Evaluation of the protein quality of rice supplemented with bean or crayfish in rats

Weanling male rats (45–60 g) were used to compare the supplemental effects to rice protein of bean or crayfish protein. Rats were fed various combinations of rice plus bean (B) or crayfish (C) to provide 1.6 g N/100 g of the daily diet for 28-day growth studies and a 7-day N balance period. Five different diets were fed. Six rats were assigned to each diet on the basis of body weight. Combinations of R:B of 80:20 and of R:C of 80:20 produced food intake, weight gain, PER, N intake, digested and retained N; and liver weight values that were comparable. However, increasing C to 30% of the dietary protein led to reduced value for food intake, weight gain, PER, N intake, digested and retained N, BV, NPU, and liver weight when compared with values obtained when B was increased to 30% (P<0.05). The results appear to indicate that, above a certain level of supplementation, brown bean protein is superior to crayfish as a supplement to rice protein.     

Protein and energy utilization of brown,undermilled and milled rices by preschool children

The protein and energy utilization of brown, undermilled and milled rices (variety IR32) were studied in 5–6 preschool children through diets in which 2/3 of N was from rice and 1/3 from casein or milk powder at 200 or 250 mg N/kg body weight. Brown rice was not significantly inferior to milled rice in terms of nitrogen absorption and retention by the children. Its energy and fat contents were, however, less utilized than those of milled rice. Children on the control casein or milk diets showed better apparent nitrogen absorption than those on the rice-based diets but nitrogen retention of all the diets was similar in all three experiments.     

Protein quality of diets based on tuber,legume, and cereal in weanling rats

Weanling male rats (45–55 g) were studied to evaluate the protein quality of diets based on combinations of yam (YA); dehulled brown bean (DBB), dehulled white bean (DWB); and corn flour (PA) that provided 1.6 g N/100 g of diet. Casein served as the reference protein. Rats fed combinations of PA, DBB, and DWB had increases in food intake, weight gain, N intake, digested and retained N, and liver N compared to those of the casein control group and the other test groups (P < 0.05). Supplementation of YA with DBB or DWB reduced weight gain, protein efficiency ratio (PER), N intake, digested and retained N, NPU and liver N values of the animals when compared with those fed the casein and the other diets containing YA. Combinations of DBB or DWB with PA appear to be the best mixtures as shown by food and N intakes, digested and retained N, liver N, and weight gain. These mixtures may possibly be economic sources of N for weaning children where these are staples in the diet.     

Metabolic responses of adult men to a daily magnesium intake of 430 mg from vegetable proteins

The retention of magnesium from low intakes of vegetable protein provided by four combinations of soya and groundnut nitrogen was studied in seven adult males. The diets furnished a protein equivalent of 0.5 g protein/kg/day and a daily magnesium intake of 5.8 mg/kg body weight. Only two subjects retained some magnesium when soya and groundnut nitrogen contributed evenly to the total nitrigen intake (diet II) or when egg was substituted for part of the nitrogen intake (diet I). Urinary and fecal magnesium excretion accounted for 52% and 56% of intake, respectively. The mean magnesium absorption (mg/kg body weight) was significantly reduced (P < 00.5) by consumption of the high groundnut diet. The mean magnesium retention for all subjects was negative throughout the experimental periods. The possible effects of nitrogen retention on magnesium utilization is discussed.     

Effect of treatment on composition and protein and energy utilization of rice and mung bean by rats

Yellow rice derived from stack-burned unthreshed grains had lower lysine content than white milled rice. Stack burning did not affect energy digestibility in growing rats but decreased true nitrogen digestibility and net protein utilization (NPU). Increasing parboiling time from 20 to 60 min had no adverse effect on energy and protein utilization of parboiled milled rice. Defatting of rice bran-polish with petroleum ether at 50°C had no effect on protein utilization but decreased energy content and utilization. Mechanical dehulling of mung bean (Vigna radiata [L.] Wilczek) reduced fiber content, increased energy and protein digestibility but decreased biological value (BV) and NPU. Toasting and winnowing the bean reduced lysine content, improved digestible energy but decreased BV and NPU. Cooking the bean preparations improved the biological value only in mechanically dehulled bean with resultant higher NPU than that of whole bean.     

