Performance and mineral fecal excretion of post weaned piglets are influenced by different sources of zinc oxide

Abstract

The supplementation of zinc oxide (ZnO) on post weaning diets is a widespread practice, with the aim of improving the growth performance and decreasing the incidence of diarrhea. The great barrier to use ZnO in piglet’s diets is due to the zinc-polluting potential, since most of the amount ingested is excreted, causing environmental pollution. The study aimed to evaluate the impact of the supplementation on post weaning diets of the conventional source of zinc oxide (ZnO) and/or a potentiated source of zinc oxide (PZnO) and different phosphorus (P) levels on productive performance, incidence of diarrhea , zinc (Zn) and copper (Cu) fecal excretion and bone resistance. A total of 84 piglets weaned at 21 days of age were allocated in a randomized block design with four treatments [T1 negative control: no inclusion of ZnO and regular P levels (0.440%; 0.420%; 0.400%; 0.380%); T2 positive control: inclusion of ZnO and regular P levels (0.440%; 0.420%; 0.400%; 0.380%); T3: association between ZnO and PZnO and 10% low P levels (0.396%; 0.379%; 0.360%; 0.340%); T4 inclusion of the PZnO and 10% low P levels (0.396%; 0.379%; 0.360%; 0.340%)], with seven repetitions and three piglets per pen. The nutritional program was divided into four dietary phases (pre-initial 1: 21 to 28 days; pre-initial II: 28 to 35 days; initial I: 35 to 49 days; and initial II: 49 to 63 days). When there was statistical difference by the F test (P < 0.05), the Tukey test was adopted to compare the means. The variable of incidence of diarrhea was analyzed by applying the generalized linear model in the GENMOD procedure (SAS INSTITUTE INC., 2011). Evaluating the period from day 1 to day 14, treatment T2 improved the average daily gain (ADG) (P = 0.0128) and BW (P = 0.0085) at day 14. From the period of day 1 to day 28, pigs fed with T2 diets showed higher ADG (P = 0.0208), ADFI (average daily feed intake) (P = 0.0099) and, consequently, higher Birth Weight (P = 0.001) at day 28. During the period from day 1 to day 42, pigs fed with PZnO diet performed the highest ADFI (P = 0.032). Regarding the bone resistance results, there was no significant differences between the treatments (P > 0.05). When evaluating overall data of diarrhea, T2 (P < 0.05) reduced the incidence of diarrhea during all periods. T4 reduced Zn and P fecal excretion during the period from 7 to 28 days (P < 0.05). Therefore, the inclusion of PZnO reduced the Zn and P fecal excretion. Furthermore, the use of ZnO and PZnO provide the same performance results of piglets on the period from day 1 to day 42 after weaning. Thus, PZnO represents a great potential to reduce the high dietary doses of the conventional source of ZnO and also to reduce the environmental pollution derived by the mineral excretion from livestock systems, especially swine production systems.