Zinc Requirement of the Baby Pig When Fed Wet-Autoclaved Spray-Dried Egg Albumen as the Protein Source

Pigs 16 d of age were allotted to eight dietary levels of total zinc (6–36 ppm in 5 ppm increments and 116 ppm) in a 28-d experiment designed to reevaluate the zinc requirement of the neonatal pig. The basal 21.0% crude protein diet contained wet-autoclaved spray-dried egg albumen (WAEA) as the protein source. Dietary zinc level did not affect (P> 0.05) pig growth for the first 14 d of the experiment. Pig growth was adequate from d 14 to 28 of the experiment with 11 ppm or more of zinc. The milligrams of zinc retained per day per pig increased (P< 0.05) with increasing dietary zinc up to 26 ppm, plateaued from 26 to 36 ppm and declined (P< 0.05) at 116 ppm. Plasma zinc levels were higher (P< 0.05) for pigs fed 31 ppm or more of zinc compared with 16 ppm or less of zinc on d 21 and 28. Tibia and femur concentrations of zinc also increased with increasing dietary zinc up to 26 ppm. Esophageal tissue was normal in the majority of pigs fed 31 ppm or more of zinc. Retention of 65Zn further suggested that diets containing 26 ppm or less zinc were deficient in this element. Thus, zinc balance, concentrations of zinc in plasma and bone, esophageal histology and retention of 65Zn indicate that the minimum zinc requirement of the neonatal pig is between 26 and 31 ppm when fed a purified diet devoid of phytate.