Changes In Nutrient Composition Research Articles

Seasonal Changes in Voluntary Intake and Digestibility by Sheep Grazing Introduced Leymus chinensis Pasture

A study was conducted to investigate the seasonal changes in nutrient composition of pasture, voluntary intake and digestibility of sheep grazing an introduced Leymus chinensis pasture located in western Jilin Province, China. The whole-plant of L. chinensis and the samples simulating ingestion by sheep (simulating sample) were collected in spring (May, 2004), summer (July, 2004), autumn (September, 2004) and the end of winter (April, 2005). The contents of gross energy (GE), organic matter (OM), crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and alkanes were determined. Voluntary intake and apparent digestibility of the nutrients in each season were also examined using 6 mature Chinese Northeast Merino ewes (differed among the seasons) grazing on a paddock of 1 ha size. The apparent digestibilities of GE, dry matter (DM), OM, CP, NDF and ADF of L. chinensis were significantly greater (p<0.05) in spring and summer than in autumn and winter. Metabolizable energy (ME) content was 12.13, 11.62, 8.66 and 10.40 MJ/kg DM for L. chinensis in spring, summer, autumn and winter respectively, and the corresponding voluntary feed intakes were 91, 119, 59 and 58 g/d per kg metabolic weight (LW 0.75 ). The ME contents and DM intakes in autumn and winter were significantly lower than in spring and summer (p<0.05). The intake of L. chinensis pasture was sufficient to provide ME requirements

Compensatory Growth and Changes in Nutrient Composition in Post-Larvae of Giant Prawn, Macrobrachium rosenbergii, Following Starvation

ABSTRACT The effect of a period of starvation and subsequent re-feeding on the weight and length gain of post-larvae of giant prawn, Macrobrachium rosenbergii, was studied during an eight-week investigation. Post-larvae of Macrobrachium rosenbergii weighing 5.15±2 mg were grown in aquaria at water temperature of 28±1°C. Post-larvae of the control treatment were fed to satiation during the experimental period while post-larvae in other three treatment groups were deprived of diet for 1, 2, and 4 weeks, respectively, and were subsequently fed to satiation during the realimentation period up to 8 weeks. Post-larvae deprived of diet for 1 and 2 weeks, compensated for lack of diet by weight gains of 1,842% and 1,813%, and better feed conversion efficiency (0.53% and 0.34%), respectively. Post-larvae deprived of diet for 4 weeks showed significantly (P < 0.05) lower gain in body weight (811%) than that of the control group (1,609%), but showed significantly higher specific growth rate (7.99±0.06) than other treatments during realimentation period. Data reported indicate that post-larvae of M. rosenbergii are able to achieve complete growth compensation within two weeks following feed deprivation of two weeks.

Effects of copper and mineral nutrition on growth, copper accumulation and mineral element uptake in two Rumex japonicus populations from a copper mine and an uncontaminated field sites

Two Rumex japonicus populations, one from a copper mine and the other from an uncontaminated site, were studied in hydroponic experiments for the plant growth, copper accumulation and mineral nutrient content under excess copper and nutrient deficiency conditions. The tolerance indices of the contaminated population were significantly higher than that of the uncontaminated population, indicating the evolution of Cu resistance in the former. At control and low Cu treatment, there was no difference in Cu accumulation in roots between the two populations. At high Cu (100 μM) treatment, however, the contaminated population accumulated less Cu in roots than the uncontaminated one, suggesting the root exclusion mechanism existing in the former. The contaminated population was also more tolerant to general nutrient deficiency than the uncontaminated one. The results indicated that the contaminated population had evolved not only Cu-tolerance but also tolerance to low nutrient supply. Under Cu stress, the contaminated population had less change in nutrient composition than the uncontaminated one. The similar result was observed in general nutrient deficiency experiment. The results indicated that the mineral composition homeostasis under the stresses was important in metal tolerance and colonizing the Cu-enriched soils for the Cu-tolerant population. At high Cu (100 μM) treatment and general nutrient deficiency treatment, the contaminated population accumulated significantly lower copper and higher phosphorus in both roots and shoots than the uncontaminated one. This was not the case for other mineral nutrients Ca, Mg and Fe except for root Mg and root Fe at Cu treatment. The result suggested that the high Ca-metabolism in R. japonicus was uncorrelated with high Cu-tolerance and that P might play an important role in governing Cu bioaccumulation.

