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Fat Concentration (fat + concentration)
Selected AbstractsEffects of grass pasture and concentrate-based feeding systems for spring-calving dairy cows in early spring on performance during lactationGRASS & FORAGE SCIENCE, Issue 3 2005E. Kennedy Abstract The effect of offering a total mixed ration of silage and concentrate (proportionately 0·44 silage) system [indoor feeding system (IF)] was compared with grazing at a high daily herbage allowance with a low level of concentrate supplementation [early grazing system (EG)] in early spring on the performance of spring-calving dairy cows in Ireland. Sixty-four spring-calving Holstein,Friesian dairy cows (mean calving date, 2 February) were allocated to one of two systems between 16 February and 4 April 2004. An equal number of primiparous and multiparous cows were assigned to each system. The dairy cows on the IF system were housed for a 7-week period and offered a diet of 10·9 kg DM cow,1 d,1 (s.d. 2·3) of concentrate, the remainder of the diet was 8·6 kg DM cow,1 d,1 (s.d. 1·9) of grass silage. The dairy cows on the EG system were offered a mean daily herbage allowance of 15·1 kg DM cow,1 d,1 (s.d. 3·7) and were supplemented with 3·0 kg DM cow,1 d,1 (s.d. 1·0) of concentrate. There was no difference in milk yield between the two systems but the cows in the EG system had a higher milk protein concentration (2·9 g kg,1) and a higher milk protein yield than in the IF system. Milk fat concentration was higher for cows in the IF than EG system (3·0 g kg,1). There was no difference in total daily dry-matter intake between the systems, measured in week 6 of the study. Mean live weight of the cows in the IF system was greater than in the EG system. The results of the study suggest that a slightly greater performance can be achieved by a system offering a high daily herbage allowance to spring-calving dairy cows in early lactation compared with a system offering a total mixed ration containing a high proportion of concentrate with grass silage. [source] Prevention of diet-induced fatty liver in experimental animals by the oral administration of a fatty acid bile acid conjugate (FABAC)HEPATOLOGY, Issue 2 2003Tuvia Gilat Fatty acid bile acid conjugates (FABACs) are a new family of synthetic molecules designed to solubilize biliary cholesterol. They were shown to prevent and dissolve cholesterol gallstones in inbred C57L/J mice fed a lithogenic, high-fat diet (HFD). In these mice, fatty liver was observed in the controls but not in the FABAC-treated ones. The present study was designed to study the effect of FABAC (arachidyl-amido-cholanoic acid) on diet-induced fatty liver in rats, hamsters, and mice. The fatty liver score (on a scale of 0-4 by light microscopy) was 4.0 in control hamsters and 0.3 in the FABAC-fed hamsters (P < .001). In mice it was 1.5 and 0.4, respectively (P < .01). The lipid/protein ratio in the liver was 1.3 ± 0.44 (mg lipid/mg protein) in control rats and 0.66 ± 0.04 in the FABAC group (P = .001) after 14 days. In hamsters it was 1.41 ± 0.27 and 1.11 ± 0.20, respectively (P = .03), after 21 days. In Imperial Charles River (ICR) mice the ratio was 0.34 ± 0.10 and 0.17 ± 0.07 (P = .03), respectively, after 24 days. Liver fat concentration, measured as mg lipid/g liver tissue, decreased similarly by FABAC feeding. The decrease in liver fat affected mainly the triglyceride levels. FABAC-fed animals gained weight similarly to the controls. Triglyceride absorption was unaffected by FABAC supplementation. In conclusion, oral FABAC therapy prevents/reduces the development of fatty liver in animals consuming a HFD. [source] Assessing levels of contaminants in breast milk: methodological issues and a framework for future researchPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 1 2008Mary J. Renfrew Summary To assess the scale of the possible exposure by the breast-fed infant to potentially harmful substances in breast milk, methodologically robust studies are essential. Many studies in this field, however, do not report details of crucial issues such as recruitment and milk sampling. The aims of the study reported here were to develop robust methods for the study of contaminants in breast milk, and to develop a framework for future research and population monitoring. Three cohorts of women and babies were recruited by midwives from five sites in northern England. Cohort 1 (cross-sectional, n = 322) were asked to provide two milk samples, one at one week following birth and one at a subsequent time point. Cohort 2 (longitudinal, n = 54) were asked to provide five samples at specified time points over the first 12,16 weeks after birth. Cohort 3 (convenience, n = 18), mothers of babies in the Special Care Unit, were asked to donate surplus breast milk. A novel method of analysing fat concentration in small volumes was developed and tested. A randomly selected set of samples from different donors and stages of lactation was screened for organochlorine pesticide residues, polychlorinated biphenyls, dioxins/furans, phthalates and heavy