Nutritional responses of rats fed mixtures of plant and animal proteins

Twenty four male rats (45–65 g) were used to determine the nutritional responses to mixed plant and animal protein diets. Rats were fed various mixtures of sorghum (S), pigeon pea (PP), bread fruit (TAP) plus crayfish (CR) to provide 1.6 g N/100g of daily diet for a 35-day study period. Three different diets were fed to 6 rats assigned to each diet on the basis of body weight. Combination of PP:CR caused increases in N intake and retention, weight gain, and PER higher than for those of the other test groups. Its values for N intake and retention, and BV were higher than for those of the control except for food intake, NPU, weight gain and PER. Substitution of CR (20%) with TAP and PP as supplements to S decreased food intake, weight gain and PER and increased N intake, digested and retained N, NPU and BV. The results appear to indicate that (a) PP:CR blend was better than other blends as judged by the parameters, and (b) TAP and PP were superior to CR alone as supplement to S.     

Protein content,distribution and retention during milling of brown rice

Brown rice of IR36 and IR42 check samples from the 1982 dry and wet season yield trials showed good correlation of milled-rice protein and brown-rice protein (r=0.97**,n=40) with 10% bran-polish removal by an emery abrasive mill. Among selected grain samples of both varieties, 80 to 86% of brown-rice protein was retained in the milled rice with both friction and abrasive mills. Stereological morphometry of 1-µm-thick sections showed that endosperm storage protein decreases in amount with increasing distance from the aleurone layer. A similar protein gradient was found in both average-protein and high-protein samples. Milling removed all of the pericarp, seed coat and nucellus, and virtually all of the aleurone layer and embryo, but removed very little of the nonaleurone endosperm, except from the lateral ridges.     

Protein and energy utilization of rice milling fractions by rats

Brown rice (variety IR32), bran, and polish had higher protein content and lysine content in protein than milled rice. Nitrogen balance in growing rats showed that brown rice had lower true digestibility, but similar biological value and NPU as milled rice. Undermilled rice had similar true digestibility, but higher biological value and NPU than milled rice. Bran and polish had lower true digestibility, but higher biological value than brown and milled rice, but polish had higher NPU than bran and the three other milling fractions. The percentage of digestible energy in the rats was lowest for bran.     

Protein and energy utilization of boiled rice-legume diets and boiled cereals in growing rats

In growing rats, boiled milled rice-legume diets (2:1 N ratio) had lower energy digestigibility than boiled milled rice and equal if not better true digestibility, biological value, and net protein utilization (NPU). Rice-soybean diets showed better NPU than the other rice-legume diets. Boiled whole-grain corn and sorghum had lower digstible energy and NPU than boiled milled rice. NPU of the diets did not follow strictly the trend of the amino acid score of the diets; phenol (tannin) content reduced energy and protein digestibility of all diets, but sugars reduced energy and protein digestibilities of rice-legume diets only.     

The nutritive value of all-vegetable protein diets based on legume,cereal and tuber in weanling rats

Thirty albino weanling male rats (45–55 g) were divided into five groups of six rats each on the basis of body weight and fed combinations of dehulled brown beans (DBB); parboiled rice (R); and cassava meal (G) which provided 10% protein for 35 days. Casein served as the reference protein. Combinations of DBB (50–80%); with R (18–48%); and G (2%) produced varied effects on body weight, nitrogen (N) intake, N digestibility and retention, BV, liver weight and plasma albumin (P<0.05).The DBB:R:G (70:28:2) blend induced decreases in all the parameters tested except for the BV and PER values. The control group produced digested and retained N, protein efficiency ratio (PER), weight gain and liver weight that were significantly higher than for those of the test diets (P<0.05). These results appear to suggest that starchy foods when blended with legumes at low levels produced good quality protein comparable to casein.     

