The objective of this study was to evaluate the effects of low ambient temperature （LAT） and dietary vitamin C （VC） sup- plementation on pulmonary vascular remodeling （PVR） and the relative expression of hypoxia...The objective of this study was to evaluate the effects of low ambient temperature （LAT） and dietary vitamin C （VC） sup- plementation on pulmonary vascular remodeling （PVR） and the relative expression of hypoxia inducible factor-la （HIF-la）, vascular endothelial growth factor （VEGF） and its receptor 2 （VEGFR-2） mRNA of lungs in 21-d-old broilers. 400 1-d-old male Cobb broilers were assigned randomly to 4 treatments as follows for 21 d： 1 ） LAT and a basal diet; 2） LAT and a basal diet supplemented with 1 000 mg kg-1 VC （LAT＋VC）; 3） normal ambient temperature （NAT） and a basal diet; 4） NAT and a basal diet supplemented with 1 000 mg kg-1 VC （NAT＋VC）. Each treatment was composed of 10 replicates of 10 birds per replicate. Samples of lung were collected after the broilers were killed at d 21. LAT increased the ratio of vessel wall area to vessel total area （WA/TA, %） and mean media thickness in pulmonary arterioles （mMTPA, %） （P〈0.05）. Dietary VC supplementation decreased mMTPA （P〈0.05）, but had no effect on the WA/TA. LAT increased （P〈0.05） the relative mRNA expression of HIF-la, VEGF and VEGFR-2, while adding VC to the diet could decrease （P〈0.05） their relative mRNA expression. A significant positive correlation existed between the level of VEGF mRNA expression and the value of WA/WT （P〈0.05） or mMTPA （P〈0.05）. These results suggested LAT resulted in pulmonary vascular remodeling, and the increase of HIF-la, VEGF and VEGFR-2 mRNA expression, and dietary VC supplementation can alleviate pulmonary vascular remodeling in broiler by affecting these gene expression.展开更多
The experiment was conducted using a total of 1392 one-day-old, Cobb commercial male broilers to investigate the effects of a commercial probiotic addition in diet on growth, the development of the small intestine and...The experiment was conducted using a total of 1392 one-day-old, Cobb commercial male broilers to investigate the effects of a commercial probiotic addition in diet on growth, the development of the small intestine and microbial populations of broilers. Broilers were randomly allotted by BW to 1 of 6 replicate cages （29 chicks per cage） for each of 8 treatments in a randomized block design involving one factorial arrangement of treatments. Dietary treatments included the basal diet （including corn, soybean, rapeseed, cottonseed meal） added with 100 mg/kg antibiotic, 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25% or 0.3%. The experiment last 42 d and divided into the starter period （1-21 d） and the finisher period （22-42 d）. The results showed that there were significant differences in broiler body weight （BW） （P〈0.001）, average daily feed intake （ADFI） （P=0.033）, relative length of the duodenum （P〈0.001）, jejunum （P=0.008）, ileum （P〈0.001） and the populations of lactobacillus （P〈0.001） and coliform （P〈0.001） in the rectum between the probiotics treatments and the control treatment only in the starter period of the trails. No significant differences were observed in intestinal morphology parameters in two periods of the experiment. Our results indicated that the probiotic was able to improve the performance of broiler chickens, and it was better in the starter period to be used than in the finisher period.展开更多
To investigate the tissue deposition and elimination of melamine （MEL） in broilers, a total of 1 920 commercial 1-d-old male Cobb broilers were randomly allotted to 6 treatments with diets contaminated by MEL at 0, ...To investigate the tissue deposition and elimination of melamine （MEL） in broilers, a total of 1 920 commercial 1-d-old male Cobb broilers were randomly allotted to 6 treatments with diets contaminated by MEL at 0, 2, 10, 30, 50, 100 mg kg-1 of diet for 42 d, and followed MEL withdrawal from diet at 50 or 100 mg kg-1 of diet for 96 h. The MEL was found in residue of plasma, liver, kidney, breast, and leg muscle with the highest level in kidney and in dose response manner （except in kidney）, but no time response （except in plasma）. The MEL residue in organ tissue was below the safe level of 50 μg mL-1 in blood or 50 μg kg-1 in tissues proposed by the US FSIS when MEL in diet was lower （2 mg kg-1）. The MEL in tissues was eliminated by withdrawal MEL from diets. The elimination half-life of MEL was from 3.2 to 6.6 h, and the clearance time, when MEL residue concentration under limit detection, was from 18.0 to 31.4 h.展开更多
