Black soldier fly larva fat inclusion in finisher broiler chicken diet as an alternative fat source

The objective of the present study was to evaluate the effects of partial or total replacement of finisher diet soybean oil with black soldier fly (Hermethia illucens L.; HI) larva fat on the growth performance, carcass traits, blood parameters, intestinal morphology and histological features of broiler chickens. At 21 days of age, a total of 120 male broiler chickens (Ross 308) were randomly allocated to three experimental groups (five replicates and eight birds/pen). To a basal control diet (C; 68.7 g/kg as fed of soybean oil), either 50% or 100% of the soybean oil was replaced with HI larva fat (HI50 and HI100 group, respectively). Growth performance was evaluated throughout the trial. At day 48, 15 birds (three birds/pen) per group were slaughtered at a commercial abattoir. Carcass yield and proportions of carcass elements were recorded. Blood samples were taken from each slaughtered chicken for haematochemical index determination. Morphometric analyses were performed on the duodenum, jejunum and ileum. Samples of liver, spleen, thymus, bursa of fabricius, kidney and heart were submitted to histological investigations. Growth performance, carcass traits, haematochemical parameters and gut morphometric indexes were not influenced by the dietary inclusion of HI larva fat. Histopathological alterations developed in the spleen, thymus, bursa of fabricius and liver and were identified in all of the experimental groups, but HI larva fat inclusion did not significantly affect (P>0.05) the severity of the histopathological findings. The present study suggests that 50% or 100% replacement of soybean oil with HI larva fat in broiler chickens diets has no adverse effects on growth performance or blood parameters and had no beneficial effect on gut health.     

Stability of Adiposity Phenotypes from Childhood and Adolescence into Young Adulthood with Contribution of Parental Measures

Objective: The stability of several indicators of body composition and adipose tissue distribution over 12 years was quantified. Research Methods and Procedures: The participants were 77 boys and 76 girls who were evaluated along with their parents at baseline as children and adolescents (8 to 18 years of age) and remeasured as young adults 12 years later. Indicators of body composition included the body mass index, fat mass, fat free mass, percentage of body fat, sum of six skinfolds (SF6), and the first principal component of six age‐adjusted skinfold residuals. Relative adipose tissue distribution was represented by the second principal component of skinfold residuals and a trunk‐to‐extremity skinfold ratio, adjusted for SF6. Results: Partial interage correlations, controlling for initial age and length of follow‐up, were 0.65 and 0.59 for the body mass index, 0.59 and 0.64 for fat mass, 0.65 and 0.57 for fat free mass, 0.50 and 0.57 for percentage of body fat, 0.66 and 0.44 for SF6, 0.64 and 0.42 for the first principal component of six age‐adjusted skinfold residuals, 0.19 and 0.31 for the second principal component of skinfold residuals, and 0.41 and 0.47 for trunk‐to‐extremity skinfold ratio, adjusted for SF6, in men and women, respectively. Multiple regression analyses indicated that the significant partial R² values of parental measurements on the prediction of their offspring in young adulthood ranged from 2% to 9%. Discussion: The results indicate moderately high stability of indicators of body composition and somewhat lower stability of measures of adipose tissue distribution. Overall, parental measures offer less predictive value than do measures of childhood and adolescent body composition and adipose tissue distribution.     

Influence of Leptin on Changes in Body Fat during Growth in African American and White Children

Objective: The aim of this study was to determine whether initial levels or temporal changes in fasting leptin were associated with longitudinal changes in body‐fat mass in children. Research Methods and Procedures: The study group consisted of 85 children (42 white and 43 African American) with a mean initial age of 8.1 ± 0.1 years. The children had between three and six annual visits for repeated measurements of body composition by DXA and fasting leptin level. Fat mass and fasting leptin level were not normally distributed and were log‐transformed. Data were analyzed using SAS Proc mixed growth models, with log fat as the dependent variable. Results: Initial leptin level was a significant predictor of the change in fat mass over time (p < 0.0001), with high initial leptin levels resulting in increased fat gain, independent of initial fat levels. This relationship remained significant when the data were analyzed separately by race (whites, p < 0.0001; African Americans, p = 0.008). The relationship between the initial level of leptin and the change in fat mass was not modified by race, sex, or Tanner Stage. The rate of change in leptin during the study was significantly related to the rate of change in fat mass in African Americans (p = 0.008) but not in whites (p = 0.490). Discussion: In conclusion, high fasting leptin level at the start of the study was significantly associated with increasing fat mass in this cohort, indicating that the children may be developing resistance to the effects of leptin.     

