Interaction Of Dietary Protein Research Articles

Growth performance, jejunum morphology and mucin-2 gene expression of broiler Japanese quails fed low-protein diets supplemented with threonine

The present experiment was conducted to examine the effects of threonine supplementation in low-protein diets on growth performance, jejunum morphology, and mucin-2 gene expression in meat-type Japanese quails. A total of 800 broiler quails were assigned to 8 dietary treatments based on a factorial arrangement (2 × 4) across 1-35-day period. Experimental treatments consisted diets with 180 g/kg (CP180), 200 g/kg (CP200), 220 g/kg (CP220), and 240 g/kg (CP240) crude protein content each supplemented with 100% and 110% threonine requirement of broiler quails. Growth performance of broiler quails was not affected by interaction of dietary protein and threonine contents while daily weight gain was higher in birds received CP240 than those given CP180 and CP200 (p < .05). Carcase yield increased in response to consumption of diets with 200 g/kg protein content and 110% threonine requirement compared to those receiving the other dietary treatments (p < .05) except for birds in CP240 group. Villus height to crypt depth ratio was higher in birds subjected to CP200 and CP240 each supplemented with 100% and 110% threonine requirement of quails, respectively, than the other groups (p < .05). Digestibility of protein was not affected by experimental treatments. Expression of mucin-2 gene decreased by dietary supplementing graded levels of protein (p < .05) while increased by graded levels of threonine (p < .05). In conclusion, reduction of dietary protein content did not affect the growth of broiler quails whenever diets added with 100% of their digestible threonine requirement. Furthermore, dietary protein content below 220 g/kg adversely affected DWG of quails. Highlights Reduction of dietary CP content did not affect the growth of broiler quails whenever diets added with 100% of their threonine requirement. Morphology of the small intestine was influenced by variations in dietary energy and protein contents. Expression of mucin-2 gene decreased when quails fed on diets with graded levels of CP while increased with graded levels of threonine.

Interaction of dietary protein and energy-protein ratio on growth performance of snakehead Channa striata

ABSTRACTThe study proposed to discover the optimum protein content and energy-protein ratio in practical diet for snakehead, Channa striata. The experiment applied complete randomized design, consisted of six treatments with four replications on each treatment. The treatments were: A (32.5%; 11.82 kcal GE/g), B (32.5%; 13.32 kcal GE/g), C (37.17%; 10.64 kcal GE/g), D (37.33%; 12.07 kcal GE/g), E (43.08%; 10.02 kcal GE/g), and F (42.88%; 10.66 kcal GE/g). Snakehead with average weight of 6.21 ± 0.03 g were reared for 8 weeks. The treatments showed significant results. Increased protein dietary level had increased the growth rate and treatment with high energy-protein ratio at the same protein dietary level provided better growth performance. However, increased energy-protein ratio at E and F treatments caused a decline in growth performance. The improvement of energy-protein dietary ratio had positive correlation with the level of lipid and protein content in fish body. Similar finding was found in liver and muscle glycogen. The results also showed that the increament of energy-protein dietary ratio was significantly and positively correlated with cholesterol, triglyceride, HDL, glucose, and albumin, yet it had no significant effect on LDL. It can be concluded that excellent growth performance was achieved by protein dietary level of 37.33% and energy-protein ratio of 12.07 kcal GE/g.Keywords: energy-protein ratio, growth, snakehead ABSTRAKPenelitian ini bertujuan untuk memperoleh kadar protein dan rasio energi-protein pakan buatan yang optimum bagi performa pertumbuhan ikan gabus. Penelitian ini mengaplikasikan rancangan acak lengkap dengan 6 perlakuan, yaitu: A (32,78%;11,82 kkal GE/g), B (32,56%;13,32 kkal GE/g), C (37,17%:10,64 kkal GE/g), D (37,33%:12,07 kkal GE/g), E (43,08%:10,02 kkal GE/g), dan F (42,88%:10,66 kkal GE/g) dan masing-masing terdiri 4 ulangan. Bobot rata-rata ikan gabus yang digunakan dalam penelitian ini yaitu 6,21 ± 0,03 g dan dipelihara selama 8 minggu. Hasil penelitian menunjukkan bahwa peningkatan kadar protein pakan meningkatkan laju pertumbuhan, dan perlakuan dengan rasio energi-protein tinggi pada level protein pakan yang sama memberikan kinerja pertumbuhan yang lebih baik. Namun demikian, pada perlakuan E dan F, peningkatan rasio energi-protein menyebabkan penurunan kinerja pertumbuhan. Peningkatan rasio energi-protein pakan berkorelasi positif terhadap kadar lemak dan protein tubuh ikan. Hal yang sama juga terjadi pada glikogen hati dan otot. Hasil penelitian juga menunjukkan bahwa peningkatan rasio energi-protein pakan berpengaruh nyata (P&lt;0,05) dan berkorelasi positif terhadap kolesterol, trigliserida, HDL, dan albumin, tetapi tidak berpengaruh nyata terhadap LDL (P&gt;0.05). Kesimpulan yang didapat adalah kinerja pertumbuhan optimal dihasilkan oleh kadar protein pakan 37,33% dan rasio energi protein pakan 12,07 kkal GE/g.Kata kunci: albumin, energi, ikan gabus, pertumbuhan, protein

