This experiment was conducted to investigate the effects of feed conditioners(single-layer, double-layer and retentionconditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout t...This experiment was conducted to investigate the effects of feed conditioners(single-layer, double-layer and retentionconditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout the growing to finishing phase. A total of 96 growing pigs((28.70±3.20) kg) were selected and randomized into three treatment groups with four replicates per group. Eight pigs were used per replicate for the 17-week feeding trial. The grower diet was given at 0 to 6 weeks and a finisher diet was given at 6 to 17 weeks. The treatments were as follows: SC diet(control; single-layer conditioning), DC diet(double-layer conditioning), and RC diet(retention-conditioning). Starch gelatinization was significantly higher(P<0.05) in the RC treatment than in the SC treatment, however, there was no significant difference in the starch gelatinization between the DC group and the RC group. In the growing phase, the feed to gain index(F:G) was significantly lower(P<0.05) in the RC group than in the SC and DC groups. Between growing and finishing, the F:G was the lowest(P<0.05) in the SC group compared to the RC or DC group. Drip loss, a measurement of meat quality, was significantly lower(P<0.05) in longissimus dorsi tissue collected from pigs fed the RC diet than in tissues collected from pigs fed the SC diet. The intestinal quality of the duodenum and jejunum tissues showed a significant increase(P<0.05) in the crypt depth and villus height in the RC group compared to the SC-or DC-treated pigs. These results demonstrated that the retentionconditioner treatment decreased the F:G in growing pigs, improved intestinal morphology and enhanced the meat quality in the finishing pigs. However, the retention-conditioner treatment had a negative impact on growth performance in the finishing pigs.展开更多
为准确、规范低场核磁共振(low field nuclear magnetic resonance,LF-NMR)检测烟草物料的水分含量及分布状态方法,以烟丝为测试样品,采用LF-NMR技术分析了样品装样量、装样密度、样品温度、重复扫描次数对弛豫时间、弛豫峰面积和峰面...为准确、规范低场核磁共振(low field nuclear magnetic resonance,LF-NMR)检测烟草物料的水分含量及分布状态方法,以烟丝为测试样品,采用LF-NMR技术分析了样品装样量、装样密度、样品温度、重复扫描次数对弛豫时间、弛豫峰面积和峰面积比例的影响。结果表明:样品装样量与T21、T22和T23均呈极显著正相关,与P22呈极显著负相关,与P23呈显著正相关;装样密度以及样品在磁体内因热传递导致的温度上升均对烟丝核磁信号强度无显著影响;随着重复扫描次数的增加,横向弛豫T2峰面积变异系数基本呈逐渐降低趋势,当重复扫描次数≥16时横向弛豫T2峰面积变异系数均<1%。当烟丝装样量为7 g、装样高度控制在40 mm内、重复扫描次数为16次时,低场核磁共振技术测试烟丝水分效果较优。展开更多
文摘目的研究甘草酸的超声最佳提取工艺参数。方法以料液比、提取时间及提取温度为主要研究因素,以提取的甘草酸含量为响应值,先利用单因素确定3个水平的拐点,再用Box-Behnken实验设计不同水平实验,运用Design-Expert 10.0.3软件对测得的结果建立二次回归模型。结果通过对单因素实验的分析,确定料液比3个水平分别取1:50、1:65、1:80(g/mL)。提取温度分别取20、25、30℃3个水平,提取时间分别取2、5、8 min 3个水平,Box-Behnken试验结果得甘草酸超声提取工艺最佳参数应为料液比为1:59(g/mL),提取温度25.5℃,提取时间5.7 min时能取得最大值。结论经过试验反复验证,所得到的实测值与预测值吻合程度良好,即说明响应面模型具有较好的预测能力,能够有效用于甘草酸提取值的预测。
基金financially supported by the National Key Research and Development Program of China(2016YFF0201800)the National Natural Science Foundation of China(31572631,31372539)+3 种基金the Beijing Technology System for Sturgeon and Salmonids,China(SCGWZJ 20171103-1)the National Basic Research Program of China(2014CB138600)the Fundamental Research Funds of China(1610382016010)the Special Scientific Research Fund of Agriculture Public Welfare Profession of China(201203015)
文摘This experiment was conducted to investigate the effects of feed conditioners(single-layer, double-layer and retentionconditioner) on the growth performance, meat quality and intestinal morphology of pigs throughout the growing to finishing phase. A total of 96 growing pigs((28.70±3.20) kg) were selected and randomized into three treatment groups with four replicates per group. Eight pigs were used per replicate for the 17-week feeding trial. The grower diet was given at 0 to 6 weeks and a finisher diet was given at 6 to 17 weeks. The treatments were as follows: SC diet(control; single-layer conditioning), DC diet(double-layer conditioning), and RC diet(retention-conditioning). Starch gelatinization was significantly higher(P<0.05) in the RC treatment than in the SC treatment, however, there was no significant difference in the starch gelatinization between the DC group and the RC group. In the growing phase, the feed to gain index(F:G) was significantly lower(P<0.05) in the RC group than in the SC and DC groups. Between growing and finishing, the F:G was the lowest(P<0.05) in the SC group compared to the RC or DC group. Drip loss, a measurement of meat quality, was significantly lower(P<0.05) in longissimus dorsi tissue collected from pigs fed the RC diet than in tissues collected from pigs fed the SC diet. The intestinal quality of the duodenum and jejunum tissues showed a significant increase(P<0.05) in the crypt depth and villus height in the RC group compared to the SC-or DC-treated pigs. These results demonstrated that the retentionconditioner treatment decreased the F:G in growing pigs, improved intestinal morphology and enhanced the meat quality in the finishing pigs. However, the retention-conditioner treatment had a negative impact on growth performance in the finishing pigs.
文摘为准确、规范低场核磁共振(low field nuclear magnetic resonance,LF-NMR)检测烟草物料的水分含量及分布状态方法,以烟丝为测试样品,采用LF-NMR技术分析了样品装样量、装样密度、样品温度、重复扫描次数对弛豫时间、弛豫峰面积和峰面积比例的影响。结果表明:样品装样量与T21、T22和T23均呈极显著正相关,与P22呈极显著负相关,与P23呈显著正相关;装样密度以及样品在磁体内因热传递导致的温度上升均对烟丝核磁信号强度无显著影响;随着重复扫描次数的增加,横向弛豫T2峰面积变异系数基本呈逐渐降低趋势,当重复扫描次数≥16时横向弛豫T2峰面积变异系数均<1%。当烟丝装样量为7 g、装样高度控制在40 mm内、重复扫描次数为16次时,低场核磁共振技术测试烟丝水分效果较优。