Ensiling of potato pulp with or without bacterial inoculants and its effect on fermentation quality, nutrient composition and nutritive value

Effect of addition of two bacteria inoculants at ensiling on the fermentation quality, change in nutrient composition and the nutritive value of potato pulp silage (PPS) was investigated. Two separate experiments were carried out on a laboratory scale using two bacterial inoculants: Lactobacillus rhamnosus alone (L), Rhizopus oryzae alone (R) and a combined application of the two inoculants (R + L). The first involved a study on the time course changes in fermentation characteristics and nutrient composition of the silage, while the second focused on the chemical composition after 50 days of ensilage. The nutritive value of PPS was studied in vivo digestibility trial using sheep in a 4 × 4 Latin square design. In both investigations, R decreased ( P < 0.05) the pH to less than 3.5 after 50 days of ensiling. Lactic acid increased in all treatments, but was low ( P < 0.05) in R inoculated silage compared to the control. The main carbohydrates in potato pulp, starch and pectin decreased while sugar increased in the inoculant added silages with length of ensilage. Although dry matter intake was higher ( P < 0.05) in L inoculated silage compared with the control, the inoculants or their combined application had no effect ( P > 0.05) on the digestibility of PPS. The results show that potato pulp can ensile well with or without bacterial inoculants. The high nutritive value of PPS (about 720 g/kg DM in TDN and 13 MJ/kg DM in digestible energy) does indicate that PPS could be used as an energy source in ruminant diets.

A validation study on food composition tables for the international cooperative INTERMAP study in Japan.

The INTERMAP Study is an international cooperative study on the relationship between macro- and micro-nutrient intakes and blood pressure. The present study-ancillary to INTERMAP-is to evaluate validity of the INTERMAP Tables of Food Composition in Japan (ITJ) formulated by modifying the Standard Tables of Food Composition in Japan (STJ), including factoring in changes in weight and nutrient composition of individual foods due to cooking. With chemical analytical values of 96 meals prepared in two university hospitals in Japan as the "gold standard", validity of calculated values based on the ITJ was examined for six major components (energy, protein, lipid, carbohydrate, sodium, potassium) by comparison of mean values, correlation, and linear regression analysis. Although both the ITJ-based and STJ-based calculated values for all six components were significantly higher than the analytical values, differences from the analytical values were generally less marked for the ITJ-based values than for the STJ-based values. The STJ-based values were significantly higher than the ITJ-based values for protein and potassium. Analytical values showed slightly stronger correlations with the ITJ-based calculated values (r=0.876 for total energy, r=0.789 for lipid, r=0.832 for potassium) than with the STJ-based calculated values, except for carbohydrates. The ITJ was considered to have greater validity than the STJ. To obtain more accaurate data in nutritional surveys, food composition tables in which changes in nutrient compositions due to cooking methods are taken into consideration should be used.

Changes in nutrient composition, phytate and cyanide contents and α-amylase activity during cereal malting in small production units in Ouagadougou (Burkina Faso)

The different traditional processes used in cereal malting were characterised and some biochemical modifications occurring in seeds during malting were studied to examine the possibility of using malted cereal flours to reduce the viscosity of gruels prepared from infant flours. Five production units (PU) of malted red sorghum seeds, two PU of malted millet seeds and one PU of malted maize seeds were selected as a function of the ability of the malt flours to fluidify high energy density gruels. Each of the 8 PU were monitored throughout the malt production process in order to describe rigorously the different steps in their malting process and to establish a detailed general production diagram. Samples were collected after soaking, germination, maturation, drying, and degerming and at the final product. They were analysed for nutrient, phytate and cyanide contents and α-amylase activity. For the 3 types of cereals, malting increased protein content while it decreased lipid and ash contents. A significant increase was observed in sucrose, glucose and fructose contents during malting, in particular during the germination step. The decrease in phytate content during malting was more obvious in millet seeds than in red sorghum and maize seeds. α-amylase activity increased during malting in all 3 types of cereals but more in red sorghum seeds than in millet and maize seeds. Cyanide content considerably increased during malting, particularly in red sorghum seeds. Sucrose content decreased during maturation while glucose and fructose contents increased. Traditional manual degerming reduced fibre and ash contents in all 3 types of cereals. Degerming had little effect on phytate content but reduced cyanide content to an acceptable level for human consumption even if it did not allow the complete elimination of cyanide. Unfortunately, degerming was accompanied by a decrease in α-amylase activity. The maturation step should be eliminated from the malting process (biochemical characteristics were not much affected as a result) and degerming of the seeds has to be systematically conducted after sun drying to achieve a significant reduction in cyanide content. Flours from malted red sorghum or millet seeds presented useful characteristics (α-amylase activity and nutrient contents) for incorporation in infant flours to improve the energy and nutrient density of gruels.

