Ingredient composition and nutrient content of experimental diets (on an air dry basis).

1Probiotic treatment was provided by the addition of ∼1010 spores/day of Bacillus pumilus WIT 588 to the non-medicated treatment.2Lactofeed 70 contains 70% lactose, 11.5% protein, 0.5% oil, 7.5% ash, and 0.5% fiber (Volac, Cambridge, UK).3Provided the following per kg of complete starter diet: Cu, 155 mg; Fe, 90 mg; Mn, 47 mg; Zn, 120 mg; I, 0.6 mg; Se, 0.3 mg; vitamin A, 6000 IU; vitamin D3, 1000 IU; vitamin E, 100 IU; vitamin K, 4 mg; vitamin B12, 15 µg; vitamin B1, 2 mg; vitamin B6, 3 mg; riboflavin, 2 mg; nicotinic acid, 12 mg; pantothenic acid, 10 mg and choline chloride, 250 mg.4Natuphos 5000 (BASF SE, Lampertheim, Germany).5Phase 1 and 2 medicated diets contained 200 mg apramycin per kg provided from Apralan G200, (Elanco Animal Health, Eli Lilly & Co., Basingstoke, Hampshire, UK).6Phase 1 and 2 medicated diets contained 2500 mg of elemental zinc per kg provided from supplemental zinc oxide (Zincotec; Provimi Ltd., NuTec Mill, Eastern Avenue, Lichfield, Staffordshire, UK) and nutritional zinc included in the vitamin and mineral premix.7Calculated values.