Effects of Added Zn Level on Growth Performance and Hemoglobin of Nursery Pigs.

An experiment was conducted to determine the effects of added Zn level on growth performance and hemoglobin of nursery pigs. A total of 673 pigs (initial BW = 6.0 kg) were used in a 45-d trial. There were 3 treatments based on added Zn level: 100, 2,000, or 3,000 mg/kg from Zn oxide. Experimental diets were fed for 21 d. After that, pigs were fed a common corn and soybean meal-based diet with 100 mg/kg added Zn for 24 d. There were 8 replicates per treatment. Pigs were weighed approximately every 10 d to evaluate growth performance, and blood samples were collected for hemoglobin analysis. Data was analyzed with SAS MIXED procedure. From d 0 to 10, there was a linear improvement (P < 0.05) in ADG, ADFI, and G:F with increasing Zn level. From d 10 to 21, increasing Zn level resulted in higher ADFI (linear, P = 0.009). However, there was no difference (P > 0.10) in ADG and G:F. From d 0 to 21, pigs fed increasing added Zn had improved (linear, P < 0.05) ADG and ADFI. From d 21 to 45, pigs previously fed high levels of added Zn had higher ADFI (linear, P = 0.023), but there was no evidence for differences (P > 0.10) for ADG and G:F. Overall (d 0 to 45), pigs fed increasing added Zn levels had improved (linear, P < 0.05) ADG, ADFI, and final BW. A quadratic response (P < 0.05) was observed for hemoglobin on d 10 and 45, with no differences (P > 0.10) observed on d 21. In summary, pigs fed high levels of added Zn presented improved growth performance. Although the response was linear in nature, the differences between pigs fed 2,000 or 3,000 mg/kg Zn were minimal for the response variables evaluated. [ABSTRACT FROM AUTHOR]