Multi-trial analysis of the effects of copper level and source on performance in nursery pigs

Wednesday, March 19, 2014: 10:00 AM
308-309 (Community Choice Credit Union Convention Center)
Yulin Ma , Novus International Inc., St. Charles, MO
Geoffrey I Zanton , Novus International, Inc., St. Charles, MO
Junmei Zhao , Novus International Inc., St. Charles, MO
Jeffery Escobar , Novus International Inc., St. Charles, MO
Mercedes Vazquez-Anon , Novus International, Inc., St. Charles, MO
Abstract Text:

Supplemental copper (Cu) is routinely used in swine nursery diets to improve growth performance. Cu(HMTBa)2 (MINTREX®, Novus International Inc., St. Charles, MO) is a chelate of 1 Cu with two 2-hydroxy-4-methylthio butanoic acid (HMTBa), providing a significant amount of available methionine equivalent and higher Cu bioavailability for animals. The higher bioavailability of Cu from Cu(HMTBa)2 could result in a different response profile compared to CuSO4.  To evaluate this hypothesis, a multi-trial analysis was conducted to evaluate the effect of different levels of Cu from Cu(HMTBa)2 or CuSO4 on growth performance. Six nursery trials were conducted from 2006 to 2012 under commercial conditions with initial BW ~5 kg at 21 d of age; the trials lasted for 42 days with 3-phase feeding program (Phase I, 7 d; Phase II, 14d; Phase III, 21d). Diets were medicated with antibiotics and supplemented with 3000 ppm ZnO during Phase I and II.  Treatments included control (<=8 mg Cu/kg) and supplemental levels of Cu (50 to 250 mg Cu/kg) from either Cu(HMTBa)2 or CuSO4; HMTBa was supplemented to make diet iso-methionine. Treatments from each trial included 6-11 replicate pens/treatment of 22-25 piglets/pen. Mixed model analysis was conducted in which trial was considered a random effect, Cu level was considered a continuous fixed effect, and Cu source was a fixed effect. Basal diet within trial and statistical tests of the intercept between sources were not different, resulting in fitting a common intercept mixed model to the overall responses across phases. ADG and ADFI responded quadratically (P<0.05) with increasing Cu supplementation; predicted optimal ADG occurred around 160 mg/kg. Increasing Cu supplementation linearly improved G:F (P=0.05). No differences were observed in ADG or ADFI among sources. Numerically, pigs fed Cu(HMTBa)2 had higher ADG and lower ADFI than CuSO4. Thus, better G:F was calculated for pigs supplemented with Cu(HMTBa)2 compared to CuSO4 (P<0.01). The linear slope for increasing Cu supplementation on G:F was 2.3-fold for Cu(HMTBa)2 than CuSO4. In summary, Cu supplementation resulted in improving performance and Cu(HMTBa)2  is more efficient than CuSO4.

Keywords: Copper, Growth performance, Pigs