metals. A total of 453 samples were donated. Cohort 3 was the least successful route of recruitment. Cohorts 1 and 2 combined were most representative of the population. Sample collection, transport and storage procedures, and the collection of data on life style and diet, were robust and acceptable to women. Midwifery involvement in recruitment was an essential component. This study offers a framework both for the conduct of future research studies, and for the establishment of regional and national monitoring mechanisms for contaminants in breast milk. Similar work on contaminants in formula as fed to babies is needed to inform risk assessment methods. [source] Lactose Synthase Components in Milk: Concentrations of ,-Lactalbumin and ,1,4-Galactosyltransferase in Milk of Cows from Several Breeds at Various Stages of LactationREPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2009GT Bleck Contents It is believed that milk production is determined by the number and activity of mammary secretory cells. Secretory activity, as assessed by milk volume, depends on secretion of the major osmole in milk, lactose, which is produced by lactose synthase. The amount of either of the two proteins in lactose synthase may regulate milk production. The objective of this study was to determine whether the concentrations in milk of the two components of lactose synthase, ,-lactalbumin (,-LA) and ,1,4-galactosyltransferase (B4GALT), were related to genetic background, stage of lactation, breed or parity of dairy cows. ,-Lactalbumin and B4GALT concentrations were measured by ELISA and by enzyme assays, respectively, from single milk samples. Two herds with a total of 279 cows were used in the analysis. One herd contained Ayrshire, Brown Swiss, Holstein and Jersey cows; the second herd contained two groups of cows; Holsteins selected for high milk production and Holsteins with 1960s genetics. The ,-LA concentration in milk was greater in Jerseys and Ayrshires than in Holsteins and Brown Swiss. However, no difference in ,-LA concentration was observed in milk from high and low genetic merit cows in the Minnesota herd or among different genetic backgrounds in the Illinois herd. ,1,4-Galactosyltransferase concentrations were similar for all groups that were analyzed. ,-Lactalbumin concentrations were positively correlated with milk protein concentration, milk fat concentration and lactose concentration. ,1,4-Galactosyltransferase concentration in milk exhibited a strong positive correlation with number of days in milk. Although the concentration of B4GALT increased as lactation progressed, the values did not show any correlation with persistency of lactation or late lactation milk production. In conclusion, this survey shows that the two components of lactose synthase are each correlated to protein concentration and individually correlated to the concentration of other milk components and stage of lactation. [source] Milk composition varies in relation to the presence and abundance of Balantidium coli in the mother in captive rhesus macaques (Macaca mulatta)AMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2007Katherine Hinde Abstract Primate infants require extensive maternal investment, and lactation is the most expensive aspect of this investment. However, the relationship between maternal condition and milk composition has been largely uninvestigated in primates. To better understand this relationship, I collected mid-lactation milk samples from 46 captive multiparous rhesus macaques (Macaca mulatta) at the Caribbean Primate Research Center, Sabana Seca Field Station, Puerto Rico. The maternal variables assessed were age, weight, weight for crown,rump length (CRL), and presence of parasites. Additionally the analysis included infant age, weight, and sex. Protein concentration in milk showed little interindividual variation, whereas fat had a high variance. Mothers without the lower intestinal parasite Balantidium coli had a significantly higher fat concentration in milk than mothers with B. coli, but other parasite species (Trichuris trichiura and Strongyloides fulleborni) were not associated with milk fat concentration. Females with younger infants had a higher fat concentration in their milk than mothers with older infants; however, the association between B. coli and milk fat remained significant after controlling for infant age. These results, obtained from a well fed captive population, indicate that even small differences among mothers are associated with milk composition. Am. J. Primatol. 