*Dr. Roger Scaletti is with Alltech Inc.
AS author Tony Robbins once said, "If you do what you've always done, you'll get what you've always gotten."
While this inspirational quotation encourages change at a personal level, some nutritionists may say the same about mineral nutrition in modern swine and poultry production.
Since the 1950s, livestock and poultry feeds have been complemented with essential trace minerals such as copper, iron, manganese, selenium and zinc; however, the primary source of these elements has been inorganic.
From the 1960s forward, genetics have played a larger role in swine and poultry production, improving reproductive performance and increasing profitability. While global food demand has intensified in recent decades, operations were able to meet the increasing production challenge as the genetic potential for growth and yields improved.
Commercial tendencies have been to increase trace mineral supplementation in order to accommodate the greater mineral requirements of superior stock reared under industrial conditions. This increased concentration of inorganic minerals in animal diets has led to several problems, such as accidental poisoning, low absorption, reduced access to enterocytes, poor retention and high excretion rates.
Due to high excretion and environmental concerns, some countries have put legislation in place regarding supplemental mineral levels. The European Union took action in 2003 and lowered the permitted levels of trace minerals. Brazil followed suit last year.
While research in trace mineral nutrition has led to the development of more bioavailable organic minerals — including trace minerals derived from chelates — some traditional nutritionists continue to use only inorganics and feed minerals only to prevent deficiency symptoms.
However, recent studies have shown that chelated minerals can be included at a lower supplementation rate than inorganic minerals in monogastric diets and can provide an equivalent, if not improved, effect on animal health, growth and productivity.
Mahan and Peters with The Ohio State University evaluated the effects of organic trace minerals (Bioplex) versus inorganic minerals on sow reproductive performance, sow milk composition and the body composition of weanling pigs and sows.
The minerals were fed at the recommended National Research Council (NRC) level, the industry level and the industry level with added calcium and phosphorus. The researchers found that sows fed organic trace minerals had one more pig per litter.
Mahan and Peters also explored the effect on the transfer of trace minerals from the sow. Their work demonstrated that mineral transfer to the developing fetus is not greatly affected by mineral source or level. However, sow tissue mineral concentration is affected by mineral level.
In 2012, Bertechini et al. evaluated the effects of diets with two levels of mineral supplementation (inorganic and organic) on the reproductive performance of sows in late pregnancy and lactation as well as the physiologic characteristics of piglets until weaning at 21 days of age.
The researchers found increased weight at birth and at 21 days and discovered an increased iron content in the blood and liver in the piglets whose mothers were given organic trace minerals.
In another trial, "Effects of Bioplex on Performance & Fecal Mineral Excretion in Grow-Finish Swine," Iowa State University researchers (Burkett et al., 2009) studied average daily gain, rate of gain to feed and daily fecal copper, iron and zinc outputs.
The study found that when feeding organic trace minerals, less was needed to achieve optimum performance compared to inorganic sources, and the organic form of minerals significantly decreased fecal excretion.
Research in the poultry sector has shown similar results. In the World Poultry Science Journal, Ao and Pierce (2013) reviewed the extensive global research to date with mineral proteinates in broilers, pullets and laying hens of different ages and in various practical raising conditions.
Two trials by Ao et al. were highlighted in the paper. Both evaluated the effects of feeding reduced levels of trace minerals in organic forms on the development and bone mineral status of white and brown pullets.
Treatments consisted of feeding a non-supplemented corn/soybean meal-based starter and grower diets (control) and diets supplemented with copper, manganese, iron and zinc at 25%, 50% or 100% of the NRC requirements as organic minerals or 100% of the NRC requirements in the inorganic form.
The results indicated that supplementing pullet diets at 25% of NRC requirements as organic minerals had no negative effects on bodyweight, uniformity and tissue mineral concentration in comparison with supplementing at 100% of NRC requirements as inorganic minerals.
A number of studies have demonstrated the increased bioavailability of trace mineral proteinates at low inclusion levels. Peric et al. (2007) reported that supplementing organic copper, manganese, iron and zinc at 30% of the NRC recommendation maintained performance of broilers in a 42-day trial.
Pierce et al. (2005) replaced copper, manganese, iron and zinc with only 25% of the NRC requirement in the form of proteinated minerals (no inorganic forms were fed). The results showed a 34% reduction in mineral excretion without compromising weight gain.
Bao et al. (2007) reported similar findings — that organically chelated minerals at levels of 4 parts per million of copper and 40 ppm of iron, manganese and zinc were sufficient to maintain performance of broilers while reducing excreted mineral losses.
The researchers drew four main conclusions:
1. Mineral proteinates have a higher retention rate and relative bioavailability value in comparison to inorganic salts.
2. The antagonism between minerals such as zinc and copper can be avoided by using organic forms.
3. Supplementing high levels of copper or zinc with the inorganic form in poultry diets can negatively affect the efficacy of phytase in the diet.
4. The replacement of inorganic minerals with lower levels of organic forms can support the optimal performance of broilers and layers and minimize the impact on the environment.
In conclusion, research has shown that if hogs and poultry are overfed inorganic trace minerals, they do not perform with optimal productivity.
By now, the poultry and swine industries should know that environmental issues are not going to go away, and regulations are probably going to get more stringent.
Does organic mineral supplementation pay off? If pigs and poultry display similar or better performance while at the same time having less fecal mineral excretion, then the answer is yes, and it may be time to consider changing the way things have always been done.
References are available upon request.