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Impact of Added Copper and Chlortetracycline on Growth Performance of Nursery Pigs
Impact of Added Copper and Chlortetracycline on Growth Performance of Nursery Pigs
Monday, March 12, 2018
Grand Ballroom Foyer (CenturyLink Convention Center)
A study was conducted to determine the impact of Cu and chlortetracycline (CTC), fed alone or in combination, on prevalence and quantification of Cu-associated antimicrobial resistance in fecal enterococci of weaned piglets. Only the effects on growth performance are reported herein. A total of 320 nursery pigs (DNA 200×400, initially 7.4±0.06 kg) were used in a 28-d trial. A common non-medicated diet was fed for 7 d after weaning. Pens were allotted to dietary treatments based on BW and location in a randomized complete block design with 5 pigs per pen and 8 replications per treatment (each replication as a pair of adjoining pens). Treatments were a 2×2 factorial with added Cu (0 vs. 200 ppm Cu sulfate) and CTC (0 vs. 440 ppm). Data were analyzed using a linear mixed model (PROC GLIMMIX, SAS®). There was no evidence for interactive effects of Cu and CTC on growth performance. From d 0-14, added Cu increased (P<0.05) ADG and ADFI and added CTC improved (P<0.01) ADG, ADFI, and G:F. From d 14-28, addition of CTC to the diet improved (P<0.01) ADG and ADFI, but there was no evidence for Cu effect. Overall, d 0-28, pigs fed diets with CTC had improved (P<0.05) ADG, ADFI, and G:F, but there was no evidence for Cu effect. The inclusion of Cu or CTC increased (P<0.05) BW on d 14 (11.2 vs. 11.5 kg, for Cu; 11.1 vs. 11.6 kg, for CTC) and d 28 (19.5 vs. 20.0 kg, for Cu; 19.2 vs. 20.3 kg, for CTC). In conclusion, these findings characterize a beneficial effect of feeding Cu for 14 d on growth performance of young pigs (7-12 kg BW) and a growth promoting effect of therapeutic levels of CTC in nursery diets. The lack of interactive effects between Cu and CTC suggests the responses on growth performance of nursery pigs are similar when fed alone or in combination.
|
Cu, ppm |
|
CTC, ppm |
|
SEM |
||
|
0 |
200 |
P< |
0 |
440 |
P< |
|
d 0 to 14 |
|
|
|
|
|
|
|
ADG, g |
271 |
294 |
0.025 |
262 |
303 |
0.001 |
7.9 |
ADFI, g |
362 |
388 |
0.011 |
360 |
390 |
0.004 |
7.0 |
G:F |
0.750 |
0.756 |
0.546 |
0.728 |
0.778 |
0.001 |
0.009 |
d 14 to 28 |
|
|
|
|
|
|
|
ADG, g |
596 |
600 |
0.693 |
574 |
622 |
0.001 |
7.6 |
ADFI, g |
884 |
895 |
0.386 |
857 |
922 |
0.001 |
11.8 |
G:F |
0.674 |
0.671 |
0.518 |
0.671 |
0.675 |
0.486 |
0.004 |