Growth,liver composition,and calcium balance of rats fed sorghum supplemented with two levels of beans

A 35-day experimental study consisting of 28-day growth and 7-day calcium (Ca) balance periods was conducted to assess the effects of fibre and N ratios on growth and Ca balance of rats. Growth and Ca balance of rats (45–80 g) fed mixtures of cooked (CS) and uncooked (RS) sorghum and dehulled (DB) and undehulled (UB) bean were studied. The diets contained 10% protein. Casein served as the control protein. The control group ate more food except for the group fed the CS:DU (60:40) diets (P<0.05) had higher values for all parameters tested than the test groups. There were increases in food and Ca intakes, fecal Ca, weight gain, protein efficiency ration (PER), liver weight and composition except for the low moisture value for the CS:DS (60:40) group when N ratios were changed from 80:20 to 60:40. These results appear to indicate that fiber and N ratio had significant effects on growth liver composition and calcium balance of the rats.     

Utilization of silage nitrogen in sheep and cows: amino acid composition of duodenal digesta and rumen microbes

Two experiments are reported. In the first experiment the amino acid compositions of rumen bacteria and protozoa isolated from sheep given a diet of grass silage were compared with those taken from sheep given a diet of hay and barley; four sheep were assigned to each diet. There were no significant differences (P<0·05) between diets in the amino acid compositions of the microbial fractions and bacterial contents of α-ɛ-diaminopimelic acid were also similar for both diets.
In the second experiment the digestion of a grass silage and barley diet (65:35; 135 g CP (kg DM)^-1) was studied using four non-lactating Ayrshire cows fitted with cannulae in the rumen and in the proximal duodenum. The mean N intake was 154 g d^-1 and the corresponding duodenal flow was 126 ± 10 g d^-1 indicating that 0·21±0·07 of the N intake was absorbed between the mouth and the duodenum. The mean rumen NH₃-N concentration was high, 297 g litre^-1, and the mean rate of microbial protein synthesis in the rumen was low, 17 g microbial N (kg OM apparently digested in the rumen)^-1. There was a low content of bacterial N in the non-ammonia N at the duodenum (mean proportion 0·52±005) and low concentrations of methionine and lysine in the duodenal digesta protein. The results are discussed in relation to previously published data on the digestion of silage diets in sheep and to the utilization of silage diets for milk production in the cow.
It is concluded that with silage diets the supply of methionine and lysine to the duodenum is likely to be low because of the low rates of microbial protein synthesis in the rumen and that in cows those two amino acids may be limiting for milk production.     

Effect of high protein rice on nitrogen retention and growth of preschool children on a rice-based diet

The effect of high protein milled rices (IR480-5-9 and IR2153-338-3, 10% protein) on the nitrogen retention and growth of preschool Indian children was assessed in two feeding trials in a residential home. The children were offered, ad libitum, a rice-based diet in four meals daily without vitamin and mineral supplement. The children in the experimental group were given the high protein rice; those in the control group were given a local rice (7% protein). The groups had similar percent apparent digestibility and retention of dietary nitrogen. Statistically significant differences in increase in height and weight between the two groups were not consistently observed at the end of 4.5 to 5 months or 1 year. Possible factors contributing to these results are discussed.     

Bioavailability of lysine in selected foods by rat growth assay

Lysine bioavailabilities in reference protein and 16 test protein diets were estimated using 10 day rat growth assays. A standard growth curve was obtained by feeding 5 diets containing casein, zein and synthetic amino acids ranging in total lysine concentration from 0.3 to 0.7%. Experimental foods were added to the basal diet at the expense of zein and/or synthetic amino acids to provide 2 specific lysine concentrations, i.e., 0.4 and 0.6%. Availabilities were established by comparing growth responses from the test food diets to the regression line of the standard growth data. Availabilities were over 88% for 13 of 16 products. Utilization was poor in pinto beans (73%), rice-wheat gluten cereal (70%), and skim milk powder heated to 100°C for 12 h (66%). Addition of excess lysine (700 mg/100 g diet) to the pinto bean diet did not improve growth response; thus poor digestibility or some unidentified growth inhibitor is indicated.     

