1,720,972 research outputs found
Effect of age and feeding on cholesterol 27-hydroxylase in pigs
Get PDFThe objective of this study was to determined the responses of hepatic mitochondrial cholesterol 27-hydroxylase to nursing in three-week-old suckling piglets and to feeding in 7-week-old weaned piglets. In feeding studies, livers were collected from 59 piglets at 0, 1, 3, and 5 hours after nursing or feeding and from ad libitum-fed piglets. In development studies, livers were collected from 21 ad libitum-fed pigs, which were fetal, suckling, 7-week-old weaned piglets and 12-week-old pigs. Cholesterol 27-hydroxylase activity was determined by incubating isolated mitochondria with 4-¹⁴C-cholesterol and by isolating the 27- hydroxycholesterol via thin-layer chromatography. Fasting for 14 hours decreased cholesterol 27-hydroxylase from 1.071 to 0.162 pmol/min.mg protein in three-week-old suckling piglets and from 1.120 to 0.273 pmol/min.mg protein in seven-week-old weaned piglets. The cholesterol 27-hydroxylase activities increased within 5 hours after fasted piglets nursed or fed, attaining the activities of the ad libitum-fed piglets. Furthermore, fasting decreased the activity of cholesterol 27-hydroxylase was determined. Additionally, the stability of the cholesterol 27-hydroxylase from fresh liver were compared with that of frozen liver and frozen mitochondria homogenates. It was found that the cholesterol 27-hydroxylase was not stable to freezing/thawing. Finally, the effect of age on the activity of cholesterol 27- hydroxylase was investigated. No significant differences in cholesterol 27-hydroxylase activities were detected among pigs of different ages
Effects of dietary CLA on fatty acid composition of egg yolks and [delta]9-, [delta]6-, and [delta]5- desaturase activities of livers of laying hens
No full textConjugated linoleic acid (CLA) alters the fatty acid composition of chicken eggs. It also decreases hepatic stearoyl-CoA desaturase mRNA in HepG2 cells. The fatty acid composition of egg yolks was investigated as a function of amount of dietary CLA for laying hens. In addition, the activities of [Delta]9-, [Delta]6-, and [Delta]5- desaturases in hen liver were investigated as a function of CLA in the diet. Forty-eight Leghorn laying hens were assigned randomly to one of four dietary treatments formulated to contain 0, 1.25, 2.5, and 5.0% CLA. The fatty acid composition of yolk lipids was altered by dietary CLA, with a decrease in unsaturated fatty acids (palmitoleyl, linolenic, and arachidonic acids). The amount of CLA in eggs increased linearly with amount of dietary CLA. [Delta]9- and [Delta]5- Desaturase activities were lower in livers from hens fed the 5% diet than in livers of hens fed the 0% diet. [Delta]6-Desaturase activity was very low in livers of hens in all groups. In summary, dietary CLA decreases the amount of unsaturated fatty acids in chicken eggs with a corresponding decrease in desaturation activity in the hen liver microsomes
Redesigning pork by type and amount of dietary fat for better human nutrition
Get PDFThe objective of this study was to alter the ratio of polyunsaturated to saturated fatty acids of muscular lipids in pork for better human nutrition. Pigs were fed either choice white grease or soybean oil at 10, 20, 30, or 40% of total calories. All diets, including a control diet, were based on corn and soybean meal. The study used 54 pigs with six pigs per treatment. Initial and slaughter weights were 54 and 110 kg, respectively. Skeletal muscle samples were taken from the longissimus dorsi, biceps femoris, and triceps brachii muscles. Adipose tissue sample were taken from the outer, middle, and inner layers of tenth rib backfat, perirenal adipose tissue, and an intermuscular fat deposit within the ham. Total lipids were extracted; fatty acid methyl esters were formed by transesterification and quantified by gas chromatography. Adding choice white grease or soybean oil to diets of growing swine did not alter animal growth rates. The outer layer of 10th rib backfat showed linear increases (P < .05) of polyunsaturated fatty acids when pigs were fed diets with increasing amounts of the soybean oil, whereas the backfat from pigs fed increasing amounts choice white grease resulted in a linear increase (P < .05) of monounsaturated fatty acids. The middle and inner layers