Acute Effect of Protein or Carbohydrate Breakfasts on Human Cerebrospinal Fluid Monoamine Precursor and Metabolite Levels

Patients with normal pressure hydrocephalus who had three lumbar punctures during 1 week ingested either water, a protein breakfast, or a carbohydrate breakfast 2.5 h before each of the lumbar punctures. The CSF was analyzed for biogenic amine precursors and metabolites. The protein meal raised CSF tyrosine levels, a finding consistent with animal data, but did not alter those of tryptophan or any of the biogenic amine metabolites. The carbohydrate meal increased CSF 3-methoxy-4-hydroxyphenylethylene glycol, an unexplained finding. The carbohydrate meal did not affect CSF tryptophan, tyrosine, 5-hydroxyindoleacetic acid, or homovanillic acid. Our results support the idea that in humans protein or carbohydrate meals do not alter plasma amino acid levels sufficiently to cause appreciable changes in CNS tryptophan levels or 5-hydroxytryptamine synthesis.     

Autogeny and endocrine involvement in the reproduction of tropical flesh flies (Diptera: Sarcophagidae)

Autogeny is highly developed among the Sarcophagidae in tropical Africa. Unlike their temperate region relatives, the tropical species examined can mature the first batch of eggs without an adult protein meal, and they do so without the long period of delay usually seen in autogenous species. Protein deprivation, however, does reduce the number of eggs matured by about one-third. The tropical and temperate flies appear to share a common endocrine mechanism controlling egg maturation. Removal of the medial neurosecretory cells of the pars intercerebralis prevents egg maturation. Reimplantation of clusters of MNC restores the ability to mature eggs. Extirpation of the corpora allata reduces the percentage of females that mature eggs to about 70%, and the females that do mature eggs produce fewer eggs. The significant difference between the tropical and temperate species centers on the trigger that sets the neuroendocrine system into action. For the tropical species, the brain is activated immediately and does not require the trigger of a protein meal.     

Protein digestibility of hydrolyzed hog hair meal for pigs

Thirty-six crossbred castrated male and female pigs, initially averaging 76.2 kg, were used in a nitrogen balance study to determine apparent digestible protein, apparent net protein utilization and apparent biological values of hydrolyzed hog hair (HHH) meal for pigs. The HHH meal contained 93.4% crude protein and 22.6 MJ per kg of gross energy. Digestibility of protein was linearly decreased (P < 0.01) as HHH meal was substituted for 25 and 50% of the maize and soya bean meal protein in a basal diet fortified with minerals and vitamins and containing 14% crude protein. There was a trend for apparent net protein utilization values to decrease and apparent biological values to increase as HHH meal was substituted. Assuming linearity, nitrogen utilization values (%) calculated by difference for HHH meal were: apparent digestible protein, 74.7 ± 1.6; apparent net protein utilization, 44.0 ± 3.4; apparent biological value, 57.2 ± 3.7.     

豆粕和土豆蛋白替代饲料中鱼粉对异育银鲫生长及能量收支的影响

利用全能量收支同步测定呼吸仪系统测定了三种不同蛋白源(鱼粉、豆粕、土豆蛋白)饲料对银鲫生长及能量收支各组分的影响。对照饲料全部以鱼粉为蛋白源,另两种饲料中30％的蛋白质分别来自豆粕和土豆蛋白。试验结果表明,银鲫对三种蛋白源的饲料的摄食率,食物转化效率均有显差异,以鱼粉组最高,豆粕其次,土豆蛋白最低。能量收支各组分也均有显差异,能量收支式如下：鱼粉88．1C=13．77F 2．95U 24．1G 41．8R 豆粕 102．3C=17．1F 2．8U 16．4G 55．4R土豆蛋白105．5C=14．9F 1．3U 14．4G 67．4R式中C、F、U、G、R分别代表摄食能、排粪能、排泄能、生长能、代谢能。     

Meat meal in the diet of the early-weaned pig. I. A comparison of meat meal and soya bean meal