Fitness Alters the Associations of BMI and Waist Circumference with Total and Abdominal Fat

Objective: We tested the following hypotheses in black and white men and women: 1) for a given BMI or waist circumference (WC), individuals with moderate cardiorespiratory fitness (CRF) have lower amounts of total fat mass and abdominal subcutaneous and visceral fat compared with individuals with low CRF; and 2) exercise training is associated with significant reductions in total adiposity and abdominal fat independent of changes in BMI or WC. Research Methods and Procedures: The sample included 366 sedentary male (111 blacks and 255 whites) and 462 sedentary female (203 blacks and 259 whites) participants in the HERITAGE Family Study. The relationships between BMI and WC with total fat mass (determined by underwater weighing) and abdominal subcutaneous and visceral fat (determined by computed tomography) were compared in subjects with low (lower 50%) and moderate (upper 50%) CRF. The effects of a 20‐week aerobic exercise training program on changes in these adiposity variables were examined in 86% of the subjects. Results: Individuals with moderate CRF had lower levels of total fat mass and abdominal subcutaneous and visceral fat than individuals with low CRF for a given BMI or WC value. The 20‐week aerobic exercise program was associated with significant reductions in total adiposity and abdominal fat, even after controlling for reductions in BMI and WC. With few exceptions, these observations were true for both men and women and blacks and whites. Discussion: These findings suggest that a reduction in total adiposity and abdominal fat may be a means by which CRF attenuates the health risk attributable to obesity as determined by BMI and WC.     

菜蛾盘绒茧蜂主要寄生因子导致的寄主小菜蛾幼虫脂肪体结构的变化

在不同的寄生状态下,菜蛾盘绒茧蜂Cotesia plutellae不同的寄生因子可引起寄主小菜蛾Plutella xylostella幼虫脂肪体结构发生相应的改变。显微和亚显微形态结构显示： 假寄生后多分DNA病毒和毒液对脂肪体结构的完整性没有显著影响,但细胞内脂质体变得小而密集,线粒体和内质网丰富,并有糖原积累; 正常寄生后,脂肪体结构被破坏,多数线粒体内嵴紊乱,脂质体也变得不规则,特别是当幼蜂完成在寄主体内发育时,寄主体内几乎无完整脂肪体存在。与此同时,同批未被寄生的小菜蛾幼虫发育到4龄末期时,体内脂肪体细胞发育正常,已开始向蛹期细胞形态转化,细胞内脂质体很大,细胞器数量较多、糖原积累丰富, 而且部分细胞已成为游离态细胞。由此证明,寄生蜂携带的寄生因子,如多分DNA病毒、毒液、畸形细胞和幼蜂等,均对寄主脂肪体结构的改变产生影响,但程度明显不同。     

高脂喂养大鼠肾小管上皮细胞SREBP-1、TGF-β1、α-SMA的表达和细胞外基质沉积

目的:探讨高脂喂养对大鼠肾脏小管上皮细胞SREBP-1、TGF-β1、α-SMA表达和细胞外基质(ECM)的影响。方法:高脂饲料喂养大鼠12周后,油红O检测肾脏脂质沉积,Masson染色检测肾小管间质细胞外基质沉积,免疫组化、Western blot和原位杂交检测SREBP-1、TGF-β1、α-SMA和FN的表达。结果:高脂喂养后大鼠体重明显增加,血糖、甘油三酯和胰岛素均升高,油红O检测显示大鼠肾小管上皮细胞内出现明显脂滴。SREBP-1蛋白和mRNA在肾小管上皮细胞内表达,高脂组高于正常对照组,分别是正常组的1.88倍和1.85倍;TGF-β1和α-SMA也定位于肾小管上皮细胞胞浆并出现上调。Masson染色显示高脂喂养大鼠肾间质ECM沉积增多,纤维粘连蛋白FN检测也显示模型组表达强于对照组。结论:高脂饮食喂养可能通过上调肾脏小管上皮细胞SREBP-1表达使细胞内脂滴沉积,并进一步诱导TGF-β1、α-SMA合成而导致细胞外基质堆积。     