of 10th rib backfat tended to contain more saturated fatty acids than did the outer layer. Addition of soybean oil to the low-fat control diet at 30 and 40% increased the ratio of polyunsaturated to saturated fatty acids to .9 and 1.26 (P < .05), respectively, in longissimus muscle. The monounsaturated fatty acids of longissimus muscle were decreased by 30% (P < .05) with the 40% soybean oil diet. Myristate, palmitate, and total saturated fatty acids in longissimus muscle decreased 27 (P < .05), 30 (P < .05), and 29% (P < .05), respectively, with the 40% soybean oil diet. Compositional changes were increasingly less dramatic with the 30, 20, and 10% soybean oil diets. The addition of choice white grease had minimal effects on the ratio of unsaturated to saturated fatty acids of muscular lipids. In conclusion, high fat diets can be used effectively to redesign pork for the health conscious consumer
Effect of stress condition, gender, and dietary dl-alpha-tocopheryl acetate on fatty acid composition and catecholamines in five selected brain regions of pigs
Get PDFThe broad objective of this project is to further define the physiological processes that contribute to the genetic disease in pigs known as porcine stress syndrome. Because several organs are affected by the disease, there exists a need for focus on a specific organ system; I have chosen the central nervous system. Accordingly, this project will focus specifically on certain physiological and biochemical changes that occur in the cerebellum, cortex, substantia nigra, caudate nucleus, and hypothalamus. During episodes of oxidative stress in pigs, reactive oxygen species, such as free radicals, peroxides, and super oxides, increase in concentration in several organs. Tissue damage may occur as a result of the reactive oxygen species, and, in fact, oxidative stress is suspected of being an agent in premature cell death. If this is the case, then increasing the capacity of the antioxidant system of an animal should help prevent the damage caused by reactive oxygen species, even in the central nervous system. Vitamin E is a potent antioxidant that is commercially available and can be incorporated easily in the diet for administration to animals. Absorption of vitamin E occurs efficiently. And the vitamin becomes distributed ubiquitously in tissues. Therefore, an experiment conducted to examine the protective effects of dietary vitamin E is necessary and beneficial because scientists may be able to use the information to delay onset of specific diseases, such as the PSS, by nutritional intervention
Influence of two different dietary fats on the composition of emu oil and meat
Get PDFThe goal of this research was to characterize the chemical composition of emu oil in order toprovide an explanation for alleged medicinal properties of the oil and to test whether two sources of dietary fat affect composition of emu oil and meat. Twenty-four emus, 12 female and 12 male,were fed two diets, one containing soybean oil and the other containing beef tallow, from the age of 8 months until slaughter at approximately 35 kilograms of body weight. The fatty acid composition and phospholipid, sterol, and DHEA/DHEAS contents of oil rendered from subcutaneous and retroperitoneal adipose tissues were determined. Adipose cellularity also was determined. Five different cuts of meat were used to determine the lipid and cholesterol contents of emu meat. Fatty acid composition of the fan cut of meat was determined. Soybean oil fed-emus had a greater percentage of linoleic and linolenic acids in their oil.
The beef tallow fed-emus had a greater percentage of palmitic acid from the retroperitoneal adipose tissue. Females had less palmitic acid in the oil from the subcutaneous adipose tissue. No phospholipids were detected. The only sterol found in the oil was cholesterol, which was present at 29.3 milligrams per 100 grams of subcutaneous adipose tissue and 41.2 milligrams per 100 grams of retroperitoneal adipose tissue. Concentrations of DHEA and DHEAS were not affected by diet, but the female emus had more DHEA. Males emus had larger adipocytes and fewer cells per gram of tissue. The retroperitoneal adipose tissue had larger cells than did the subcutaneous adipose tissue. Emu meat was relatively low in fat (2.2 percent) and cholesterol (32.2 milligrams per 100 grams tissue).