Seventy-two pigs, initially weighing 4–5 kg, were fed on wheat-based diets supplemented with soya bean meal and/or meat meal in two experiments each of 4 weeks' duration.In the first experiment, 0, 25, 50 or 100% replacement of soya bean meal protein supplement with meat meal was associated with a linear decrease in weight gains (341-280 g/d), a linear increase in feed conversion ratios (1.64–2.35) and a linear decrease in apparent digestibility of dry matter (80.1–73.4%). There was no change in the apparent digestibility of nitrogen.In the second experiment, bone meal was added to provide 0.80, 1.55 and 3.05% calcium in diets in which the protein supplements were either soya bean meal or meat meal. The addition of bone meal to the diets containing soya bean meal did not affect the performance of the pigs, but it caused a linear decrease in the apparent digestibility of dry matter, nitrogen and calcium. The addition of bone meal to the diet containing meat meal reduced the feed intakes of the pigs from 617 to 516 g/d and the weight gains from 414 to 324 g/d.Weight gains of pigs were similar when their diets contained soya bean meal or meat meal as the protein supplement in the second experiment when the calcium content of the diets was 0.8%. The meat meal included in the diet was manufactured from soft offal.     

黄颡鱼对四种动物性蛋白原料在不同制粒工艺下的表观消化率研究

实验以三氧化二铬(Cr₂O₃)为外源指示剂,采用“70%基础饲料+30%实验原料”的方法配制实验饲料,测定了初始体质量为(28.68±0.49) g的黄颡鱼(Peltobagrus fulvidraco)对国产鱼粉、进口鱼粉、进口鸡肉粉和脱脂黄粉虫粉在膨化制粒和非膨化制粒两种工艺下的干物质、粗蛋白、粗脂肪和氨基酸表观消化率。结果显示,在非膨化制粒工艺下,黄颡鱼对进口鸡肉粉的干物质表观消化率显著高于另外3种原料(P<0.05),黄颡鱼对黄粉虫粉蛋白消化率最低(P<0.05),黄颡鱼对进口鸡肉粉脂肪表观消化率显著高于国产鱼粉和进口鱼粉(P<0.05); 在膨化制粒工艺下,进口鸡肉粉的干物质表观消化率显著低于另外3种原料(P<0.05),国产鱼粉和进口鱼粉的粗蛋白质消化率达94%以上,显著高于另外两种原料(P<0.05),但进口鸡肉粉的脂肪表观消化率显著低于其他原料(P<0.05)。在非膨化制粒工艺和膨化制粒工艺下国产鱼粉、进口鱼粉和黄粉虫粉的干物质表观消化率无显著性差异,但在非膨化制粒工艺下进口鸡肉粉的干物质表观消化率显著高于膨化制粒工艺(P<0.05)。对于国产鱼粉、进口鱼粉和黄粉虫粉而言,非膨化制粒工艺的蛋白消化率显著低于膨化制粒工艺(P<0.05),而鸡肉粉则相反。膨化加工工艺进口鱼粉的脂肪表观消化率显著高于非膨化加工工艺(P<0.05),而膨化加工工艺的黄粉虫脂肪表观消化率显著低于非膨化加工工艺(P<0.05)。氨基酸的消化率结果与粗蛋白的表观消化率变化趋势基本一致。由此可知,对于黄颡鱼饲料,国产鱼粉和进口鱼粉是最佳的蛋白质来源,进口鸡肉粉和黄粉虫亦可以作为其优质的蛋白质来源。对于进口鱼粉、国产鱼粉和黄粉虫粉,膨化制粒工艺更有利于黄颡鱼对其干物质、蛋白、脂肪和氨基酸等营养元素的消化利用,而对于进口鸡肉粉,非膨化制粒工艺更有利于黄颡鱼对营养元素的消化利用。     

Elimination of protein-food ingested into the crop, and failure of ovarian development in female mosquitoes, Culex pipiens pollens.

