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Epidemiological studies have suggested that intake of whole grains is inversely associated with coronary artery disease. The mechanisms, however, are not completely clear. We tested the hypothesis that intake of wheat bran or corn bran would (1) increase the plasma concentration of phenolic antioxidants and (2) reduce atherosclerosis in apo E-knockout mice. Apo E-knockout (E-KO) mice were fed for 18 weeks with a 0.1% cholesterol-supplemented diet in the absence of grain brans or the presence of 1.7% yellow dent corn bran or 3.3% hard red spring wheat bran. The concentration of antioxidant ferulic acid in plasma and urine was measured by HPLC to monitor the bioavailability of grain phenolics. Plasma lipoprotein profiles were determined by a combination of HPLC and online enzymatic methods. Urinary 15-isoprostane F(2t), an in vivo LDL oxidation biomarker, and atherosclerotic lesions were analyzed by ELISA and histological methods, respectively. Dietary supplementation with corn or wheat bran resulted in a 4- and 24-fold increase, respectively, in urinary excretion of ferulic acid. The urinary recovery rate of ferulic acid from the two brans in apo E-KO mice was approximately 1.9-2.9%. Dietary corn bran but not wheat bran also significantly increased the concentration of total ferulic acid in plasma. Nevertheless, the supplementation with either bran product for 18 weeks did not significantly alter the urinary excretion of 15-isoprostane F(2t), change the lipoprotein profiles, nor reduce the atherosclerotic lesion development in this animal model. The results suggest that phenolic antioxidants from the two types of bran may not be sufficient to reduce atherosclerosis in this animal model.

Short hot and dry spells before, or during, silking have an inordinately large effect on maize (Zea mays L.; corn) grain yield. New high yielding genotypes could be developed if the mechanism of yield loss were more fully understood and new assays developed. The aim here was to determine the effects of high temperature (35/27 degrees C) compared to cooler (25/18 degrees C) temperatures (day/night). Stress was applied for a 14 d-period during reproductive stages prior to silking. Effects on whole plant biomass, ear development, photosynthesis and carbohydrate metabolism were measured in both dent and sweet corn genotypes. Results showed that the whole plant biomass was increased by the high temperature. However, the response varied among plant parts; in leaves and culms weights were slightly increased or stable; cob weights decreased; and other ear parts of dent corn also decreased by high temperature. Photosynthetic activity was not affected by the treatments. The (13)C export rate from an ear leaf was decreased by the high temperature treatment. The amount of (13)C partitioning to the ears decreased more than to other plant parts by the high temperature. Within the ear decreases were greatest in the cob than the shank within an ear. Sugar concentrations in both hemicellulose and cellulose fractions of cobs in sweet corn were decreased by high temperature, and the hemicellulose fraction in the shank also decreased. In dent corn there was no reduction of sugar concentration except in the in cellulose fraction, suggesting that synthesis of cell-wall components is impaired by high temperatures. The high temperature treatment promoted the growth of vegetative plant parts but reduced ear expansion, particularly suppression of cob extensibility by impairing hemicellulose and cellulose synthesis through reduction of photosynthate supply. Therefore, plant biomass production was enhanced and grain yield reduced by the high temperature treatment due to effects on sink activity rather than source activity. Heat resistant ear development can be targeted for genetic improvement.

An experimental (7B) and a commercial (AMA) formulation of enzymes, both primarily with alpha-amylase activity, were evaluated for activity at various pH values, stability in ruminal fluid, the potential to improve in vitro ruminal fermentations, and the potential to improve production performance of lactating cows. When incubated (40 degrees C) in buffer with a pH between 5.4 and 6.0, 7B had about 10 to 25 times greater amylase activity than AMA, and enzyme activity in this range increased by 100% for 7B, whereas activity decreased by about 26% for AMA. Both formulations maintained enzyme activity when they were incubated in in vitro ruminal fermentations for 24 h. After 6 h of ruminal in vitro fermentation, additions of 7B resulted in linear increases in apparent total volatile fatty acid production for flint and dent corn but had no effect on floury corn. In a lactation trial, 28 Holstein cows (68 +/- 31 d in milk, 46.9 +/- 9.1 kg of milk/d) were fed a total mixed ration (TMR) supplemented with nothing (CON), a low dose of 7B [7BL, 0.88 mL/kg of TMR dry matter (DM)], a high dose of 7B (7BH, 4.4 mL/kg of TMR DM), or AMA (0.4 g/kg of TMR DM). The experiment was conducted as a 4. 4 Latin square design with 21-d periods. Cows fed 7BL, 7BH, and AMA ate similar amounts of DM, and cows fed the latter 2 diets consumed more DM than did cows fed CON. Cows fed 7BL produced more milk than cows fed CON and 7BH, but produced similar amounts to cows fed AMA. The production of 3.5% fat-corrected milk was greater from cows fed 7BL and AMA compared with cows fed CON. The percentages of milk fat and milk protein were unaffected by treatment. Total-tract digestion of DM and organic matter were greater for cows fed 7BL compared with those fed CON. The addition of exogenous amylase enzymes to the diets of lactating dairy cows has the potential to improve animal productivity.

(...) Field studies were conducted from 1983 to 1986 to determine impact of female row position relative to male pollinator rows on yield of inbred dent corn grown under hybrid seed production conditions. During the first 2 yr, three inbred genotypes differing in pollen production were used as pollen sources with a common female inbred. During the last 2 yr, three female genotypes were used with a common male. When compared with rows adjavent (30 in.) to pollinator rows, each additional 30 in. row distance from the pollinator caused an average reduction of about 550000 seeds/acre. (...)

(...) The objective of this study was to determine the relative forage yields, forage quality, and returns over production costs of the four crops. The silage fermentation characteristics of each crop also were determined. Studies were conducted in southern Minnesota on a Waukegan silt loam (fine-silty, over sandy-skeletal, mixed mesic Typic Hapludoll) and a Webster clay loam (fine-loamy, mixed mesic Typic Haplaquoll). Fodder dry matter yields of popcorn and sweet corn were similar and averaged 42% lower than those of dent corn and sorghum (average yield of 8.9 ton/acre). (...)

Improvement of expansion volume, defined as the volume of popped corn per gram of unpopped corn, generally is considered the most important objective of popcorn (Zea mays L.) breeding programs. Popcorn, however, generally is inferior to dent corn with respect to yield and other agronomic characteristics. Detailed information on the inheritance of expansion volume and grain yield in popcorn × dent corn crosses was not available in the literature. The objective of this study was to determine the inheritance of expansion volume and grain yield, including yield components, in two popcorn × dent corn crosses (...)

