Low Protein-high Energy Diets Research Articles

CARCASS QUALITY OF RAW AND SMOKED FISH FILLETS PREPARED FROM CAGE RAISED RIVER CATFISH (Hemibagrus nemurus Valenciennes, 1840) FED HIGH PROTEIN-LOW ENERGY AND LOW PROTEIN-HIGH ENERGY DIETS

The purpose of this study was to evaluate the effect of high protein-low energy and low protein-high energy diet on carcass quality of raw and smoked river catfish fillets. Two diets containing high protein-low energy (40 % protein, 2.75 kcal g–1 energy, diet A) and low protein-high energy (34 % protein, 3.00 kcal·g-1 energy, diet B) which produced the best growth in our previous feeding trial were fed to river catfish. The fish, 40.14 g to 42.64 g in weight were stocked in commercial fish cage at dencity of 50 fish per m3and fed the experimental diets for 90 d. At the end of the experiment, all fish was weighed for weight gain, 20 fish were evaluated for carcass quality and other 20 fish were filleted and hot smoked. Smoked fillets were assessed for smoking yield, proximate composition, sensory quality and overall acceptability. Edible flesh, dressing percentage and flesh water holding capacity of the fresh raw were higher for the fish fed diet A; but carcass waste was higher for the fish fed diet B. Protein composition was higher for the fish fed diet A; however, fat composition was higher for the fish fed diet B. In terms of smoking yield and overall acceptability of smoked fish, there was no difference between smoked fillets prepared from the fish fed the two diets, while appearance and texture were higher for the smoked fillets prepared from fish fed diet A; and odor as well as flavor were higher for smoked fillets prepared from fish fed diet B.

Methylmalonic and propionic aciduria

Methylmalonic and propionic aciduria (PA) are the most frequent forms of branched-chain organic acidurias. These autosomal recessive disorders result from deficient activity of methylmalonyl-CoA mutase and propionyl-CoA carboxylase, respectively. Clinically, acute or chronic neurologic signs are caused by the accumulation of toxic compounds proximal to the metabolic block. Phenotype varies from severe neonatal-onset forms with high mortality and poor outcome to milder forms with a later onset. In both cases the clinical course is dominated by the risk of relapses of life-threatening episodes of metabolic decompensation and of severe organ failure. Despite improvement of treatment, the overall outcome remains disappointing with no major differences between the two diseases. The diagnosis is based on the presence of characteristic compounds in body fluids as detected by organic acid analysis in urine and acylcarnitine profile in blood. Therapy is based on low-protein high-energy diet, carnitine supplementation, and metronidazole. Some patients with methylmalonic aciduria (MMA) respond to pharmacological doses of vitamin B12. Given the poor long-term prognosis, liver transplantation has been recently attempted as an alternative therapy to conventional medical treatment to cure the underlying metabolic defect. Nevertheless, the overall experience to date does not clearly demonstrate its effectiveness in preventing further deterioration or improving survival and quality of life. The recent implementation of neonatal screening by electrospray tandem mass spectrometry has decreased early mortality and improved the short-term outcome, without changing the detection rate of both diseases in the screening population compared to clinically detected cases. However, the limited number of patients and the short duration of their follow-up do not yet permit drawing final conclusions on its effect on the long-term outcome of methylmalonic and propionic acidemia.

Medullation and average fibre diameter vary independently in the wool of Romney sheep

The proportion of medullation was less in wool from a line of Romney sheep selected for High staple tenacity (HST) than in one selected for Low staple tenacity (LST) (1.15% versus 1.58% in 1991‐born ram hoggets, P < 0.076; 1.90% versus 3.10% in 1992‐born ewe hoggets, P< 0.001). This occurred despite the HST line having the greater mean fibre diameter (ram hoggets 35.2 versus 33.1 μm, P < 0.001 ; ewe hoggets 35.1 versus 31.8 μm, P < 0.001 ). Rams from the selection lines were fed diets containing high and low levels of protein and energy. During the treatment period, the high protein diets increased average fibre diameter by 14% (P < 0.001) and the proportion of medullation to 5.6% compared with 3.8% for the low protein diets (P < 0.001). During the post‐treatment period, fibre diameter was 12% higher in the groups fed the high protein diet relative to the low protein diet (P < 0.001), but the proportion of medullation fell to 4.9% for the high protein diets, increased to 4.4% for the low protein low energy diet, and fell slightly for the low protein high energy diet (P < 0.067). The results of these experiments indicate that the proportion of medullation in Romney wool can vary independently of average fibre diameter.