ABSTRACT. Sugar-free egg albumin solution was 'force fed' to female C.pipiens pallens Coquillett, by first stimulating their labella briefly with 1.0 M sucrose, so that they then took the protein meal into the crop. This protein-food was nevertheless easily eliminated by the females, totally undigested, so that it failed to activate oogenesis, just as sugared albumin fails to do so also.     

Apparent digestion coefficients for dry matter, protein and essential amino acids in terrestrial ingredients for Pacific shrimp Litopenaeus vannamei (Decapoda: Penaeidae)

Protein quality mainly depends on the essential amino acid (EAA) profile, but also on its bioavailability, because EAA digestibility is generally lower than the analyzed amounts. This information is needed in the aquaculture industry for aquafeed formulation. For this purpose, the apparent digestibility coefficients of dry matter, protein, and essential amino acids of eight feedstuffs of terrestrial origin were determined for the juvenile whiteleg shrimp Litopenaeus vannamei (15-19 g), using 1% chromic oxide as an inert marker. A reference diet was formulated and produced in the laboratory. Eight experimental diets were prepared each with 30% of one of the experimental ingredients added to the reference diet: casein, porcine byproduct meal poultry byproduct meal, corn meal, wheat gluten meal, soybean paste, sorghum meal, and wheat meal. The experiment consisted of a single-factor, completely randomized design with three replicates per treatment. Samples of ingredients, diets and feces were analyzed for nitrogen and amino acids. For amino acid assay, we used reverse-phase high performance liquid chromatography. To avoid partial loss of methionine and cystine, samples of ingredients, diets, and feces were oxidized with performic acid to methionine sulfone and cysteic acid prior to acid hydrolysis. The apparent dry matter and protein digestive utilization coefficients varied from 68% to 109% and from 70% to 103%, respectively. Apparent digestibility of protein for casein, soy paste, wheat meal and wheat gluten were very high (over 90%), corn gluten and poultry byproducts meal showed high protein digestibility (over 80%), but porcine byproducts meal and sorghum meal had low digestibility (76% and 70%, respectively). There was a reasonable, but not total, correspondence between apparent protein digestibility and average essential amino acid digestibility coefficients, except for arginine in corn gluten, phenylalanine and leucine in sorghum meal, phenylalanine in soy paste and lysine in wheat meal and poultry by-product meal. The most digestible feed ingredients for whiteleg shrimp were: wheat gluten, wheat meal and soy paste; poultry byproduct meal and corn gluten were less digestible and the lowest digestibility occurred in porcine byproduct meal and sorghum meal. Feedstuffs exhibited great variability in dry matter, protein and amino acid digestive utilization coefficients, which should be considered when formulating shrimp feeds.     

Role and Metabolism of Free Leucine in Skeletal Muscle in Protein Sparing Action of Dietary Carbohydrate and Fat

Feeding rats with either a carbohydrate meal or a fat meal to the previously fasted rats caused significant decrease in urinary output of urea and total nitrogen. The content of free leucine in skeletal muscle decreased in the rats fed either a carbohydrate meal or a fat meal. Feeding of either a carbohydrate meal or a fat meal stimulated incoiporation of l-leucine-1–¹⁴C into protein fraction of skeletal muscle and reduced its oxidation to ¹⁴CO₂.

These results suggest that the metabolism of leucine is under nutritional regulation and that the decrease in content of free leucine in skeletal muscle might be caused by enhanced reutilization of leucine into protein by the feeding of a carbohydrate meal or a fat meal. The role of free leucine in skeletal muscle as a regulator of protein turnover in the tissue are discussed in relation to the metabolism of this branched chain amino acid.     