Progression of mycotoxin and nutrient concentrations in wheat after inoculation with Fusarium culmorum

The objective of this study was to follow the mycotoxin formation and changes in nutrient composition of wheat (cv. Ritmo) artificially inoculated with Fusarium culmorum. From anthesis until harvest, samples were taken once a week from the inoculated and control plots. The investigations were focused on monitoring the progression of the contamination of the wheat kernels with deoxynivalenol (DON) and zearalenone (ZON). Both the uncontaminated control kernels and the contaminated kernels were examined also for the presence of zearalenone-4-beta-D-glucopyranoside and several trichothecenes at harvest. Furthermore, the impact of the Fusarium inoculation on some nutrients as starch, crude protein, amino acid composition, crude ash, non starch polysaccharides (NSP) as well as viscosity and thousand seed weight (TSW) was examined. Also proteolytic and amylolytic activity as well as the NSP-degrading enzyme activities of inoculated and control samples were analysed at the time of harvest. DON was detected in higher concentrations and in earlier stages, while ZON was found later and in smaller amounts. On average 7.79 mg/kg DM of DON and 100 μg/kg DM of ZON were found in the inoculated kernels at the time of harvest. Neither in the contaminated nor in the control samples glucose conjugates of ZON (Zearalenone-4-beta-D-glucopyranoside) were detected. Moreover, the infection with Fusarium culmorum had pronounced effects on some quality parameters. The crude protein content of the inoculated kernels showed significantly higher values over the whole period compared to the control kernels. The protein content of the inoculated kernels amounted 13.9% DM at harvest, while only a concentration of 12.5% DM was detected in the control samples. Similarly, in almost all stages of development the crude ash content of inoculated samples was higher than in control samples. These distinct differences in kernel composition resulted possibly from the changes of the thousand seed weight. In the present work the grain harvested from the control plots showed a significantly higher TSW (24.2 g) as compared to their inoculated counterparts (15.5 g). Despite lower extract viscosity of inoculated samples at time of harvest, the content of soluble NSP of inoculated plots was higher than in control samples at the same time. Moreover, inoculation resulted in markedly increased activities of protease, amylase and several NSP-degrading enzyme activities. This would suggest that the cell wall penetrating properties of the fungus itself and/or that the fungus induced alterations of the metabolic activity of the embryo or other constituents of the wheat kernel could be responsible.

Measurement and Estimation of Changes in Nutrient Composition and Nutrient Losses during Hay and Silage Making in Field Curing

Measurement and Estimation of Changes in Nutrient Composition and Nutrient Losses during Hay and Silage Making in Field Curing

Effects of Cutting Height and Maturity on the Nutritive Value of Corn Silage for Lactating Cows ,

We studied the effect of increasing the cutting height of whole-plant corn at the time of harvest from 12.7 (NC) to 45.7 (HC) cm on yield and nutritive value of silage for dairy cows. Three leafy corn silage hybrids were harvested at NC and HC at about 34% dry matter (E) and 41% DM (L) and ensiled in laboratory silos. Increasing the height of cutting lowered yields of harvested DM/ha. In addition, the concentrations of DM and starch were higher but the concentrations of lactic acid, crude protein, neutral detergent fiber (NDF), and acid detergent fiber were lower in HC than in NC. The concentration of acid detergent lignin was also lower in HC, but only in corn harvested at E. In vitro digestion (30h) of NDF was greater in HC (50.7%) than NC (48.3%). Calculated yield of milk per tonne of forage DM was greater for HC than for NC at E but not at L. In a lactation experiment, increasing the height of cutting of another leafy corn silage hybrid, TMF29400, in general also resulted in similar changes in nutrient composition as just described. When fed to lactating dairy cows, HC corn silage resulted in tendencies for greater NDF digestion in the total tract, higher milk production and improved feed efficiency, but there were no differences in 3.5% fat corrected milk between treatments. Results of this study suggest that increasing the cutting height of whole plant corn at harvest can improve the nutritive value of corn silage for lactating dairy cows.

