ABSTRACT This study investigated the effect of calcium (Ca) and phytase interaction on growth performance and bone quality in 1-42-day-old broiler chickens. A total of 624 female one-day-old Ross 308 broilers were allotted to 13 treatments with four replicates and 12 birds per replicate. A 2 × 6 factorial experiment was designed to test the combinations of 0.50% and 1.00% Ca with 0, 500, 1,000, 2,500, 5,000, and 10,000 FTU/kg phytase in the basal diet (0.25% non-phytate phosphorus, NPP). The control diet contained adequate Ca and phosphorus (P). Dietary Ca, phytase, and their interaction affected growth performance and bone mineralization of broilers at 1-42 days of age (p<0.05). The broilers fed with 1.00% Ca had lower body weight gain (BWG) and feed intake (FI) compared with the birds fed with 0.50% Ca (p<0.05). The BWG, FI, leg bone weight, and ash weight of the broilers fed with 0.25% NPP were lower than those of birds fed with the control diet (p<0.05). The addition of 500-10,000 FTU/kg phytase improved growth rate and leg bone quality, especially at 1.00% Ca (p<0.05). No differences were observed in growth performance and bone quality of 42-day-old broilers fed with 1.00% Ca + 2,500-10,000 FTU/kg phytase and the control diet (p>0.05). These data indicated that high doses of phytase (2,500-10,000 FTU/kg) alleviate the negative effects of Ca and P imbalance (Ca-to-NPP ratio = 4.0) on growth performance and bone mineralization of broiler chickens.

ABSTRACT The objective of this study was to investigate the optimal zinc (Zn) requirement of broiler chickens based on Zn retention. On the day of hatch, 350 male Ross 308 broilers were randomly assigned to seven treatments with five replicates of ten birds each. Zinc was supplemented as ZnSO4·7H2O at 0, 20, 40, 60, 80, 100, or 120 mg/kg in the starter diet (fed from 1 to 21 d of age) and at 0, 16, 32, 48, 64, 80, or 96 mg/kg in the grower diet (fed from 22 to 42 d of age). The analyzed Zn levels were 34.98 and 27.57 mg/kg in the basal starter and grower diets, respectively. Supplemental Zn levels did not influence body weight gain, feed intake, feed conversion ratio, or liver Zn content of broilers at 21 and 42 d of age (p>0.05). Tibia ash Zn content of 21-d-old broilers increased when Zn supplementation level increased from 0 to 40 mg/kg Zn in (p<0.05). The highest breast muscle Zn content in 42-d-old broilers was observed when 100 and 80 mg Zn/kg was supplemented in the starter and grower diets, respectively. Fecal Zn content, Zn intake, Zn excretion, and Zn retention of 31- to 33-d-old broilers linearly increased with supplemental Zn levels (p<0.05). Zinc retention values, calculated as the difference between Zn intake and Zn excretion, were negative, about zero, and positive when starter/grower diets were supplemented with 0/0 and 20/16, 40/32, and 60/48 and 120/96 mg/kg, respectively. These results indicate that supplementing 40 and 32 mg Zn/kg in starter and grower diets, respectively, promote the growth performance of broiler chickens, while reduce Zn excretion in the environment.

Melanocyte loss in vitiligo vulgaris is believed to be an autoimmune process. Macrophage migration inhibitory factor (MIF) is involved in many autoimmune skin diseases. We determined the possible role of MIF in the pathogenesis of vitiligo vulgaris, and describe the relationship between MIF expressions and disease severity and activity. Serum MIF concentrations and mRNA levels in PBMCs were measured in 44 vitiligo vulgaris patients and 32 normal controls, using ELISA and real-time RT-PCR. Skin biopsies from 15 patients and 6 controls were analyzed by real-time RT-PCR. Values are reported as median (25th-75th percentile). Serum MIF concentrations were significantly increased in patients [35.81 (10.98-43.66) ng/mL] compared to controls [7.69 (6.01-9.03) ng/mL]. MIF mRNA levels were significantly higher in PBMCs from patients [7.17 (3.59-8.87)] than controls [1.67 (1.23-2.42)]. There was also a significant difference in MIF mRNA levels in PBMCs between progressive and stable patients [7.86 (5.85-9.13)vs 4.33 (2.23-8.39)] and in serum MIF concentrations [40.47 (27.71-46.79) vs 26.80 (10.55-36.07) ng/mL]. In addition, the vitiligo area severity index scores of patients correlated positively with changes of both serum MIF concentrations (r = 0.488) and MIF mRNA levels in PBMCs (r = 0.426). MIF mRNA levels were significantly higher in lesional than in normal skin [2.43 (2.13-7.59)vs 1.18 (0.94-1.83)] and in patients in the progressive stage than in the stable stage [7.52 (2.43-8.84)vs 2.13 (1.98-2.64)]. These correlations suggest that MIF participates in the pathogenesis of vitiligo vulgaris and may be useful as an index of disease severity and activity.