Available carbohydrates of cereal grains as affected by storage and insect infestation

Total soluble sugar, reducing sugar, non-reducing sugar and starch contents of wheat, maize and sorghum grains were affected adversely at 25, 50 and 75% insect infestation caused byTrogoderma granarium Everts andRhizopertha dominica Fabricius, separately and mixed population.R. dominica caused significant (P<0.05) reduction in available carbohydrates at 50 and 75% infestation levels whereasT. granarium achieved similar effect at 75%. Mixture of both insect species caused intermediate losses. Storage of cereal grains up to 4 months resulted in substantial increase in sugars and decrease in starch content, but storage for a shorter period of time did not cause any significant changes in levels of carbohydrates.     

Vitamin contents of cereal grains as affected by storage and insect infestation

There were substantial losses in thiamine, riboflavin and niacin contents of wheat, maize and sorghum grains at three infestation levels (25, 50 and 75%) caused by releasing two insect species viz.,Trogoderma granarium andRhizopertha dominica separately and mixed population. Losses were to the extent of 65 to 69% (thiamine), 50 to 67% (riboflavin) and 10 to 32% (niacin) due toT. granarium and 23 to 29% (thiamine), 13 to 18% (riboflavin) and 4 to 14% (niacin) due toR. dominica at 75% level of infestation in three cereal grains. Storage of grains (1–4 months) in insect free conditions did not show appreciable changes in the vitamin contents.     

Nutritional evaluation of spent grains from sorghum malts and maize grit

Potential use of the high protein by-product of beer production from 77% sorghum malt and 23% maize grit was investigated. Red sorghum spent grains (RSSG) and white sorghum spent grains (WSSG) contained 23.4 and 19.3% crude protein (CP), 54 and 43% dietary fiber (NDF), 1.44 and 0.78% ash, 4.5 and 3.2% hexane extract and tannin content of 7.5 and 1.0 mg/g catechin equivalent respectively. Magnesium was the most abundant mineral in both RSSG and WSSG — 185 and 140 mg/kg, respectively. Calcium, zinc, iron and copper were generally low. Both samples contained cadmium 1.12 (WSSG), 1.19 (RSSG) and lead at 1.38 mg/kg. Lysine was the limiting amino acid (chemical score 0.55) in both samples. Other essential amino acids were adequate or surplus. Stearic acid was the predominant fatty acid with varying levels of lauric, myristic, palmitic, and oleic acids in both samples. Feed intake and weight gain were highest in rats fed 26.3% WSSG (contributing 50% of the diet protein) but protein efficiency ratio (PER) and net protein retention (NPR) were highest in diets where spent grains contributed just 25% of the diet protein. True digestibility of diets decreased as dietary fiber content increased such that animals on diets containing 100% spent grain protein (above 20% NDF) lost weight.     

Amino acid composition and chemical evaluation of protein quality of cereals as affected by insect infestation

A significant decrease in essential amino acids of wheat, maize and sorghum was observed due to grain infestation caused by mixed populations ofTrogoderma granarium Everts andRhizopertha dominica Fabricius (50:50). Non-essential amino acids were also adversely affected. Among the essential amino acids, maximum reduction was found in methionine, isoleucine and lysine in infested wheat, maize and sorghum grains, respectively. Lysine, with lowest chemical score in uninfested and infested grains of three cereals, is the first limiting amino acid. Insect infestation caused significant (p<0.05) reduction in the chemical score of all the essential amino acids, yet did not change the position of first and second limiting amino acids in wheat and sorghum. However, in case of maize, isoleucine became the second limiting amino acid. Infested grains also showed substantial reduction in essential amino acid index, calculated biological value and requirement index.     

Protein quality evaluation of a weaning food based on malted ragi and green gram

The nutritional quality of a malted weaning food developed using malted ragi (Eleusine coracana) and green gram (Phaseolus radiatus) was evaluated by rat feeding trials. The protein score of the weaning food was 70 calculated according to FAO/WHO (1973) pattern. The protein efficiency ratio (PER), net protein utilization (NPU), biological value (BV) and true digestibility (TD) values for the weaning food proteins at 10% level of protein intake were 2.2, 51.6, 73.8 and 82.8, respectively and the relative protein value (RPV), determined at 5, 8 and 11% levels of protein intake was 84. Supplementation of the weaning food with 10% skim milk powder enhanced the PER to 2.7 and NPU to 63.0. The nutritional quality of a roller dried proprietary weaning food was also evaluated along with malted weaning food for comparison and it was observed that the nutritional quality of the two products were comparable.     

