Changes in body composition of germ-free and conventional chickens during starvation

• 1.1. Changes in body composition during starvation were compared between germ-free (GF) and conventionalized (CVL) chicks in experiment 1. At 8 days of age, the GF birds were divided into two groups, i.e. GF and CVL groups. The CVL birds were inoculated with faeces from conventionally reared birds. Until 14 days of age, both birds were fed a diet ad lib, and thereafter starved for 6 days.
• 2.2. Nitrogen loss during starvation was significantly lower in CVL birds, though the reverse was true for water loss. Fasting heat production was comparable between two environments.
• 3.3. Influence of the gut microflora on body weight and nitrogen losses during starvation was investigated in birds prefed diets high or low in dietary protein in experiment 2.
• 4.4. No significant effect of the gut microflora was observed in body weight and nitrogen losses. Body weight was severely reduced in birds prefed the high protein diet and nitrogen loss was lower in birds prefed the low protein diet.

     

Responses of channel catfish (Ictalurus punctatus) swim-up fry to dietary calcium in soft and hard water

• 1.1. Responses of channel catfish (Ictalurus punctatus) swim-up fry to dietary calcium in soft (< 1 mg/1 as CaCO₃) and hard (> 100 mg/1 as CaCO₃) water were determined by feeding purified egg-white diets containing 0, 0.5, 1.0, or 2.0% calcium from CaCO₃ for 8 weeks.
• 2.2. Catfish fry fed the basal diet (0.03% Ca) in hard and soft water had lower whole-body ash and whole-body calcium concentrations but higher weight gain and survival than those fed calcium-supplemented diets.
• 3.3. Fry in soft water generally had lower whole-body ash, whole-body calcium, and survival, as well as a higher incidence of spinal deformities than fry in hard water.
• 4.4. Feeding higher levels of calcium to fry reared in soft water did not increase whole-body calcium levels or decrease spinal deformities to the levels observed for fry reared in hard water and fed supplemental calcium.
• 5.5. These data indicate that calcium derived solely from dietary or environmental sources was not sufficient for optimum health of channel catfish fry.

     

Effects on growth and respiration due to the ingestion of the rapeseed meal glucosinolates in young larvae of Tenebrio molitor

• 1.1. We investigated the effects of the ingestion of naturally occurring glucosinolates in rapeseed meal on growth rate, metabolic efficiency and respiratory rate in larvae of the yellow mealworm, Tenebrio molitor L.
• 2.2. In our feeding studies, larvae were reared on one of seven different diets, including a whole ground wheat control diet and rapeseed meal from six rapeseed varieties. Dry weight gain of larvae and dry food assimilated were measured after 4 weeks of rearing, and the conversion of food into insect biomass was determined. The results may be explained by variations in the glucosinolates content of the diets.
• 3.3. The effect of glucosinolates on food consumption, larval growth, expired carbon dioxide, oxygen uptake and respiratory quotient were studied.
• 4.4. Glucosinolates did not reduce food assimilation or growth after 1 day of experimentation, but they caused some inhibition of respiratory exchanges and increased the RQ ratio.

     

Adaptive changes in total pyruvate dehydrogenase activity in lipogenic tissues of rats fed high-sucrose or high-fat diets

• 1.1. Pyruvate dehydrogenase complex (PDC) activity was measured in several tissues of rats fed for 7 or 15 days on control, or high-sucrose or high-fat diets.
• 2.2. Total activity in adipose tissue increased in the three groups 3–4-fold as compared with chow-fed animals in the first week. Total activity was 60% lower in rats fed the diet containing 22% corn oil for 2 weeks.
• 3.3. Hepatic total and PDCa activities were 50–80% higher in rats fed the sucrose diet for 7 or 15 days and decreased 30–40% in those fed on the high-fat diet for 2 weeks.

     

Studies on the enzymatic activities related to varied pattern of diets in the air-breathing cat fish,clarias batrachus (Linn.)

