Background: Marbling, or intramuscular fat, is an important factor contributing to the palatability of beef. Vitamin A, through its active metabolite, retinoic acid, promotes the formation of new fat cells(adipogenesi...Background: Marbling, or intramuscular fat, is an important factor contributing to the palatability of beef. Vitamin A, through its active metabolite, retinoic acid, promotes the formation of new fat cells(adipogenesis). As intramuscular adipogenesis is active during the neonatal stage, we hypothesized that vitamin A administration during the neonatal stage would enhance intramuscular adipogenesis and marbling.Methods: Angus steer calves(n = 30), in a completely randomized design, were randomly allotted to three treatment groups at birth, receiving 0, 150,000, or 300,000 IU of vitamin A at both birth and one month of age.A biopsy of the biceps femoris muscle was collected at two months of age. After weaning at 210 d of age, steers were fed a backgrounding diet in a feedlot until 308 d of age, when they were transitioned to a high concentrate finishing diet and implanted with trenbolone/estradiol/tylosin mixture. Steers were harvested at an average of 438 d of age. All diets were formulated to meet nutrient requirements.Results: Weaning weight and weight during the backgrounding phase were linearly increased(P < 0.05) by vitamin A level, though no difference in body weight was observed at harvest. Intramuscular fat of steers at 308 d of age, measured by ultrasound, quadratically increased(P < 0.05) with vitamin A level from 4.0±0.26 % to 4.9±0.26 %.Similarly, carcass marbling score in the ribeye quadratically increased(P < 0.05).Conclusion: Administration of vitamin A at birth increased weaning weight and enhanced marbling fat development.Thus, vitamin A administration provides a practical method for increasing marbling and early growth of beef cattle.展开更多
A high performance liquid chromatographic method for the simultaneous determination of four fat soluble vitamins: retinol (vitamin A), cholecalciferol(vitamin D), tocopherol(vitamin E) and phylloquinone(vitamin K_1) i...A high performance liquid chromatographic method for the simultaneous determination of four fat soluble vitamins: retinol (vitamin A), cholecalciferol(vitamin D), tocopherol(vitamin E) and phylloquinone(vitamin K_1) in fortified milk powders and egg yolk has been developed. The method requires enzymatic hydrolysis of lipid component of the sample as a pretreatment. Several factors which influence the enzymatic hydrolysis were studied-Separation was achieved using μ-Bondapak C-18 column(3.9×300mm), 98% methanol as mobile phase, a double channel detection was selected; vitamins D_3 E_1 K_1 were detected by UV spectrophotometry (265 nm) first, then vitamin A by fluorometry (EX 325nm, EM 480mm). The retention times of vitamin A_1 D_3, E and K_1 4.87, 9.00, 10.58 and 15.45 min respectively. Detection limit were 0.64, 0.25, 0.50 and 0.07 ng; and the recoveries were 90.5%～103.6% 90.0%～95.6%, 91.7%～98.8%, 91.5%～98.6%, respectively. The vitamins A, D_0, E, K_1 contents in foods were determined satisfactorily.展开更多
The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transiti...The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows. 48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period. Treatments were： 1） 1 500 IU d^（-1） vitamin E without fat supplementation（1 500VE-F）; 2） 1 500 IU d^（-1） vitamin E with fat supplement（1 500VE＋F）; 3） 3 000 IU d^（-1） vitamin E without fat supplementation（3 000VE-F）; and 4） 3 000 IU d^（-1） vitamin E with fat supplement（3 000VE＋F）. Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum. Dry matter intake（DMI） was unaffected（P〉0.05） by prepartum treatment. Regardless of vitamin E supplementation, DMI was greater（P〈0.01） in fat-supplemented cows compared with un-supplemented cows（19.60 vs. 18.45 kg d^（-1）; SEM=0.42） during the postpartum period. Energy balance and body weight were not affected（P〉0.05） by treatments. Postpartum diets had no significant effect on milk yield or milk composition. Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected（P〉0.05） by treatments. Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater（P〈0.05） in fat-supplemented cows compared with un-supplemented cows during the postpartum period. These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.展开更多
目的评估自动化磁珠法提取血清脂溶性维生素应用液相色谱串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)检测的性能。方法收集200例临床剩余血清样本,采用自动化磁珠法提取血清中脂溶性维生素A,D_(2),D_(3),E和K...目的评估自动化磁珠法提取血清脂溶性维生素应用液相色谱串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)检测的性能。方法收集200例临床剩余血清样本,采用自动化磁珠法提取血清中脂溶性维生素A,D_(2),D_(3),E和K;同时联合LC-MS/MS检测脂溶性维生素A,D_(2),D_(3),E和K的线性、定量限、精密度、正确度、携带污染率等性能指标以及基质效应。并比较此方法与传统萃取法检测结果的一致性。结果自动化磁珠法提取脂溶性维生素A,D_(2),D_(3),E和K线性相关系数均>0.99;五种物质的定量限分别为5,0.25,0.25,125和0.025ng/ml;批内精密度和批间精密度分别为0.66%~4.83%,0.15%~3.70%;平均加标回收率为87.05%~111.11%;基质效应为95.43%~99.07%;高-低值样本循环进样结果均值与低-低值样本循环进样结果均值之差,均小于低-低值样本循环进样结果均值的3s;统计学结果显示自动化磁珠法和传统萃取法提取的脂溶性维生素结果相关性良好(r>0.99),两种方法的检测结果无显著偏倚。结论自动化磁珠法提取脂溶性维生素的检测性能良好,有望提高样品通量和分析效率。展开更多