The regular cut of meat had the highest percentage of fat, and the fan cut had the most cholesterol. Diet and gender did not affect the fatty acid composition, cholesterol concentration, or percentage of lipid in the meat. In conclusion, the fatty acid composition of emu oil, but not emu meat, depends on the gender of the emu, source of dietary fat, and the anatomical site of the adipose tissue from which the oil is derived
Hypocholesterolemic effects of orally administrated Eubacterium coprostanoligenes in cynomolgus monkeys
Get PDFOrally administrated E. coprostanoligenes has been shown to decrease blood cholesterol concentrations in cholesterol-fed rabbits. In this study, the safety and efficacy of dietary E. coprostanoligenes to decrease blood cholesterol concentration were evaluated in cynomolgus monkeys. Nine adult male cynomolgus monkeys (Macaca fascicularis) were divided randomly into two groups: group A (five monkeys) and group B (four monkeys). Both groups were fed a hypercholesterolemic diet for 10 weeks. Then, group A received the hypercholesterolemic diet supplemented with E. coprostanoligenes (4 x 1010 cells) daily for 10 weeks and then the hypercholesterolemic diet with the same amount of heat-treated (1200C for 15 minutes) E. coprostanoligenes for another 10 weeks. Group B received the hypercholesterolemic diet with 4 x 1010 heat-treated E. coprostanoligenes daily for 10 weeks and then the same amount of live E. coprostanoligenes for another 10 weeks. No treatment-associated illness or death was observed throughout the experiment. Body weight and body temperature of individual monkeys were normal throughout the experiment. Oral administration of E. coprostanoligenes causes a significant (P < 0.05) decrease in plasma cholesterol in high-response monkeys.
Low response monkeys fed dead E. coprostanoligenes experienced no change (P > 0.05) in blood cholesterol. Feeding E. coprostanoligenes markedly increased the ratio of coprostanol to cholesterol in contents and of mucosal cells of the stomach and all sections of the small and large intestine. Weight ratios of coprostanol to cholesterol in feces also were increased because of feeding the E. coprostanoligenes. Thus, viable E. coprostanoligenes reached the small intestine where they reduced cholesterol to coprostanol, thereby potentially decreasing cholesterol absorption. We hypothesize that this probable decrease in cholesterol absorption caused the observed decrease in blood cholesterol. In general, no adverse effects were shown on animals' general health status, hematology, blood biochemistry, gut mucosal histology parameters, or the incidence of bacterial translocation. These results suggest the use of a dietary supplement of E. coprostanoligenes to decrease the cholesterol in human
Animal Nutritionists at Iowa State University
Get PDFThis research project aims to provide biographical information on previous animal nutritionists at Iowa State University. Educational histories, personal backgrounds, and research interests were collected from personal interviews, printed works, or online publications. This project will supply future animal nutritionists with reference material on their predecessors. In addition, it will provide students with a better understanding of the possibilities for careers and research fields within animal nutrition. It may also foster connections and mentorships between students and prior professors. This information will be printed in a book format, to which information about each successive animal nutritionist may be added upon their retirement
Pork with a high content of polyunsaturated fatty acids lowers LDL-cholesterol in women
Get PDFTwenty women, aged 19-24 with normal plasma lipid levels, were assigned to either a complete diet containing standard pork (STD) or modified pork (MOD). All fat in the diet originated from the pork and lard from pigs fed either a diet containing a high concentration of saturated fatty acidsor a diet containing a high concentration of polyunsaturated fatty acids. After 4 wks of dietary treatment, each group was divided in half. One half continued to be fed either the original STD or MOD diet while the other half of each group was crossed over to the alternate diet. As a percentage of energy, the measured diet composition was 15% protein, 43% carbohydrate and 42% fat. Fatty acid content (FA) of the STD diet was 40% saturated fatty acids (SFA), 45% monounsaturated fatty acids (MUFA) and 15% polyunsaturated fatty acids(PUFA).
