[Shock, acidosis and lipolysis].
Explore the source record for details and available documents.
Acid-Base Equilibrium↗
SEARCH · Search PubMed
Results for “Fat Substitutes”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Genomic organization of the DGAT2/MOGAT gene family in cattle (Bos taurus) and other mammals.
We report the cloning and initial characterization of the genes encoding DGAT2 (diacylglycerol transferase 2), MOGAT1 and MOGAT2 (monoacylglycerol transferases 1 and 2) in domestic cattle (Bos taurus). The three closely related genes belong to a gene family with at least eight members in mammals and are candidate genes for quantitative traits related to dietary fat uptake, lipid synthesis and storage. MOGAT2 and DGAT2 form a tandem and were mapped to bovine chromosome (BTA) 15q25-->q26 by fluorescence in situ hybridization. MOGAT1 was localized to BTA 2q43-->q44. The three genes were investigated for polymorphisms that might be associated with breeding values for milk fat percentage in the dairy breeds German Holstein, German Simmental and German Brown. All the detected polymorphisms were located outside exons or, with one exception, were silent. In MOGAT1, a missense mutation in exon 4 was found that causes a non-conservative substitution of cysteine170 (uncharged, hydrophobic) by lysine (positively charged, hydrophilic). However, allele frequency estimates from pooled DNA samples revealed no significant association of the observed polymorphisms with breeding values for milk fat percentage. A comparative analysis of chromosomal locations and exon-intron structure of the known members of the DGAT2/MOGAT gene family in humans, rodents and cattle indicates an ancient tandem duplication of the ancestor gene combined with an intron gain (or loss) in one copy. Further members of the family may have arisen by duplications of this gene tandem via two rounds of interchromosomal or genome duplications as well as further local (single) gene duplication and loss events.
Acyltransferases↗
Association of a single nucleotide polymorphism in the calpastatin gene with carcass and meat quality traits of beef cattle.
Calpastatin (CAST) is a naturally occurring protein that inhibits the normal tenderization of meat as it ages postmortem. A SNP was identified in the CAST gene (a G to C substitution) and genotyped on crossbred commercially fed heifers (n = 163), steers (n = 226), and bulls (n = 61) from beef feedlots, and steers (n = 178) from a University of Guelph feeding trial. The association of the CAST SNP with carcass and meat quality traits was studied. Carcass traits included fat, lean, and bone yield; grade fat; LM area; and HCW. Meat quality traits included marbling grade; i.m. fat content of LM; tenderness evaluation of LM (Warner-Bratzler shear force) at 2, 7, 14, and 21 d of postmortem aging; and tenderness evaluation of semitendinosus muscle at 7 d of postmortem aging. The mixed model used in the analyses included fixed effects of CAST genotype, sex, slaughter group, and breed composition (linear covariate); sire was a random effect. For the analysis of shear force, i.m. fat content of LM was also included in the model as a linear covariate. Shear force measures were analyzed within days of postmortem aging and by repeated measures analysis. The CAST SNP allele C was more frequent (63%) in the crossbred population than allele G. The CAST SNP was associated with shear force across days of postmortem aging (P = 0.005); genotype CC yielded beef that was more tender than GG (-0.32 kg +/- 0.13), and CG had intermediate tenderness. The corresponding average allele substitution effect (G to C substitution) was also highly significant (-0.15 +/- 0.05 kg, P = 0.002). A lower percentage of unacceptably tough steaks (shear force > 5.7 kg) at 2 and 7 d postmortem was associated with an increasing number of C alleles (P < or = 0.05). At 7 d postmortem, the percentage of unacceptably tough steaks decreased by 24 and 35%, respectively, for animals carrying 1 and 2 copies of the C allele relative to animals with no C alleles. However, genotype CC had a greater fat yield (+1.44 +/- 0.56%; P = 0.037) than genotype GG, with a corresponding allele substitution effect of 0.67 +/- 0.27% (P = 0.015). Therefore, the CAST SNP allele C was associated with increased LM tenderness across days of postmortem aging and, importantly for the beef industry, had a significant reduction in the percentage of steaks rated unacceptably tough by consumers based on an assumed threshold level.