The effect of dietary sericin on rats

Dietary proteins have been reported to be beneficial for lipid metabolism, tissue growth, development, and repair, as well as immune response. The interactions of dietary proteins and their digested products may regulate the physiology and metabolism of the gastrointestinal tract. However, proteins are largely digested before reaching the large intestine. The present study investigated the use of the non-dietary protein, silk sericin, in rats. Rats were fed either with casein or sericin proteins. Their body weight, food consumption, and complete blood count were measured. The results showed that during the experimental periods, rats fed with casein and sericin diets had no significant changes on body weight, food consumption, or complete blood count. Sericin-fed rats had a significantly decreased CD8a and CD80 positive cells when compared with standard casein protein. In conclusion, dietary proteins may have a differential impact on the leukocyte profile. The mechanisms underlying these changes are not clear but they might be due to the different amino acid compositions of the proteins studied.

Effect of Dietary Protein and Lipid Levels on Growth and Nutrient Utilization of Freshwater Angelfish Pterophyllum scalare

Nine semi-purified diets containing three levels of protein (300, 350, 400 g/kg) and three levels of lipid (60, 80, 100 g/kg) were fed ad libitum to juvenile freshwater angelfish Pterophyllum scalare (1.64±0.01 g) to determine the optimum dietary protein and lipid levels. Fish were stocked in 27 flow-through fiber-reinforced plastic tanks with 100 l water (10 fish/replicate) and fed 60 days. Fish were batch-weighed every 15 days to determine growth. The dietary protein level had a significant effect on protein efficiency rate (PER) but not on weight gain, feed conversion ratio (FCR), or specific growth rate (SGR). In contrast, the dietary lipid level had a significant effect on weight gain, FCR, and SGR but not on PER. The interaction of dietary protein and lipid had a significant effect on weight gain, FCR, SGR, and PER. No protein-sparing effect of the lipid was observed. Fish fed the diet containing 300 g protein and 60 g lipid per kg diet had a significantly better weight gain, SGR, PER, and FCR.

Nutrition interacts with parasitism to influence growth and physiology of the insectManduca sextaL.

The influence and interaction of dietary protein:carbohydrate balance and parasitism by Cotesia congregata on nutrient intake and growth were examined over the last two larval stadia of Manduca sexta. Effects of nutritional status on host blood metabolite concentrations were also determined. Six fat-free chemically defined diets were tested, each having the same total level of casein and sucrose, but with casein to sucrose ratios varying from low protein/high carbohydrate to equal levels of both nutrients through to high protein/no carbohydrate. Nutrient ratio and parasitism each affected nutrient consumption and growth. Feeding responses differed between normal and parasitized larvae, as illustrated by nutrient arrays, two-dimensional plots of protein and carbohydrate consumption on diets having different nutrient ratios. Normal larvae consumed more nutrients and took longer to develop as dietary nutrient ratio was displaced from equal levels of both nutrients. Except on the diet having the same amount of protein and carbohydrate, parasitized larvae consumed less nutrients than normal larvae, although on all diets parasitized larvae took longer to develop. When the contribution of parasite biomass was excluded, parasitized larvae showed lower mass gain than normal larvae on all diets. Total mass gain by normal and parasitized larvae with parasite biomass included, however, was similar on diets having intermediate nutrient ratios. Differences in mass gain between diets relative to nutrient consumption were evident from multi-dimensional representations of mass gain with protein and carbohydrate consumption. Three-dimensional plots and contour maps of normal and parasitized larvae were different. When differences in nutrient consumption between diets were taken into account, protein consumption had a greater effect on growth than carbohydrate consumption and normal larvae generally displayed greater mass gain than parasitized larvae on the same diets. Utilization efficiency, the efficiency of conversion of ingested food to body mass, was, therefore, generally reduced in parasitized insects. Concentrations of blood protein, total free amino acids and trehalose were each influenced by dietary nutrient ratio and parasitism. Concentrations of protein and free amino acids generally increased and trehalose concentration decreased as dietary protein increased and carbohydrate decreased. The opposite was the case as dietary carbohydrate increased and protein decreased. Dietary nutrient ratio, however, affected normal and parasitized larvae differently. Parasitized larvae had higher overall trehalose concentrations while normal larvae had higher protein and total free amino acid concentrations. When differences in nutrient consumption between diets were accounted for, protein consumption had a greater effect on blood protein and free amino acid concentrations than did dietary nutrient ratio or parasitism. Protein consumption, however, did not affect trehalose concentration. Carbohydrate consumption had no effect on the concentration of any of the metabolites after differences in nutrient consumption were taken into account. Effects of nutrient consumption on trehalose concentration, therefore, were due to dietary nutrient ratio and parasitism. The potential relevance of the above findings to the biology of parasitized M. sexta larvae is discussed.

