Department of Animal Science
Mimeograph Series No. AN67-2
September, 1966


Florida Agricultural
Experiment Stations
Gainesville, Florida


A HIGH LEVEL COPPER PREFERENCE STUDY
WITH GROWING PIGS 1

H. D. Wallace, R. H. Houser and G. E. Combs -


Numerous experiments have demonstrated that high levels of dietary copper im-
prove the feedlot performance of growing pigs. It is also quite clear that toxicity
is a problem to be reckoned with. Several investigators have encountered toxicity
with copper levels similar to those found effective for the improvement of feedlot
performance. The use of high level copper in swine feeding has not been widely ac-
cepted in the United States because of the toxicity hazard. However, the economic
advantage potential which is associated with high level copper feeding warrants fur-
ther study of the problem.

The experiment described here was designed to allow the pig an opportunity to
help define a dietary copper level. Hopefully, this level might then prove stimula-
tory from a productive standpoint with reduced danger of toxicity.

Experimental

Forty crossbred pigs (Duroc-Landrace x Hampshire), averaging approximately 32
lb., were divided into 4 similar groups of ten pigs each. The pigs were confined to
concrete pens and given free access to water. Each pen of pigs was supplied with
five self-feeders which offered, respectively, a basal feed mixture (Table 1) supple-
mented with 0, 125, 250, 500 and 1000 ppm copper as copper sulfate (CuSO4). Feeders
were rotated positionwise daily. Special care was taken to keep feed in the feeders
clean, fresh and available at all times. Weekly feed consumption from each feeder
was recorded and the experiment was conducted for 56 days.


















1/ Supported in part by a grant from International Copper Research Association,
Inc., New York.

2/ Wallace, Animal Nutritionist; Houser, Graduate Assistant; and Combs, Associate
Animal Nutritionist, Department of Animal Science.







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Table 1. Basal feed mixture.


Ingredient


Ground yellow corn
Soybean oilmeal (507%)
Defluorinated phosphate
Iodized salt
Trace mineral pre x /
B-vitamin premix -
Vitamin B12 premix 3/


77.37
20.00
2.00
0.50
0.05
0.05
0.03


1/ Calcium Carbonate Co. swine mix. Contained 11% calcium, 10% manga-
nese, 10% iron, 10% zinc, 1% copper, 0.3% iodine and 0.1% cobalt.

2/ Contained 8,000 mg. riboflavin, 14,720 mg. d-pantothenic acid,
36,000 mg. niacin and 40,000 mg. choline chloride per lb.

3/ Contained a minimum of 20 mg. B12 per lb.


Results and Discussion


Results of the experiment are summarized in tables 2, 3 and 4.

As shown in Table 2, the pigs ate more of the feed containing no added copper
than any of the other mixtures. They ate progressively less of the various feed


Table 2. Percent consumption of total feed as influenced by copper level
(all lots combined).


Copper, ppm
Week 0 125 250 500 1000


1 48.5 20.2 16.3 9.5 5.5
2 63.6 8.0 14.1 8.8 5.5
3 50.5 21.3 17.4 6.1 4.7
4 34.6 35.1 14.8 11.9 3.6
5 29.7 29.3 30.7 8.2 2.1
6 28.8 22.9 25.0 14.8 8.5
7 38.2 32.6 16.7 9.8 2.7
8 36.3 35.9 18.7 6.8 2.3








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mixtures involved as the level of copper added increased from 0 to 1000 ppm. The
two highest levels of copper supplementation (500 and 1000 ppm) clearly reduced the
acceptability of the feed mixtures to the pigs. From week to week the pattern of
intake was fairly consistent, and there is no suggestion in the data that the pref-
erence for the various mixtures changed over the eight-week period.

The data in Table 3 illustrate how the replicated lots of pigs .performed. In
general, the selection pattern was similar for the four lots. Pigs in lot 4, for
no clear reason, seemed to have a stronger preference for copper supplemented feed,
especially the mixture containing 500 ppm. This resulted in a considerably higher
average copper intake for this lot, as shown in Table 4. The average overall intake
of copper for all pigs was 170 ppm.





Table 3. Feed consumption by lot in total pounds and as a percent of total
feed consumed as influenced by copper level.



Lot Copper, ppm
No. 0 125 250 500 1000



1 Pounds total feed 1052 1056 259 111 79
% of total feed 41.1 41.3 10.2 4.3 3.1

2 Pounds total feed 946 557 345 59 59
% of total feed 48.1 28.3 17.6 3.0 3.0

3 Pounds total feed 835 585 566 138 78
% of total feed 38.0 26.7 25.5 5.9 3.6

4 Pounds total feed 749 370 647 582 101
% of total feed 29.5 14.7 26.6 22.9 6.3








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Table 4. Average copper consumption by the replicated lots.



Lot number Copper consumed, ppm



1 130

2 128

3 161

4 264

Average 170


Summary

Forty pigs were fed in 4 replicated lots to determine the preference level for
dietary copper. Feed mixtures containing 0, 125, 250, 500 and 1000 ppm were offered
to each group of pigs. Pigs consumed 39.1, 27.8, 20.0, 9.0 and 4.0 percent of the
feed mixtures, respectively. The average overall consumption level of copper was
170 ppm. This is less than the level of 250 ppm which has been suggested as optical
for stimulation of feedlot performance.


HDW:gem
9/20/66
1200 copies