Animals↗
A cross-national investigation of diet and bladder cancer.
The existence of a large unexplained portion of attributable risk, and the marked variation in bladder cancer rates globally, have stimulated an interest in the role of nutrition in cancer of the urinary bladder. For this cross-national comparison study, we had complete data available for 50 countries. Using stepwise regression followed by general linear modelling, age-truncated (45-74 years), world-standardised, sex-specific bladder cancer mortality rates were regressed on an array of nutritional and socioeconomic independent variables in an effort to identify important predictors of bladder cancer mortality. Separate principal components analyses were used to summarise the nutritional and the socioeconomic (SES) variables. In the stepwise analyses, using food scores expressed in kcal/day per capita (as opposed to the nutritional components), total fat consistently entered the model first, and explained the greatest share of variability (R2) for both males and females. General linear models were fitted that included total fat, tobacco, alcohol, the three SES components (comprising seven socioeconomic predictors) and two food categories found significant in stepwise modelling, roots/tubers and vegetable oil. The R2 values were 0.84 for male rates and 0.77 for female rates, meaning that these study factors account for 84% of bladder cancer mortality in men and 77% in women. Substitution of the nutritional components for the foods resulted in general linear models with slightly higher R2 values (0.85 for males, 0.77 for females), but with attenuated fat effects. Results are discussed in light of biological plausibility.
Aged↗
Impact of protease inhibitor substitution with efavirenz in HIV-infected children: results of the First Pediatric Switch Study.
OBJECTIVE: Simplification of antiretroviral regimen in human immunodeficiency virus (HIV)-infected children has not yet been investigated. In general, children have a more difficult time maintaining viral suppression because of many factors, including frequent nonadherence and less availability of antiretrovirals in palatable forms. In addition, many serious metabolic complications have emerged in HIV-infected adults and are believed to be attributable to antiretroviral therapy. Some of these complications--hypercholesterolemia, hypertriglyceridemia, and insulin resistance--are believed to be the result of the use of protease inhibitor (PI) therapy, whereas the cause of others, such as lipodystrophy, remains undetermined. Recent reports underline that children experience long-term metabolic abnormalities in the same manner that adults do, and perhaps these consequences are even more worrisome in children secondary to long-term expected survival. We report here the results of the first open-label PI-switch study in HIV-infected children. METHODS: Seventeen children, 24 to 160 months of age (median: 120), were enrolled into the study. All were receiving a stable PI-containing antiretroviral regimen that containing 2 to 3 nucleoside analogue reverse transcriptase inhibitors (NRTIs) in addition to 1 to 2 PIs for a median duration of 21 months (range: 5-50) before study entry. All children had HIV-1 RNA <400 copies/mL at screening; their baseline plasma HIV-1 RNA level had been <400 copies/mL for a median of 13 months (range: 4-55) before study entry. All patients were naïve to nonnucleoside reverse transcriptase inhibitor therapy. Their protease inhibitor(s) was switched to efavirenz while their NRTI therapy was maintained. RESULTS: All children were heavily pretreated; 88% of the patients had previous NRTIs, and 41% had previous PI use. The most common PI at study entry was nelfinavir (47%), followed by ritonavir (29%), then amprenavir (18%); only 1 was on saquinavir/ritonavir. At study entry, the duration of previous antiretroviral therapy was between 21 and 123 months (median: 88). All patients completed the 48-week study. No acquired immunodeficiency syndrome-defining events occurred. There were no rashes and no changes in liver transaminases. Mild, transient insomnia and dizziness each occurred in 1 child. Two other subjects (6 and 8 years old) experienced unusual vivid dreams, mostly pleasant, which decreased in intensity and frequency after the first 12 weeks of the study. One subject, a 10-year-old girl, had an episode of generalized seizure at week 6; study drugs were not interrupted, and seizure never recurred. The patient