Nutritional Value Of Maize Research Articles

EFFECT OF FERTILIZERS ON THE FODDER YIELD AND NUTRITIVE VALUE OF MAIZE

This study evaluated the effect of fertilizers on the fodder yield and nutritive value of maize. Urea (T2), Nat-soil (T3) and Wonder (T4) fertilizers were applied with No fertilizer (T1 – control) laid out in a completely randomized design experiment. The agronomic parameters estimated include number of leaves, plant height, plant width, leaf length, leaf width, number of cob, and cob weight. The result of this experiment indicated that T4 was significantly higher (p<0.05) in plant height, plant width, leaf number, leaf length, leaf width, stem girt and yield parameters compared to other fertilizer treatments. However, the agronomic and yield parameters of all the fertilizer treatments were significantly better (p<0.05) than the control treatment. The chemical analysis of maize hay, T1 had the highest DM value (29.95%) while T4 had the least DM value (27.50%). T4 had the highest CP value (12.19%) while T2 and T3 had relatively the same CP value (10.6% and 10.64% respectively) as the least CP value was recorded in T1. The CF value was higher in T1 and T4 (32.32% and 32.40% respectively) as the least CF value (30.34%) was recorded in T3. T2 had the highest ADF value (43.21%) while T4 had the least ADF value (35.85%). T3 had the highest NDF value while T1 had the least value. It could be concluded that maize treated with fertilizers had better growth, yield as well as nutritive value. However, maize treated with wonder fertilizer showed outstanding response.

Yield and nutritive value of maize (Zea mays L.) forage as affected by plant density, sowing date and age at harvest

The current study was carried out in Alexandria, Egypt and investigated the effect of sowing date; 1st May, 1st July, and 1st September 2017 and 2018, and age at harvest; 45, 55 and 65 days after sowing (DAS) on yield and quality of maize green forage grown with three plant densities (120, 160, and 200 kg ha–1). Sowing at 1st of May produced the highest significant amount of fresh yield (41.51 t ha–1 in average). Sowing at 1st of July resulted in the production of significantly lower yield (24.54 t ha–1 in average), however, higher dry matter content (175.99 g kg–1 in average), compared to sowing at 1st of May (143.62 g kg–1 in average). A pronounced increase in fresh yield was observed when maize was harvested at 55 DAS (30.89 t ha–1 in average) compared to harvesting at 45 DAS (22.92 t ha–1 in average). Meanwhile, the increase in fresh yield from 55 DAS to 65 DAS was non-significant. The effect of sowing date on quality parameters was greatly dependent on the age of plant at harvest. Harvesting maize green forage at 65 DAS, reflecting an advanced stage of maturity, caused a significant reduction in the crude protein (CP), and a significant increase in the neutral and acid detergent fibre fractions (NDF and ADF), resulting in a decline in the digestible organic matter (DOM). Plant density exerted non-significant influence on the fresh yield and DM content, minimal effect on the CP content, while the effect on the NDF and ADF contents was dependent on the age at harvest. The lignin content (ADL) of the herbage significantly decreased with increasing the plant density. Variations in the DOM were most dependent on the variations in CP content, followed by the variations in ADF and ADL contents. In conclusion, it is recommended to grow green forage maize twice a season on the 1st of May and 1st of July, with intermediate plant density (160 kg ha–1), and harvest it not later than 55 DAS to achieve the optimum balance between herbage productivity and nutritive value.