Farmers’ perceptions and management practices of insect pests on stored sorghum in southwestern Ethiopia

Surveys were undertaken in six districts of southwestern Ethiopia from July to October 2003 to investigate farmers’ perceptions and management practices of insect pests on traditionally stored sorghum. The survey involved 138 randomly selected farmers who were interviewed using a semi-structured questionnaire. Storage insect pests were perceived as the major insect pests of sorghum. The majority of the farmers estimated sorghum yield losses of up to 50% due to insect damage during storage. High temperature and lack of storage hygiene were cited as the major factors resulting in insect infestation of stored sorghum. Infestations of stored sorghum insect pests were common on different forms of sorghum, which stored in various types of farm storage. Farmers classified sorghum varieties according to the level of resistance to stored sorghum insect pests. Only about 32% of the farmers had access to chemical insecticides for the control of stored sorghum insect pests, while the majority of them used cultural practices and locally available plant materials as storage protectants.     

Re-ensiling effects on inoculated sorghum: Intake,apparent digestibility,nitrogen balance,and animal feeding behaviour

This study aimed to determine whether using inoculants and re-ensiling in sorghum silages affect the intake and feeding behaviour, apparent digestibility, digestible energy, and nitrogen balance of sheep in maintenance. Half the sorghum was inoculated on the day of harvest, and the other half received the same inoculation volume but with water. Sorghum was ensiled in 100 experimental metal drum silos of 200 L covered with plastic: 50 silos with inoculants and 50 without them. After 56 days, 25 drums with inoculants and 25 without were exposed to air for 48 h. The other silos remained closed. The treatments were arranged in a 2 × 2 factorial scheme with inoculation and re-ensiling. The sheep received the silages after 211 days of ensiling and 155 days of re-ensiling to determine the intake, apparent digestibility, and feeding behaviour of animals. The experimental design was a simultaneous double 4 × 4 Latin square. The re-ensiling process increased silage pH, N-NH₃.TN⁻¹, butyric acid, and propionic acid. The inoculant increased propionic acid in ensiled and re-ensiled silages. Lactic acid concentration presented a statistical interaction with the inoculated and ensiled silage, 58% higher than the other treatment averages. The ADFap digestibility showed a complex interaction, in which the control ensiled and the inoculated and re-ensiled silages were about 35% lower than the inoculated ensiled silage. The Nbal:Nint ratio (g.g⁻¹) in the inoculated and re-ensiled silage had lower nitrogen retention than intake compared with the other treatments. These results indicate that exposing inoculated silages to air does not compromise their use in sheep feeding.     

Biological utilisation of pearl millet fluor fermented with yeasts and lactobacilli

Mixed culture fermentation of pearl millet flour withSaccharomyces diastaticus, Saccharomyces cerevisiae, Lactobacillus brevis andLactobacillus fermentum brought about an improvement in its biological utilisation in rats. Protein efficiency ratio, feed efficiency ratio, apparent protein digestibility, true protein digestibility, net protein utilisation, net protein retention, protein retention efficiency and utilisable protein values in case of pure culture fermented pearl millet four were higher than the control. Feeding of the fermented products did not bring about physiological, histopathological and haematological changes in rats.Chapaties and cutlets prepared from the fermented products were organoleptically acceptable.     

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.     

