Tribasic Copper Chloride Source Shows Promise in Weanling Pig Performance

By Ryan Samuel

One of the many challenges in swine production is getting newly weaned pigs off to a good start. Antimicrobial agents are often included in nursery pig diets due to significant improvements in pig growth performance. Traditional antimicrobial agents include in-feed antibiotics; however, restrictions on the use of antibiotic growth promoters in food animal production are in place in several countries with the intent to reduce pools of antibiotic-resistant genes.

Research focused on alternatives to antibiotic growth-promoting technologies includes the 1928 report by Evvard, et al., indicating that feeding copper sulfate at concentrations from 100 to 300 parts per million improved growth performance. Thereafter, the inclusion of levels of copper and zinc drastically higher than nutritionally required (i.e. pharmacological levels) has become a recognized strategy to improve nursery pig growth performance.

Although the original research was based on the feeding of copper sulfate, supplemental copper may be added to nursery pig diets in different forms. Cromwell, et al., (1998) evaluated dicopper chloride trihydroxide, more commonly known as tribasic copper chloride, supplementation in nursery pigs diets and observed TBCC to be equally effective as copper sulfate. Similarly, University of Illinois (Espinosa, et al., 2017; 2019) research demonstrated that TBCC supplemented into nursery pig diets was effective at improving growth performance and intestinal health of weanling pigs.

Evaluating TBCC Sources

Two sources of TBCC were evaluated at the South Dakota State University commercial wean-to-finish research facility. On the day of weaning, 44 pens of 26 mixed-gender weaned pigs were assigned to receive one of four dietary treatments: 1) Control (no pharmacological levels of copper or zinc), 2) Control plus 100 ppm of copper from SAM TBCC (SAM Nutrition, Eden Prairie, Minn.), 3) Control plus 150 ppm of copper from SAM TBCC, or 4) Control plus 150 ppm of copper from IC TBCC (Micronutrients, Indianapolis, Ind.).

The diets were standard commercial diet formulations composed primarily of corn, soy protein and other commonly included commodities fed in four dietary phases. The treatment diets were produced by the addition of TBCC containing 58% copper to provide additional 100 or 150 ppm of copper to the diets. The two sources were used to investigate a specific newer source compared to a more-established source, looking at the effectiveness and benefits provided from the TBCC in comparison with other commercial sources.

Findings

The addition of copper from TBCC into the diet linearly improved the average daily gain of nursery pigs between Days 14 to 21 and Days 35 to 42 compared to pigs fed the control diet (P <0.05) (Table 1).

There were no differences in pig performance between levels of addition of SAM TBCC or between sources providing 150 ppm copper into the nursery pig diets. During the week of Days 14 to 21, pigs fed both forms of TBCC at 150 ppm grew significantly faster than pigs fed the control diet, but not different from the pigs fed the 100 ppm inclusion of SAM TBCC.

TABLE 1. AVERAGE DAILY GAIN OF PIGS IN THE NURSERY, POUNDS/DAY

Overall, there were no differences in average daily feed intake that approached significance. This suggests that the increases in growth were a result of improved gut health and the increased ability to metabolize dietary fats as described by Espinosa, et al., 2019.

Though not statistically significant, it is notable that from Day 7 to Day 14, and every subsequent week, the pigs fed 100 ppm of SAM TBCC numerically outperformed the pigs fed the control diets. Furthermore, from the weeks of Day 21 to Day 28 and Day 28 to Day 35, the pigs fed 100 ppm of SAM TBCC performed identical to pigs fed 150 ppm of IC TBCC. This may indicate an opportunity to reduce the amount of SAM TBCC needed in the later nursery phases which would save money and reduce the environmental copper loading.

The addition of copper from TBCC was able to improve the average daily gain of nursery pigs, but did not affect their average daily feed intake nor their feed-to-gain performance. There were no significant differences between the TBCC sources; however, the average daily gain of nursery pigs fed diets with 100 ppm of copper from SAM Nutrition TBCC numerically matched the average daily gain of nursery pigs fed diets with 150 ppm of copper from IC TBCC.