УРОЖАЙНОСТЬ И ПИТАТЕЛЬНАЯ ЦЕННОСТЬ КУКУРУЗЫ И ИХ СМЕСЕЙ ДЛЯ ЗАГОТОВКИ СОЧНЫХ КОРМОВ В УСЛОВИЯХ ЦЕНТРАЛЬНОЙ ЯКУТИИ

УРОЖАЙНОСТЬ И ПИТАТЕЛЬНАЯ ЦЕННОСТЬ КУКУРУЗЫ И ИХ СМЕСЕЙ ДЛЯ ЗАГОТОВКИ СОЧНЫХ КОРМОВ В УСЛОВИЯХ ЦЕНТРАЛЬНОЙ ЯКУТИИ

Heavy metal induced oxidative damage and root morphology alterations of maize (Zea mays L.) plants and stress mitigation by metal tolerant nitrogen fixing Azotobacter chroococcum

Heavy metals are one of the major abiotic stresses that adversely affect the quantity and nutritive value of maize. Microbial management involving the use of plant growth promoting rhizobacteria (PGPR) is a promising inexpensive strategy for metal clean up from polluted soils. Considering these, metal tolerant plant growth promoting nitrogen fixing rhizobacterial strain CAZ3 identified by 16SrRNA gene sequence analysis as Azotobacter chroococcum was recovered from metal polluted chilli rhizosphere. When exposed to varying levels of metals, A. chroococcum survived up to 1400 and 2000 µg mL−1 of Cu and Pb, respectively and expressed numerous plant growth promoting activities even under metal stress. Strain CAZ3 secreted 65.5 and 60.8 µg mL−1 IAA at 400 µg mL−1 each of Cu and Pb, respectively and produced siderophores, ammonia and ACC deaminase under metal pressure. The melanin extracted from A. chroococcum revealed metal chelating ability under EDX. Following application, strain CAZ3 enhanced growth and yield of maize grown both in the presence of Cu and Pb. The dry biomass of roots of inoculated plants grown with 2007 mg Cu kg−1 and 585 mg Pb kg−1 was increased by 28% and 20%, respectively. At 585 mg Pb kg−1, the bioinoculant also increased the kernel attributes. At 2007 mg Cu kg−1 strain CAZ3 enhanced the number, yield and protein of kernels by 10%, 45% and 6%, respectively. Interestingly, strain CAZ3 significantly reduced the levels of proline, malondialdehyde and antioxidant enzymes in foliage. The roots of inoculated plants accumulated greatest amounts of metals compared to other organs. In kernels, the concentration of Pb was more as compared to Cu. The metal concentrations in roots, shoots and kernels, however, declined following CAZ3 inoculation. Copper and lead had substantial distortive impact on root and leaf morphology while cell death were visible under CLSM and SEM. Conclusively, A. chroococcum CAZ3 could be a most suitable and promising option to increase maize production in metal polluted soils despite the soils being contaminated with heavy metals.

Improving iron bioavailability and nutritional value of maize (Zea mays L.) in sulfur-treated calcareous soil

ABSTRACTSoil factors such as pH, calcium, carbonate, and bicarbonate precipitation products in calcareous soils reduce iron (Fe) availability to crops and limit grain Fe concentrations. In the present greenhouse study, we evaluated the potential of Fe fertilizer amendments combined with organic amendments, like biochar (BC) and poultry manure, in sulfur (S)-treated low pH calcareous soils (pHS1) to assess Fe biofortification of maize. Elemental sulfur (S) was used both for lowering soil pH and Fe solubilization. Soil pH was successfully lowered down from 7.8 to 6.5 by S application at the rate of 2.5 g kg−1 soil. Pot experiment results revealed that Fe fertilizer combined with BC and S (pHS1) significantly increased root and shoot dry weight, grain weight, photosynthetic rate, transpiration rate, and stomatal conductance by 69%, 86%, 28%, 74%, 57%, and 33%, respectively, relative to the control. Similarly, combined application of Fe + BC in S-amended (pHS1) soil increased starch (34%), protein (64%), and fat (1 fold) while antinutrient phytate and polyphenols were decreased up to 29% and 40%, respectively, over control. Regarding the maize nutrients profiles, application of Fe with BC gave the maximum increase of Fe and ferritin was increased 1.7 fold at pHS1. The results of this study showed that Fe fertilization with BC at pHS1 soil is beneficial for crop growth and Fe bioavailability.