had a strong family history of epilepsy, although she had never experienced previous seizures. No anticonvulsants were given. Sixteen of 17 patients had HIV-1 RNA levels of <50 copies/mL (1 HIV-1 RNA was 61 copies/mL) at week 48. The mean CD4% remained stable initially from a mean of 35.1% (+/-2.8%) at baseline to 36.8% (+/-5%) at week 24, but increased to 38% (+/-6%) at week 48. Fasting triglycerides decreased from a mean of 126 mg/dL (+/-50) at baseline to 86 mg/dL (+/-45) at week 24 and to 94 mg/dL (+/-38) at week 48. At study entry, 12 (71%) of 17 children had triglyceride levels greater than the 95th percentile for age, race, and gender, compared with only 6 (35%) of 17 at week 48. Fasting cholesterol levels decreased from a mean of 203 mg/dL (+/-50) at baseline to 173 mg/dL (+/-31) at week 24 and to 174 mg/dL (+/-27) at week 48. At study entry, 5 (29%) of 17 children had cholesterol levels greater than the 95th percentile for age, race, and gender, compared with only 1 (6%) of 17 at week 48. The decrease in low-density lipoprotein cholesterol was also significant, from a mean baseline of 124 mg/dL (+/-42) to 100 mg/dL (+/-28) at week 24 and to 105 mg/dL (+/-20) at week 48. High-density lipoprotein (HDL) cholesterol did not change significantly, but the changes in cholesterol:HDL ratio, a better marker of atherogenic risk, significantly decreased from a mean baseline of 3.8 (+/-0.8) to 3.2 (+/-0.7) at week 24 and to 3 (+/-0.6) at week 48. Detailed dietary history revealed no significant changes during the study. In addition, none of the patients initiated therapy with lipid-lowering agents. There were no significant changes in insulin or C-peptide throughout the study period. In addition, anthropometric measurements that included mid-thigh and mid-arm circumferences, triceps and thigh skinfolds, and waist:hip ratio were stable throughout the study period. For bioelectrical impedance measurements, lean body mass increased from a mean baseline of 32.1 lb (+/-9.3) to 35.7 lb (+/-11.4) at week 24 and to 36.5 lb (+/-11.5) at week 48. Bioelectrical impedance measurements of fat content were unchanged throughout the study period. CONCLUSION: This is the first study in children to evaluate the substitution of PI in a virologically successful regimen with efavirenz, a potent once-daily nonnucleoside reverse transcriptase inhibitor therapy. We were able to show significant improvement in fasting total cholesterol, low-density lipoprotein cholesterol, triglycerides, and, more important, the cholesterol:HDL ratio. In addition, switching to an efavirenz-containing regimen was well tolerated and successfully maintained virologic suppression in all HIV-infected children in this study. This study should encourage large randomized trials to investigate simplification strategies in HIV-infected children.
Age Factors↗
Dietary treatment of malnutrition. Balance-sheets of the main nutrients. Part II.
Results of a balance study of nitrogen, fat, electrolytes and trace-elements (Fe, Cu, Zn, Mn) with 3 1/i to 9 years old malnourished children in the Kwilu region (Zaïre) are given. The main components of the diets were fish, lactose free milk, caseinate, partial hydrolasate of albumin, fermented corn and soya (Soy-Ogi), medium-chain triglycerides, rice and the local foods manioc, peanuts and caterpillars. The lactose free milk and the Soy-Ogi were well tolerated since we found only a small quantity of non absorbed sugar in the faeces. Our results show that in children who have secondary intestinal malabsorption the use of a partial hydrolysate of lactalbumin and the medium-chain triglycerides is recommended and the substitution of the manioc by rice also. Caseinate gave satisfactory results in adult-malnutrition. We found a good retention of nitrogen, fat and phosphorus. For the latter an addition was necessary. The potassium balance was also positive, a content of 5 meq/kg body weight in the food gave a sufficient retention time. The sodium chloride content of the diet must be moderate because of the oedemas (2 meq/kg body weight). The determination of the vitamin content in the diet and their urinary excretion gave some indication of the balance of these nutrients. Children who had intestinal troubles showed only a slight positive or negative balance of calcium, magnesium, zinc, copper and manganese, since we found a high faecel excretion for these elements. These rather unsatisfactory results emphasis the necessity of first curing any intestinal aliments.