The objectives of this study were to determine the effect of enzyme and yeast dose on starch-to-glucose and glucose-to-ethanol conversions for the production of ethanol and sugars during the simultaneous saccharification and fermentation (SSF) process used in the dry grind ethanol industry. Fermentations were performed on a yellow dent corn hybrid with 3 enzymes doses (80, 110, and 140 µL) of spirilizyme glucoamylase enzyme and 3 yeast doses (2, 4, and 6 mL of 0.1 g/mL of yeast water slurry) with 3 replicates. Samples were drawn after 2, 4, 6, 8, 10, 12, 24, 48, and 72 hours from the start of the fermentation. Samples were analyzed using HPLC and FT-NIR spectroscopy for the ethanol and sugar contents. Enzyme and yeast doses both had significant effects on the level of sugar present during the SSF process. However, only yeast dose significantly affected ethanol content. Measuring enzyme and yeast dose using NIR provides a dynamic way to optimize the process.

The objectives of this experiment were to determine effects of reducing particle size on growth performance, carcass characteristics, stomach morphology, and VFA concentration in the hindgut of growing-finishing pigs if diets were formulated to a constant ME. Thirty-six gilts and 36 barrows (32.00 ± 1.58 kg initial BW) were individually penned and randomly allotted to 4 dietary treatments in a 2 × 4 factorial design with sex (gilts and barrows) and corn particle size (i.e., 865, 677, 485, and 339 μm) as factors. The ME was determined in the same 4 batches of corn in a previous experiment to be 3,826, 3,868, 3,895, and 3,964 kcal/kg DM, respectively. Pigs were fed a 3-phase program from 32 to 129 kg. Within each phase, 4 corn-soybean meal diets were formulated, and the only difference among diets was that the corn used was ground to the 4 specified particle sizes and soybean oil was added to the diets in decreasing amounts as the corn particle size was reduced to reflect the increased ME in corn with reduced particle size. Results of the experiment indicated that initial BW, final BW, overall ADFI, and overall ADG were not different among treatments, but final G:F for gilts decreased from 0.38 to 0.35 (linear, < 0.05) as the particle size decreased from 865 to 339 μm, but no difference was observed for barrows (interaction, < 0.05). However, G:F did not change if calculated based on HCW because dressing percentage increased (linear, < 0.01) from 79.30 to 80.29% as the particle size decreased, which was partly due to a reduction (linear, < 0.01) from 3.01 to 2.52 kg in empty intestinal weight. Back fat depth, HCW, loin eye area, and carcass fat-free lean percentage were not different among treatments. There were no incidences of ulcers in the esophageal region of the stomach regardless of the particle size of corn, but parakeratosis in the esophageal region increased ( < 0.05) as the particle size of corn decreased. The concentration of acetate, proprionate, and butyrate in the cecal contents decreased (linear, < 0.01) from 2,537 to 1,846, from 872 to 617, and from 702 to 226 μg/mL, respectively, and the pH in the cecal and colon contents increased (linear, < 0.01) from 6.04 to 6.64 and from 5.85 to 6.25, respectively, as the particle size decreased. In conclusion, by using corn ground to a smaller particle size, the amount of added fat may be reduced in the diets without affecting growth performance of barrows or carcass composition of barrows and gilts.

The best operational conditions for puffing dent corn grits with a rice cake machine were 14% grit moisture, 215°C and 9 sec. Salting and steaming, low pH soaking medium, larger corn grit sizes, 2% glycerin, and 2% corn oil tended to increase puffed volume of the corn cakes. Smaller grit sizes, 3% alcohol and high pH soaking medium had negative effects on corn cake volume. Acid-modification of corn starch, 1% or 3% corn oil, and up to 10% sugar had no effect.

Laboratory-reared adults of the tachinid parasitoid, Archytas marmoratus Townsend, were released and evaluated against larvae of Heliothis zea (Boddie) in whorl stage corn during 1986–1988. Resulting rates of parasitism by A. marmoratus on H. zea larvae occurring at 0.3, 0.5, and 1.0 per row-m were 58.3, 44.2, and 52.8%, respectively, when about 340 females/ha were released, and 45.9, 38.2, and 32.1%, respectively, when about 170 females/ha were released. In both studies, no significant differences ( P > 0.05) in rates of parasitism were found between host densities. The number of H. zea larvae parasitized by A. marmoratus increased linearly over the range of host densities studied. This suggests that per capita mortality is density-independent and, therefore, should not increase or decrease as host density is varied within the range of early season populations. A. marmoratus females appeared to disperse predominately into the prevailing wind. Rates of A. marmoratus parasitism were significantly higher (P < 0.05) on fourth and fifth instars than on third instars. Approximately 370 and 860 female A. marmoratus /ha would be needed to yield 50 and 80% parasitism of fourth and fifth instars of H. zea , respectively, in 9–14-leaf stage dent corn. Data suggest that A. marmoratus females are highly efficient in finding larvae of H. zea in whorl stage corn, and that rates of parasitism observed in the relatively small release areas are likely far lower than could be expected from sustained releases throughout large corn ecosystems wherein the effects of predominately unilateral movement from release areas would be minimized. With the development of economical methods of mass propagation, A. marmoratus likely could play a major role in the safe, efficient, and selective management of the early season populations of H. zea in whorl stage corn.

Additional index words. Zea mays, Sphacelotheca reiliana, vegetable breeding Abstract. The inheritance in corn (Zea mays L.) of resistance to head smut disease incited by Sphacelotheca reiliana (Kuhn) Clinton was studied in the field on crosses of resistant dent corn line N6 with two susceptible sweet corn (su1) inbred lines. Disease incidence in the resistant parent (Pr) was 0% to 4%, and 83% to 96% in the susceptible parent (Ps). Predisposition of seedlings by clipping just above ground level increased percent infected in progeny populations by as much as 4-fold, but did not affect disease incidence in the, parents. At the lower disease incidence of unclipped plots, the F1, F2, and BCr means were close to the mean of Pr, suggesting dominance of resistance. At the high disease incidence of clipped plots, the relationship of parent and progeny means "suggested additive inheritance. Epistasis was also generally present with a higher level indicated for unclipped plots. Inheritance was concluded to be quantitative. Reciprocal differences were observed only in backcrosses. In the F 2 and BCS populations, plants grown from dent (Su1) seed were lower in disease incidence than plants grown from sul seed. Head smut, incited by Sphacelotheca reiliana, affects corn, sorghum, and sudan grass (Halisky, 1963). The disease is ini- tiated by infection of seedlings, either through the roots or co- leoptile (Kruger, 1962). The mycelium becomes systemically established in the meristem and eventually produces large sori that replace the normal ears and sometimes form in the tassel (Halisky, 1963; Potter, 1914). Because loss of the ear is assured when the seedling is infected, degree of host susceptibility is expressed by disease incidence. Corn cultivars differ in potential for infection under a particular set of conditions that involve environmental factors such as soil moisture, level of smut in- oculum in the soil, and host predisposition (Ali and Baggett, 1986; Baggett and Koepsell, 1983; Baier and Kruger, 1962; Halisky, 1963; Mack et al., 1984; Matyac and Kommedahl, 1985). Wide differences in cultivar susceptibility to head smut have been reported (Baggett and Koepsell, 1983; Foster and Frederiksen, 1977; Kruger, 1962; Ma et al., 1983; Stromberg et al., 1984). Several studies of the inheritance of resistance to head smut have been reported. Mei et al. (1982), in China, reported that the inheritance of resistance is quantitative. In 69 of 85 crosses studied, inheritance was mainly additive, with the F 1 close to the midparent in disease incidence. In 14 of 85 crosses, disease incidence was higher than in the midparent, and in 2 of 85 crosses, disease incidence was lower than in either parent, in- dicating resistance was over-dominant. Ma et al. (1983), also in China, reported that resistance was quantitatively inherited and was dominant, recessive, or controlled by the interaction of several non-allelic genes, depending on the parents. Additive gene effects were also important and there was a positive cor- relation between resistance in the F 1 and the parents. Stromberg et al. (1984) found that F 1 hybrids were intermediate between Pr and Ps in smut incidence. Our objective was to elucidate the inheritance of resistance to head smut as expressed by infection incidence in the field under natural conditions but with high infection potential pro- vided by seed furrow inoculation. We also sought to compare