69:625,634, 2007. © 2007 Wiley Liss, Inc. [source] Substrate oxidation and retention in pigs and poultryANIMAL SCIENCE JOURNAL, Issue 2 2002André CHWALIBOG ABSTRACT A model combining data from gas exchange measurements with nutrient balances, demonstrating energy transfer between the pools of protein, carbohydrate and fat and their partition in the body, is described. Data from energy metabolism experiments with growing pigs and laying hens is incorporated into the model in order to illustrate methods of calculations and interpretations of the model. The experiments with pigs were carried out with growing pigs (20,100 kg) measured alternately on high (ad libitum) and low (near maintenance) feed levels on diets with low or high fat concentration. When energy intake from digested carbohydrate covered the requirements for growth, heat from oxidation of carbohydrate contributed 85,90% to the total heat production, while there was no net oxidation of fat. When the intake of digested carbohydrate was not sufficient to cover requirements, fat was mobilized from the body and oxidized. Energy from oxidation of carbohydrate was in all measurements below the energy in the carbohydrate pool, indicating transfer of energy from carbohydrate to fat metabolism in the process of de novo lipogeneis. The experiments with hens were carried out with 62 hens during the laying period from 26 to 47 weeks of age. The hens originated from two strains (A and B); they were kept in battery cages either individually or 3 hens/cage and fed ad libitum with an identical commercial diet. The partition of the protein pool between oxidation and retention was not influenced by the housing system. However, the genetic origin of hens effected protein utilization with relatively lower oxidation and higher retention in Strain B. The main part of the carbohydrate pool was oxidized (45,60%), but the hens kept individually oxidized more carbohydrate than those kept 3 hens/cage. Further, there were significant differences between the strains. Generally, about half of the fat pool originated from de novo lipogenesis from carbohydrate, indicating the importance of this process for fat retention in eggs. Fat oxidation depended on the energy supply from carbohydrate, hence with higher use of carbohydrate for oxidation in Strain B less fat was oxidized and more was used for fat synthesis. The presented results indicate that by combining results from gas exchange measurements with nitrogen and energy balances it is possible to evaluate the contribution of nutrients to the oxidative processes and the energy transfer between substrate pools. [source] Effect of feed composition and feeding frequency on growth, feed utilization and nutrient retention in juvenile Atlantic cod, Gadus morhua L.AQUACULTURE NUTRITION, Issue 6 2004G. Rosenlund Abstract Juvenile Atlantic cod (Gadus morhua) were fed extruded feeds formulated to contain 360,660 g kg,1 protein, 80,280 g kg,1 lipid and 80,180 g kg,1 starch at feeding frequencies of either once per day or every second day to satiation. The trial was conducted at 8 °C and lasted for 28 weeks during which fish were weighed five times at regular intervals. Sampling for proximate analysis was performed at the start, after 12 weeks and at the end of the trial. Fish grew from an average weight of 192 g to between 750 and 866 g, with growth being negatively affected by low dietary protein concentration. High dietary starch concentrations had some negative effects on growth, whereas changes in dietary fat concentration had no significant effect on growth. Liver indices (at the end of the experiment) varied between 80 and 170 g kg,1, and there was a negative correlation between the ratio of protein to fat and liver index. Feed conversion ratio (FCR) ranged between 0.74 and 0.88, and feed utilization improved with increasing concentrations of dietary protein and fat. Increasing dietary starch concentrations resulted in poorer feed utilization. To achieve good growth and protein retention, and avoid excessive liver size in juvenile cod, feeds should contain 500,600 g kg,1 crude protein, 130,200 g kg,1 lipid and <150 g kg,1 starch. [source] Protein to carbohydrate ratio in high-energy diets for Atlantic salmon (Salmo salar L.)AQUACULTURE RESEARCH, Issue 7 2001Marie Hillestad Abstract The effect of dietary protein to carbohydrate ratios (P/CH, weight percentage) of P34/CH21, P39/CH15 and P44/CH10 was studied in Atlantic salmon (Salmo salar L.) with respect to growth and feed conversion ratio (FCR) in one medium-scale experiment (Experiment 1) and to slaughter quality in two production scale experiments (Experiments 2A and 2B). The dietary fat was maintained at 290 g kg,1 whereas the protein (fish meal) was exchanged with carbohydrate (wheat). Fish grown from approximately 1 to 4 kg were fed a restricted diet (iso-energetic on gross energy basis) or to satiation. Nitrogen, fat, starch and energy digestibilities were measured in a separate experiment. There were slight tendencies for lower growth (P = 0.06) and for higher FCRs (P = 0.06) in Experiment 1, and a slight tendency for a lower dress-out percentage in Experiments 2A and 2B (P = 0.10 and 0.20 respectively) with decreasing P/CH. The P/CH had no effect on the fat concentration of fillets, flesh colour or sexual maturation. The digestibility of starch decreased from 62.1% to 46.1% and the digestibility of energy from 84.9% to 79.5% when P/CH decreased from P44/CH10 to P34/CH21. Growth per unit digestible protein increased with decreasing P/CH. Feeding to satiation improved the growth but the FCR was higher than it was for restricted feeding. The calculated starch