Carbohydrate Metabolism↗
Genetic and functional confirmation of the causality of the DGAT1 K232A quantitative trait nucleotide in affecting milk yield and composition.
We recently used a positional cloning approach to identify a nonconservative lysine to alanine substitution (K232A) in the bovine DGAT1 gene that was proposed to be the causative quantitative trait nucleotide underlying a quantitative trait locus (QTL) affecting milk fat composition, previously mapped to the centromeric end of bovine chromosome 14. We herein generate genetic and functional data that confirm the causality of the DGAT1 K232A mutation. We have constructed a high-density single-nucleotide polymorphism map of the 3.8-centimorgan BULGE30-BULGE9 interval containing the QTL and show that the association with milk fat percentage maximizes at the DGAT1 gene. We provide evidence that the K allele has undergone a selective sweep. By using a baculovirus expression system, we have expressed both DGAT1 alleles in Sf9 cells and show that the K allele, causing an increase in milk fat percentage in the live animal, is characterized by a higher Vmax in producing triglycerides than the A allele.
Acyltransferases↗
Association of fatty acid synthase gene and malic enzyme gene polymorphisms with fatness in turkeys.
A candidate gene approach was carried out on a commercial line of turkeys to assess the association between fatness variability and polymorphisms of genes involved in lipid metabolism. Four restriction fragment length polymorphisms (RFLP) were typed on the fatty acid synthase gene (MspI/pF5), on the malic enzyme gene (HindIII/em), as well as on the acetyl coenzyme A carboxylase and delta9 desaturase genes. Fatness level was estimated in vivo by an ultrasonic instrument. Fat yield was assessed after slaughter by calculating the ratio of the leg skin plus subcutaneous fat weight to the whole leg weight. Finally, the lipid content was determined by extraction from the boneless leg. The 84 female turkeys sampled were full and half-sibs born from eight sires, seven of which were heterozygous for MspI/pF5 or HindIII/em RFLP and one of which was double homozygous at these loci. The analyses of variance used to compare the genotypes at each RFLP suggested a major role associated with the fatty acid synthase gene polymorphism in the explanation of fatness variability. One homozygous genotype for MspI/pF5 was about 1.5 standard deviations leaner than the other two homozygous genotypes. An analysis of the average effects of gene substitution confirmed the association between leanness and one allele of the fatty acid synthase polymorphism. It also identified a significant association between leanness and one malic enzyme RFLP allele, congruent with a strictly additive determinism for the effect associated with this polymorphism. This experiment provided new evidence of the association between both fatty acid synthase and malic enzyme gene polymorphisms and fatness variability in turkeys.
Animals↗
Studies on in vitro synthesis of serum lipoproteins in rats maintained on normal and atherogenic diets: effects of cobalt and manganese supplements at deficient and abundant doses.