Effects of feeding program and crude protein intake during rearing on fertility of broiler breeder females

Arbor Acres broiler breeder pullets were grown from hatch to 24 wk on one of four feeding programs that achieved similar cumulative intakes of ME and CP at 24 wk, but not 20 wk (photostimulation), in Experiment 1. Graphing the four programs in terms of feed per bird per day by week of age gave the general shapes of linear, convex, concave, and deeply concave with respect to 0 and 24 wk reference points. The linear program, which achieved 1,192 g CP at 20 wk (photostimulation), as compared to < 1,150 g CP for the two concave programs, exhibited the best fertility. Although the pullets reared on the convex program consumed 1,255 g CP, fertility was poor, probably due to the reduced rate of increase in feed allocation late in rearing that delayed oviduct development. In Experiment 2, pullets were fed to the same cumulative ME intake at 20 wk using either a concave or convex feeding program with respect to 0 and 20 wk reference points with two levels of dietary protein. The higher level of CP intake (1,363 vs 1,212 g) produced higher fertility. A significant feeding program by dietary protein interaction was found. Level of CP intake at photostimulation had no effect on fertility with the concave feeding program but the convex program decreased fertility at the lower CP intake as in Experiment 1.

Immune competence, resistance to Escherichia coli and growth in male broiler parent chicks fed different levels of crude protein.

Immune competence, resistance to Escherichia coli and growth were measured in female chicks of broiler male parent lines from four different commercial sources. These chicks were fed with three levels of dietary crude protein (CP) from day-old. The protein contents in the diets were 18%, 20.5% and 23%; these diets are referred to as the low-, medium- and high-protein diets, respectively. There was a significant genotype by dietary protein interaction for body weight at 35 days of age but not at 14 or 28 days of age. At 14 days of age, the chicks fed on the high-protein diet weighed significantly more than those fed on the low-protein diet, but there were no differences between the chicks fed on the medium-and low-protein diets. The influence of CP content on body weight had disappeared by 28 days of age. There were significant differences between the genotypes-in antibody production in response to sheep red blood cell (SRBC) inoculation, but no such differences were observed between the chicks fed the different levels of dietary protein. Chicks fed on the high-protein diet had lower lesion scores following E. coli inoculation than those fed on the low-protein diet. There were also significant differences in lesion scores among the genotypes. Genotypes with heavier body weights had significantly higher lesion scores and lower antibody titres than those with less body weight. Also, genotypes of lower body weight had a greater cutaneous basophilic hypersensitivity response to phytohaemaglutinin-P inoculation, and a better humoral response against SRBC and a lower heterophil to lymphocyte ratio.

Interaction of Dietary Protein and Alpha-Linolenic Acid on Polyunsaturated Fatty Acid Composition of Liver Microsomal Phospholipids and Eicosanoid Production in Streptozotocin-lnduced Diabetic Rats

The effect of dietary protein, either casein (CAS) or soybean protein (SOY), on the polyunsaturated fatty acid (PUFA) composition of liver microsomal phospholipids and eicosanoid production was compared in normal and streptozotocin-induced diabetic rats fed diets containing perilla oil rich in alpha-linolenic acid. In normal rats the linoleic acid desaturation index in liver microsomal phospholipids was significantly higher in the CAS group than in the SOY group, whereas it was reversed in diabetic rats. The proportion of eicosapentaenoic acid (EPA) decreased in diabetic rats, in particular those fed SOY, whereas it was vice versa for arachidonic acid (AA). The ratio of aortic prostacyclin production to platelet thromboxane A2 production decreased only in diabetic rats fed SOY reflecting a reduction of the EPA/AA ratio. Thus, dietary protein differently modified the PUFA composition and eicosanoid balance even in the diabetic rat. In this respect, alpha-linolenic acid seemed to be less influential than linoleic acid.