BACKGROUND Both obesity and vitamin D deficiency are important health issues in Pakistan.The connection between body composition, Vitamin D and leptin in young adults is important to be studied as body composition may...BACKGROUND Both obesity and vitamin D deficiency are important health issues in Pakistan.The connection between body composition, Vitamin D and leptin in young adults is important to be studied as body composition may affect bone health and therefore the possibility of osteoporosis in later life. Few studies have attempted to investigate the effect of body composition and leptin with vitamin D in adolescence.AIM To investigate the association of serum leptin with body composition, lipids and25-hydroxyvitamin D(25 OHD) in adults.METHODS This cross-sectional study was conducted on 167 apparently healthy adults.Demographics were recorded, bioelectrical impedance analysis was performed and clinical history noted. Serum leptin was measured using DIA source kit on ELISA and total 25 OHD was measured on ADVIA-Centaur; Siemens. Total cholesterol and high density lipoprotein cholesterol were quantified using Enzymatic Endpoint Method and Cholesterol Oxidase-Phenol Aminophenazone method respectively. Biochemical analysis was done in the Departments of Pathology and Laboratory Medicine and Biological and Biomedical Sciences, Aga Khan University Hospital Karachi Pakistan.RESULTS Median age of the group(n = 167) was 20 years(IQR 27-20); 55.7% were females.Majority(89.2%, n = 149) of the study group was 25 OHD deficient, 6%(n = 10)had insufficient serum 25 OHD levels and 4.8%(n = 8) had sufficient D levels.Females, had higher median leptin levels [2.71(IQR 4.76-1.66 ng/mL)] compared to their counterparts [1.3(3.60-0.54 ng/mL), P < 0.01]. Multiple regression analysis suggested that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25 OHD were the most contributing factors to serum leptin levels. Bone mass and serum 25 OHD in fact bore a negative correlation with leptin.CONCLUSION The results indicate that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25 OHD have an impact on serum leptin. Being a cross sectional study causal relationship between leptin and other variables could not be determined.展开更多
基金supported by Agriculture and Food Research Initiative Competitive Grants no.2015–67015-23219 and 2016–68006-24634 from the USDA National Institute of Food and Agriculture
文摘Background: Marbling, or intramuscular fat, is an important factor contributing to the palatability of beef. Vitamin A, through its active metabolite, retinoic acid, promotes the formation of new fat cells(adipogenesis). As intramuscular adipogenesis is active during the neonatal stage, we hypothesized that vitamin A administration during the neonatal stage would enhance intramuscular adipogenesis and marbling.Methods: Angus steer calves(n = 30), in a completely randomized design, were randomly allotted to three treatment groups at birth, receiving 0, 150,000, or 300,000 IU of vitamin A at both birth and one month of age.A biopsy of the biceps femoris muscle was collected at two months of age. After weaning at 210 d of age, steers were fed a backgrounding diet in a feedlot until 308 d of age, when they were transitioned to a high concentrate finishing diet and implanted with trenbolone/estradiol/tylosin mixture. Steers were harvested at an average of 438 d of age. All diets were formulated to meet nutrient requirements.Results: Weaning weight and weight during the backgrounding phase were linearly increased(P < 0.05) by vitamin A level, though no difference in body weight was observed at harvest. Intramuscular fat of steers at 308 d of age, measured by ultrasound, quadratically increased(P < 0.05) with vitamin A level from 4.0±0.26 % to 4.9±0.26 %.Similarly, carcass marbling score in the ribeye quadratically increased(P < 0.05).Conclusion: Administration of vitamin A at birth increased weaning weight and enhanced marbling fat development.Thus, vitamin A administration provides a practical method for increasing marbling and early growth of beef cattle.
文摘A high performance liquid chromatographic method for the simultaneous determination of four fat soluble vitamins: retinol (vitamin A), cholecalciferol(vitamin D), tocopherol(vitamin E) and phylloquinone(vitamin K_1) in fortified milk powders and egg yolk has been developed. The method requires enzymatic hydrolysis of lipid component of the sample as a pretreatment. Several factors which influence the enzymatic hydrolysis were studied-Separation was achieved using μ-Bondapak C-18 column(3.9×300mm), 98% methanol as mobile phase, a double channel detection was selected; vitamins D_3 E_1 K_1 were detected by UV spectrophotometry (265 nm) first, then vitamin A by fluorometry (EX 325nm, EM 480mm). The retention times of vitamin A_1 D_3, E and K_1 4.87, 9.00, 10.58 and 15.45 min respectively. Detection limit were 0.64, 0.25, 0.50 and 0.07 ng; and the recoveries were 90.5%～103.6% 90.0%～95.6%, 91.7%～98.8%, 91.5%～98.6%, respectively. The vitamins A, D_0, E, K_1 contents in foods were determined satisfactorily.