The effects of Co(II) and Mn (II) supplements at abundant as well as, deficient doses on in vitro synthesis of serum lipoproteins in rats maintained on normal and atherogenic diets were studied. While an adequate oral supplement of Co(II) or iv administration of Mn (II) at very low doses to the experimental rats fed on salt-free stock ration diet produces hyperlipidemic changes in increasing C/P ratio in serum and also the serum LP content. On the other hand, the animals on atherogenic diet supplemented with deficient Co(II) or excess Mn(II) results in a lowering of hyperlipidemia and hyperlipoproteinemia, with concomitant decrease in C/P ratio. Dietary lipids (eg. cholesterol, butter-fat etc.) vis-a-vis Mn (II) deficiency or Co(II) in excess reflect a homeostatic control mechanism for keeping the excess lipid in a state of solution as lipoprotein complexes. Deficient Co(II) or excess Mn (II) in turn, results in a decrease in protein synthesis and a relatively impaired rate of secretion of protein from liver to serum. Moreover, Mn (II) deficiency increases, while its abundance, significantly restricts 14C- labelled amino acid incorporation into alpha 2-lipoprotein molecules. Neither cobalt depletion, nor its adequate oral substitution help improvise the hepatic synthesis of alpha 2-apolipoproteins in experimental animals. This situation remains unaltered even by overloading the diets with saturated fats or by other atherogenic agents, instead of vegetable oils preferably rich in mono or dienoic fatty acids.
Animals↗
Incorporating soy protein into a low-fat, low-cholesterol diet.
The US Food and Drug Administration recommends including four servings of at least 6.25 g each (25 g/day) of soy protein into a diet low in saturated fat and cholesterol to reduce the risk of heart disease. Patients are more likely to comply with this dietary change if they have their physician's support. The author discusses how the clinician can help patients incorporate soy protein into a low-cholesterol, low-fat diet. A meta-analysis found that soy protein consumption achieved an average 9.3% decrease in total cholesterol, a 12.9% decrease in low-density lipoprotein (LDL) cholesterol, and a 10.5% decrease in triglycerides. Soy pills and supplements such as isoflavone are not recommended. The cholesterol-lowering benefit has only been observed when the intact soy protein is used. Soy milk can be used in place of milk in coffee or over breakfast cereal, as well as in milkshakes and other blended drinks. Soy milk can be substituted for milk in many recipes.
Cholesterol↗
Frequency distribution of a Cys430Ser polymorphism in peroxisome proliferator-activated receptor-gamma coactivator-1 (PPARGC1) gene sequence in Chinese and Western pig breeds.
Identification of major genes, that genetically impact fat tissue formation is important for successful selection of lean animals with good meat quality. Because of its central role in fat cell differentiation and muscle fibre type determination, PPARGC1 is a potential candidate gene affecting fattening traits and pig meat quality. In this study, a T/A substitution at position 1378 (GenBank accession no. AY346131) in the porcine PPARGC1 gene causing a Cys430Ser amino acid substitution at position 430 was genotyped on a total of 239 animals, including 101 from seven Chinese and 138 from six Western pig breeds. Bayesian analysis revealed that the mean frequency of allele T (Cys) was 92.64 +/- 4.82% in Chinese pigs, and 45.99 +/- 4.13% in Western pigs. The 95% interval of the posterior mean frequency of allele T was 0.82-1.00 in Chinese pigs and 0.38-0.54 in Western pigs, indicating these two groups of pigs diverged at this locus during genetic evolution of the breed. Because marked differences in fat and lean tissue deposition exist between Western and Chinese pig breeds, this Cys430Ser exchange in the PPARGC1 gene deserves further evaluation to determine its phenotypic effect on fattening and carcass traits in commercial pig populations.
Amino Acid Substitution↗
The inhibitory effect of soy products on nonheme iron absorption in man.
Radioiron absorption studies were performed in male volunteer subjects to determine the effect on nonheme iron absorption of various semipurified proteins. When egg albumen and casein were substituted in protein-equivalent quantities in a semisynthetic meal, similar mean absorptions of 2.5 and 2.7% were observed. In contrast, isolated soy protein reduced absorption sharply, to an average of 0.5%. When egg albumen in the semisynthetic meal was replaced with full fat soy flour, textured soy flour, and isolated soy protein, absorption fell from 5.5 to 1.0, 1.9, and 0.4%, respectively, indicating an inhibitory effect by a wide range of soy products. The effect of substituting textured soy flour for meat in a meal containing a hamburger, french fries, and a milkshake was also evaluated. With 3:1 and 2.1 ratios of meat to unhydrated textured soy flour, absorption decreased by 61 and 53%, respectively. The soy products tested in this study have a pronounced inhibitory effect on the absorption of nonheme iron.