基金supported by grants from the National Natural Science Foundation of China (31101733)
文摘The objective of this study was to evaluate the effects of low ambient temperature （LAT） and dietary vitamin C （VC） sup- plementation on pulmonary vascular remodeling （PVR） and the relative expression of hypoxia inducible factor-la （HIF-la）, vascular endothelial growth factor （VEGF） and its receptor 2 （VEGFR-2） mRNA of lungs in 21-d-old broilers. 400 1-d-old male Cobb broilers were assigned randomly to 4 treatments as follows for 21 d： 1 ） LAT and a basal diet; 2） LAT and a basal diet supplemented with 1 000 mg kg-1 VC （LAT＋VC）; 3） normal ambient temperature （NAT） and a basal diet; 4） NAT and a basal diet supplemented with 1 000 mg kg-1 VC （NAT＋VC）. Each treatment was composed of 10 replicates of 10 birds per replicate. Samples of lung were collected after the broilers were killed at d 21. LAT increased the ratio of vessel wall area to vessel total area （WA/TA, %） and mean media thickness in pulmonary arterioles （mMTPA, %） （P〈0.05）. Dietary VC supplementation decreased mMTPA （P〈0.05）, but had no effect on the WA/TA. LAT increased （P〈0.05） the relative mRNA expression of HIF-la, VEGF and VEGFR-2, while adding VC to the diet could decrease （P〈0.05） their relative mRNA expression. A significant positive correlation existed between the level of VEGF mRNA expression and the value of WA/WT （P〈0.05） or mMTPA （P〈0.05）. These results suggested LAT resulted in pulmonary vascular remodeling, and the increase of HIF-la, VEGF and VEGFR-2 mRNA expression, and dietary VC supplementation can alleviate pulmonary vascular remodeling in broiler by affecting these gene expression.
文摘The experiment was conducted using a total of 1392 one-day-old, Cobb commercial male broilers to investigate the effects of a commercial probiotic addition in diet on growth, the development of the small intestine and microbial populations of broilers. Broilers were randomly allotted by BW to 1 of 6 replicate cages （29 chicks per cage） for each of 8 treatments in a randomized block design involving one factorial arrangement of treatments. Dietary treatments included the basal diet （including corn, soybean, rapeseed, cottonseed meal） added with 100 mg/kg antibiotic, 0%, 0.05%, 0.1%, 0.15%, 0.2%, 0.25% or 0.3%. The experiment last 42 d and divided into the starter period （1-21 d） and the finisher period （22-42 d）. The results showed that there were significant differences in broiler body weight （BW） （P〈0.001）, average daily feed intake （ADFI） （P=0.033）, relative length of the duodenum （P〈0.001）, jejunum （P=0.008）, ileum （P〈0.001） and the populations of lactobacillus （P〈0.001） and coliform （P〈0.001） in the rectum between the probiotics treatments and the control treatment only in the starter period of the trails. No significant differences were observed in intestinal morphology parameters in two periods of the experiment. Our results indicated that the probiotic was able to improve the performance of broiler chickens, and it was better in the starter period to be used than in the finisher period.
基金supported by the Special Fund for Establishment of Maximum Residue Limit of MEL in feed (Ministry of Agriculture,China)
文摘To investigate the tissue deposition and elimination of melamine （MEL） in broilers, a total of 1 920 commercial 1-d-old male Cobb broilers were randomly allotted to 6 treatments with diets contaminated by MEL at 0, 2, 10, 30, 50, 100 mg kg-1 of diet for 42 d, and followed MEL withdrawal from diet at 50 or 100 mg kg-1 of diet for 96 h. The MEL was found in residue of plasma, liver, kidney, breast, and leg muscle with the highest level in kidney and in dose response manner （except in kidney）, but no time response （except in plasma）. The MEL residue in organ tissue was below the safe level of 50 μg mL-1 in blood or 50 μg kg-1 in tissues proposed by the US FSIS when MEL in diet was lower （2 mg kg-1）. The MEL in tissues was eliminated by withdrawal MEL from diets. The elimination half-life of MEL was from 3.2 to 6.6 h, and the clearance time, when MEL residue concentration under limit detection, was from 18.0 to 31.4 h.