Assessment of egg nutrient compositional changes and residue in eggs, tissues, and excreta following oral administration of atorvastatin to laying hens.

Laying hens were fed a control diet alone or with 0.06 g of atorvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, per 100 g of diet for 20 days. Compared to controls, egg yolks from treated hens contained greater amounts of amino acids and reduced levels of total fatty acids and cholesterol. In contrast, egg albumen amino acid contents were unaffected by dietary treatments. In a residue study, seven hens each received a single oral dose of approximately 20 microCi of [(14)C]atorvastatin. Approximately 71% of the radioactivity was recovered in the excreta and liver, whereas virtually no radioactivity was detected in kidney, heart, muscle, bile, plasma, or egg albumen at 15 days postdosing. Yolk radioactivity peaked at 4 days postdosing in six of the seven birds and was absent in eggs laid after day 10. Reminiscent of that of certain antibiotic drugs, the atorvastatin egg residue pattern appeared to coincide with the physiological pattern of daily yolk accretion within the ovary.

Food Safety Evaluation of Crops Produced through Biotechnology

Agricultural biotechnology has been widely adopted in agriculture but is also the focus of controversy. Questions have arisen regarding food and environmental safety. In the US, responsibility for ensuring agricultural and environmental safety is delegated to the USDA and EPA, respectively. The FDA has primary responsibility for food safety, with the exception that the EPA has responsibility for the safety of proteins in plants associated with insect defense mechanisms. The food safety assessment, whether performed by the FDA or the EPA, requires evaluation of the safety of 1) the newly added DNA, 2) the safety of the newly introduced gene product and 3) the overall safety of the balance of the food. A paradigm called “Substantial Equivalence” guides the assessment. The principal food safety issues for new varieties crops are 1) potential toxicity of the newly introduced protein(s), 2) potential changes in allergenicity, 3) changes in nutrient composition, 4) unintended effects giving rise to allergenicity or toxicity and 5) the safety of antibiotic resistance marker-encoded proteins included with the transgene. All of these must be taken in the context of the predicted range of dietary exposures. The evaluation seeks to establish that there is a “reasonable likelihood of safety” and that new varieties are as safe as or safer than crops produced by traditional methods. Indeed, after extensive safety testing and some five years of experience with such crops in the marketplace, there is not a single report that would lead an expert food scientist to question the safety of such transgenic crops now in use.

Progression of the mycotoxin and nutrient concentration in wheat after inoculation withFusarium culmorum

The aim of the study was to follow the mycotoxin formation and the changes in nutrient composition of wheat artificially inoculated withFusarium cuimorum. From anthesis until harvest, samples were taken once a week from the inoculated and control plots. The investigations were focused on the progression of the contamination of the wheat with deoxyni-valenol (DON) and zearalenone (ZON). Furthermore, the impact of the Fusarium inoculation on the quality parameters starch, crude protein, crude ash, viscosity, non starch polysaccharides (NSP) and thousand seed weight was examined. Deoxynivalenol was detected in higher concentrations and in earlier stages, while zearalenone was found later and in smaller amounts. Moreover, the infection withFusarium cuimorum had pronounced effects on some quality parameters.

Psychobiology of food preferences.

Investigations with laboratory animals can reveal much about the basic psychobiological determinants of food preference and diet-induced overeating. When offered a choice of foods, rats typically prefer high-fat and/or high-sugar food items over their nutritionally balanced chow diet. In addition, they may increase their total energy intake by 20-40% and consequently develop mild to moderate obesity. The role of flavor and postingestive nutritional actions on the preference for and overconsumption of fat- and sugar-rich foods has been questioned. To evaluate flavor and nutritional effects independently, recent studies have used self-regulated intragastric feeding paradigms. The results indicate that enhancing the flavor of food can significantly increase energy intake when nutrient composition is held constant. Similarly, changes in nutrient composition (ie fat-carbohydrate ratio) can significantly influence energy intake when flavor is held constant. In addition, postingestive nutrient actions can significantly alter flavor preferences through a conditioning process as function of nutrient type and concentration. Thus, food preferences and overeating result from interactions between the orosensory and nutritional properties of food.