Protein sparing effect and nutritive significance of lipid supplementation in carp diets.

Although carp is in a position to utilize carbohydrates efficiently, lipids are an important energy source in carp diets. In general fat-enriched high-energy diets result in rapid growth and favourable feed conversion. Many authors emphasize the protein-sparing effect of lipid supplementation in carp diets. For efficient protein-utilization an optimal protein/energy ratio in feed is necessary. Good results may be obtained with diets containing 30-50% high-quality protein, > 14 MJ digestible energy/kg and a lipid level of at least 15%. Low protein-high energy diets bring about low nitrogen excretion which is important for maintenance water quality. Lipid-supplemented diets lead to increased lipid content in the carp. Fingerling carp with high fat deposits exhibit an improved overwintering ability. By using fish oil as lipid source it is possible to produce carp meat with high concentrations of n-3 polyunsaturated fatty acids which are beneficial for human health.

Differential effect of age on metabolisable energy content of high protein-low energy and low protein-high energy diets in young broiler chicks.

1. An experiment was carried out with 6-d old male broiler chicks in an attempt to understand better the effect of age on dietary AMEn of high protein-low energy (HPLE) and low protein-high energy (LPHE) diets which are used in the determination of the AMEn content of grains when substituted for the entire diet. The experiment was carried out in a split-plot design in which the effects of 2 diets (HPLE-reference and LPHE-test, containing maize) on food intake, faecal excretion, dietary AMEn and the utilisation of the nutrients were evaluated in 3 age periods (A = 11-13, B = 15-17 and C = 20-22 d of age). 2. Chicks fed on the HPLE diet consumed significantly less food than those fed on the LPHE diet during periods A and B, but not in C. They also produced a significantly larger amount of droppings during periods B and C. Food-to-droppings ratio, which was consistently and significantly lower in chicks fed on the HPLE diet, decreased markedly in period C only in these birds. 3. Absolute and relative retention (RR) of dry matter (DM) and starch, and RR of nitrogen (N) from birds fed on the HPLE diet, were consistently and significantly lower than from those fed on the LPHE diet, but fat retention (absolute and relative) was higher. RR of DM and of N in period C was significantly lower than in periods A and B, while RR of fat and of starch was not affected by age. The effect of age on RR of N was observed only with the HPLE diet. 4. AMEn of the HPLE diet, but not of the LPHE diet, in period C was significantly lower than in periods A and B, resulting in a significant interaction between age and diet and a general reduction with age. The calculated AMEn contents of the maize in periods A and B were essentially the same (14.91 and 14.85 MJ/kg, respectively), and lower than in period C (15.28 MJ/kg). It is concluded, therefore, that because of its effect on AMEn of the HPLE reference diet in chicks older than 17 d, bird age is of considerable importance in the determination of AMEn in grains when substituted for the entire diet.

Divergent Selection for Growth in Japanese Quail Under Split and Complete Nutritional Environments.: 2. Water and Feed Intake Patterns and Abdominal Fat and Carcass Lipid Characteristics

A study was conducted to investigate water and feed intake patterns, abdominal fat and carcass lipid levels, feed efficiency and growth in high (H) and low (L) body weight lines of Japanese quail divergently selected under complete diet (CD) or split diet (SD) environments. Birds under the SD environment could self-select from high-protein low-energy or low-protein high-energy diets. Progeny from both the selected and control (C) lines were evaluated under the SD environment in Generations 6 and 10, and under the CD environment in Generation 10.Under the SD environment, body weights of the H lines were similar as were body weights of the L lines; however, under the CD environment, there were significant differences between H lines and between L lines. Body weights were higher under the CD than under the SD environment. Differences between H and L lines in body weights and 1-wk relative growth rates within SD and CD environments were attributed to differences in water and feed consumption and feed efficiency. Water consumption was greater in the SD than CD environments. Feed consumption was greater in the SD than CD environment from 0 to 2 wk of age; thereafter, feed consumption was higher in the CD environment. Abdominal fat and carcass lipid levels were greater in H than L lines, with the magnitude of the difference greater in the SD environment, indicating that the SD may be a better environment than the CD environment for the study of abdominal fat and carcass lipids in Japanese quail.