load per kg of fish growth increased with decreasing P/CH, whereas the effluent nitrogen decreased. [source] Long-term Administration of Rapamycin Reduces Adiposity, but Impairs Glucose Tolerance in High-Fat Diet-fed KK/HlJ MiceBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2009Geng-Ruei Chang In this study, we investigated the metabolic effects of rapamycin in an obese animal model, KK/HlJ mice. Mice were treated with a daily intraperitoneal injection of rapamycin at 2 mg/kg or vehicle for 42 days on a high-fat diet. Treated mice lost body weight and adiposity, reduced weight gain and retroperitoneal and epididymal fat pads/body weight, decreased serum leptin and plasma triglyceride levels and had lower liver fat concentration. However, treated mice had higher serum insulin levels and food intake. Dissection of rapamycin-treated mice revealed a marked reduction in fatty liver scores and fat cell size in retroperitoneal and epididymal adipocytes. Moreover, Western blot analysis revealed that rapamycin treatment resulted in decreasing adipophilin expression, as a marker of lipid accumulation, and reducing phosphorylation of mTOR downstream targets S6K1 compared to control group. Unfortunately, rapamycin-treated animals showed a marked decline in glucose tolerance as judged by the 180-min. area under the curve for plasma glucose levels, paralleled by increased generation of plasma reactive oxygen species. These results suggest that continual rapamycin administration may help to prevent diet-induced obesity, while prolonged use of rapamycin may exacerbate glucose intolerance. [source] Mechanical and fracture properties for predicting cracking in semi-sweet biscuitsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 4 2005Qasim Saleem Summary Mechanical and fracture properties required for predicting crack development in semi-sweet (,rich tea') biscuits have been experimentally determined. Pilot-scale biscuits of different fat concentrations were prepared and studied with commercial biscuits at different moisture contents. Bending modulus, fracture stress and strain were measured using three-point bending tests. All biscuit types showed considerable dependence on moisture content over a range of 4,12%. Young's modulus and failure stress showed a uniform decrease and failure strain showed an increase with increasing moisture content. For pilot-scale biscuits of different fat concentrations, an increase in fat level caused a decrease in modulus and failure stress values; however, the failure strains were very similar for all the fat types. The testing of the samples with top surface up and top surface down revealed that the sample orientation does not affect the measured parameters. The measured parameters also did not show any directional dependence within the plane, thus assuring that the assumption of an isotropic material would be valid for modelling. The mechanical and fracture properties measured in this study will serve as a very useful set of data to predict the stress state and cracking of the checked biscuits. [source] Do changes in Atlantic salmon, Salmo salar L., fillet fatty acids following a dietary switch represent wash-out or dilution?AQUACULTURE RESEARCH, Issue 13 2003Test of a dilution model, its application Abstract The fatty acid compositions of fish tissue lipids usually reflect those of the feed lipids, but few attempts have been made to predict the way in which the profiles change or assess the time required for the fatty acid profile to stabilize following a dietary change. The present focus on the influences of vegetable oils and fish oils on the fatty acid compositions and sensory attributes of fish fillets increases the interest in the ability to make such predictions. A dilution model was tested using data for the influences of feed oils (rape/linseed (V) vs. sand-eel (F)) and dietary fat concentrations (ca. 30% (H) vs. ca. 20% (L)) on the body growth and fatty acid compositions of the fillets of Atlantic salmon, Salmo salar L., parr and post smolt. Fish given HV or LV feeds during freshwater rearing (mass increase from ca. 19 g to ca. 130 g) were switched to HF and LF feeds following parr,smolt transformation. The changes in fillet percentages of 18:1, 18:2 (n-6) and 18:3 (n-3) during 98 days of on-growing in seawater (mass increase from ca. 130 g to ca. 380 g) conformed closely to predictions made on the basis of the dilution model. Model applications require information about the proportionate increase in fillet fat over time, but the relative changes in body mass can be used as a surrogate provided that both fillet yield (as a % of body mass) and fillet fat percentage change little over time. This is not the case for small salmon, but does seem to apply to larger salmon as they approach harvest size. This means that, for large salmon, ratios of changes in body mass can be substituted for ratios in the quantitative change in fillet fat without the introduction of a large error in the prediction of the change in fillet fatty acid profile following the introduction of a novel feed. [source] | ||||||||||||||||