1. Specific activity of amylase, cellulase, protease and lipase in the intestines of the air-breathing catfish, Clarias batrachus (Linn.) has been studied.
2. Excepting amylase and protease, the activity of lipase and cellulase showed practically no changes with change in the nutritional status of the diets.
3. pH optima of all enzymes were between 6.9 and 7.6
4. There is reason to believe from cellulase and high amylase activity in the intestine of the species that its culture operation could be done more economically by giving them a supplementary diet from indigeneously available raw material particularly from plant origin.

     

Food consumption,assimilation and rate of food passage in the cape rock elephant shrew,Elephantulus edwardii (macroscelidea: Macroscelidinae)

• 1.1. Food consumption, assimilation and passage rates of an elephant shrew, Elephantulus edwardii, on three natural diets (cockroaches, locusts and termites) and one artificial cereal diet (Pronutro) were compared.
• 2.2. Daily food consumption varies significantly between the diets and was partly related to % assimilation, which was highest on Pronutro and cockroaches (71%) and lowest on termites (31%).
• 3.3. Throughput times were estimated using soluble (⁵¹ Cr-EDTA) and particulate markers in the Pronutro diet. First appearance of the soluble marker (0.5 hr) was significantly earlier than for the particulate marker (1.85 hr); 50% appeared at 3.2 and 3.35 hr for the soluble and particulate markers, respectively.
• 4.4. The distribution of particulate markers in the digestive tract showed some retention in the stomach, ileum and colon, but rapid movement through the duodenum and very little entry to the caecum.

     

Serum and urine biochemical indicators of nutritional status in adult female collared peccaries,Tayassu tajacu (tayassuidae)

• 1.1. Physiological responses of 13 adult female collared peccaries (Tayassu tajacu) to high quality and low quality diets, fed for 15 weeks, were examined. The low quality diet simulated energy and protein intake of peccaries during poor range conditions resulting from drought. Blood samples were collected after 10 and 15 weeks of dietary treatment; urine samples were collected after 15 weeks of treatment.
• 2.2. Females receiving the low quality diet for 15 weeks lost 27.4% of their original body weight, compared to no weight change among high quality-fed females.
• 3.3. Red blood cell counts, hematocrits, and hemoglobin concentrations were significantly greater among females fed a high quality diet compared to those receiving a low quality diet. High quality-fed females also had a higher mean corpuscular hemoglobin concentration. Plasma fibrinogen concentration was nearly twice as great among females receiving the low quality diet compared to the high quality group.
• 4.4. Consumption of the low quality diet resulted in significantly elevated serum levels of nonesterified fatty acids, alkaline phosphatase, phosphorus, alpha-2 globulin and alpha globulin: beta globulin ratio.
• 5.5. Consumption of the low quality diet resulted in significantly lowered serum levels of urea nitrogen, calcium, zinc, calcium: phosphorus, urea index, beta-1 flobulin, beta globulin: albumin ratio, thyroxine and triiodothyronine.
• 6.6. Serum levels ofcreatinine, total bilirubin, glucose, cholesterol, gamma glutamyltransferase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, potassium, copper, magnesium, sodium chloride, total protein and gamma globulin were unaffected by diet quality.
• 7.7. Urine chemistry results suggested pH, osmolarity, albumin, creatinine phosphokinase, calcium and phosphorus concentrations might be useful indices for assessing nutritional status in female peccaries.

     

Effects of high dietary methionine on activities of selected enzymes in the liver of kittens (felis domesticus)

• 1.1. Growing male kittens were fed an 18% casein diet supplemented with 2, 3, or 4% l-methionine (MET) for 6 weeks.
• 2.2. Free MET concentration in liver increased 30-fold and cystathionine two- to three-fold; the activity of adenosyl-MET transferase and cystathionase also increased but remained lower than previously found in rats.
• 3.3. Taurine concentration in liver decreased in cats fed excess MET and appeared to depend on taurine intake.
• 4.4. Alanine aminotransferase activity was high in all groups while serine dehydratase activity was very low.
• 5.5. Pyruvate kinase and malic enzyme activities which are normally low in cat liver increased after excess MET. Also, glucose 6-phosphate and 6-phosphogluconate dehydrogenases increased.
• 6.6. Cat liver metabolism showed limited adaptation to an excess dietary intake of methionine compared to that found in rats.

