A 3 × 4 factorial experiment was con- ducted to determine the effect of dietary nutrient den- sity on growth performance, physiological parame- ters, and small intestinal epithelial phosphate trans- porter expres...A 3 × 4 factorial experiment was con- ducted to determine the effect of dietary nutrient den- sity on growth performance, physiological parame- ters, and small intestinal epithelial phosphate trans- porter expression in broiler chicks fed different dietary nutrient density （DND） and non-phytate phosphorus （NPP） levels. Dietary energy densities used had ME values of 2,850, 2,950, and 3,050 kcal/kg of diet and the NPP levels were 0.35%, 0.40%, 0.45%, and 0.50% within each ME value. Crude protein and essential amino acids levels were maintained propor- tionally to dietary ME levels. Each of the twelve diets was fed to five pens of seven male broiler chicks from 1 to 21 days of age. Broiler growth performance, ser- um physiological parameters, 1-hydroxylase activity in the kidney, type-IIb sodium phosphate co-trans- porter （NaPi-IIb）, and vitamin D receptor （VDR） expression levels in the duodenal mucosa were deter- mined. Our results showed that an increase in dietary nutrient density increased body weight and improved feed conversion. Additionally, serum parathyroid hormone concentration, 1-a-hydroxylase activity in the kidney, NaPi-IIb mRNA expression and VDR protein expression in the duodenal mucosa increased as DND increased. Feed intake and body weight in- creased as NPP levels increased. Serum parathyroid hormone, VDR and NaPi-IIb gene expression also in- creased as the level of NPP in the diet increased at the medium range level. The results of this study suggest that high DND can increase small intestinal type IIb sodium dependent phosphate co-transporter mRNA expression by up-regulating parathyroid hormone and activation of 1-ot-hydroxylase activity which might be in consistent with high growth rate of broilers. Small intestinal NaPi-IIb mRNA expression increases linear- ly only within the range of dietary NPP dosage levels close to the requirement recommended in the broilers feeding standards.展开更多
The experiment was conducted to evaluate the low phosphorus diets supplemented with different sources of phytase in low metabolizable energy （ME） and crude protein （CP） diets in broilers. Four levels of non-phytat...The experiment was conducted to evaluate the low phosphorus diets supplemented with different sources of phytase in low metabolizable energy （ME） and crude protein （CP） diets in broilers. Four levels of non-phytate phosphorus （NPP） （0.33%, 0.36%, 0.39% and 0.42% of the diet） were employed in six dietary treatments in such a way that the least level of NPP （0.33%） was supplemented with two phytase enzymes namely 6-phytase （Natuphos-5,000） and 3-phytase （Sunphase） along with low nutrient composition viz. 2750 kcal ME/kg and CP 18% in growing phase （21 d-42 d）. A total of 1,400 birds were exposed to six treatments in three replicates except for the phytase supplemented diets which were replicated four times each. Non-significant results are obtained from all performance parameters （body weight gain, feed intake and feed gain） and serum minerals （calcium and phosphorus） between 21 days to 42 days. Non-significant results are seen among all treatments; even supplementation of both types of enzymes did not affect the overall results. The results of the present study demonstrate 0.33% P level without phytase are sufficient in low ME and CP diets.展开更多
基金supported by the ear-marked fund for Modern Agro-Industry Technology Research System
文摘A 3 × 4 factorial experiment was con- ducted to determine the effect of dietary nutrient den- sity on growth performance, physiological parame- ters, and small intestinal epithelial phosphate trans- porter expression in broiler chicks fed different dietary nutrient density （DND） and non-phytate phosphorus （NPP） levels. Dietary energy densities used had ME values of 2,850, 2,950, and 3,050 kcal/kg of diet and the NPP levels were 0.35%, 0.40%, 0.45%, and 0.50% within each ME value. Crude protein and essential amino acids levels were maintained propor- tionally to dietary ME levels. Each of the twelve diets was fed to five pens of seven male broiler chicks from 1 to 21 days of age. Broiler growth performance, ser- um physiological parameters, 1-hydroxylase activity in the kidney, type-IIb sodium phosphate co-trans- porter （NaPi-IIb）, and vitamin D receptor （VDR） expression levels in the duodenal mucosa were deter- mined. Our results showed that an increase in dietary nutrient density increased body weight and improved feed conversion. Additionally, serum parathyroid hormone concentration, 1-a-hydroxylase activity in the kidney, NaPi-IIb mRNA expression and VDR protein expression in the duodenal mucosa increased as DND increased. Feed intake and body weight in- creased as NPP levels increased. Serum parathyroid hormone, VDR and NaPi-IIb gene expression also in- creased as the level of NPP in the diet increased at the medium range level. The results of this study suggest that high DND can increase small intestinal type IIb sodium dependent phosphate co-transporter mRNA expression by up-regulating parathyroid hormone and activation of 1-ot-hydroxylase activity which might be in consistent with high growth rate of broilers. Small intestinal NaPi-IIb mRNA expression increases linear- ly only within the range of dietary NPP dosage levels close to the requirement recommended in the broilers feeding standards.
文摘The experiment was conducted to evaluate the low phosphorus diets supplemented with different sources of phytase in low metabolizable energy （ME） and crude protein （CP） diets in broilers. Four levels of non-phytate phosphorus （NPP） （0.33%, 0.36%, 0.39% and 0.42% of the diet） were employed in six dietary treatments in such a way that the least level of NPP （0.33%） was supplemented with two phytase enzymes namely 6-phytase （Natuphos-5,000） and 3-phytase （Sunphase） along with low nutrient composition viz. 2750 kcal ME/kg and CP 18% in growing phase （21 d-42 d）. A total of 1,400 birds were exposed to six treatments in three replicates except for the phytase supplemented diets which were replicated four times each. Non-significant results are obtained from all performance parameters （body weight gain, feed intake and feed gain） and serum minerals （calcium and phosphorus） between 21 days to 42 days. Non-significant results are seen among all treatments; even supplementation of both types of enzymes did not affect the overall results. The results of the present study demonstrate 0.33% P level without phytase are sufficient in low ME and CP diets.