Effects of ensiling density on nutritive value of maize and sorghum silages

Studies were conducted to determine the effects of different ensiling densities on fermentation, aerobic stability, and nutritive value of maize and sorghum silages. Maize and sorghum were harvested at dough (363 g/kg) and milk stages (275 g/kg), respectively. Herbages were chopped approximately 1.5 cm after harvest and then ensiled in mini silos at high and low-bulk densities for 8.5 weeks. Different bulk densities were achieved by ensiling different weights of herbage in the fixed-volume mini silos (1.5-L anaerobic jars, Weck, Germany). The obtained dry matter (DM) densities were 168 and 216 kg of DM/m3 for maize forage and 132 and 178 kg of DM/m3 for sorghum forage. Fermentation kinetics, the rate of aerobic deterioration upon aerobic exposure, and nutrient digestibility were followed during the periods of ensiling (on days 2, 4, 8, 15, and 60). In all cases, increased packing density resulted in silages with lower acetate content, ammonium N levels, and fermentation losses, but lactate content did not differ. Butyrate was detected in appreciable amounts only in sorghum silage. Propionate was not detected in any silage. Tightly packed silages remained stable upon exposure to air. Tight packing increases the digestibly of nutrients and improves the energy content of silages. These data show that high density limits air infiltration and reduces the oxidation loss during storage and feed-out. As a consequence, more dry matter is recovered and more energy is preserved.

Genome-Wide Analysis of the Lysine Biosynthesis Pathway Network during Maize Seed Development.

Lysine is one of the most limiting essential amino acids for humans and livestock. The nutritional value of maize (Zea mays L.) is reduced by its poor lysine content. To better understand the lysine biosynthesis pathway in maize seed, we conducted a genome-wide analysis of the genes involved in lysine biosynthesis. We identified lysine biosynthesis pathway genes (LBPGs) and investigated whether a diaminopimelate pathway variant exists in maize. We analyzed two genes encoding the key enzyme dihydrodipicolinate synthase, and determined that they contribute differently to lysine synthesis during maize seed development. A coexpression network of LBPGs was constructed using RNA-sequencing data from 21 developmental stages of B73 maize seed. We found a large set of genes encoding ribosomal proteins, elongation factors and zein proteins that were coexpressed with LBPGs. The coexpressed genes were enriched in cellular metabolism terms and protein related terms. A phylogenetic analysis of the LBPGs from different plant species revealed different relationships. Additionally, six transcription factor (TF) families containing 13 TFs were identified as the Hub TFs of the LBPGs modules. Several expression quantitative trait loci of LBPGs were also identified. Our results should help to elucidate the lysine biosynthesis pathway network in maize seed.

Evaluation of the impact of maize endosperm vitreousness on in vitro starch digestion, dry matter digestibility and fermentation characteristics for pigs

The interest in the study of the effect of endosperm vitreousness (VT) on the nutritive value of maize is increasing in pig nutrition. Therefore, an experiment was conducted to determine the effect of maize VT on starch digestion, resistant starch (RS) content, dry matter digestibility as well as on large intestine fermentation kinetics and related end products by using several in vitro techniques specifically designed for pigs. A set of 30 maize grains was selected to represent a wide range of VT (as a proportion of vitreous in total endosperm) determined by a manual dissection method. Five distinct VT classes were designed [very low (vlVT), low (lVT), medium (mVT), high (hVT) and very high (vhVT)] and identified by a specific VT value (i.e., 291, 357, 432, 611 and 830g/kg endosperm, respectively), calculated as the mean of VT values of maize samples entering the specific class. Starch digestion (expressed as predicted glycemic index) and the rate of starch digestion decreased linearly (ranging from 42.5 to 14.5 and from 0.018 to 0.006/min respectively, for vlVT and vhVT; P<0.05), whereas RS increased linearly (from 183 to 381g/kg dry matter; P<0.05) with VT classes. The total tract in vitro dry matter digestibility decreased linearly (from 0.96 to 0.75; P<0.05) with VT classes. The in vitro fermentation showed that the rate of fermentation decreased (from 0.060 to 0.044/h; P<0.05), whereas the total short chain fatty acid (SCFA) production increased (ranging from 6.29 to 7.29mmol/g dry matter incubated; P<0.05) linearly with VT classes. The molar ratio of acetate linearly increased, ranging from 0.50 to 0.55 (P<0.05) with VT classes, whereas no differences were observed for other individual SCFA. The loading plot of principal component analysis revealed significant relationships between VT and variables of interest. Results indicated that VT promoted marked effects on in vitro parameters related to starch and dry matter digestibility and fermentable kinetics for pigs. Further in vivo validations are required to validate these findings.