Disease and pest resistance in grains of sorghum and millets

In this review available information on the mechanisms of resistance to insect pests and fungal pathogens in sorghum and millets is discussed. The primary source of resistance lies in the chemical and physical make up of the grain. Phenolic compounds such as ferulic acid and tannins present in some sorghums are potent inhibitors of pests and pathogens. Grain hardness is a major deterrent to infection and infestation in low tannin grains. The prolamins, the grain storage proteins of sorghum, are organized into protein bodies and provide a physical and a nutritional barrier since they are resistant to digestion by insect and fungal proteases. A plethora of proteins that belong to the ‘pathogenesis related protein’ group are distributed in various parts of the grain. Some of them are located in protein bodies. Notwithstanding, sorghum is still susceptible to insect pests and fungal pathogens. An understanding of the natural mechanisms of resistance in the grain is paramount for the development of durable resistance against pests and pathogens. The pyramiding of resistance genes and the development of transgenic lines based on this understanding are two sources of hope for the future protection of sorghum and millets.     

Influence of processing conditions on the nutritive value of Ogi-baba,a Nigerian fermented sorghum gruel

The effect of germination, cowpea fortification and fermentation on thechemical and amino acid composition of ogi-baba, a Nigerian fermented sorghum gruelwas investigated. The lowest protein value of 1.4% was obtained in the traditionally preparedsample, while samples prepared from germinated, fortified sorghum had 13%. The ash ranged from 0.9% to above 2%, while the fat was in the range of 1.2% to2.8%. Generally, fortification, in addition to germination, improved the chemicalcomposition of ogi-baba relative to the control sample. There was improvement in the amino acidprofile of all the ogi-baba samples compared to the unprocessed sorghum grains.Lysine, a limiting amino acid in sorghum, increased more than 50% in ogi-baba. However, samples prepared using germinated sorghum without the addition of cowpeas hada lower lysine content.     

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.     

Intercropping of orchardgrass and alfalfa improves soil fertility,forage yield,feeding values and land use efficiency while limiting ruminal greenhouse gas emissions

Intercropping has been a globally accepted practice for forage production, however, consideration of multiple performance criteria for intercropping including forage production, feed use efficiency and ruminal greenhouse gas emissions needs to be further investigated. A two-year field study was conducted to evaluate forage dry matter (DM) yield, nutritive value, feeding values and land-use efficiency as well as ruminal carbon dioxide (CO₂) and methane (CH₄) emissions of intercropped orchardgrass (Dactylis glomerata) and alfalfa (Medicago sativa) sown in five intercropping ratios (100:0, 75:25, 50:50, 25:75, and 0:100, based on seed weight) and three nitrogen (N) fertilizer levels (0, 50, and 100 kg ha⁻¹). Increasing alfalfa proportion and N fertilizer level increased soil nutrients and the two-year total DM yield. Intercropping increased both land and nitrogen use efficiency (NUE) compared with monocultures. Greater NUE was obtained when N fertilizer was applied at 50 kg ha⁻¹, compared with 100 kg ha⁻¹. Increasing the proportion of alfalfa in intercrops increased the crude protein yield and rumen undegraded protein yield. Harvested forage intercrops were incubated with ruminal fluid for 48 h. Degraded DM yield, CO₂ and CH₄ emissions increased with increasing alfalfa proportion in intercrops. Overall, the 75:25 of orchardgrass-alfalfa intercrops was recommended as the best compromise between high forage productivity, superior feed use efficiency and low ruminal greenhouse gas emissions through complementary effects. The results indicate that the appropriate N fertilization level would be 50 kg ha⁻¹ for acquiring higher nitrogen use efficiency and forage productivity.     

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.     

Effect of incorporating ragi (Eleusine Coracana) husk in semisynthetic diets

The effect of including ragi husk in the diet, at the 8 per cent level, on growth and body composition of pair-fed albino rats was studied. Even on equal food intake by both control as well as the experimental animals, the incorporation of ragi husk promoted better growth, nitrogen retention and protein efficiency ratio. Protein content of the carcass and liver of rats fed diets containing ragi husk was higher than the control group. The growth response of rats fed ragi husk appeared to increase with the content of nitrogen in the husk.     