Four hybrids of yellow dent com were harvested at three levels of moisture content. After drying, samples were analyzed for stress cracking and susceptibility to breakage in Wisconsin (WBT) and Stein (SBT) breakage testers. Significant differences in stress cracking and breakage susceptibility as determined with the WBT and the SBT were observed among the four hybrids. Breakage susceptibility as measured with the WBT and SBT significantly increased as the harvest moisture increased. Stress cracks increased significantly as harvest moisture increased within the drying air temperatures of 49, 71, and 93° C. WBT breakage susceptibility significantly increased as drying air temperature increased. Stress cracking was more highly correlated with WBT breakage than with SBT breakage.

A modification of the conventional dry grind process for producing ethanol from yellow dent corn is considered with respect to its economic value. Process modifications include recycling distillers' grains, after being pretreated and hydrolyzed, with the ground corn and water to go through fermentation again and increase ethanol yields from the corn starch. A dry grind financial model, which has been validated against other financial models in the industry, is utilized to determine the financial impact of the process changes. The hypothesis was that the enhanced process would yield higher revenues through additional ethanol sales, and higher valued dried distillers' grains (DDGS), due to its higher protein content, to mitigate the drop in DDGS yields. A 32% increase in net present value (NPV) for the overall operation is expected when applying the process modifications to a 100million gallon ethanol plant, and an enzyme cost of $0.20 for each additional gallon of ethanol produced. However, there may be no value added to the enhanced dried distillers' grains (eDDGS), even in light of its higher protein levels, as current pricing is expected to be more sensitive to the amino acid profile than the total protein level, and the eDDGS has lower lysine levels, a key amino acid. Thus, there is a decrease in revenue from eDDGS due to the combination of no price change and loss of DDGS yield to ethanol. The financial improvements are a result of the increased revenue from higher ethanol yields outpacing the sum of all added costs, which include higher capital costs, larger loan payments, increased operating costs, and decreased revenues from dried distillers' grains.

Two hundred and fifty-nine F2:3 families, developed from the cross between a dent corn inbred line Dan232 and a popcorn inbred line N04, were evaluated for its starch content in the replicated experiments under two environments. One hundred and eighty three pairs of SSR markers were selected to construct a genetic linkage map, covering 1,762.2 cM (centiMorgan) and on the average distance of 9.63 cM between the markers. Quantative trait loci (QTL) were identified and its effects were analyzed, using the triploid endosperm genetic model and the interval mapping method. Ten QTL, detected on chromosome 1, 3, 4, 5 and 7 respectively, were mapped in spring and in summer. All detected QTL in spring were also identified in summer. The phenotypic variation of a single QTL varied from 4.74% to 11.26%, and the total contributions of all QTL under two environments were 36.84% and 72.65%, respectively. Two QTL of all identified QTL in spring showed over-dominant effects, but additive and partially dominant in summer respectively, the amounts of other QTL showing Additive, partially dominant and over-dominant effects were 2, 1, 5 respectively. The positive alleles of three QTL were contributed by the normal corn parent Dan232, and the other positive alleles were contributed by the popcorn parent N04.

Eight cannulated Holstein steers (average BW: 251 kg) were used in 2 simultaneous 4 x 4 Latin squares in a split-plot arrangement to test the effects of processing method [dry-rolled (DR) vs. steam-flaked (SF); main plot] and vitreousness (V, %; subplot) of yellow dent corn (V55, V61, V63, and V65) on site of digestion of diets containing 73.2% corn grain. No vitreousness x processing method interactions were detected for ruminal digestion, but ruminal starch digestion was 14.4% lower (P < 0.01) for DR than for SF corn. Interactions were detected between vitreousness and processing method for postruminal (P < 0.10) and total tract digestion (P < 0.05). With DR, vitreousness tended to decrease (linear effect, P < 0.10) postruminal OM and starch digestion. With SF, vitreousness did not affect (P ≥ 0.15) postruminal digestion of OM and starch. Postruminal N digestion tended to decrease (linear effect, P = 0.12) as vitreousness increased. Postruminal digestion was greater for SF than for DR corn OM (25.7%, P < 0.05), starch (94.3%, P < 0.10), and N (10.7%, P < 0.01). Steam flaking increased total tract digestion of OM (11%, P < 0.05), starch (16%, P < 0.01), and N (8.4%, P < 0.05) but decreased total tract ADF digestion (26.7%, P < 0.01). With DR, total tract starch digestion was lower for V65 (cubic effect, P < 0.10) than for the other hybrids. With SF, total tract starch digestion was not affected (P ≥ 0.15) by vitreousness. Fecal starch and total tract starch digestion were inversely related (starch digestion, % = 101 - 0.65 x fecal starch, %; r 2 = 0.94, P < 0.01). Ruminal pH was greater for steers fed DR than for steers fed SF corn (6.03 vs. 5.62, P < 0.05). Steam flaking decreased (P < 0.01) the ruminal molar proportion of acetate (24%), acetate:propionate molar ratio (55%), estimated methane production (37.5%), and butyrate (11.3%, P < 0.05). There was a vitreousness x processing interaction (P < 0.01) for acetate:propionate. For DR, acetate:propionate tended to increase (linear effect; P < 0.10) with increasing vitreousness. With SF, acetate:propionate was greater (cubic effect, P < 0.01) for V65. Starch from more vitreous corn grain was less digested when corn grain was DR, but this adverse effect of vitreousness on digestion was negated when the corn grain was SF. Of the 19% advantage in energetic efficiency associated with flaked over rolled corn grain, about 3 / 4 can be attributed to increased OM digestibility, with the remaining 1 / 4 ascribed to reduced methane loss.