Nutritional assessment of transgenic lysine‐rich maize compared with conventional quality protein maize

The gene sb401 encoding a lysine-rich protein has been successfully integrated into the genome of maize (Zea mays), its expression showing as increased levels of lysine and total protein in maize seeds. As part of a nutritional assessment of transgenic maize, nutritional composition, especially unintended changes in key nutrients such as proximates, amino acids, minerals and vitamins as well as in antinutrient (phytate phosphorus), and protein nutritional quality were compared between transgenic maize (inbred line 642 and hybrid line Y642) and conventional quality protein maize (QPM) Nongda 108. The contents of total protein, lysine, some other amino acids, several minerals and vitamin B₂ in transgenic inbred line 642 and hybrid line Y642 were significantly higher than those in conventional QPM. Water-soluble protein and G2-glutelin were significantly promoted in transgenic maize Y642. Insertion of the lysine-rich sb401 gene increased the total protein and lysine content of transgenic maize varieties, leading to an improved amino acid score and therefore an improvement in the nutritive value of maize.

Identification of Low Phytic Acid in a Maize Inbred Line and Primary Screening of Its Molecular Markers

Reducing the content of phytic acid (PA, myo-inositol-1,2,3,4,5,6-hexakis phosphate) is important for improving the nutritional value of maize (Zea mays L.). The identification and application of low phytic acid (lpa) maize germplasm is an economical and effective approach in breeding program. In our previous study, Qi319 was identified as a low phytic acid inbred line. In this study, we found that the content of phytic acid phosphorus in Qi319 kernels is about one fourth of normal maize inbred lines based on quantitative analysis. The characterization of agronomic traits revealed that the germination rate of Qi319 was 75.5%, lower than that of normal inbred lines, however, Qi319 plants grew normally in the field. F2 population was generated by crossing between Qi319 and Lpa241, segregation was found for the content of phytic acid among F2 populations. The segregation ratio of 3:1 confirmed that the lpa trait was determined by a single recessive gene. We then identified two molecular markers (IDP7818 and IDP7635) located on the long arm of chromosome 2 that were co-segregated with low phytic acid loci. This result provides a fundamental basis for marker-assisted maize lpa selection process.

Effect of fermentation on the nutritive value of maize

SummaryThe effects of fermentation on protein, in vitro protein digestibility (IVPD), amino acid, total phenolics, phytic acid and colour values of four maize cultivars (two bi‐colour waxy corn and two super sweet corn), namely Jing Tian Zi Hua Nuo NO. 2, Jing Tian NO. 3, Bright Jean and Su Ke Hua Nuo 2008, were determined and compared with those of their unfermented counterparts. Results showed that fermentation caused significant increase in protein (43.5% largest increase), most kind of amino acid (131.5% largest increase in lysine content) and total phenolic content (23.4% largest increase), but significant reduction in phytic acid content (24.3% largest reduction) of four maize cultivars. The IVPD of four maize cultivars, except Suke2008, did not change significantly. Colour values of two waxy corn were resulted in the increase in a‐values and reduction in L‐values.