     

Lipid digestion in cod (gadus morhua)

• 1.1. Cod, 2.6–3.4 kg. were fed a mixed diet of sprat, capelin oil and wheat flour.
• 2.2. Lipids from the feed, stomach and four intestinal segments were separated into tri-, di- and monoglycerides and free fatty acids and analysed by GLC.
• 3.3. All lipolytic products were concentrated in 14:0, 16:0 and 18:0, up to 60% and extremely low in the ω-3 fatty acids.
• 4.4. Residual triglycerides contained 80% of saturated and monoenoic fatty acids.
• 5.5. Linoleic acid increased from 2% in feed TG to 10% in TG of the rectum.

     

A comparison of aspartate transcarbamylase activity in juvenile pacific oysters (Crassostrea gigas) when fed various diets

• 1.1. The optimum pH for measurement of aspartate transcarbamylase activity in oyster tissue was determined to be 9.35 while the optimum temperature was 39.5°C.
• 2.2. Aspartate transcarbamylase activity varied significantly over short periods of time (hr) possibly due to fluctuations in the amount of food digested.
• 3.3. The composition of the oyster's diet also affected the levels of aspartate transcarbamylase activity in oyster tissues.
• 4.4. Those oysters fed an egg yolk-starch diet contained significantly lower aspartate transcarbamylase activity than oysters fed an egg yolk-starch-salmon oil diet or a casein-starch-salmon oil diet.
• 5.5. The aspartate transcarbamylase activities in oysters fed Phacedactylum tricornutum or a starch diet were not significantly different from the activities in oysters fed the egg yolk-starch diet.

     

Effects of starvation and a carbohydrate-rich diet on glycogen metabolism in a gastropod mollusc,Megalobulimus oblongus

• 1.1. Administration of a carbohydrate-rich diet increased haemolymph glucose levels and glycogen concentration in hepatopancreas, mantle and muscle.
• 2.2. Glycogen concentration in tissues decreases after 2 weeks of starvation and haemolymph glucose levels did not change significantly.
• 3.3. However, starvation did not induce a decrease in the intrinsic synthetic capacity in tissues.
• 4.4. Glycogen synthesis in tissues from animals fed with lettuce or a carbohydrate-rich diet, increases with increasing glucose concentration in the media.
• 5.5. However, in mantle slices from snails adapted on a carbohydrate-rich diet, the glycogen synthetic capacity was lower than in slices from snails fed with lettuce.

     

Differential post-receptor responses of adenylate cyclase in white and brown adipose tissue membranes of rats fed high-energy diets

• 1.1. Adenylate cyclase activity was determined in membranes of white and brown adipose tissue (WAT and BAT, respectively) from rats fed a high-energy diet (EXP group) vs those fed a nutritionally balanced one (CON group).
• 2.2. The isoproterenol- and guanine nucleotide-induced adenylate cyclase activity in WAT membranes of EXP rats was lower than that in CON rats.
• 3.3. Relative adenylate cyclase activity in like treated BAT membranes was higher in EXP than in CON rats.
• 4.4. It is concluded that feeding high-energy diets to rats induces similar post-receptor modifications of adenylate cyclase as found in genetic obese rodents.

     

Effects of soluble corn bran hemicellulose on lipid metabolism

• 1.1. Since soluble corn bran hemicellulose (CBH) was found to reduce serum cholesterol level in the rat fed with a high cholesterol diet, rats were fed with diets containing orotic acid (OA) to investigate the effect of CBH on lipid metabolism.
• 2.2. Hepatic lipid accumulation induced by OA was reduced by feeding with CBH in rats. The reduction was not due to inhibition of intestinal absorption of OA by CBH.
• 3.3. Administration of acetate or propionate, colonie fermentation products of CBH, tended to alleviate the hepatic lipid accumulation by OA in rats.
• 4.4. OA feeding decreased activities of some hepatic enzymes involved in fatty acid synthesis except for acetyl CoA carboxylase. The decreases were reversed by the concurrent feeding of CBH.