Interaction of Dietary Protein and Fat on Plasma Cholesterol and Amino Acid Levels, Fatty Acid Desaturation, and Prostacyclin Production in Exogenous Hypercholesterolemic Rats

The interaction of dietary protein, casein (CAS) or soybean protein (SOY), and fats (perilla oil high in α-linolenic acid or safflower oil high in linoleic acid) on various lipid parameters and plasma amino acids was studied in a rat model sensitive to dietary cholesterol (exogenous hypercholesterolemic (ExHC) rats). The hypolipidemic effect of SOY in comparison with that of CAS was confirmed in this model irrespective of the fat source. Thus, the hypocholesterolemic effect of SOY appeared to be intrinsic. However, the effects of dietary protein on the fatty acid composition of tissue phospholipids, Δ6 desaturase activity in liver microsomes and aortic prostacyclin production were marginal. An analysis of plasma amino acids suggests a regulatory role of specific amino acid(s) in the hypocholesterolemic effect of SOY.

Interaction of dietary protein, cholesterol and age on lipid metabolism of the rat.

1. Male rats at 1 (young) and 9 months (adult) of age were fed on purified diets, supplemented with or without cholesterol, containing 200 g protein/kg (casein (CAS), whey protein (WHY) or soya-bean protein (SOY] for 4 weeks. 2. SOY exerted a hypocholesterolaemic effect in young rats regardless of dietary cholesterol, whereas in adult rats it was observed only when a cholesterol-enriched diet was given. WHY was also hypocholesterolaemic in rats of both ages given cholesterol. SOY tended to reduce the liver cholesterol both in young and adult rats. 3. The liver hydroxymethylglutaryl-CoA reductase (NADPH) (EC 1.1.1.34) activity tended to be lower in the vegetable-protein groups than in the animal-protein groups in young rats, but the age-related reduction was observed only in the latter groups. 4. There was no significant age-related difference in the activity of liver cholesterol 7 alpha-monooxygenase (EC 1.14.13.17) in response to diets. However, when cholesterol was given, activity tended to decrease with age. Rats given SOY excreted more faecal steroids than those given casein, particularly adult rats. 5. The fatty acid profile of phosphatidylcholine and the delta 6-desaturase activity of liver microsomes indicated the reduced desaturation of linoleate in the SOY and WHY groups compared with the CAS groups. 6. The results thus showed a complex interaction of protein type, cholesterol and age on cholesterol homeostasis.

Protein-fat interaction on the cholesterol level and fatty acid desaturation in rats consuming alcohol.

The interaction of dietary protein (casein, soybean protein and milk whey protein) and fat (mold oil containing γ-linolenic acid, palm olein and safflower oil) on various lipid parameters were studied in rats consuming alcohol. Alcohol reduced the hypocholesterolemic effect of soybean protein and whey protein compared with casein. Safflower oil, compared with palm olein, reduced the plasma and liver cholesterol levels, whereas the effects of mold oil and palm olein were comparable. Casein promoted the desaturation of linoleic acid in the liver phosphatidylcholine compared with soybean protein; the effect of whey protein was comparable with that of casein. The aortic production of prostacyclin (PGI2) was significantly higher in the casein group than in the soybean protein group, whereas dietary fat did not influence the protein effect. The effect of whey protein on the plasma concentration of prostaglandin E2 was comparable with that of casein. Thus, different dietary proteins differently influenced variou...

Biochemical observations on rat aorta: interaction of dietary protein and cholesterol.

1. The effect of cholesterol feeding during and after a period of protein malnutrition lasting 4 weeks was examined in the rat. Indices measured were plasma total cholesterol, triglycerides and protein levels, and aorta total cholesterol, triglycerides, hexosamine and hydroxyproline concentrations. 2. In both plasma and aorta, total cholesterol and triglycerides levels were higher in the low-protein diet group than in the standard-protein diet group, when cholesterol was supplied in both diets. 3. During the malnutrition period, cholesterol feeding led to a greater decrease in plasma protein than that promoted by the low-protein diet without cholesterol, while aorta hexosamine levels decreased to a lesser extent. 4. Cholesterol feeding with a standard-protein diet promoted a slight and temporary increase in aorta hydroxyproline levels, while a decrease in aorta hexosamine concentration was observed. Cholesterol feeding with the low-protein diet, on the other hand, also promoted a decrease in aorta hexosamine levels but to a lesser extent. 5. During the recovery period, cholesterol feeding impaired the return of plasma protein, aorta hexosamine and lipid levels to that of the control values. 6. These findings demonstrate that cholesterol feeding promotes different changes in aorta and plasma, depending on whether or not protein is supplied by the diet in adequate amounts. This point could be important in relation to the development of atherosclerosis during recovery from a period of malnutrition.

