268 Copper Methionine Hydroxy Analogue Chelate in a Reduce and Replace Copper Strategy Improves Nutrient Availability in Growing Pigs

Abstract

Abstract Research has shown that methionine hydroxy analogue chelated minerals [MHAC; MINTREX Trace Minerals (Novus International Inc., St. Charles, MO)] are more available than inorganic trace minerals. In growing pigs, 50 mg/kg of Cu as Cu-MHAC has been shown to reduce feed conversion compared with feeding 125 mg/kg Cu as CuSO4 and 150 mg/kg Cu as tri-basic copper chloride (TBCC). A metabolism study was conducted using 2 groups of 10 barrows (average BW of 33.2 + 3.03 kg) fed either 50 mg/kg Cu as Cu-MHAC or 150 mg/kg Cu as TBCC. There was a 14-d acclimation period followed by 3-d of total fecal and 5-d of total urine collection. Corn-soybean meal diets with 15% distillers dried grains and < 1% fat as soy oil were formulated to 0.98% SID lysine with 0.65% Ca and 0.49% P. Phytase was included at 1,500 FTU/kg. A common basal trace mineral premix supplying 120 mg/kg Zn, 10 mg/kg Cu and 20 mg/kg Mn in the SO4 form was used. Diets were provided in meal form twice daily at 5% of body weight per day. The total trial period was 21-d with BW measured at d 0 and 21. Feed disappearance was recorded throughout. Data were analyzed using the PROC MIXED procedure of SAS with treatment and initial BW as fixed effects and group as a random effect. Pigs fed Cu-MHAC gained 816 g/d compared with 787 g/d for those fed TBCC (P = 0.55). Feed conversion was 2.07 for TBCC pigs and 1.98 for Cu-MHAC pigs (P = 0.48). Dry matter digestibility was 90.9% and 89.9% (P = 0.18) for Cu-MHAC and TBCC pigs respectively. Dry matter fecal output was 9% less for Cu-MHAC pigs (P = 0.24). Cu retention percent was not different between Cu sources (64.4% Cu-MHAC vs 62.4% TBCC; P = 0.63). Cu excretion was less for Cu-MHAC pigs (41.3 mg/d Cu-MHAC vs. 103.9 mg/d TBCC; P < 0.001) as a result of reduced Cu intake. Cu-MHAC increased Zn (P < 0.05) and Mn (P < 0.01) retention by 8.9 and 11.1 percentage points, respectively. Iron absorption (P = 0.86) and retention (P = 0.81) were not affected by Cu source. Calcium absorption and retention were 3.8 percentage points greater (P = 0.12) for Cu-MHAC pigs. Absorption and retention of P was 3.4% (P = 0.25) and 2.7% greater (P = 0.49) for pigs fed Cu-MHAC. Cu-MHAC resulted in 1.9% greater N absorption (P = 0.06) and 8.7% greater N retention (P = 0.06%) than when 150 mg/kg Cu in the TBCC form was fed. These results indicate a reduce and replace Cu strategy with Cu-MHAC can reduce Cu excretion by 60% and improved overall mineral and N retention with the exception of Fe. These nutrient availability improvements may contribute to the improved feed conversion observed in performance trials with Cu-MHAC vs inorganic sources.