Normal maize germplasm could be used to improve the grain yield of popcorn inbreds. Our first objective was to locate genetic factors associated with trait variation and make first assessment on the efficiency of advanced backcross quantitative trait locus (AB-QTL) analysis for the identification and transfer of favorable QTL alleles for grain yield components from the dent corn inbred. A second objective was to compare the detection of QTL in the BC2F2 population with results using F(2:3) lines of the same parents. Two hundred and twenty selected BC2F2 families developed from a cross between Dan232 and an elite popcorn inbred N04 were evaluated for six grain yield components under two environments, and genotyped by means of 170 SSR markers. Using composite interval mapping (CIM), a total of 19 significant QTL were detected. Eighteen QTL had favorable alleles contributed by the dent corn parent Dan232. Sixteen of these favorable QTL alleles were not in the same or near marker intervals with QTL for popping characteristics. Six QTL were also detected in the F(2:3) population. Improved N04 could be developed from 210 and 208 families with higher grain weight per plant and/or 100-grain weight, respectively, and 35 families with the same or higher popping expansion volume than N04. In addition, near isogenic lines containing detected QTL (QTL-NILs) for grain weight per plant and/or 100-grain weight could be obtained from 12 families. Our study demonstrated that the AB-QTL method can be applied to identify and manipulate favorable QTL alleles from normal corn inbreds and combine QTL detection and popcorn breeding efficiently.

The amylose: amylopectin ratio in corn starch is known to affect its chemical characteristics. Yellow dent corn contains 20 to 30% amylose and 70 to 80% amylopectin. Effects of amylose: amylopectin ratios on corn starch fermentation characteristic were investigated. Commercially available starches Hylon VII (70% amylose and 30% amylopectin) and Amioca (100% amylopectin) were mixed in varying proportions. Fermentations were performed using granular starch hydrolyzing enzyme and conventional enzymes. Differences were found in ethanol yield among starches containing different ratios of amylose and amylopectin and among enzymes used. Ethanol concentrations varied from 2.2 to 9.1 (% v/v) for fermentation with granular starch hydrolyzing enzyme and from 6.7 to 9.3 (% v/v) for conventional enzymes.

Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV is quantitatively inherited and 3-4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) x flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3, 8 and 10, which together explained 62% of the phenotypic variance (sigma2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of sigma2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of sigma2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22) and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.

We constructed a genetic linkage map with Isaac-TD, SSR, and SNAP markers in a RIL population which had been derived from a cross of waxy corn (KW7) and dent corn (Mo17). A total of 368 markers, including 241 Isaac-TD, 121 SSR, and 6 SNAP markers, were assigned to 10 linkage groups, encompassing 1687.0 cM, with an average genetic distance of 4.6 cM between markers. SSR markers were utilized as chromosome anchors, in order to assign the Isaac-TD markers to the chromosomes, and the number of markers in each of the linkage groups ranged between 22 and 49. The majority of the Isaac-TD markers were determined to have been distributed throughout the ten maize chromosomes. In linkage analysis of the Isaac-TD markers with genes of agronomic interest, six genes related with maize kernel starch biosynthesis, ae1, bt2, sh1, sh2, su1, and wx1, were analyzed and shown that they were closely linked with either the Isaac-TD or SSR markers on chromosomes of 3, 4, 5, and 9. We observed and mapped segregation-distorted markers on chromosomes 1, 5, 6, 7, 8, and 10, where these markers were clustered. The Isaac-TD or SSR markers which were closely linked with starch synthesis genes may prove useful in marker-assisted breeding programs.

Corn dry milling produces germ, pericarp fiber and grits (endosperm particles). Grits can be ground into flour and fermented into ethanol using a conventional dry grind ethanol process. Combining dry milling before the dry grind ethanol process would allow recovery of germ and pericarp fiber as coproducts prior to fermentation of flour obtained from grits. Fermentation characteristics of dry milled flour were evaluated using two saccharification and fermentation processes. Yellow dent corn samples were tempered, degermed and defibered to recover germ and pericarp fiber. Grits were milled to obtain flour. Flour was mixed with water and liquefied by enzymatic hydrolysis. Liquefied slurry was fermented using either separate saccharification (SS) and fermentation or simultaneous saccharification and fermentation (SSF). Corn germ soak water and Bvitamins were added to the fermentation substrate to study the effect of micronutrient addition. Ethanol and sugar profiles were monitored using HPLC. The SSF process produced higher ethanol yields than SS. Addition of B-vitamins and germ soak water to mash with SSF produced 2.6 and 2.3% (v/v) higher ethanol concentrations respectively compared to control with no B-vitamins or soak water added. Addition of germ soak water and B-vitamins also increased fermentation rates.

Two yellow dent corn hybrids (33A14 and 34B23) were harvested at three different moisture contents (13.9 to 53.7% dry basis) and dried at three temperatures (30, 60 and 90oC). Extractable starch content was measured by a standard 100 g wet milling laboratory procedure. Whole corn samples were milled and liquefied by enzymatic hydrolysis. Liquefied mash was simultaneously saccharified and anaerobically fermented. Ethanol and sugar profiles in mash were monitored using an HPLC method. The harvest moisture content had a significant effect (a =0.05) on the starch yields for both hybrids. However, drying temperature had a significant effect on starch yields and ethanol concentrations for hybrid 34B23. Drying temperature had no effect on starch yields for hybrid 33A14. These results show that certain hybrids are more sensitive to harvest conditions and the post harvest processing.

Two experiments were conducted to determine the effects of corn particle size (CPS) on site and extent of starch digestion in lactating dairy cows. Animals were fitted with ruminal, duodenal, and ileal cannulas. Dry corn grain accounted for 36% of dry matter intake. In experiment 1, 6 cows were used in a duplicate 3 x 3 Latin square design. Semiflint corn was used. Corn processing methods were grinding, medium rolling, and coarse rolling. The mean particle size of the processed corn was 730, 1807, and 3668 microm, respectively. Rumen digestibility of starch linearly decreased from 59% with ground corn to 36% with coarsely rolled corn. Similarly, small intestine digestibility linearly decreased with increased CPS, and consequently, the amount of starch digested in the small intestine was not affected by corn processing. In experiment 2, 4 cows were used in a 2 x 2 crossover design. Dent corn was used. Corn processing methods were grinding and coarse rolling. The mean particle size of the processed corn was 568 and 3458 microm, respectively. Rumen digestibility of starch decreased from 70% with ground corn to 54% with coarsely rolled corn. Small intestine digestibility of starch was not significantly affected by CPS, and the amount of starch digested in the small intestine tended to be greater for rolled than for ground corn. In both experiments, starch total tract digestibility decreased with increased CPS. In conclusion, CPS is an efficient tool to manipulate rumen degradability of cornstarch. In midlactation cows, the decrease in the amount of starch digested in the rumen between grinding and coarse rolling is partly compensated for by an increase in the amount of starch digested in the small intestine with dent genotype, but with semiflint genotype postruminal digestion is not increased and rumen escape starch is not utilized by the animal.