Interaction of dietary protein and trypsin inhibitor on plasma cholecystokinin and pancreatic growth in rats.

Pancreatic exocrine secretion in the rat is inhibited by trypsin, chymotrypsin and elastase in the proximal small intestine (Green and Lyman, 1972; Schneeman and Lyman, 1973; Green and Levan, 1985). Recent studies have supported the hypothesis that this negative feedback control of pancreatic secretion is mediated by cholecystokinin (CCK). Orogastric administration of trypsin inhibitors to rats caused a transient reduction of intestinal levels of CCK (Brand and Morgan, 1981) and greatly increased plasma levels of CCK (Liddle, Goldfine and Williams, 1984). Diversion of bile-pancreatic juice from the intestine increased plasma CCK levels, which were returned to normal by intraduodenal infusion of trypsin (Louie et al, 1985; Fölsh et al, 1984). The mechanism by which pancreatic proteases inhibit CCK release is not known. Miyasaka and Green (1983) hypothesized that trypsin inhibited pancreatic secretion by inactivating an intraluminally-secreted peptide, possibly a CCK-releasing factor.

Interactions of dietary proteins with the mucosal immune system as a component of safety evaluation

Recent and historical data suggest that the interaction of antigenic materials, including food proteins, with the mucosal immune system is an important component of certain diseases, causative either of an important manifestation of or the disease itself. The adequacy of existing knowledge concerning digestion and absorption of dietary proteins, disposition of absorbed antigens, and potential adverse effects to meet requirements of a safety evaluation is addressed. Currently, the immunological consequences of introducing new food proteins (e.g., leaf and bean protein concentrates), new processing technologies (food irradiation, chemical sterilization), and changes in traditional foods through emerging technologies (genetic engineering) can be neither predicted nor routinely measured.

Interaction of Dietary Protein with Cellulose in the Adaptation to Caloric Dilution by Weanling Rats

The adaptive response of food intake to increasing levels of dietary cellulose was studied in weanling rats fed limiting amounts of dietary protein of different qualities. At low levels of dietary cellulose, the food intake depends on protein quality. As the cellulose levels were increased, the diet and gross energy digestibilities diminished, yielding diets with lower digestible energy contents. The rats fed the higher quality protein were able to compensate for this caloric dilution, increasing their food consumption enough to keep constant their digestible energy intake. The animals fed a lower quality protein, however, were unable to make this adaptive increase in food intake. As a result, although gross food intake remained stable, cellulose constituted an increasing proportion of it and the digestible energy consumption of these animals diminished. Water consumption in this trial appears to reflect the animal's digestible energy intake rather than cellulose consumption. The above observations may be considered as an indication that a smooth regulation of the energy intake occurs only with a complete or non-deficient diet and that deficient, abnormal or unusual diets upset this process. In the present experimental situation, when dietary protein is inadequate, the animal can no longer make appropriate compensatory increases in its food consumption to keep its digestible energy intake constant.cellulose dietary protein caloric dilution food intake

The effect of reproduction on the interaction of dietary protein and calcium

1. Rats were maintained from the age of 3 weeks until the end of a second reproductive cycle on diets having different protein values and Ca concentrations. 2. Reproductive performance was judged from the number of viable young, their size, body composition and rate of growth during suckling. 3. The size and quality of the bones of the mothers and offspring were assessed from radiographs, histological appearance, total weight of ash, ash/cm3and ash:organic matter ratios of dry fat-free bone. 4. At the end of gestation the mean numbers and total weights of foetuses were low when the mothers had received diets of low protein value: there were smaller differences in the body-weight, water, ash and N contents of the individual foetuses. 5. When 0.44% Ca was included in the diet of low protein value, only one (three rats) of the six litters born survived beyond 1 week of age. 6. At weaning, the young born of and suckled by the protein-calorie deficient dams were only about half the weight of those from mothers receiving the high-protein diets; Ca deficiency produced relatively minor changes. 7. All the mothers lost weight during lactation irrespective of the protein value or Ca concentration of the diet; their bones had lower radiographic densities and less ash/cm3than is usual in non-pregnant rats of similar age. 8. The interaction of protein and Ca and their relative importance in maintaining the skeletal structure of mother and offspring during pregnancy and lactation are discussed.