Performance of guinea fowl fed hevea seed meal or cashew nut meal as a partial substitute for soya bean meal

Guinea fowl production is increasing in developing countries and has a crucial role in the fight against poverty. However, the feed cost is very high, especially the soya bean meal cost, and farmers cannot afford to buy commercial feed. Consequently, animals do not receive feed adapted to their nutritional needs and they exhibit poor performance. The aim of this paper is to partially substitute soya bean meal by local by-products, discarded, in abundant supply and not used in human nutrition. French Galor guinea fowl (Numida meleagris) and local African guinea fowl (150 birds per breed) were reared for 16 weeks and fed the same starter diet for the initial 4 weeks. From 4 weeks of age, experimental birds from each breed were randomly assigned to three grower isoproteic and isolipidic dietary treatments, each containing five replications (floor pens); each replication included 10 birds of the same breed. The guinea fowl of each breed were fed either control grower diet using soya bean meal as the protein supplement GS, or trial grower diet GN (soya bean meal supplement partially substituted by 15% cashew nut (Anacardium occidentale) meal) or trial grower diet GH (soya bean meal supplement partially substituted by 15% hevea seed (Hevea brasiliensis) meal). The results indicated that hevea seed meal contained a high content of n-3 polyunsaturated fatty acids (PUFAs) (21.2% of total fatty acids (FAs)). The use of hevea seed meal in guinea fowl grower diet was found to exert no adverse effect on growth performance and carcass yield. However, the use of cashew nut meal led to negative effects on performance like daily weight gain and feed conversion ratio. Therefore, cashew nut meal cannot be considered as a suitable partial substitute for soya bean meal in diets. The use of hevea seed meal led to a very low abdominal fat proportion and low blood triglyceride and cholesterol content. Additionally, inclusion of dietary hevea seed meal resulted in guinea fowl meat enriched in PUFAs, especially n-3 FAs, thereby significantly improving the nutritional value.     

Effect of dietary carbohydrate source on soluble protein glucose concentration and enzyme activity (aldolase) of European eels (Anguilla anguilla L.)

This study was undertaken to determine the influence of dietary carbohydrate sources: wheat meal, bread meal, soluble corn starch, native potato starch and sorghum meal, on soluble protein, enzyme activity (aldolase) and glucose concentration in muscle and liver of European eels (Anguilla anguilla). There was less soluble protein in both muscle and liver of eels fed 30% wheat meal or bread meal than the other experimental groups. However, eels fed 30% bread meal or soluble corn starch had a higher glucose concentration in muscle and liver than the other experimental groups. High enzyme activity (aldolase) was found in the liver of eels fed 30% wheat meal, bread meal or soluble starch.     

Postprandial glucose, insulin and glucagon responses to meals with different nutrient compositions in non-insulin-dependent diabetes mellitus

Postprandial glycaemic and hormone responses to meals with different nutrient compositions and their heterogeneity were evaluated in 16 non-insulin-dependent diabetic patients and 5 healthy volunteers. Five kinds of nutrient stimulation--75 g glucose, a Japanese mixed meal (400 kcal, carbohydrate 60%, protein 14%, fat 26%), a high protein meal (300 kcal, C 26%, P 64%, F 10%), a high fat meal (300 kcal, C 23%, P 5%, F 72%) and 20 g iv glucose--was given to each subject. On the average, in both normal and diabetic subjects, the increases in plasma glucose (PG) and insulin (IRI) were the largest with the oral glucose load and the smallest with the high protein meal. The ratio of increase in IRI and PG (sigma delta IRI/sigma delta PG) was the highest with the high protein meal and the lowest with the oral glucose load. sigma delta IRI with the high protein meal and the high fat meal were the same in normal and diabetic subjects. However, each of the 16 NIDDM patients and 5 normal volunteers exhibited a different pattern of response to the nutrient stimuli and no definite subgroup could be classified. There was no correlation between metabolic responses and family history of diabetes mellitus, duration of diabetes, body mass index and fasting plasma glucose. The present results suggest the nearly intact capacity of insulin secretion in NIDDM in response to a high protein or high fat meal and the difficulty of subclassification in NIDDM according to the glycaemic and hormone responses to the different nutrient stimuli.     