Biological evaluation for protein quality of supplementary foodsbased on popped cereals and legumes suitable for feeding rural mothers andchildren in India

Eight different formulations of supplementary foods (FS) based on poppedcereals (wheat, ragi, bajra and sorghum) and legumes (soy and bengalgram)were prepared. Four of the FS were produced with cereals, soy flour (SF)and bengalgram (BG) dhal and the other four were prepared with combinationsof cereals and SF. These blends were evaluated for food efficiency ratio(FER), protein efficiency ratio (PER) and net protein utilization (NPU)using growing albino rats. Skim milk powder (SMP, standard reference protein)was used in the control diet. In general the FER (0.28 to 0.34), PER (2.7to 2.9) and NPU (62 to 68) results of the FS were not significantly (p>0.05)different among the FS groups or compared with FER (0.36), PER (3.0) and NPU(73.5) of the control SMP. It is evident from the results that all eight FSwere nutritionally and biologically as good as SMP with regard to proximatecomposition, PER and NPU.     

Iron and phosphorus utilization in rats fed soaked and dehulled bambara groundnut supplemented with sorghum or crayfish

Thirty-six adult Wistar albino male rats (75–128 g) of age 8 weeks were used to study the effect of dehulled and soaked bambara groundnut combined with sorghum or crayfish on iron and phosphorus balances of rats fed for 10 days. Three out of the ten days were for adjustment and the rest for the balance period. Six diets were formulated and fed to the rats. The mixed protein diets provided 10% protein daily for the entire study period. Casein(CA) served as a reference protein. Rats fed the CA diet had significant decreases (p < 0.05) in food intake, maintenance body weight, phosphorus intake and phosphorus balance when compared with those of the test groups. As judged by iron nutriture, dehulled brown bambara groundnut (DBGB) appeared to be superior to the white variety. Soaking seriously affected iron utilization in brown variety. Dehulling produced significant increases (p < 0.05) in phosphorus balance in animals fed the white variety of bambara groundnut compared with the brown variety. On the other hand, soaking produced positive phosphorus balance in rats consuming the brown variety. Addition of crayfish produced a slight nonsignificant decrease (p > 0.05) in rodents eating the brown variety. These results suggested that varietal difference and treatment affected iron and phosphorus utilization in rats fed bambara groundnut in conjunction with sorghum and/or crayfish.     

Biological utilization of vegetable peas: Effect of cooking and varietal differences

The flour of raw as well as cooked vegetable pea cultivars (Arkal and Bonneville) was used for biological evaluation of their protein quality. Cooking did not have a significant influence on the food intake. There were some differences in the food as well as protein intake and gain in body weights of rats when fed uncooked or cooked pea flour diets. Varietal differences did not seem to influence on apparent digestibility, true digestibility, biological value, net protein utilization and utilisable protein but cooking brought a significant (p<0.05) improvement in all of above mentioned parameters. Varietal differences as well as cooking exhibited no influence or serum protein concentration.     

Supplementation of irradiated and non-irradiated cowpea bean (Vigna unguiculata L. Walp) protein with cereal proteins

The quality of the cowpea bean protein was improved through supplementations with flours from beans exposed to microwave oven treated with cereal proteins such as wheat, rice, corn, and sorghum. Biological assays results with these blends showed that the casein exceeded the other diets concerning digestibility only; however, in parameters such as biological value, net protein utilization (NPU), protein efficiency ratio (PER) and nutritional efficiency ratio (NER), no significant differences occurred. Among all elaborated blends, the one with irradiated beans submitted to microwave oven for 30 minutes (65%) + rice (35%) presented the best results. The soup elaborated with the best supplemented blend was satisfactory concerning color, odor, flavor and texture.     

Biological evaluation of pearl millet protein: effect of different treatments and storage

Whole grain flour of one variety (HC-4) of pearl millet (Pennisetum americanum L. Leeke) after giving different treatments (defatting, butylated hydroxyanisole, ascorbic acid and thermal) was stored in earthen pots at prevailing room temperature (28–34°C) and relative humidity (70–80%) for 30 days. The flour samples were evaluated for protein quality using rats. Storage of flour for 30 days markedly reduced the protein quality. The values of protein efficiency ratio, true digestibility, biological value, net protein retention and net protein utilisation were significantly (P<0.05) higher in fresh and treated flour than untreated flour. Among treated flours, defatted flour showed best growth followed by butylated hydroxyanisole, thermal and ascorbic acid treated flour.