In 3 experiments, New Hampshire x Columbian male chicks were fed carbohydrate-soybean meal (SBM) or casein diets from 0 to 21 d of age, and MEn was determined at 0 to 2, 3 to 4, 7, 14, and 21 d of age. Carbohydrate sources evaluated in experiment 1 were dextrose (D-glucose), conventional cornstarch, dextrinized cornstarch, corn-syrup solids, pregelatinized unmodified cornstarch, pregelatinized tapioca starch, tapioca dextrin, high-amylose starch, and polycose (mixed glucose polymers). Carbohydrate sources evaluated in experiments 2 and 3 were conventional corn, waxy corn, high-oil corn, corn flour, rice flour, dextrose, and sucrose. In experiment 1, chicks fed the dextrose diet had the highest weight gains, and the chicks fed high-amylose starch and pregelatinized unmodified cornstarch diets had the lowest weight gains. The MEn values varied among carbohydrate sources with MEn being highest for the dextrose diet and lowest for the high amylose starch diet. In experiment 2, chicks fed waxy corn, high-oil corn, or dextrose-SBM diets had (P < 0.05) higher growth rates than chicks fed conventional corn, corn flour, or rice flour. The MEn values increased with age for all diets except the dextrose-SBM, which was consistently high at all ages. In experiment 3, the dextrose diets (SBM or casein) yielded higher growth performance and MEn values than the sucrose-diets, and the differences were greater at younger ages. The MEn values were also much higher for the casein than the SBM diets, and MEn of the SBM diets increased with increasing age. The results of this study indicate that MEn, varies among carbohydrate sources and increases with age for most carbohydrate-SBM diets.

Ethanol yields from six yellow dent corn hybrids of different endosperm hardness were studied. Corn samples were milled, liquefied, saccharified and fermented.Endosperm hardness of hybrids was classified according to their true density. Ethanol and sugar levels in the mash were monitored using an HPLC method. Solids in the thin stillage and wet distillers grains were measured using a standard oven method. It was observed that ethanol yields increased with true density of corn hybrids. Thin stillage and wet distillers grain did not show any significant correlation (R2

Shelled yellow dent corn samples were conditioned to three moisture content levels (12%, 15%, and 18% w.b.) and mixed with a prescribed amount of broken corn particles of known size (geometric mean diameter of 1.0, 1.4, 2.0, 2.8, and 4.0 mm) and concentration (2.5%, 5.0%, and 7.5% by weight) levels. The initial bulk density and grain compaction under simulated overburden pressure tests were determined for each sample. Uniaxial compression tests were performed for seven vertical pressure levels (3.4, 6.9, 14, 28, 55, 110, and 165 kPa) with a minimum of three replications each. Tests were performed at two locations with identical apparatus, which was fully described by Thompson and Ross (1983). These devices used compressed air injected beneath a rubber diaphragm to apply vertical pressure uniaxially to a volume of granular material. Deflections of the grain mass were measured with a dial gauge and were used to calculate changes in bulk density and grain packing. Statistical models were tested for the initial bulk density and packing factor as a function of moisture content, broken corn particle size, and broken corn concentration level and their interactions. For clean corn, the initial bulk density was inversely affected by grain moisture while packing increased slightly with grain moisture. For corn mixed with fines, the initial bulk density decreased with grain moisture and the interaction of broken corn particle size and concentration but increased with the interaction of grain moisture and concentration of fines. Packing of corn mixed with fines increased slightly with grain moisture and broken corn concentration. For a given pressure, the predicted bulk density from the developed model was within 4% of the observed value, which was within the variation among test replications and may in fact represent observed differences in bulk density caused by bin loading methods that have been reported by other engineers. The results can improve predictions by WPACKING, the ASAE standard for estimating capacities of cylindrical grain storage structures.

Bu çalışma, Uludağ Üniversitesi Fen Bilimleri Enstitüsünde İlhan Turgut'un danışmanlığında Ahmet Duman tarafından hazırlanan "Bursa koşullarında bazı mısır varyete gruplarında en uygun tozlama zamanlarının belirlenmesi" adlı teze dayanılarak hazırlanmıştır. Atdişi mısırda en uygun çiçek tozu verme zamanlarının (gün ve saat) belirlenmesi amacıyla yapılan deneme, Uludağ Üniversitesi Tarımsal Araştırma ve Uygulama Merkezi deneme alanında 2001 ve 2002 yıllarında yürütülmüştür. Araştırmada, koçan püskülü çıkışını izleyen 10 gün boyunca, her günde 4 ayrı saatte (Saat 08.00, 11.00, 14.00 ve 17.00) tozlama yapılmıştır. Araştırmada iki yıllık birleştirilmiş sonuçlar incelendiğinde, en yüksek tane tutma oranı koçan püsküllerinin görünmesinden 3 gün sonra yapılan toz verme işlemleri sonucunda % 93.0 değeri ile elde edilmiştir. Toz verme saatleri bakımından ise en yüksek tane tutma oranı saat 11.00 ve 08.00’de yapılan toz verme işlemlerinden % 52.7 ve % 50.6 değerleri ile elde edilmiştir. This study was carried out to determine optimum pollination time (day and hour) on dent corn in Research and Application Center of Faculty of Agriculture of the Uludağ University in 2001-2002. Pollination were made in every day at different four hour (08:00, 11:00, 14:00 and 17:00) and during 10 days after silk emerging in this study. According to the results of two-years the highest filled seed percentage (% 93.0) was obtained from pollination in three day after silk emerging. The highest filled seed percentages as pollination hour were obtain at 11.00 and 08.00 (52.7 % and 50.6 %) respectively.