Response of Iron Content in Milled Rice to Nitrogen Levels and Its Genotypic Differences

To investigate the effect of nitrogen (N) level on iron (Fe) content in milled rice, a field experiment was carried out under three N application levels including 0, 150 and 300 kg/hm² by using 120 rice genotypes. In addition to the genotypic differences of iron content in milled rice, grain yield, 1000-grain weight and N content in grains under the same N level, there were also variations in the response of Fe content in milled rice to N levels. Based on the range and variation coefficient of Fe content in milled rice under the three N levels, the response of Fe content in milled rice to N levels could be classified into four types including highly insensitive, insensitive, sensitive and highly sensitive types. A significant quadratic correlation was found between the Fe content in milled rice and 1000-grain weight or the N content in grains. However, no significant correlation between the Fe content in milled rice and grain yield was detected. In conclusion, there are genotypic differences in the effects of N levels on Fe content in milled rice, which is favorable to breeding of Fe-rich rice under different N environments. Furthermore, high yield and Fe-rich rice could be grown through the regulation of nitrogen on Fe content in milled rice, 1000-grain weight and N content in milled rice.     

Effect of Barley Fibres and Barley Intake on the Ileal Endogenous Nitrogen Losses in Piglets

Ileal endogenous N losses (ENL) were measured, using the¹⁵N isotope dilution technique, in piglets (17 kg) fed different barley genotypes (naked, spring, winter with low/high beta -glucan content) or diets containing 330, 530, 730 or 930 g of a blend of barleys/kg diet. The apparent protein and amino acid digestibilities of the naked variety and the winter variety with a high beta -glucan content were, on average, significantly higher than those for the other two varieties. The ENL were inversely correlated (p<0·01) with the apparent digestibilities but the difference between each of them was not significant (p>0·05). The ENL increased linearly with the inclusion level of barley in a N-free basal diet (2 mg endogenous N/g barley). Isolated hulls added to a N-free diet at the rate of 100 or 200 g/kg diet exerted no significant effect on the ENL (1·80 g endogenous N/kg diet in both cases vs. 1·76 g for the basal level). On the contrary, the effect of isolated bran, measured under similar conditions, was significantly higher and dependent on fibre intake (2·59 and 3·31 g N/kg diet, respectively). It is concluded that the ENL are affected by the insoluble bran fibre but not by the hulls, nor by the level of beta -glucan.     

施氮处理对水稻精米中铁含量的影响及基因型差异

以120份国内外水稻基因型为材料,设置0、150、300kg/hm23个氮素水平,研究施氮处理对水稻精米中Fe含量的影响及其基因型差异。除相同氮素条件下水稻精米中的Fe含量、产量、千粒重及籽粒含氮量存在基因型差异外,精米中的Fe含量对氮素反应的敏感性也存在显著差异。以各基因型水稻在不同氮素条件下精米中Fe含量的极差和变异系数为指标,通过系统聚类的方法,可将上述120份水稻基因型对氮素反应的敏感性分为极钝感型、钝感型、敏感型和极敏感型共4种类型。同时,相关性分析表明,水稻精米中的Fe含量与产量的相关性不显著,而与粒重、籽粒含氮量呈显著或极显著的二次曲线关系。由此说明,施氮处理对水稻精米中Fe含量的影响具有基因型差异,充分利用这种差异一方面有利于对氮环境适应性强的富铁水稻的选育;另一方面,由于精米中的Fe含量与产量无必然联系,可通过氮肥对水稻(尤其是敏感和极敏感类型水稻)精米中的Fe含量和粒重、籽粒含氮量的调节,实现富铁、高产水稻的种植。     