Effects of intercropping and fertilizer application on the yield and nutritive value of maize and amaranth forages in Nigeria

AbstractMaize and amaranth forages, produced during the wet season, have the potential to bridge the gap in forage supply to ruminants during the dry season in Nigeria. In two growing seasons (2006 and 2007), effects of intercropping and fertilizer application on dry matter (DM) yield and chemical composition of forages, and land use efficiency, were studied in two experiments. The digestibility of sun‐dried or ensiled maize, amaranth or maize–amaranth mixtures was measured using West African dwarf sheep in a third experiment. Maize showed a higher response to fertilizer application than amaranth or maize–amaranth mixtures. With fertilizer application, DM yield varied significantly (P &lt; 0·05) between species and intercropped mixtures. Dry matter yield ranged from 7·1 (amaranth) to 12·6 t ha−1 (maize) in 2006 and 6·9 (amaranth) to 11·3 t ha−1 (70:30 maize–amaranth population mixture) in 2007. Crude protein (CP) concentration of whole plants ranged from 99·0 (maize) to 227·0 g kg−1 DM (amaranth). Dry matter digestibility values of sun‐dried maize, sun‐dried maize:amaranth 50:50 mixture, sun‐dried amaranth, ensiled maize, ensiled maize:amaranth 50:50 mixture and ensiled amaranth were 0·718, 0·607, 0·573, 0·737, 0·553 and 0·526 respectively. Intercropping increased forage yield and land use efficiency compared to amaranth but had no yield advantage over maize. Although DM digestibility of maize was higher than that of amaranth or the maize:amaranth mixture, digestible CP yield ha−1 was higher with amaranth in the cropping mixture, showing that amaranth could complement maize in systems where CP is the limiting factor to livestock production.

Variability analysis of normal and opaque2 maize inbred lines

Nutritional value of maize is poor due to deficiency of two essential amino acids - tryptophan and lysine. It was shown than opaque2 (o2) mutations can nearly double the lysine and tryptophan content of the endosperm compared with the normal type. Maize Research Institute Gene bank maintains a collection of opaque2 inbred lines developed in the seventies, primarily based on kernel hardness and analytical methods. In order to describe these lines in more detail they were analyzed for tryptophan content and subjected to SSR analysis with opaque2 markers, a marker for endosperm hardness modifier gene and the most significant amino acid modifier markers. Also, a pathogenicity test for inbred lines tolerance to Fusarium spp., which is one of the most important maize pathogens in our region and a causer of maize stalk, root and ear rot, was performed. Differences in tryptophan content between normal and opaque2 lines were significant. All primers used for distinguishing alleles between normal and opaqu2 inbred lines gave positive results. Each genotype gave a specific allelic pattern with amino acid modifier gene primers, without any obvious correspondence to the tryptophan content. Phythopathogenicity test showed on average higher susceptibility to Fusarium graminearum of opaque2 genotypes. These results gave an insight into the applicability of the methods in describing opaque2 lines to be converted into quality protein maize QPM - genotype in which opaque2 has been incorporated along with associated modifiers.

Intestinal function and body growth of broiler chickens on diets based on maize dried at different temperatures and supplemented with a microbial enzyme.