     

The effect of starvation on energy turnover and protein metabolism in Ophiocephalus punctatus bloch

1. At 20°C, fish starved for various durations took less food than unstarved fish. At 28°C, 20-day starved fish alone consumed more food.
2. The maximum feeding was during the second ten days at 28°C but in the first ten days at 20°C.
3. Absorption efficiency was unaffected by temperature and starvation.
4. Absorption rate reflected feeding rate.
5. At 28°C the conversion efficiency was high for the ten-day starved fish but at 20°C the 30-day starved fish showe high conversion efficiency.
6. Conversion rate is governed not only by feeding rate but also by conversion efficiency.
7. At 28°C the 20-day starved fish alone compensated for loss of energy, total and protein nitrogen. At 20°C the loss was compensated for by all fish.

     

In vitro substrate utilization for lipid synthesis in liver explants from hyperthyroid chickens

• 1.1. Indian River male broiler chickens growing from 7 to 28 days of age were fed diets containing 12, 18, 24 and 30% protein + 0 or 1 mg triiodothyronine (T₃)/kg of diet to study energetic costs of lipogenesis and the use of various substrates for in vitro lipogenesis.
• 2.2. De novo lipid and CO₂ production were determined in the presence of [1-¹⁴C]pyruvate, [2-¹⁴q]pyruvate, [3-¹⁴C]pyruvate, [2-¹⁴C]acetate and [U-¹⁴C]alanine.
• 3.3. Oxygen consumption was determined in mitochondrial preparations to estimate the energetic costs in expiants synthesizing lipid.
• 4.4. Radiolabeled CO₂ derived from [1-¹⁴C]pyruvate was used as an estimate of coenzyme A availability in liver expiants. Lipids derived from [2-¹⁴C]pyruvate, [2-¹⁴C]acetate and [U-¹⁴C]alanine estimate relative substrate efficiency.
• 5.5. Labeled CO₂ production from [1-¹⁴C]pyruvate was greatest in that group fed a 12% protein diet and least in the group fed a 30% protein diet.
• 6.6. In addition, T₃ increased CO₂ production from [1-¹⁴C]pyruvate.
• 7.7. The production of ¹⁴CO₂ from the second carbon of pyruvate or acetate was increased by T₃.
• 8.8. The low-protein diet (12% protein) increased (P <0.05) lipogenesis.
• 9.9. Adding T₃ to the diets decreased carbon flux into lipid from all substrates, but increased CO₂ production from all substrates without changing stage 3 and 4 respiration rates in mitochondrial preparations.
• 10.10. These observations imply that coenzyme A availability may have regulated de novo lipogenesis in the present study.
• 11.11. It was also concluded that previously noted effects of T₃ on intermediary metabolism may involve metabolic pathways that do not involve changes in mitochondrial function.

     

Specific dynamic action (SDA) in the supralittoral isopod,Ligia pallasii: Identification of components of apparent SDA and effects of dietary amino acid quality and content on SDA

• 1.1. Specific Dynamic Action (SDA) effects of diet were investigated in the supralittoral isopod, Ligia pallasii, using defined chemical diets.
• 2.2. “Apparent SDA”, or the total rise in metabolic rate following a meal, was resolved in animals eating a nutritionally complete chemical diet into three components: 8% mechanical costs of moving food through the gut, 40% “excitement costs” due to investigator disturbance and presence of food, and 52% SDA.
• 3.3. Excitement costs in animals exposed to food but which chose not to eat showed non-significant variation between diets containing different levels of chemical nutrients, but were significantly less on a diet containing only cellulose and agar.
• 4.4. SDA increased with increasing concentration of amino acids in the diet.
• 5.5. Substitution of whole-protein casein for free amino acids in the diet had no significant SDA effect, while substitution of free amino acids in the ratio found in casein more than doubled the SDA effect.
• 6.6. Deletion of alanine from the diet caused no significant effect on SDA, while deletion of phenylalanine caused a highly significant elevation in SDA.