Determination of the best level of dietary energy with two diet formulation methods based on total and digestible amino acid on broiler diet

In order to evaluate the effects of different levels of energy and methods of formulation of Amino Acid (AA) requirements of diets, this experiment was conducted using 392 broiler chicks. The experiment was carried out using a complete randomize block design with 7 levels of energy 3175, 3075, 2975, 2875, 2775, 2675 and 2575 kcal kg(-1) for grower diet and 3225, 3125, 3025, 2925, 2825, 2725 and 2625 kcal kg(-1) for finisher diet and two methods of formulation of diets AA requirements (total and digestible) as a factorial arrangement. Results showed that by increasing level of energy feed intake, body weight and FCR were promoted in grower diet (p<0.05). Effect of decreasing level of energy up to 2725 and 2825 kcal kg(-1) was not significant on body weight and FCR in finisher diet, respectively. Formulating of diet based on total or digestible AA affected feed intake and FCR in finisher diet (p<0.05). Interaction effect of independent factors affected on body weight in grower diet (p<0.05). Decreasing level of energy increased gastrointestinal tract percentage weight (p<0.05). Formulation of diet based on digestible AA decreased gastrointestinal tract percentage weight (p<0.05). Abdominal fat decreased significantly as ME content of diets decreased. Results showed that it's possible to reduce the level of energy up to 3175 kcal kg(-1) in grower and 2725 kcal kg(-1) in finisher diet for giving the best and economical performance response. Formulation of diet based on digestible AA in finisher diet resulted in promotion of performance.     

Studies on weaning diets in Nigeria: 2 protein sources

Protein isolates were extracted from melon, groundnut, and soybean cakes in an aqueous system that could potentially yield both oil and protein from oilseeds quantitatively. Protein isolates obtained were 91.2, 78.6 and 79.5% of the total protein content of melon, groundnut and soybean cakes respectively. Both cakes and isolates were assessed in a rat bioassay while breadfruit, cassava, and corn starch were also investigated as sources of carbohydrate. Results showed that there were no significant differences between feed intake, weight gain and PER of rats fed the cake and the protein isolates except in soybean. Weight gain, PER and NPR were highest in cassava-soybean protein isolate diet followed by cassavacasein diet (control) while performance was only moderate with melon- and groundnutcassava diets. With melon protein isolate, cassava and breadfruit were better carbohydrate sources than corn starch. In simulated weaning diets, cassava-sucrose-melon-soybean protein isolate based diet performed better (weight gain 33.4 g, PER 1.63, NPR 2.23) than a commercial weaning food (weight gain 30.6 g PER 1.57, NPR 2.18) while replacement of sucrose and cassava at 30% by breadfruit yielded a cost effective diet with good performance (weight gain 29.4 g, PER 1.51, NPR 2.12). Diets where soybean protein served as the sole source of protein or breadfruit, white and yellow maize ogi served as the main source of carbohydrate performed only moderately.     

Comparative Protein Digestibility in Growing Rats of Cooked Rice and Protein Properties of Indica and Japonica Milled Rices

College,Laguna, Philippines.Received 1 ABSTRACT Eight indica and japonica milled rices with low amylose content and low starch gelatinisation temperature were analysed for cooked rice energy and N balance in growing rats and for protein properties. Digestible energy values were similar. Japonica rices Koshihikari and Sasanishiki had higher true digestibility (TD) and net protein utilisation in rats than indica rices IR24 and PR23383-15. Similar results were obtained from in vitro proteolysis. High TD of cooked rices was not significantly correlated with low prolamin content in raw rice and with low waxy gene product (protein bound to starch granule) but was significantly correlated with low cysteine content in protein and with low denatured prolamin content in cooked rice. In two pairs of cooked waxy milled rices, which are devoid of waxy gene product, japonica rice still tended to show higher rat TD and in vitro protein digestibility than indica rice, consistent with lower cysteine content in japonica protein.