不同饲料原料对黄颡鱼表观消化率及消化酶活性的影响

实验研究黄颡鱼(Pelteobagrus fulvidraco)对分别含有豆粕、发酵豆粕、菜粕和发酵菜粕的4种饲料以及这4种原料的干物质、蛋白、能量及氨基酸的表观消化率, 为黄颡鱼饲料的配制提供科学依据, 同时测定不同原料对消化道胰蛋白酶、糜蛋白酶及淀粉酶活性以及血液指标谷丙转氨酶、谷草转氨酶、总蛋白及碱性磷酸酶的影响。结果显示: 黄颡鱼对4种原料的干物质的表观消化率有显著差异, 其利用率由高到低依次为豆粕、发酵豆粕、菜粕及发酵菜粕(P<0.05)。黄颡鱼对发酵菜粕的蛋白质表观消化率显著低于其他3种原料(P<0.05), 而4种原料能量的表观消化率没有显著性差异(P>0.05)。黄颡鱼对各原料蛋氨酸和组氨酸的表观消化率没有显著性差异且低于83%(P>0.05), 而对各原料中其他氨基酸的表观消化率均有显著性差异, 在85%—98%之间, 发酵菜粕各氨基酸的表观消化率显著低于其他3种原料(P<0.05)。胰蛋白酶活力在菜粕组显著高于其他原料组(P<0.05), 活力呈现出前肠>中后肠>胃的趋势, 糜蛋白酶活力在不同原料间无显著差异, 糜蛋白酶活力呈现胃>前肠>中后肠的趋势, 淀粉酶活性呈现前肠>胃>中后肠。血液指标谷草转氨酶在豆粕组显著高于其他原料组(P<0.05), 菜粕与发酵菜粕组最低, 而谷丙转氨酶、总蛋白、碱性磷酸酶在各原料组间没有显著性差异(P>0.05)。综上所述, 豆粕、发酵豆粕、菜粕和发酵菜粕均可以作为黄颡鱼饲料中优质的蛋白源。     

Amino Acid Profile of Escaped Feed Protein After Rumen Incubation and Their Intestinal Digestibility

The crude protein content and amino acid profile of seven feedstuffs (linseed meal, maize gluten meal, rapeseed meal, rapeseed meal protected, soybean meal, fullfat soybean extruded and sunflower meal) were determined before and after ruminal incubation for 16h in three bulls with large rumen cannulas. The intestinal disappearance of amino acids was measured using mobile bag technique. Ruminal incubation affected amino acid profile of all experimental feedstuffs. Crude protein degradation varied from 29.3% for maize gluten meal to 86.4% for rapeseed meal. A tendency towards increased disappearance was observed for glutamic acid, histidine, lysine and proline and decreased disappearance for branched-chain amino acids. The intestinal crude protein digestibility was higher than >80%, except rapeseed meal (66.4%) and sunflower meal (77.8%). The least digestible individual amino acids were methionine and isoleucine in rapeseed meal, histidine and methionine in rapeseed meal protected and arginine in sunflower meal. In general, the lowest amino acid digestibilities were found in feedstuffs with the highest fibre content. The feedstuffs show that they have different potential for supplying of limiting amino acids. Of particular value are the feedstuffs with low crude protein degradability in the rumen and high intestinal digestibility of amino acids.     

Duckweed (Lemna polyrhiza) leaf meal as a source of feedstuff in formulated diets for rohu (Labeo rohita Ham.) fingerlings after fermentation with a fish intestinal bacterium