Low Protein—High Energy Diet Induces Repressed Transcription of Albumin mRNA in Rat Liver

The effects of diet at the molecular level were investigated by feeding rats control or protein-deficient diets. Each of the control and the protein-deficient groups was further divided into three subgroups according to the level of energy intake. Liver DNA, RNA and total cellular protein concentrations and serum albumin and albumin mRNA concentrations were determined. Protein deficiency caused a marked inhibition of liver growth but the size of most cells remained normal. The low protein diet caused concurrent decreases in the levels of serum albumin and serum albumin mRNA. However, this effect was observed only with the combination of a low protein diet and normal energy intake. The low protein-low energy diet failed to induce the low serum albumin level. Our findings suggest that the altered balance between at least two factors of protein and energy intake serves as a trigger for several metabolic changes which ultimately regulate specific genes.

Development of less-polluting diets for practical fish culture. I. Development of low protein-high energy diets for practical carp culture with special reference to reduction of total nitrogen excretion.

Two feeding experiments were conducted for both practical and experimental scales to develop low-protein high-energy diets (less-polluting diets) for practical carp culture in order to reduce the total nitrogen excretion from the fish. Results of both the experiments have demonstrated that diets containing 32-37% crude protein (CP) with digestible energy (DE) above 340kcal/100g diet enriched with carbohydrate or lipid were found to be better than a commercial cazp diet containing CP above 40% in growth and feed efficiency. This fact indicated that CP content in practical carp feeds can be reduced from 40% to around 30% without reduction of growth rate and feed efficiency, if a high quality protein is used as protein source and DE content is increased by carbohydrate or lipid to about 340kcal/100g diet. The total nitrogen excretion from carp was also found to be reduced by 30-48% of the present value by feeding these low protein-high energy diets.

Development of less-polluting diets for practical fish culture. II. Changes in proximate and fatty acid compositions of carp fed low protein-high energy diets due to starvation during winter.

This experiment was conducted to examine the effect of a low protein-high energy diet or a high protein-high energy diet given to carp kept in net cages in Lake Kasumigaura before winter on the proximate and fatty acid compositions of carp harvested in spring after starvation for 128 days. Condition factor and visceral and gonad somatic indices were not much affected by the quality of diets in terms of the protein and energy levels given to the fish before winter starvation. Decrease of muscle protein and visceral lipid due to starvation suggested that the fish used mainly visceral lipid and muscle protein as energy source and not so much muscle lipid during winter starvation. In the fatty acid compositions of muscle total lipids from carp on each diet, some fatty acids such as 16:0, 20:1 and 22:1 increased, and 18:1 and 18:3ω3 decreased slightly due to starvation. However, there was no marked difference in the fatty acid distribution between males and females in each lot which showed almost the same pattern in changes of the fatty acid profile before and after winter.

Development of practical carp diets for reduction of total nitrogen loading on water environment.

Feeding experiments were conducted twice in practical culture scale to develop practical carp diets which are effective to reduce nitrogen excretion from carp without reduction of growth, feed effciency and increase of feed cost. For this purpose, the experimcntal diets were propared by using locally available low cost ingredients and fed to carp in net cages in Lake Kasumigaura. Results of two experiments suggested that dietary protein level could be reduced from 39% of the official standard for carp feeds in Japan to 30-35% by elevating energy level with carbo-hydrate such as wheat flour or with lipid such as beef tallow. The use of practical ingredients in these experiments resulted in reduction of feed cost. The most suitable protein and digestible energy levels in diets for carp cultured in Lake Kasumigaura to reduce N excretion are suggested to be about 35% and 350 kcal/100g diet. Total nitrogen excretion per ton of carp production was reduced by 22 to 36% of the value from commercial diets with CP above 39% by feeding these low protein-high energy diets.

The effects of defaunation of the rumen on the growth of cattle on low-protein high-energy diets.

1. The effects of defaunation of the rumen of cattle on low-protein diets was studied using animals given free access to a basal diet of liquid molasses and 1500 g oaten straw/head per d. These diets induced moderate numbers of protozoa in the rumen. 2. Nonyl phenol ethoxylate (trade name teric GN9) was used for defaunation; 100 g teric GN9 was found to be sufficient to eliminate protozoa from the rumen. 3. In cattle given the basal diet without bypass protein supplementation, defaunation had no effect on growth rates. Addition of 240 g of a feed pellet containing bypass protein increased growth rate significantly. Growth rates were significantly increased by 43% in cattle on the higher protein intake and where protozoa were removed. Intake of molasses was apparently stimulated by a protein supplementation but not by defaunation and this finding is discussed. 4. The results demonstrate that in cattle given a molasses-based diet, low in bypass protein, growth rates can be stimulated by defaunation without an effect on feed intake, the main effect apparently arising through an increased efficiency of utilization of feed.