The predominance of vitreous endosperm in hard texture flint corn (Zea mays L.) can decrease ruminal starch digestion comparatively to the farinaceous endosperm of dent corn, reducing energy content of the grain. The objective of this experiment was to evaluate the effects of texture and maturity stage on ruminal degradability of corn grain. Two dent and two flint hybrids were harvested at the early dent, half milk line, and black layer stages. The proportion of vitreous endosperm (vitreousness) in dent hybrids was 44.3%, while in flint it was 67.0%. There was a linear increase in vitreousness with advancing maturity. Flint hybrids at the early dent stage were more vitreous than dent at the black layer stage. The increase in vitreousness per maturation day was greater for flint hybrids. Grains were incubated in situ in the rumen of 6 cows. The 24-hour ruminal dry matter degradation was 63.3% for dent corn and 52.4% for flint corn. The 72-hour incubation residues of dent and flint hybrids were 7.6% and 15.6%, respectively. Ruminal degradability was similar between hybrids at the early dent and half milk line stages. There was a marked texture effect on ruminal degradability at the black layer stage (quadratic effect of maturity stage and interaction between texture and maturity stage). Use of dent hybrids, compared to flint hybrids, may result in smaller relative reduction in ruminal starch digestion in situations of late grain harvesting. A predominância de endosperma vítreo em milho (Zea mays L.) flint de textura dura pode deprimir a digestão ruminal do amido comparativamente ao endosperma farináceo de milho dentado, reduzindo o conteúdo energético do grão. O objetivo deste experimento foi avaliar os efeitos da textura e do estádio de maturidade sobre a degradabilidade ruminal de grãos de milho. Dois híbridos dentados e dois duros foram colhidos nos estádios dentado inicial, metade da linha do leite e linha preta. A proporção de endosperma vítreo (vitreosidade) dos híbridos dentados foi 44,3% e a dos duros foi 67,0%. Ocorreu aumento linear na vitreosidade com o avançar da maturidade. Os híbridos duros no estádio dentado inicial foram mais vítreos que os dentados no estádio linha preta. O aumento na vitreosidade por dia de maturação foi maior nos híbridos duros. Os grãos foram incubados in situ no rúmen de 6 vacas. A degradação ruminal da matéria seca em 24 horas foi 63,3% nos grãos dentados e 52,4% nos duros. O resíduo após 72 horas de incubação de híbridos dentados e duros foram 7,6% e 15,6%, respectivamente. A degradabilidade ruminal dos híbridos foi similar nos estádios dentado inicial e metade da linha do leite. O efeito da textura sobre a degradabilidade ruminal foi acentuado no estádio linha preta (P < 0,01 para o efeito quadrático de estádio de maturação e para a interação entre textura e estádio de maturação). A utilização de híbridos dentados, comparativamente a híbridos duros, pode resultar em menor queda relativa na digestão ruminal do amido em situações de colheita tardia dos grãos.

O milho cultivado no Brasil e predominantemente de textura dura, e mais propenso a reducao na digestibilidade do amido em situacao de colheita tardia que hibridos dentados. Este trabalho testou a utilizacao de milho dentado como maneira de ampliar o periodo de ensilagem sem reduzir o desempenho animal e avaliou o potencial da cana-de-acucar em dietas para vacas leiteiras de alta producao. Nove vacas Holandesas foram alocadas em tres quadrados latinos 3 ' 3 e alimentadas com 200 g de fibra em detergente neutro oriunda de forragem por kg de materia seca como milho de textura dura ensilado no estadio de maturacao "metade da linha do leite", milho de textura macia no estadio "linha negra" ou cana-de-acucar. Nao foi detectada diferenca entre hibridos de milho na producao (34,2 vs 34,6 kg d-1) e na composicao do leite, no consumo de materia seca (23,0 vs 23,2 kg d-1) e na digestibilidade aparente de nutrientes no trato digestivo total. A cana-de-acucar deprimiu o consumo (21,5 kg d-1) e a producao de leite (31,9 kg d-1). A digestibilidade da materia orgânica, a atividade mastigatoria e o pH ruminal nao foram diferentes entre tratamentos. A cana-de-acucar parece ser uma opcao para alimentar grupos de vacas Holandesas durante fases da lactacao na qual a demanda nutricional nao e a maxima. O desempenho de vacas leiteiras alimentadas com milho dentado ensilado em estadio de maturacao "linha negra" foi similar ao de vacas alimentadas com milho duro ensilado no estadio "metade da linha do leite".

Corn cultivated in Brazil is predominantly of hard texture, and more propense to decreased starch digestibility under late harvesting situations than dent hybrids. This work tested the utilization of dent corn as a way of extending the ensilage period without reducing animal performance, and evaluated the potential of sugarcane as a forage for high-producing dairy cows. Nine lactating Holstein cows were allocated to three 3 ' 3 latin squares and were fed 200 g of forage neutral detergent fiber per kg of dry matter as either hard texture corn ensiled at the half milk line stage of maturity, soft texture corn ensiled at the black layer stage, or sugarcane. There were no detectable differences between corn hybrids with regard to milk yield (34.2 vs 34.6 kg d-1) and composition, dry matter intake (23.0 vs 23.2 kg d-1) and total tract apparent digestibility of nutrients. Sugarcane decreased feed intake (21.5 kg d-1) and milk yield (31.9 kg d-1). Organic matter digestibility, chewing activity and rumen pH did not differ among treatments. Sugarcane seems to be a viable option to feed groups of Holstein cows during lactation stages in which nutrient demand is not at a maximum. The performance of dairy cows fed dent corn ensiled at the black layer stage of maturity was similar to the performance of cows fed flint corn ensiled at the half milk line stage. O milho cultivado no Brasil é predominantemente de textura dura, e mais propenso a redução na digestibilidade do amido em situação de colheita tardia que híbridos dentados. Este trabalho testou a utilização de milho dentado como maneira de ampliar o período de ensilagem sem reduzir o desempenho animal e avaliou o potencial da cana-de-açúcar em dietas para vacas leiteiras de alta produção. Nove vacas Holandesas foram alocadas em três quadrados latinos 3 ' 3 e alimentadas com 200 g de fibra em detergente neutro oriunda de forragem por kg de matéria seca como milho de textura dura ensilado no estádio de maturação "metade da linha do leite", milho de textura macia no estádio "linha negra" ou cana-de-açúcar. Não foi detectada diferença entre híbridos de milho na produção (34,2 vs 34,6 kg d-1) e na composição do leite, no consumo de matéria seca (23,0 vs 23,2 kg d-1) e na digestibilidade aparente de nutrientes no trato digestivo total. A cana-de-açúcar deprimiu o consumo (21,5 kg d-1) e a produção de leite (31,9 kg d-1). A digestibilidade da matéria orgânica, a atividade mastigatória e o pH ruminal não foram diferentes entre tratamentos. A cana-de-açúcar parece ser uma opção para alimentar grupos de vacas Holandesas durante fases da lactação na qual a demanda nutricional não é a máxima. O desempenho de vacas leiteiras alimentadas com milho dentado ensilado em estádio de maturação "linha negra" foi similar ao de vacas alimentadas com milho duro ensilado no estádio "metade da linha do leite".