Expression of rat L-FABP in mouse fibroblasts: role in fat absorption

Fatty acid-binding proteins (FABP) are abundant cytosolic proteins whose level is responsive to nutritional, endocrine, and a variety of pathological states. Although FABPs have been investigatedin vitro for several decades, little is known of their physiological function. Liver L-FABP binds both fatty acids and cholesterol. Competitive binding analysis and molecular modeling studies of L-FABP indicate the presence of two ligand binding pockets that accomodate one fatty acid each. One fatty acid binding site is identical to the cholesterol binding site. To test whether these observations obtainedin vitro were physiologically relevant, the cDNA encoding L-FABP was transfected into L-cells, a cell line with very low endogenous FABP and sterol carrier proteins. Uptake of both ligands did not differ between control cells and low expression clones. In contrast, both fatty acid uptake and cholesterol uptake were stimulated in the high expression cells. In high expression cells, uptake of fluorescent cis-parinaric acid was enhanced more than that of trans-parinaric acid. This is consistent with the preferential binding of cis-fatty acids to L-FABP but in contrast to the preferential binding of trans-parinaric acid to the L-cell plasma membrane fatty acid transporter (PMFABP). These data show that the level of cytosolic fatty acids in intact cells can regulate both the extent and specificity of fatty acid uptake. Last, sphingomyelinase treatment of L-cells released cholesterol from the plasma membrane to the cytoplasm and stimulated microsomal acyl-CoA: cholesteryl acyl transferase (ACAT). This process was accelerated in high expression cells. These observations show for the first time in intact cells that L-FABP, a protein most prevalent in liver and intestine where much fat absorption takes place, may have a role in fatty acid and cholesterol absorption.Abbreviations FABP fatty acid-binding protein - L-FABP liver fatty acid-binding protein - I-FABP intestinal fatty acid-binding protein - H-FABP heart fatty acid-binding protein - A-FABP adipocyte fatty acid-binding protein - PMFABP plasma membrane fatty acid-binding protein - SCP-2 sterol carrier protein-2 - Dehydroergosterol (DHE) d-5,7,9(11),22-ergostatetraene-3b-ol - cis-parinaric acid-9Z, 11E, 13E, 15Z-octatetraenoic acid - trans parinaric acid, 9E, 11E, 13E, 14E-octatetraenoic acid - BSA bovine serum albumin - KRH Krebs-Ringer-Henseleit buffer     

Late‐moulting Black‐necked Grebes Podiceps nigricollis show greater body mass in the face of failing food supply

From August to December, thousands of Black‐necked Grebes Podiceps nigricollis concentrate during the flightless moult period in salt ponds in the Odiel Marshes, southern Spain, where they feed on the brine shrimp Artemia parthenogenetica. We predicted that because Black‐necked Grebes moulted in a food‐rich, predator‐free environment, there would be no net loss of body mass caused by the use of fat stored to meet energy needs during remigial feather replacement (as is the case for some other diving waterbirds). However, because the food resource disappears in winter, we predicted that grebes moulting later in the season would put on more body mass prior to moult because of the increasing risk of an Artemia population crash before the moult period is completed. Body mass determinations of thousands of birds captured during 2000–2010 showed that grebes in active wing‐moult showed greater mass with date of capture. Early‐moulting grebes were significantly lighter at all stages than late‐moulting birds. Grebes captured with new feathers post‐moult were significantly lighter than those in moult. This is the first study to support the hypothesis that individual waterbirds adopt different strategies in body mass accumulation according to timing of moult: early‐season grebes were able to acquire an excess of energy over expenditure and accumulate fat stores while moulting. Delayed moulters acquired greater fat stores in advance of moult to contribute to energy expenditure for feather replacement and retained extra stores later, most likely as a bet hedge against the increasing probability of failing food supply and higher thermoregulatory demands late in the season. An alternative hypothesis, that mass change is affected by a trophically transmitted cestode using brine shrimps as an intermediate host and Black‐necked Grebes as final host, was not supported by the data.