Impact of starvation on survival, meat condition and metabolism ofChlamys farreri

The effects of 60-day starvation on survival rate, condition index (CI), changes of nutrient composition of different tissues, respiration and excretion of scallopChlamys farreri were studied in laboratory from Oct. 17 to Dec. 15, 1997. Two groups (control and starvation with 200 individuals each) were cultured in two 2 m3 tanks, with 31 to 32 salinity water at 17°C. Starvation effects were measured after 10, 20, 40 and 60 days. There was no mass mortality of scallops of the two tanks and survival rates of the control and starvation groups were 93.5% and 92.0%, respectively. Starvation had strong effect on the meat condition of the scallops, especially after 10 days; when relative lipid percentage dropped sharply while relative protein percentage increased. The impact of starvation on the oxygen consumption rate (OCR) and the ammonia-N excretion rate (AER) was obvious. The OCR increased rapidly after 10 days but decreased after 20 days. The AER increased after 10 days and 20 days, but decreased obviously from 20 to 40 days. The O∶N ratios varied to different degrees, and minimized after 20 days. The low O∶N ratios implied that the protein was the main material for the metabolism ofC. farreri.

Gaseous Emission and Changes in Nutrient Composition During Deep Litter Composting

Composting of deep litter during storage may cause emission losses of ammonia (NH 3 ), nitrous oxide (N 2 O) and methane (CH 4 ). Emissions of NH 3 , N 2 O and CH 4 from deep litter compost were measured using a dynamic chamber over a period of 57 days from 2 July to 26 August 1997. High concentrations of N 2 O inside the compost heap were found initially and after 20 days of composting. Methane concentrations in the heap were high during days 8-15. As a result of NH 3 volatilization, 2.2 kg NH 3 -N t -1 (23% of total N) was lost in the first 5 days. Emissions of N 2 O amounted to 0.22% of the total N present at the start of the experiment and CH 4 emission represented 0.01% of total C. In this experiment no leaching occurred, and thus non-volatile nutrients were conserved during composting. The population of nitrifying bacteria remained low throughout the experiment (around 105 cells g -1 dry matter) and the density of denitrifying bacteria stayed high (4.2 2 107 cells g -1 dry matter).

Growth, transpiration, root‐born cytokinins and gibberellins, and nutrient compositional changes in sesame exposed to low root‐zone temperature under different ratios of nitrate: Ammonium supply

The growth of sesame (Sesamum indicum L.) was studied at three root temperature regimes (25/25, 20/10 and 15/15°C day/night) factorially combined with three NO3 ‐: NH4 + ratios (mM ratios, 10:0, 8:2, or 6:4), as a source of nitrogen (N), in the irrigation solution. The air temperature was kept constant at 30°C. Transpiration, nutrient composition, and level of root‐born cytokinins and gibberellins in the xylem exudate were monitored. The two low root temperature regimes, 15/15 and 20/10°C, restricted the growth of sesame, reduced transpiration and increased the accumulation of soluble carbohydrates in the shoot and in the roots compared to the 25/25°C regime. The NO3:NH4 + ratios had no effect on growth. Nutrient contents in the shoot at low root temperatures, particularly K+, NO3 ‐, and H2PO4 ‐ were decreased markedly, but Na+ increased relative to it's content in the 25/25°C regime. Increasing NH4 + proportion in the irrigation solution raised total N concentration in the plant tissues at all root temperatures. The amounts of cytokinins and gibberellins in the xylem exudate decreased at the low root temperature regimes relative to the 25/25°C regime. Low root temperature reduced xylem transport of nutrients and root born‐phytohormones, most probably because of reduced water flow through the plant relative to the 25/25°C regime.

Comparison of diet and faecal collection methods for assessment of seasonal variation in dry matter intake by sheep maintained on a Cenchrus ciliaris pasture

Four diet collection methods: clipping(C), mouth grab (MG), plucking (P) and oesophageal extrusa (OE) and two faecal output estimation methods: faecal bag (FB) and Cr 2O 3 marker (I) were compared to assess seasonal changes in nutrient composition of diet and dry matter intake of sheep on Cenchrus ciliaris pasture. Crude protein (CP) and lignin contents of OE were higher than C, MG and P during all the seasons. Fiber fractions were lowest in MG, highest in C and intermediate in OE and P methods. Pooled CP contents of diet samples declined ( P < 0.01) from 12.7% in monsoon to 9.3 and 7.9% in winter and summer while ADF, cellulose and lignin increased from monsoon to summer. Clipped samples had lower NDF, ADF, cellulose, hemicellulose and gross energy digestibility compared to P, MG and OE methods in all the seasons. Nutrient digestibility declined from monsoon to winter and summer in all the diet samples collected by the four techniques. CP digestibility showed marked depression from 63.1% in monsoon to 44.1 and 14.4% in winter and summer. Faecal collection bag and Cr 2O 3 marker methods estimated similar faecal outputs in all the seasons. The OE method estimated a lower DM intake of the animals (mean 960 g/day) compared to C, P and MG methods (mean 1381 g/day). Animals consumed more dry matter during winter (mean 1706 g/day) than during monsoon and summer (mean 1030 g/day) seasons. It is concluded that diet sampling method and season had an influence on the estimated diet composition and DMI of sheep on semi-arid pastures. Both methods of faecal collection, however, estimated similar daily faecal output in sheep.