A study was conducted to evaluate the effects of varying drying temperature (Fresh, 85, 95 or 105 degrees C) on the nutritive value of maize and response of broiler chickens to diets based on such grain, and supplemented with a microbial enzyme (Avizyme 1500). The chemical composition of the grain was affected by drying temperature. Starch and amylopectin contents were increased while there was a reduction in amylose content. These changes were expected to underlie the response of chicks to the diets. Total feed intake over 28 days was increased (P < 0.05) as a result of heat-treating the maize up to 95 degrees C. The final body weight of chicks on the diet based on fresh maize was improved (P < 0.05) by the microbial enzyme supplement (MES). There was no effect of the enzyme supplement on body weight when assessed at earlier ages. Over the entire feeding period, feed conversion efficiency (FCE) declined (P < 0.001) with increasing oven temperature, regardless of the supplementation with the microbial enzyme. Body weight was influenced (P < 0.05) by the microbial enzyme only when assessed over the entire trial period. The weight of visceral organs, protein content and activities of pancreatic and jejunal digestive enzymes were unaffected by grain heat treatment or MES. The ileal digestibility of calcium was reduced (P < 0.001) on diets based on fresh maize and maize that was oven-dried at 105 degrees C. Heat-treatment also improved (P < 0.05) the ileal digestibility of phosphorus in chicks on the diets without MES. There were no effects of grain heat treatment or MES on the ileal digestibility of energy, protein, Ca and amino acids. The results indicate some variations in grain quality as a result of heat treatment but the differences were not significant enough to stimulate major responses to the MES. Further studies should examine samples from commercial drying processes or samples obtained from a closer simulation of commercial conditions, to arrive at more practical conclusions.

Nutritive value of maize stover/pasture legume mixtures as dry season supplementation for sheep

Two experiments were carried out to determine the nutrient contents and relative preferences of maize stover and three legumes forages and their feeding on intake and digestibility of sheep. Maize stover was blended with three legumes, stylo ( Stylosanthes guainensis), siratro ( Macroptilium atropurpureum) and centro ( Centrocema pubescens), to produce four treatments, namely, only maize stover (control), stover/stylo, stover/siratro and stover/centro mixtures. The first experiment evaluated the relative preference of the stover and the various stover/legume mixtures when offered to sheep. Six rams were offered pair combinations of the treatments in a 6×6 Latin square with a split plot arrangement such that each ram had access to two feeds at a time in each period of 6 days. The second experiment included measurements of intake and digestibility of the stover and stover/legume mixtures. Four intact and four castrated male sheep were used in two, 4×4 Latin squares with 21-day periods. The least ( P<0.05) preferred feed was maize stover when it was offered as the sole feed. There were no significant differences in preference among the stover/legume mixtures. Dry matter intake (DMI) was highest ( P<0.05) when sheep were offered the stover/centro mixture and lowest ( P<0.05) when maize stover was fed as the sole feed. Dry matter digestibility did not differ significantly among treatments. Sheep that were offered maize stover only lost weight, those fed stover/centro gained weight and those that were fed either stover/siratro or stover/stylo maintained weight. However, these short-term weight changes may reflect changes in fill as much as changes in body tissue. Addition of legumes to maize stover improved the nutritive value, possibly by increasing the nitrogen content of the stover. The results suggest that maize stover, which is normally left to rot in the field, could be better utilised by intercropping with legumes and allowing animals access after grain harvest.

Influence of maturity stage on in situ dry matter degradability of six maize varieties in fistulated sheep

The fresh weight, dry matter (DM) contents and nutritional quality in maize vary considerably with variation in varieties, stages at which harvested, climatic conditions and agronomic factors. Recently, agronomists, nutritionists, and dairy producers have placed increased emphasis on factors affecting the nutritive value of maize. However, very little information is available on quantitative variability of the feed value of maize fodder as affected by such factors. This study was, therefore, carried out to assess the effect of harvesting of six different maize varieties at two stages (dates) of grain maturity on quality of both the stover and cobs.

Chemical evaluation of the effect of roasting on the nutritive value of maize ( Zea mays, Linn.)

