Selection Criteria for Trace Mineral Supplementation

Trace Minerals are required by all the animal species. In general, the concentration of trace minerals (Zinc, Copper, Manganese etc) present in most of the animal feeds is inadequate for growth, milk production, reproduction and reproductive performance. If trace mineral requirement is not met, deficiency symptoms are likely to occur. Poor bioavailability of various minerals and also mineral’s interaction create the necessity for use of highly bioavailable sources of minerals among feed producers, premix producers and farmers.

Today’s concern with trace minerals

In Europe, it is identified that zinc excretion in to the environment through animal nutrition is 14599 ton per year (EFSA Journal, 2014). EFSA is aiming to reduce 20% zinc excretion coming in the environment through animal nutrition.

Kemin has taken the lead towards creating awarness for understanding the basic selection criteria of minerals.

Ideal mineral quality and characteristics are based on following parameters:

  1. Solubility
  2. Dissociation
  3. Absorption
  4. Retention

 

Solubility of Zinc Sources

An in vitro experiment was conducted to evaluate the uptake and solubility of zinc provided as KemTRACETM Zn MP and zinc sulfate by caco-2 cells after ruminal and intestinal digestion.  For the uptake experiment, caco-2 cells were grown in plastic tissue culture wells using standard tissue culture method. Test solution of 200 µM zinc was prepared using KemTRACE Zn MP and Zn sulfate, separately.

Research showed that zinc from KemTRACE Zn MP was more soluble than zinc sulfate; similarly zinc uptake was also greater from digestion containing 200 µM zinc from KemTRACE Zn MP, Graph 1.

Absorption and Retention of Zinc Sources

The bioavailability of minerals is difficult to assume with the higher absorption only, because it  takes in to account only excretion of mineral in the faeces. It is equally important to check urinary excretion of mineral to arrive to the bioavailability or retention of mineral for biological significance.

The major concern with the source of zinc is its lower retention in animal body and higher excretion through urine and faeces. If the supplemental zinc is excreted in the environment, it not only affects profitability of the farmer but also creates concern for the environmental pollution.

In a research trial conducted on lambs, 93.1 % Zn was excreted in Zinc sulfate group where as in the KemTRACE Zn MP group, 75.1 % zinc was excreted. The net retained zinc (mg/kg) was significantly higher in KemTRACE Zn MP group, Table 1.

Table 1: Zinc excretion and retention pattern in different source of zinc supplementation 

Parameter

Zinc Sulfate

KemTRACETM Zn MP*

Animals/treatment

6

6

Zinc intake, mg/day

51.3

56.9

Fecal Zinc, mg/day

47.4

42.3

Urinary Zinc, mg/day

0.39

0.44

Total Excretion, mg/day

47.79

42.74

Total Excretion %

93.1

75.1

Zinc absorption, %

7.56

25.7

Zinc retained, mg/day

3.5a

14.1b

*KemTRACE Zn MP contains 27% Zinc in highly bioavailable form, a,b – different at P< 0.05

Difference in Plasma Zinc Concentration

In another trial on Holstein cows, change in plasma zinc concentration was studied. Cows were fed 300 ppm of supplemental zinc either from zinc sulfate or KemTRACE Zn MP. There were four cows per treatment. Plasma serum zinc concentration was measured at 0, 4 and 8 hours post-bolusing for three days. KemTRACE Zn MP had the significantly higher serum zinc level than zinc sulfate group, Table 2.

Table 2: Serum zinc concentration in different source of zinc supplementation 

Mineral Source

0 Hours

4 Hours

8 Hours

Zinc Sulfate

1.36 a

1.51 a

1.63 a

KemTRACE Zn MP

1.55 a

1.79 b

1.97 b

a, b Superscripts indicate statistically different (p<0.05) serum zinc level (MQ/l) after 4 hours post administration.
C.S. Ballard, C.J. Sniffen and Larry Schlatter, Miner Institute, NY, BB-03-00253

Conclusion

Feeding zinc based on above mentioned criteria not only help in reducing environmental excretion of zinc but also improve retention of minerals in animal’s body for various biological functions.