Fatty acid content of the MOD diet was 25% SFA, 34% MUFA and 41% PUFA. Plasma total cholesterol and LDL-cholesterol significantly decreased by 8 wks when fed the MOD diet (P [less than or equal to] 0. 0076) and (P [less than or equal to] 0. 0382), respectively. Plasma HDL2-cholesterol in subjects fed the STD diet increased by 8 wks, whereas plasma HDL2-cholesterol decreased in subjects fed the MOD diet (P [less than or equal to] 0.0405). SFA from the plasma cholesterol ester fraction was higher in subjects fed the STD diet, whereas it decreased in those fed the MOD diet. MUFA from the plasma cholesterol ester, free fatty acid, phospholipid and triacylglycerol fractions increased in subjects fed the STD diet and decreased in subjects fed the MOD diet. In the red blood cell phospholipid fraction, MUFA decreased in MOD-fed subjects.
The PUFA of the plasma and red blood cell cholesterol ester, free fatty acid, phospholipid, and triacylglycerol fractions significantly increased in subjects fed the MOD diet. The PUFA from platelets significantly increased in subjects fed the MOD diet. The results indicate that the MOD pork diet significantly lowered plasma total cholesterol and LDL-cholesterol and shifted the fatty acid composition from SFA to PUFA in plasma, platelets and red blood cells
Nucleotide sequence variations in the displacement-loop region of bovine mitochondrial DNA
Get PDFSequence variations in the displacement-loop (D-loop) region of bovine mitochondrial DNA (mtDNA) were determined for 36 Holstein dairy cattle from North Carolina. Mitochondrial DNA was isolated from frozen leukocytes and cleaved into three fragments. The 4.3 kb fragment containing the D-loop region of mtDNA subsequently was cloned into the multicloning region of phagemid vector pUC 119. Two recombinant clones from 36 cows of 18 different maternal lineages; two cows from each of 16 lineages, one cow from one lineage, and three cows from one lineage, were analyzed for sequence variations by using the dideoxy chain termination method. Twenty-two different nucleotide site variations were found in the 18 maternal lineages analyzed. In addition, D-loop mtDNA sequence variations differed between the two maternally related Holsteins in 82 % (14 out of 17) of the maternal lineages analyzed. Heteroplasmic mtDNA, defined as more than one type of mtDNA in an animal, cell, or mitochondrion, was found to exist in 11 % (4 out of 36) of the Holstein cows. Also, a mtDNA segregation marker that was identified previously (Laipis et al., 1988) at nucleotide (nt) 364 was identified but found to vary from as many as 3 nucleotides rather than just 2 nucleotides as described previously. The additional finding of an adenine at nt 364 could affect previously calculated mtDNA segregation rates from these studies. Three new heteroplasmic nucleotide sites at nt 16050 , 16135, and 16200 were identified in the D-loop region of mtDNA of cattle. Comparisons of nucleotide sequence variations in the D-loop from 54 and 36 dairy cattle from Iowa State University and North Carolina State University herds revealed 8 common sites of nucleotide sequence variation. Six of these 8 nucleotide sequence variations have been identified previously as statistically significant with either reproduction, health, or milk production traits in dairy cattle from the Iowa State University herd (Schutz, 1991).
Sequence variations in the displacement-loop (D-loop) region of bovine mitochondrial DNA (mtDNA) have been correlated previously with milk production and reproduction traits in dairy cattle. To further study the effects of mtDNA on reproduction, a technique using the polymerase chain reaction has been developed to allow nucleotide sequence determination of the 0-loop region of mtDNA from a single bovine oocyte. A single oocyte was lysed, and a 1,073base pair fragment containing the entire 0-loop region of bovine mtDNA was amplified by use of the polymerase chain reaction. Verification that the amplified fragment was the 0-loop region of bovine mtDNA was accomplished by direct sequencing of the purified fragment by the dideoxy chain termination method and comparing the sequence with that published for bovine mtDNA. This technique should prove valuable for analysis of bovine mtDNA genotypes from oocytes being used for embryo manipulation technologies such as in vitro fertilization and nuclear transfer
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