RESUMO
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.(AU)
Assuntos
Animais , Feminino , Calcificação Fisiológica/efeitos dos fármacos , Galinhas/fisiologia , Fósforo/análise , Cálcio da Dieta/análise , Fenômenos Fisiológicos da Nutrição AnimalRESUMO
As a member of the POU-domain family, the POU1F1 is a positive regulator for growth hormone, prolactin and thyroid-stimulating hormone b, by binding to target DNA promoters as a dimer in mammals. This study described the polymorphisms at the goat POU1F1-DdeI locus and analyzed the distribution of alleles in 15 indigenous Chinese goat breeds. The PCR-RFLP analysis showed a predominance of the D1D1 genotype and the D1 allele, with average frequencies of 0.550 and 0.790, respectively, irrespective of goat utility type. The D1D2 genotype was the second most frequent, with a mean frequency of 0.371. The distributions of genotypic and allelic frequencies at this locus were found to be significantly different among populations based on a Chi square test (P < 0.001), suggesting that the breed factor significantly affected the molecular genetic character of the POU1F1 gene. The genetic diversity analysis revealed that Chinese indigenous populations had a wide spectrum of genetic diversity at the goat POU1F1-DdeI locus. However, an ANOVA analysis revealed no significant differences in gene homozygosity, gene heterozygosity, effective allele numbers, or polymorphism information content among meat, dairy, and cashmere utility types (P > 0.05). This suggests that the goat utility types had no significant effect on the spectrum of genetic diversity.