Absorption↗
Decreasing sedentary behaviors in treating pediatric obesity.
BACKGROUND: Epidemiological studies have shown television watching to be a risk factor for the development of obesity in children. The effect of reducing television watching and other sedentary behaviors as a component of a comprehensive obesity treatment program has not been thoroughly tested. OBJECTIVE: To compare the influence of targeting decreases in sedentary behavior vs. increases in physical activity in the comprehensive treatment of obesity in 8- to 12-year-old children. DESIGN: Randomized, controlled outcome study. SETTING: Childhood obesity research clinic. DESIGN: Ninety families with obese 8- to 12-year-old children were randomly assigned to groups that were provided a comprehensive family-based behavioral weight control program that included dietary, and behavior change information but differed in whether sedentary or physically active behaviors were targeted and the degree of behavior change required. RESULTS: Results during 2 years showed that targeting either decreased sedentary behaviors or increased physical activity was associated with significant decreases in percent overweight and body fat and improved aerobic fitness. Self-reported activity minutes increased and targeted sedentary time decreased during treatment. Children substituted nontargeted sedentary behaviors for some of their targeted sedentary behaviors. CONCLUSION: These results support reducing sedentary behaviors as an adjunct in the treatment of pediatric obesity.
Behavior Therapy↗
Absence of genetic variation in some obesity candidate genes (GLP1R, ASIP, MC4R, MC5R) among Pima indians.
OBJECTIVE: To examine the obesity candidate genes glucagon-like-peptide receptor (GLP1R), agouti signaling protein (ASIP) and the melanocortin receptors 4 and 5 (MC4R and MC5R) for DNA polymorphisms in their coding regions. SUBJECTS: Unrelated, non-diabetic Pima Indians (8 to 12 from each extreme of body fat). MEASUREMENTS: DNA sequencing within the coding regions of each gene. RESULT: Only one variant was detected, a silent substitution in exon 6 of GLP1R. CONCLUSION: The exclusion of any common amino-acid polymorphisms (allele frequency > or = 0.20). implies that structural variants of these genes do not contribute to variation in the high level of obesity observed among the Pima Indians.
Agouti Signaling Protein↗
Greater dietary intake of simple carbohydrate is associated with lower concentrations of high-density-lipoprotein cholesterol in hypercholesterolemic children.
Hypercholesterolemic children are increasingly being treated with lipid-lowering diets, but little research has focused on the effects of specific dietary substitutions on HDL cholesterol. We examined the relation between carbohydrate intake and HDL cholesterol in hypercholesterolemic children consuming fat-restricted diets. We obtained 3-d food records for 67 children (mean age: 5.8 +/- 2.5 y) referred for the treatment of hypercholesterolemia. Mean plasma HDL cholesterol was 1.12 +/- 0.21 mmol/L and total cholesterol was 5.99 +/- 1.39 mmol/L. Dietary intake comprised (percentage of total energy) 24.9 +/- 5.1% fat, 59.9 +/- 6.5% carbohydrate, and 16.5 +/- 3.4% protein. Carbohydrate intake included 30.7 +/- 7.4% from simple and 22.6 +/- 6.2% from complex carbohydrates. HDL cholesterol was positively correlated with intake of total fat (r = 0.44, P < 0.001) and saturated fatty acids (r = 0.43, P < 0.001) and inversely correlated with intake of total carbohydrate (r = -0.55, P < 0.001) and simple carbohydrate (r = -0.40, P < 0.001), but not with complex carbohydrate (r = -0.02). The significant inverse relation between simple carbohydrate intake and HDL cholesterol remained after intakes of saturated, monounsaturated, and polyunsaturated fatty acids; intake of complex carbohydrates; dietary cholesterol; plasma triacylglycerol; and age were adjusted for with multivariate techniques. In summary, higher dietary intake of simple carbohydrates was associated with lower HDL-cholesterol concentrations in hypercholesterolemic children consuming reduced-fat diets.