THE UTILISATION OF AN EMBRYO BREEDER TECHNIQUE FOR MATURATION OF SOMATIC EMBRYOS

The formation of embryos from somatic tissue may require several transfers to different media before ripe embryos can be harvested. In a semiopen system, where fresh medium is delivered continuously to the cells through a semipermeable membrane, the problem of repeated transfer can be avoided or the number of transfers reduced. Two types of culture vessels were constructed for studying the growth and differentiation of cells on the membrane. Because cells and embryos are stationary, not moving around as in shaking cultures, it is called an embryo breeder (EB) system. This equipment allows culture periods of unlimited duration without transfer of cultured tissues and any kind of changes in nutrient composition during the culture period. In addition, selection of a membrane with an appropriate molecular weight cut-off (MWCO) enables control of molecule transfer through the membrane. The first prototype was made of Teflon® and the second one of polycarbonate. Both EBs are autoclavable and consist of upper and lower compartments separated by a semipermeable membrane. The cells to be cultured are located in the upper compartment and the nutrients are pumped slowly by a tubing pump through the lower compartment. In preliminary experiments, EBs were loaded with carrot somatic cells and globular embryos. During the culture period of 2 to 4 weeks, differentiation of so-called torpedo-stage embryos with clearly visible shoot and root initials could be observed.

Estimation of Intake in High Producing Holstein Cows Grazing Grass Pasture

The objectives were to estimate intake of pasture and total DMI by high producing cows grazing grass pastures and to measure changes in nutrient composition of grass pasture during the grazing season. Sixteen multiparous Holstein cows averaging 31kg of 4% FCM/d at the start of the trial grazed grass pastures at a stocking rate of 2.5 or 3.9 cows/ha from April until October 1990. Intake was estimated using Cr2O3 as an indigestible fecal marker. Pasture samples were analyzed for nutrient composition at six times during the grazing season corresponding to the times of intake estimation. Total daily DMI increased from 21.3kg in early spring to 22.4kg in late spring and then decreased as lactation progressed; however, DMI exceeded NRC recommendations during most of the grazing season. Daily pasture DMI varied with season, ranging from 11.6 to 15.6kg and was lowest (11.6kg) in the summer. Estimated NEL intakes were lower than NRC recommendations in early spring. During the grazing season, pasture ranged from 39 to 48% NDF and from 22 to 30% CP with 15 to 20% ruminally degradable protein on a DM basis. Grazing cows consumed adequate DM from pasture except in early spring. Although nutrient composition of pasture varied with season, quality remained high.

Evaluation of the nutritive value of yellow rice in rats and broiler chicks.

Yellow discoloration often develops in rice kernels during post-harvest storage, due possibly to fungal activity. The present study examined the changes in nutrient composition taking place during yellowing of rice, and the effects of feeding rats and broiler chicks on a moderately yellow rice at 600 g/kg diet. Nitrogen content was found to be higher in rice grains that had become more yellow, only part of the increase being in non-protein-N; however, relative to crude protein (N x 6.25) the concentrations of lysine, methionine, cystine and arginine were lower. There were no significant differences between white and yellow rice in the food intake, weight gain and efficiency of food utilization (EFU) of rats and chicks when diets were formulated to contain similar nutrient concentrations, or the same basal ingredient composition. Diet pelleting increased food intake and weight gain in both animal species, but reduced dry matter and energy digestibility in rats; effects on nutrient retention in chicks were largely non-significant. Liver weights of rats and chicks and pancreas weights of chicks were unaffected by yellow rice; however, chicks fed on mash had a larger pancreas on average than those fed on pellets. Thus, whilst the nutrient composition of rice is altered during yellowing, a moderately yellow rice is unlikely to produce major adverse effects when fed to rats and broiler chicks.