Zinc-amino acid complexes for swine.

Area of Science:

• Animal Nutrition
• Swine Physiology
• Trace Mineral Metabolism

Background:

• Dietary zinc is crucial for swine growth, feed efficiency, and overall health.
• Understanding the bioavailability of different zinc sources is essential for optimizing swine diets.
• Organic zinc compounds are often promoted for enhanced absorption, but their efficacy requires rigorous evaluation.

Purpose of the Study:

• To evaluate the impact of various dietary zinc sources on swine performance and key physiological indicators.
• To compare the efficacy of zinc sulfate, zinc methionine, and zinc methionine with picolinic acid in swine diets.
• To determine if picolinic acid enhances zinc absorption and utilization in pigs.

Main Methods:

• Two experiments involving 96 pigs each were conducted over different growth periods (28-d, 21-d nursery, 56-d growing, 56-d finishing).
• Pigs were fed diets supplemented with different levels (9 or 12 ppm) of zinc from zinc sulfate, zinc methionine, or zinc methionine with picolinic acid.
• Corn oil was included as a variable in the first experiment but omitted in the second; performance metrics and blood/bone zinc levels were assessed.

Main Results:

• In the first experiment, pigs fed zinc methionine with picolinic acid showed improved average daily gain and feed conversion, but this was not superior to zinc sulfate or diets without supplemental zinc.
• No significant differences in growth, feed intake, or serum zinc/copper were observed among treatments during nursery and growing periods in the second experiment.
• During the finishing period, zinc-supplemented diets increased average daily gain and intake, and bone ash zinc content was higher compared to non-supplemented diets, irrespective of the zinc source.

Conclusions:

• The tested sources of dietary zinc (zinc sulfate, zinc methionine, zinc methionine with picolinic acid) exhibit similar biological value for swine.
• The inclusion of picolinic acid in zinc methionine did not demonstrate a significant benefit in enhancing zinc absorption or improving pig performance.
• Supplemental zinc is necessary for optimal finishing pig performance and bone mineralization, but the source does not appear to be a critical factor among those tested.