An HPLC method was developed using the C-30 carotenoid column to separate and identify the major xanthophylls in corn (lutein, zeaxanthin, and β-cryptoxanthin). A photodiode array detector and a mobile phase consisting of methyl tert-butyl ether/methanol/water was used. All three xanthophylls eluted in less than 25 min. Yellow dent corn had a total xanthophyll content of 21.97 μg/g with lutein content of 15.7 μg/g, zeaxanthin content of 5.7 μg/g, and β-cryptoxanthin of 0.57 μg/g. Commercial corn gluten meal had a 7 times higher concentration of xanthophylls (145 μg/g), and deoiled corn contained 18 μg/g, indicating that the xanthophylls are probably bound to the zein fraction of corn proteins. Keywords: Xanthophylls; lutein; zeaxanthin; corn; HPLC

Six Suffolk wether lambs (40.9+/-1.05 kg) surgically fitted with ruminal and double-L-shaped duodenal and ileal cannulas were used in a 3 x 6 Latin rectangle design to investigate the effects of three corn hybrids on site and extent of disappearance of nutrients and rumen characteristics. Treatments were 1) a conventional yellow dent corn (CC) diet, 2) a NutriDense corn (NC) diet, and 3) a waxy corn (WC) diet. Diets consisted of 43.9% cracked corn grain, 39.1% cottonseed hulls, 15.3% soybean meal, 1.49% vitamin and mineral supplement, and 0.21% chromic oxide (DM basis). Lambs were fed twice daily at 1.8 x NEm requirement. Ruminal pH, fluid dilution rate, volume, NH3 N, and total VFA concentrations, as well as molar proportions of isobutyrate, butyrate, and valerate, were similar (P0.10) among dietary treatments. Apparent and true OM disappearances (g/d and percentage of OM intake) from the stomach were similar (P0.10) among dietary treatments. Apparent OM disappearance (percentage of duodenal OM flow) from the small intestine was higher (P0.05) for the WC than for the NC treatment. Apparent total tract OM disappearance (percentage of OM intake) was also similar (P0.10) among dietary treatments. Total apparent and true starch disappearances (g/d) from the stomach were higher (P0.05) for the WC diet than for the CC and NC diets. However, apparent and true starch disappearances from stomach as percentage of starch intake were higher (P0.05) for the WC diet than for the CC diet. Starch disappearance (g/d) from the small intestine was higher (P0.05) for the CC diet than for the WC diet; however, apparent starch disappearance (percentages of duodenal starch flow) from the small intestine was higher (P0.05) for the WC diet than for the CC diet. Duodenal flows of total N, bacterial N, NH3 N, and non-NH3 nonbacterial N (g/d) and efficiencies of bacterial protein production (g of bacterial N/kg of true or apparent OM disappearing in the stomach) were similar (P0.10) among dietary treatments. Apparent and true N disappearance from stomach (g/d) and apparent total tract N disappearance (percentage of N intake) were also similar (P0.10) among dietary treatments. Total N disappearance from the hindgut was -0.81, -1.06, and -1.46 g/d for CC, NC, and WC, respectively, and was different (P0.05) between CC and WC diets. Results indicated that higher ruminal starch disappearance in WC did not increase microbial N production or efficiency when compared to CC.

Popping expansion volume is the most important quality trait in popcorn ( Zea mays L.), but its genetics is not well understood. The objectives of this study were to map quantitative trait loci (QTLs) responsible for popping expansion volume in a popcorn x dent corn cross, and to compare the predicted efficiencies of phenotypic selection, marker-based selection, and marker-assisted selection for popping expansion volume. Of 259 simple sequence repeat (SSR) primer pairs screened, 83 pairs were polymorphic between the H123 (dent corn) and AG19 (popcorn) parental inbreds. Popping test data were obtained for 160 S(1) families developed from the [AG19(H123 x AG19)] BC(1) population. The heritability ( h(2)) for popping expansion volume on an S(1) family mean basis was 0.73. The presence of the gametophyte factor Ga1(s) in popcorn complicates the analysis of popcorn x dent corn crosses. But, from a practical perspective, the linkage between a favorable QTL allele and Ga1(s) in popcorn will lead to selection for the favorable QTL allele. Four QTLs, on chromosomes 1S, 3S, 5S and 5L, jointly explained 45% of the phenotypic variation. Marker-based selection for popping expansion volume would require less time and work than phenotypic selection. But due to the high h(2) of popping expansion volume, marker-based selection was predicted to be only 92% as efficient as phenotypic selection. Marker-assisted selection, which comprises index selection on phenotypic and marker scores, was predicted to be 106% as efficient as phenotypic selection. Overall, our results suggest that phenotypic selection will remain the preferred method for selection in popcorn x dent corn crosses.

Genetic diversity in corn (maize) has contributed to variability in corn processing characteristics. Differences in acetylated dent corn starch pasting properties and reaction efficiencies due to hybrid were assessed. Nine dent corn hybrids grown during 1998 and eight dent corn hybrids grown during 1999 were wet milled in the laboratory. Starch from each hybrid was modified using a laboratory scale acetylation procedure. NaOH consumed and reaction time were recorded for each reaction. A Rapid Visco Analyzer (RVA) was used to measure starch pasting properties. Acetyl content was measured by a spectrophotometric method, from which reaction efficiency was calculated. Differences in peak, trough, final and setback viscosities and pasting temperature were found among 1998 hybrids. Differences in trough, breakdown and final viscosities were found among 1999 hybrids.

Following harvest, corn raised for grain is subject to infection and deterioration due to storage fungi. Laboratorystorage studies done on yellow dent corn in the 1960s established dry matter loss, as estimated by CO2 evolution duringstorage, to be a usable indicator of corn deterioration during storage. As a result of these studies, equations were developedto predict CO2 evolution of stored corn as a function of moisture content, temperature, and mechanical damage level. Laterresearch has added information on genetic hybrid resistance to fungal growth and fungicide effects. This article assemblesthe original equations derived from 1960s studies, plus relevant results from later research, into a comprehensive set ofequations to predict CO2 evolution and dry matter loss for corn stored at 15 to 35% moisture content (wet basis) andtemperatures from 0 to 49C. Effects of mechanical damage, genetic resistance to fungi, and fungicides are considered. Atable of predicted shelled corn storage times for 0.5% dry matter loss and a table of multipliers for other dry matter loss levelsare presented.

A variety of popcorn (Zea mays everta) grown in Ohio was analyzed for CP and amino acids and subsequently used in diets for growing turkeys. The objective of the experiment was to evaluate popcorn as a substitute for standard, Number 2 yellow dent corn in conventional diets for starting and growing turkeys. In comparison with Number 2 yellow dent corn, popcorn was higher in CP and methionine but similar in lysine. There were no effects due to corn type on BW at 4 or 18 wk, feed conversion from 7 to 14 days, or fecal dry matter from 7 to 14 days. Popcorn can be an effective partial or full substitute for Number 2 yellow dent corn in diets for turkeys, and cost makes it an attractive alternative.