This study reports on the effects of roasting on the chemical composition of maize ( Zea mays). Proximate analysis showed no significant difference ( p > 0·05) between raw and roasted maize in ether extract, crude protein, crude fibre, ash and carbohydrate content; except moisture content ( p < 0·05), which showed a 42·3% decrease. Elemental composition analysis showed decreases of potassium (13·8%) and calcium (41·1%). Significant differences ( p < 0·05) were observed for vitamins B 1, B 2 and C contents with 26·8%, 32·4% and 35·1% destruction, respectively. Amino acid analysis showed losses for lysine (26·7%), iso-leucine (20·8%) and leucine (23·4%). There was significant ( p < 0·05) variation in phytic acid, oxalic acid, tannin and hydrocyanic acid with reductions of 15·4%, 6·02%, 51·3% and 34·6% respectively. The effect of these changes on the nutritive value of roasted maize is discussed.

INFLUENCE OF POPULATION DENSITY AND HYBRID MATURITY ON PRODUCTIVITY AND QUALITY OF FORAGE MAIZE

Nine maize hybrids, representing early, medium and late maturities (maximum 3000 corn heat units), were grown at 75 000 and 100 000 plants/ha for 2 yr at two locations in order to examine the in vitro digestible dry matter (DDM) yield and quality of whole-plant (shoot) and stover components. Early hybrids produced 90% as much DDM yield as medium or late hybrids. Comparing densities, the higher density resulted in a greater increase in DDM yield at Surrey than at Agassiz and it did not depress whole-plant dry matter (DM) content. Whole-plant DM digestibility (DMD) was 2% lower for early hybrids compared to mediums or lates. Density had no influence on whole-plant DMD at Surrey, but the higher density reduced it by 1% at Agassiz. Stover DDM yield was greater at Surrey than at Agassiz whereas whole-plant DDM yield was greater at Agassiz. Harvest index was positively, but not closely, correlated with whole-plant DMD (r = 0.28***) and was inversely correlated with stover DMD (r = − 0.45***). Thus, nutritive value of maize was only marginally dependent on the grain component. Results suggest that, in the marginal corn-growing environments of the region studied, it may be beneficial to use hybrids considerably later than those normally adapted and grow them at a density approaching 100 000 plants/ha to maximize digestible yields and quality. The harvested forage may have a DM content too low for direct ensiling, but this can be rectified by addition of dry high-protein supplements (e.g. alfalfa cubes) at ensiling time.

Food protein sources.

Work on food, planned by the U.M. (Use and Management) Section of the U.K. committe, was limited to sources of protein because we agreed that more problems calling for research were likely to arise in getting adequate supplies of protein than of other types of food. Deer meat can be produced on land too rough and exposed for sheep; parts of the work on their metabolism and food requirements necessitated building a mobile laboratory. The manner in which the nutritive value of maize is affected by changes in the ratios in which the component proteins are present, stimulated similar studies on barley and groundnut. There is good quality protein in coconuts and leaves but its use in human food is restricted by the presence of fibre. Methods for separating protein from fibre and other deleterious components were improved. In cooperation with scientists in India and Nigeria, the potential yield of protein-deficient foods. e.g. cassava, were 'ennobled' by growing micro-organisms on them with the addition of a cheap source of nitrogen.

Influence of cooking upon the nutritive value of potato and maize in diets for growing pigs

AbstractDiets containing 50% of the dry matter (DM) as barley, cooked flaked maize, ground maize, cooked flaked potato, or 22% of the DM as raw potato had metabolisable energy (ME) values of 14.5, 15.2, 15.1, 15.1 and 14.5 MJ/kg DM respectively, and efficiencies of N retention of 0.40, 0.41, 0.42, 0.42 and 0.31. Cooking potato had a positive effect upon the ME value and the efficiency with which ingested nitrogen (N) was retained. Any single nutritive value for raw potato was considered inappropriate due to the influence of raw potato on the digestibility of other diet components.Pigs fed a diet containing cooked potato grew faster and converted feed to live weight more efficiently than pigs fed the same amount of a diet containing between 14 and 26% of the DM as raw potato. The presence of raw potato in diets was also found to reduce appetite. Cooking maize appeared to have only a small effect upon the nutritive value of maize. Pigs fed diets containing cooked flaked maize grew slightly faster than pigs fed ground maize.