Eight isonitrogenous (35% crude protein approximately) and isocaloric (4.2 kcal g(-1) approximately) diets were formulated including raw and fermented duckweed (Lemna polyrhiza) leaf meal at 10%, 20%, 30% and 40% levels. A particular bacterial strain (Bacillus sp.) isolated from carp (Cyprinus carpio) intestine and having extracellular amylolytic, cellulolytic, proteolytic and lipolytic activities was used for leaf meal fermentation for 15 days at 37 degrees C. The fibre content of leaf meal reduced from 11.0% to 7.5% and the antinutritional factors, tannin and phytic acid, were reduced from 1.0% to 0.02% and 1.23% to 0.09%, respectively after fermentation. However, the available reducing sugars, free amino acids and fatty acids increased in the fermented leaf meal. The response of rohu, Labeo rohita, fingerlings fed the experimental diets for 80 days was compared with fish fed a fish meal based reference diet. On the basis of growth response, food conversion ratio and protein efficiency ratio, 30% fermented Lemna leaf meal incorporated in the diet resulted in the best performance of rohu fingerlings. In general, growth and feed utilization efficiencies of fish fed fermented leaf meal containing diets were superior to those fed diets containing raw leaf meal. The apparent protein digestibility (APD) decreased with increasing levels of leaf meal irrespective of treatment. The APD for raw leaf meal was lower at all levels of inclusion in comparison to those for the fermented meals. The highest carcass protein and lipid deposition was recorded in fish fed the diet containing 30% fermented leaf meal. The results showed that fermented Lemna leaf meal can be incorporated into carp diets up to 30% level compared to 10% level of raw meal.     

Utilization of copra meal in the formulation of compound diets for rohu, Labeo rohita, fingerlings

Six isonitrogenous (35% crude protein) experimental diets were formulated with raw and soaked de-oiled copra meal substituted for fish meal in the diet at 20, 30 and 40% levels by weight. The tannin content of raw de-oiled copra meal was reduced from 2.4 to 0.9% by soaking it in water for 16 h at room temperature. The response of rohu, Labeo rohita (Hamilton), fingerlings fed these diets for 80 days was compared with fish fed a fish meal-based control diet. On the basis of growth response, food conversion ratio and protein efficiency ratio, the 30% soaked copra meal diet resulted in the best fish performance (P < 0.01). The growth response of the fish was significantly (P < 0.01) affected by both type and inclusion level of the oilseed meal. The growth of fish declined with the increasing level of inclusion of copra meal, irrespective of the type of meal used. The apparent protein digestibilities (APDs) for the raw copra meal were lower at all levels of inclusion in comparison with those for the soaked meals. The highest amount of carcass protein was recorded in the fish fed the diet containing 30% soaked copra meal. The results showed that de-oiled copra meal can be incorporated into carp diets up to 20% in the raw condition and up to 30% in the treated condition without any deleterious effects on growth performance of Labeo rohita fingerlings.     

Nutritive value of rumen contents for monogastric animals

Rumen contents were investigated as a possible feed for farm animals. Although their composition varied to some extent, an average sample contained 21.8% crude protein, 30.3% crude fibre, 6.1% fat and 11.5% ash in the dry matter. Of total crude protein, 73.4% was amino acids. The raw rumen material was dried using the “organic carrier method” by previous mixing with maize meal (3 parts raw rumen contents/1 part maize meal). The product, RM meal (12.5% crude protein, 10.8% crude fibre, 5% fat, 4.9% ash), was used for feeding broiler chicks.The nutritive qualities of dried rumen contents (DRC) were assessed by biological tests on rats. Two levels of DRC (10% and 24%) were included in diets containing blood meal as a protein source and maize (Experiment I). The lower level of DRC (10%) did not reduce the growth rate of young rats (2.4 g/day), but the food consumption was increased. The total body composition of the rats was not changed (55.3% crude protein, 34.1% fat, 9.6% ash). The higher concentration of DRC decreased the growth rates markedly, as well as the apparent digestibility of dry matter and protein, and changed the body composition of rats.The apparent digestibility by rats of rumen protein in a semi-synthetic diet containing 50% DRC (Experiment II) was 44.6% and of dry matter, 56%.The RM meal was given to broiler chicks (0–8 weeks of age) as 23% or 60% of the diet which also contained soya bean meal, blood meal and sunflower meal as protein supplements (Experiment III). The chicks consumed all diets readily. The diet containing 23% RM meal (corresponding to 6.4% DRC) supported a better performance than the control diet. The larger amount of RM meal (corresponding to 17% DRC) reduced the final body weights of chicks.     

