125 Effects of copper hydroxychloride and increasing concentrations of dietary fat on growth performance, total tract endogenous loss of fat, and apparent total tract digestibility of fat by growing pigs

Abstract

Abstract Two experiments were conducted to test the hypothesis that Cu hydroxychloride (IntelliBond C, Micronutrients, LLC, Indianapolis, IN) improves gain:feed of pigs by increasing apparent total tract digestibility (ATTD) of fat. In experiment 1, 144 pigs (15.40 ± 2.39 kg) were allotted to 1 of 6 treatments. Four diets contained 0, 2, 4, or 6% choice white grease (CWG) and 2 diets contained 150 mg/kg Cu from Cu hydroxychloride and 0 or 2% CWG. Data for growth performance were analyzed by contrast statements, and Cu equivalency of CWG was determined using prediction equations derived from regression procedures using SAS. Results indicated that gain:feed linearly increased (P ≤ 0.05) as CWG concentration increased in diets (Table 1). Supplementation of Cu hydroxychloride to diets improved (P ≤ 0.05) gain:feed of pigs, which resulted in a CWG equivalence of 2.8 to 3.8% for 150 mg/kg Cu hydroxychloride. In experiment 2, 80 pigs (18.24 ± 1.81 kg) were housed individually in metabolism crates and randomly allotted to 1 of 10 diets. Eight diets contained 0, 15, 30, or 45% distillers dried grains with solubles (DDGS) and 0 or 150 mg/kg Cu hydroxychloride. Two additional diets contained 2% CWG and 15% DDGS and 0 or 150 mg/kg Cu hydroxychloride. Feces were collected for 4 d after 5 d adaptation. Data were analyzed by contrast statements and regression procedures using SAS. Supplementation of Cu to diets improved (P ≤ 0.05) ATTD of fat by 20% due to reduced (P ≤ 0.05) endogenous loss of fat (from 11.23 to 7.14 g/kg dry matter intake), but did not affect energy digestibility or true total tract digestibility of fat. In conclusion, supplementation of 150 mg/kg Cu hydroxychloride to diets improved gain:feed of pigs with a CWG equivalence of 2.8 to 3.8%, but this was not due to improved energy digestibility.