Body Mass Index↗
Studies of the utilization of high and low erucic acid rapeseed oils by the chick.
Experiments were conducted to compare energy utilization, growth and tissue composition of chicks fed diets containing 10 or 20 parts of either high erucic acid rapeseed oir 24 days. Results showed that chicks fed diets containing 10 or 20 parts LER grew at the same rate, utilized energy just as efficiently, had similar heart to body weight ratios and levels of heart lipids equal to or less than chicks fed comparable diets containing SFO. The substitution of 10 or 20 parts HER for an equienergetic amount of SFO depressed gorwth, feed consumption and carcass fat deposition but had no effect on level of cardiac lipid or relative heart size when fed from 4 to 11 days of age. When fed from 4 to 25 days of age, chicks fed 20 parts HER grew slower, consumed less feed, and when pairfed, deposited less carcass fat, utilized energy less efficiently, had increased heart to body weight ratios but a lower level of cardiac lipid than chicks fed comparable diets containing SFO. Irrespective of the type of rapeseed oil or of the age of the chick, heart lipids contained less erucic acid than carcass fat, indicating that chick heart is as capable of disposing of erucic acid as carcass tissue. It was also found that irrespective of the diet fed, a greater percentage of erucic acid appeared to be oxidized than of eicosenoic acid.
Animals↗
Improved N-retention during L-carnitine-supplemented total parenteral nutrition.
The influence of intravenously administered L-carnitine on lipid- and nitrogen-metabolism was studied during total parenteral nutrition of piglets (mean weight 4077 g; n = 9). The infusion protocol was divided into three isocaloric and isonitrogenous 48-hr periods. Amino acids (3 g/kg day) were administered throughout all three periods: 140 cal/kg/day were given as nonprotein calories, consisting only of glucose during period 1; during periods 2 and 3, an amount of glucose calorically equivalent to 4 g fat/kg/day was substituted with a lipid emulsion, and L-carnitine (1.5 mg/kg/day) was added in period 3. Key parameters of fat- and nitrogen-metabolism were determined during the entire regime. Indirect calorimetry was performed and the respiratory quotient calculated during all three periods. The results demonstrate a more effective lipolysis and oxidation of fatty acids during L-carnitine supplementation. These changes produce an increased energy gain from exogenously administered fat and a distinct improvement in nitrogen balance.
Amino Acids↗
Wheat straw or alfalfa hay in diets with 30% neutral detergent fiber for lactating Holstein cows.
Twenty-four Holstein cows near peak lactation were fed diets formulated to contain 30% NDF with forage NDF from chopped wheat straw or chopped alfalfa hay in proportions of 0:3, 1:2, 2:1, and 3:0 in an 8-wk trial to evaluate effects of fiber source on lactational performance. Concentrate was based on highly degradable carbohydrate in steam-flaked sorghum grain. Forage to concentrate ratio decreased from 49:51 to 28:72 when straw was substituted for alfalfa hay. Milk yield (38.4 kg/d) and DMI (23.1 kg/d) were not influenced by forage source. Milk fat percentage decreased and milk protein percentage increased linearly with increasing straw. Yields of 3.5% FCM and fat showed linear and quadratic responses, because they appeared to be reduced only on the 0:3 diet, and protein yield showed a quadratic response and was highest for the 1:2 diet. Digestibility of NDF averaged 43.5, 45.4, 40.7, and 31.2%, and acetate to propionate ratio was 3.0, 2.4, 2.2, and 1.9 with increasing dietary straw. Passage rates were not influenced by diet and averaged 9.3, 7.6, 6.1, and 4.7%/h for fluid, grain, alfalfa hay, and wheat straw, respectively. It is suggested that the ratio of forage NDF to ruminally degradable starch be maintained greater than or equal to 1:1 when diets based on low quality forage are fed to cows in early lactation.
Animal Feed↗