Marine ash‐products influence growth and feed utilization when Atlantic cod Gadus morhua L. are fed plant‐based diets

Atlantic cod Gadus morhua L. were fed high plant protein diets added to either shrimp‐shell meal or crab‐shell meal. The aims were to investigate if diluting dietary energy would reduce the liver index (HSI) and if marine ash would add value to plant protein‐based diets. Two control diets were used: a high plant protein control diet (PP) with no marine ash addition, and a fishmeal‐based diet (FM) with no marine ash addition. All diets were evaluated in small cod (initial weight 79 ± 15g) and in market‐size cod (initial weight 1579 ± 20 g). Addition of crab‐shell meal up to 20% and shrimp‐shell meal up to 10% did not influence liver size in either small or market‐size cod. An addition of up to 20% crab‐shell meal and 10% shrimp‐shell meal improved growth compared to the PP control diet, and stimulated increased feed intake. However, 10% shrimp‐shell meal and 20% crab‐shell meal diets resulted in a similar intake of energy and protein as the control groups. Increasing shrimp‐shell meal to 20% resulted in reductions in feed intake, fat digestibility and growth, and in altered gut histology. All diets, except the 20% shrimp added diet, resulted in normal ranges of plasma nutrients and blood hematological values, showing good fish health with or without the marine ash addition.     

Value of lucerne juice and grass juice as sources of protein for the growing pig

Six experiments, involving a total of 282 individually-fed pigs, were completed in which the value of lucerne juice, and in one experiment of grass juice, as a source of protein for the growing pig was determined. The juices were products of a green crop fractionation process.The juice was preserved in three ways and was stored for feeding over several weeks. Pigs weighing up to 54 kg received sufficient juice to replace either all or half of the protein provided by the 7% white-fish meal included in an all-meal control diet. From 54 kg to 90 kg liveweight, juice replaced all of the protein supplied by the 3.5% white-fish meal included in the all-meal diet. In carrying out the replacement, all nutrients in the juice other than protein were ignored.When the juice was given according to its true protein content, as determined every 14 days, and was used to replace 3.5% white-fish meal protein throughout the growing period from 20 to 90 kg liveweight, performance and carcass quality were closely comparable to those of control pigs fed on meal only, and the consumption of white-fish meal was reduced by 70%. When the juice replaced 7% white-fish meal protein, the results were poorer than those of the all-meal control pigs.Satisfactory results were also obtained when the juice was given in conjunction with liquid cheese whey (replacing, on a dry matter basis, 30% of the barley meal in the all-meal control diet).Propionic acid (1%) was ineffective as a preservative of the juice. The addition of 1.4 g/l of sodium metabisulphite together with acidification with HCl to pH 3 significantly reduced the rate of loss of true protein during storage of the juice; if, in addition, the juice was heated to 85°C for a few seconds, loss of true protein over a period of many weeks was negligible.     

Differential effects of dietary flaxseed protein and soy protein on plasma triglyceride and uric acid levels in animal models

The effect of dietary soy protein and flaxseed meal on metabolic parameters was studied in two animal models, F344 rats with normal lipid levels and obese SHR/N-cp rats with elevated levels of cholesterol and triglyceride. The rats were fed AIN 93 diet differing only in the source of protein. The rats were fed either 20% casein, 20% soy protein or 20% flaxseed meal. Plasma was analyzed for cholesterol, triglyceride, uric acid, blood urea nitrogen (BUN), creatinine and total protein. In both strains of rats, flaxseed meal significantly decreased plasma cholesterol and triglyceride concentrations. The effect of soy protein on lipids was not as striking as that of flaxseed meal. Flaxseed meal also lowered uric acid in F344 rats and BUN in SHR/N-cp rats. Since cholesterol, triglyceride and uric acid are independent risk factors for cardiovascular disorders, our data show that both flaxseed meal and soy protein may have beneficial effects. Which chemical constituent(s) of flaxseed meal or soybean is (are) responsible for the beneficial effects need to be identified.