     

Effect of dietary d-amino acids on growth,survival, ammonia excretion and specific dynamic action in the supralittoral isopod,Ligia pallasii

• 1.1. Growth, survival, ammonia excretion and Specific Dynamic Action (SDA) were assessed in the supralittoral isopod Ligia pallasii eating chemical diets with differing proportions of d- and l-amino acids. Growth and survival decreased in direct proportion to increasing dietary intake of d-amino acids.
• 2.2. Survival on diets with greater than 50% content of d-amino acids (based on total amino acids in diet) was lower than that expected based on previous work, suggesting a deleterious effect of the d-isomers.
• 3.3. Ammonia excretion and SDA correlated negatively with increasing dietary content of d-amino acids.
• 4.4. The general conclusion is that d-amino acids play no role in anabolic or energy metabolism in Ligia, and that poor performance at higher dietary levels of d-amino acids may relate to their interference with transport pathways for the normal l-forms.

     

Lipoxygenase and other enzymes of arachidonic acid metabolism in the brain of chicks affected by nutritional encephalomalacia

• 1.1. Prostaglandin endoperoxide synthetase (PES) and lipoxygenase (Lox) activities were compared in the cerebella and cerebra of vitamin E-sufficient young chicks and in chicks in which nutritional encephalomalacia (NE) was induced by a diet deficient in vitamin E.
• 2.2. Eicosanoid production patterns were qualitatively similar in the brains of both groups of chicks, but prostaglandin production was 50–60% less in cerebella of ataxic chicks, compared to control cerebella, while the opposite trend was observed in the cerebellar Lox pathway, as measured by radioimmunoassay of 15-HETE.
• 3.3. Cerebellar phospholipase A, activity was twice that of the cerebrum but was not affected by NE.
• 4.4. Purification of Lox activity from the cerebellar homogenates produced a lower yield and enrichment when the starting material was taken from ataxic chicks, compared to the controls.
• 5.5. In addition there were qualitative differences in the purified fractions from both groups, as seen by pH optima and kinetics.
• 6.6. The results are consistent with the view that the cerebellum has less antioxidant protection than the cerebrum and that its higher phospholipase A₂ activity and greater propensity to oxygenate arachidonic acid via the Lox pathway at the expense of the PES pathway may render this region of the brain particularly vulnerable to oxidative damage in NE.

     

Studies on intestinal protease: Isolation,purification and effect of dietary proteins on alkaline protease activity of the air-breathing fish,Clarias batrachus (Linn.)

1. The effect of dietary protein levels on the proteolytic activity in the intestines of the air-breathing fish, Clarias batrachus (Linn.) has been studied
2. Activity of proteolytic enzymes increased significantly in fishes maintained with a 50% protein diet from those maintained with a 25% protein diet; still higher dietary protein percentage showed no further stimulation of enzyme activity.
3. In a study on the determination of sub-cellular localisation, it has been found that protease activity is more prominent in lysosomes than in other organelles of the cell.
4. A sixty fold purification of alkaline protease from the intestine of Clarias batrachus has been achieved by ion exchange chromatography on DEAE cellulose which has been further checked by polyacrylamide gel electrophoresis.

     

Effect of temperature and diet on polyamine concentrations of the European sea bass (Dicentrarchus labrax L.)

• 1.1. A fall of environmental temperature causes a decrease in total polyamine concentrations of heart, red and white muscles of sea bass fed on a diet containing 70% herring meal (diet S).
• 2.2. When sea bass was fed with a diet partially replaced by casein (diet A), an increase of total polyamine concentration in liver and heart was observed at a lower temperature.
• 3.3. In all tissues studied an increase of putrescine concentrations and a parallel decrease of spermidine and spermidine levels were found for both groups S and A of sea bass when the temperature was lowered.
• 4.4. In general concentrations of putrescine, spermidine and spermine were considerably higher in group A when the temperature was lowered.