feed
cost per piglet weaned is reduced. Se-yeast, not inorganic selenium, reduces
the cost of production. Is that not the goal of modern, profitable swine production…to
reduce the cost of production while optimizing performance?
Current production and management practices have enabled the selection of
hyperprolific swine genetics that may have outgrown components of our current
feeding recommendations. Today’s high producing animals require advanced
plains of nutrition and inorganic sources of selenium may not be sufficient
to deliver the optimal performance and best cost of production. Research is
continually evolving and the transfer of “university data” to commercial
application has proven to be economically viable, especially in the case of
Se-yeast versus inorganic selenium in sow reproduction rations. Based on the
compelling research data, Se-yeast is the recommended choice for selenium supplementation
in swine lactation and gestation rations.
1. Fortier, M.E. and J.J. Matte. 2005. In: Nutritional Biotechnology in the
Feed and Food Industry. Proceedings of Alltech’s 21st Annual Feed Industry
Symposium. Nottingham University Press, Nottingham, U.K. pp175-184.
2. Gourley, G., J.F. Lampe and J.C.Sparks. 2006. Response to Sel-Plex®;sow
reproductive performance and piglet mortality. Nutritional Biotechnology in
the Feed and Food Industries. Proceedings of Alltech’s 22nd Annual Symposium.
Abstracts of Posters presented. pp 51
3. Hooge, D.M. 2006. Dietary organic selenium may be benefit sow and pre-wean
pigs. Feedstuffs. Volume 78, Issue 26. June 26, 2006.
4. Jacques K.A. 2001. Selenium metabolism in animals: relationship between
dietary selenium form and physiological response. Science and Technology in
the Feed Industry. Proceedings of Alltech’s 17th Annual Symposium. pp
5. Lampe, J., G. Gourley, J. Sparks and T. Stumpf. 2005a. Prewean piglet survivability:Sel-Plex® versus
sodium selenite as selenium sources in sow and nursery phase diets. J Anim.
Sci. 83(Suppl. 2):51.
6. Lampe, J., G. Gourley, J. Sparks and T. Stumpf. 2005b. Postwean piglet
survivability:Sel-Plex® versus sodium selenite as selenium sources in sow
and nursery phase diets. J Anim. Sci. 83(Suppl. 2):51.
7. Mahan, D.C. and Y.Y. Kim. 1996. Effect of inorganic or organic selenium
at two dietary levels on reproductive performance and tissue selenium concentration
in first-parity gilts and their progeny. J Anim. Sci. 74:2711-2718.
8. Mahan, D.C. and N.A. Parrett. 1996. Evaluating the efficiency of selenium
enriched yeast and sodium selenite on tissue Se concentration and serum
GSH-Px activity in grower and finisher swine. J. Anim. Sci. 74:2967-2974.
9. Mahan, D.C., T.R. Cline and B. Richert. 1999. Effects of dietary levels
of selenium-enriched yeast and sodium selenite as selenium sources fed to growing-finishing
pigs on performance, tissue selenium, serum glutathione peroxidase activity,
carcass characteristics and loin quality. J. Anim. Sci. 77:2172-2179.
10. National Research Council. Nutrient requirements of Swine. 1998. Tenth
Revised Edition. National Academic Press. Washington D.C.
11. Surai, P.F. 2006. Selenium in Nutrition and Health. Nottingham University
Press, Nottingham, U.K., pp. 445-486.