269 Copper Methionine Hydroxy Analogue Chelate as a Reduce and Replace Cu Strategy in Growing Pigs

Abstract

Abstract Research has shown that minerals supplied in the methionine hydroxy analogue chelate (MHAC; MINTREX Trace Minerals [Novus International Inc., St. Charles, MO]) form are more available than inorganic trace minerals. Research in weaned pigs demonstrated improved pig performance when Cu was provided in the Cu-MHAC form compared with inorganic Cu sources. In the growing pig it may be desirable to reduce the amount of total Cu fed to minimize Cu excretion while maintaining animal performance. Data from 8 studies, 4 studies per Cu source comparison, was used to compare 50 mg/kg of Cu as Cu-MHAC with either 125 mg/kg Cu as CuSO4 or 150 mg/kg Cu supplied in the tri-basic copper chloride (TBCC) form. There were 44 pens of 23 pigs per pen for each Cu source in the Cu-MHAC vs TBCC comparison and 39 pens of 22 pigs per pen for each Cu source for the Cu-MHAC vs. CuSO4 comparison. Cu-MHAC was compared with CuSO4 in separate trials from those comparing Cu-MHAC vs TBCC. Trials were conducted across all seasons. Pigs had previously received either CuSO4 or TBCC during the nursery phase. Data were analyzed with the PROC MIXED procedure of SAS using trial as a random effect. Outlier analysis was conducted for each parameter with any observation greater than 3 standard deviations from the treatment mean removed. Pigs in the Cu-MHAC vs CuSO4 comparisons averaged 29.3 + 2.18 kg of BW while those used in the Cu-MHAC vs TBCC comparisons averaged 31.0 + 2.33 kg of BW. Average study duration was 105 days. Average market weight sold was 0.45 kg/pig (P = 0.52) and 0.59 kg/pig (P = 0.46) less for Cu-MHAC than CuSO4 and TBCC pigs respectively. Adjusted feed conversion was 4 points lower (P = 0.12) and 2 points lower (P = 0.25) for the Cu-MHAC vs CuSO4 and TBCC pigs respectively. Removal percentage during the studies ranged from 3.63% to 4.91% with the Cu-MHAC pigs having 0.6 percentage points less removals than the CuSO4 (P = 0.52) and 0.7 percentage points less removals than the TBCC (P = 0.38) treatment. The fewer removals resulted in the Cu-MHAC treatment having 3 points decreased feed conversion (P = 0.25) than TBCC pigs and 6 points decreased feed conversion (P = 0.12) than CuSO4 pigs on a pen basis. The combined Cu-MHAC analysis vs combined inorganic Cu source analysis showed that Cu-MHAC pigs had 4 points less feed conversion on both an adjusted (P = 0.06) and closeout (P = 0.06) basis than pigs fed inorganic Cu. The cumulative removal rate was 0.7 percentage points less for the Cu-MHAC pigs (P = 0.29). These results indicate supplying Cu as 50 mg/kg Cu-MHAC can reduce feed conversion compared with 125 mg/kg Cu as CuSO4 and 150 mg/kg Cu as TBCC in growing-finishing diets.