Evaluation of copper feeding strategies and sources on nursery and finishing pig performance.

Two experiments evaluated the use of approximately 150 mg/kg of added Cu in nursery and finishing pig diets. In Exp. 1, 2204 pigs (initially 5.3 ± 0.09 kg) were used in a 38-d study with 29 pigs/pen and 19 pens/treatment. Pens of pigs were allotted to four feeding strategies in a randomized complete block design. Strategies consisted of feeding duration of 150 mg/kg added Cu: (i) control with 17 mg/kg added Cu, (ii) 150 mg/kg added Cu in phase 3, (iii) 150 mg/kg added Cu in phases 2 and 3, and (iv) 150 mg/kg added Cu in all phases. Treatment diets were fed based on feed budgets of 1.8 kg/pig for phase 1 (d 0 to approximately 10), 5.4 kg/pig for phase 2 (approximately d 10 to 24), and phase 3 was fed for the remainder of the trial (approximately d 24 to 38). Diets within each phase contained either 17 mg/kg (base) or the 17 mg/kg provided by the premix with an additional 150 mg/kg Cu from tribasic copper chloride (NexTrace TBCC, 58%, SAM Nutrition, Bloomington, MN). All diets contained 3000 mg/kg Zn in phase 1 and 2000 mg/kg Zn in phase 2. In phase 2, pigs fed 150 mg/kg added Cu had greater average daily gain (ADG;