基金Isfahan University of Technology (IUT, Isfahan, Iran) for their financial support of this studythe personnel of Lavark Research Station (IUT) for their diligent animal care throughout the experiment
文摘The objective of this study was to evaluate the effects of vitamin E（VE; 1 500 or 3 000 international units（IU） d^（-1）） and fat（2% of dry matter calcium salt of soybean oil） supplementation during the transition period on feed intake, milk yield and composition and blood metabolites of dairy cows. 48 multiparous Holstein cows were randomly assigned into one of four treatments in a 2×2 factorial arrangement of vitamin E and supplemental dietary fat during the transition period. Treatments were： 1） 1 500 IU d^（-1） vitamin E without fat supplementation（1 500VE-F）; 2） 1 500 IU d^（-1） vitamin E with fat supplement（1 500VE＋F）; 3） 3 000 IU d^（-1） vitamin E without fat supplementation（3 000VE-F）; and 4） 3 000 IU d^（-1） vitamin E with fat supplement（3 000VE＋F）. Dietary treatments were initiated at approximately 28 d before expected calving dates and continued through 28 d postpartum. Dry matter intake（DMI） was unaffected（P〉0.05） by prepartum treatment. Regardless of vitamin E supplementation, DMI was greater（P〈0.01） in fat-supplemented cows compared with un-supplemented cows（19.60 vs. 18.45 kg d^（-1）; SEM=0.42） during the postpartum period. Energy balance and body weight were not affected（P〉0.05） by treatments. Postpartum diets had no significant effect on milk yield or milk composition. Plasma concentrations of non-esterified fatty acids, glucose, and insulin were not affected（P〉0.05） by treatments. Regardless of vitamin E supplementation, plasma β-hydroxybutyrate concentration was greater（P〈0.05） in fat-supplemented cows compared with un-supplemented cows during the postpartum period. These results showed no indication of positive effects on lactation performance associated with vitamin E and dietary fat supplement in transition cows.
文摘目的评估自动化磁珠法提取血清脂溶性维生素应用液相色谱串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)检测的性能。方法收集200例临床剩余血清样本,采用自动化磁珠法提取血清中脂溶性维生素A,D_(2),D_(3),E和K;同时联合LC-MS/MS检测脂溶性维生素A,D_(2),D_(3),E和K的线性、定量限、精密度、正确度、携带污染率等性能指标以及基质效应。并比较此方法与传统萃取法检测结果的一致性。结果自动化磁珠法提取脂溶性维生素A,D_(2),D_(3),E和K线性相关系数均>0.99;五种物质的定量限分别为5,0.25,0.25,125和0.025ng/ml;批内精密度和批间精密度分别为0.66%~4.83%,0.15%~3.70%;平均加标回收率为87.05%~111.11%;基质效应为95.43%~99.07%;高-低值样本循环进样结果均值与低-低值样本循环进样结果均值之差,均小于低-低值样本循环进样结果均值的3s;统计学结果显示自动化磁珠法和传统萃取法提取的脂溶性维生素结果相关性良好(r>0.99),两种方法的检测结果无显著偏倚。结论自动化磁珠法提取脂溶性维生素的检测性能良好,有望提高样品通量和分析效率。
文摘BACKGROUND Both obesity and vitamin D deficiency are important health issues in Pakistan.The connection between body composition, Vitamin D and leptin in young adults is important to be studied as body composition may affect bone health and therefore the possibility of osteoporosis in later life. Few studies have attempted to investigate the effect of body composition and leptin with vitamin D in adolescence.AIM To investigate the association of serum leptin with body composition, lipids and25-hydroxyvitamin D(25 OHD) in adults.METHODS This cross-sectional study was conducted on 167 apparently healthy adults.Demographics were recorded, bioelectrical impedance analysis was performed and clinical history noted. Serum leptin was measured using DIA source kit on ELISA and total 25 OHD was measured on ADVIA-Centaur; Siemens. Total cholesterol and high density lipoprotein cholesterol were quantified using Enzymatic Endpoint Method and Cholesterol Oxidase-Phenol Aminophenazone method respectively. Biochemical analysis was done in the Departments of Pathology and Laboratory Medicine and Biological and Biomedical Sciences, Aga Khan University Hospital Karachi Pakistan.RESULTS Median age of the group(n = 167) was 20 years(IQR 27-20); 55.7% were females.Majority(89.2%, n = 149) of the study group was 25 OHD deficient, 6%(n = 10)had insufficient serum 25 OHD levels and 4.8%(n = 8) had sufficient D levels.Females, had higher median leptin levels [2.71(IQR 4.76-1.66 ng/mL)] compared to their counterparts [1.3(3.60-0.54 ng/mL), P < 0.01]. Multiple regression analysis suggested that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25 OHD were the most contributing factors to serum leptin levels. Bone mass and serum 25 OHD in fact bore a negative correlation with leptin.CONCLUSION The results indicate that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25 OHD have an impact on serum leptin. Being a cross sectional study causal relationship between leptin and other variables could not be determined.