The objectives of this study were to determine the effects of NutriDense and waxy corn hybrids as silage and grain sources on milk yield, milk composition, digestibility of dietary components, and rumen characteristics. Six multiparous (intact) and six primiparous (ruminally cannulated) Holstein cows were assigned at 72 to 90 d of lactation to a 3 x 6 Latin rectangle design experiment to treatment of: 1) control diet, 2) NutriDense corn diet, and 3) waxy corn diet. Diets consisted of 10.9% alfalfa silage, 32.8% corn silage, 27.9% cracked corn grain, and 28.4% other ingredients (DM basis). Milk, FCM, and milk fat and protein yields were higher for cows fed the waxy diet than those fed the control diet. Milk protein percentage tended to be higher for cows fed the control and waxy diets than those fed the NutriDense diet. Dry matter intake tended to be higher for cows fed the waxy diet than the NutriDense diet. Apparent DM, OM, CP, ADF, NDF, and gross energy digestibilities were similar among dietary treatments, while apparent starch digestibility was higher for the waxy corn than for the NutriDense corn. Rumen NH3-N concentration was higher for cows fed the NutriDense diet than for those fed the control and waxy diets. The proportion of ruminal propionate was higher for the waxy diet than the control diet. NutriDense and waxy corn hybrids can be effective substitutes for conventional yellow dent corn hybrids in lactating dairy cow rations.

Isoform patterns of chitinase and beta-1,3-glucanase of maturing kernels of yellow dent corn (Pioneer 3394) infected with Aspergillus flavus at the milk stage were investigated through polyacrylamide gel electrophoresis (PAGE). Proteins on the sodium dodecyl sulfate (SDS) gel with an apparent molecular mass range of 23-46 kDa were differentially present in the kernels infected with both aflatoxin-producing and non-aflatoxin-producing strains of A. flavus. From in-gel (native PAGE) enzyme activity assays, three bands corresponding to chitinase isoforms and two bands corresponding to beta-1,3-glucanase isoforms were detected in the infected kernels. One chitinase isoform of 29 kDa was present only in the infected kernels, and another one of 28 kDa was present in both infected and noninfected kernels. They were judged to be acidic on the basis of their migration on an acrylamide isoelectric focusing (IEF) gel. For the beta-1,3-glucanase, one isoform of 35 kDa was present in both infected and noninfected kernels, but another one, a 33 kDa isoform, was present only in the infected kernels. Both acidic and basic beta-1,3-glucanase isoforms were detected in the IEF gel. The results of this study are the first to demonstrate patterns of enhanced or inducible proteins in maturing corn kernels in response to A. flavus infection at the milk stage. The results also indicate that only particular isoforms of the two hydrolytic enzymes are involved in the maturing corn kernels infected at the milk stage with A. flavus.

Enzymes affecting corn lipids were inactivated by adjusting whole dent corn to 15% moisture and gradually heating it to 91° or 96°C during passage through a two‐stage steam‐jacketed conveyer, followed by cooling. Heat‐processed and untreated products were then milled by a four‐break, 96% extraction procedure. Processed and untreated meals were formulated into self‐rising meals and stored at 37°C for 6 months. Processed meal formulations were significantly (P < 0.05) more stable during storage than those from untreated meal as indicated by lower fat acidity values and greater carbon dioxide retention. Corn bread prepared from stored enzyme‐inactivated meal had greater volume and maintained more uniform shape than that from stored untreated meal.

El propósito de esta tesis fue investigar algunas aspectos básicas de la moliendahúmeda convencional de maíz y evaluar la capacidad de molienda de tres híbridosregionales de este grana: dentada, semidentado y colorada dura. Otras objetivasfixeran evaluar la incidencia de las condiciones past-cosecha en el rendimiento ycalidad de la fiacción amilácea, determinar la cinética de difusión y de reacciónquímica del anhídrido sulfuraso en el grano de maíz y proponer modificaciones en lamolienda húmeda tradicional con miras a reducir el tiempo y casta del procesa. Seevaluó el efecto del secado en el rendimiento de almidón de maíz dentada y coloradadura. El rendimiento decrece al aumentar la temperatura y contenida de humedadinicial de las granos. La reducción en la recuperación de almidón y la contaminaciónproteica fue mayor en maíz colorada dura. El hinchamiento, solubilidad y temperaturade gelatinización del almidón aislada fue afectada por el secado. La constante cinéticade reacción de SO2 en maíz fue evaluada par un método isotérmico en el rango detemperaturas de 25-55°C. La pérdida de SO2 por reacción química sigue una cinéticade primer arden con una constante que varía de 4.3 a 9.9x10-7 s-1 ; la energía deactivación file de 60.6 kJ/mol. La cinética de difusión y reacción de SO2 en el grano sesimuló mediante la ecuación de difusión con reacción química simultánea. Loscoeficientes de difusión se evaluaron por resolución del modelo propuesta; la energíade activación del procesa difusivo fue de 39.8 kJ/mol. El efecto relativo deldescascarado, pretratamiento con solución de KOH y emulsión de aleato de etila en lavelocidad de absorción de agua durante la maceración se comparó can la absorción demuestras de maízsin pretratar. Dichas pretratamientos aumentan la absorción de aguatanto en maíz dentada cama en colorada duro. La absorción de agua en el granamacerado en presencia de ácida láctico. Para concentraciones de ácida láctico 0.5% (v/v)y mayores se encontró que se incrementa ligeramente la velocidad de absorciónde agua durante la maceración. Las muestras de maíz pretratados can KOH tuvieranmenor rendimiento que las muestras sin tratar. Sin embargo, la presencia de ácidoláctico en las aguas de maceración aumentaron el rendimiento en almidón de lashíbridos dentado y colorado duro, particularmente en las muestras tratadas ensolución alcalina. Para el maíz colorado duro se encontraron condiciones de moliendaóptimas a las 24 horas de maceración. The purpose of this thesis was to investigate some fundamentals aspects of theconventional corn wet milling as well as to evaluate the millability of the three regionaltypes: dent, semident and flint corn. Other objectives were to evaluate the incidence ofpost-harvesting conditions on the yield and quality of the isolated starch, to determinethe kinetics of difusion and chemical reaction of sulfur dioxide in corn grain and topropose modifications of to the classical wet milling to reduce the time and cost of thehybrids under various drying conditions and the results compared with undriedsamples. The starch recovery of undried samples was similar for flint and dent corn. Itdecreased as both initial moisture content of the grains and drying air temperatureincreased. The reduction of starch recovery and contamination by protein was greaterfor flint than for dent corn. Swelling, solubility and gelatinization range of isolatedcorn was affect by the drying conditions. The reaction kinetics of sulfur dioxide in cornwas evaluated by isothermal method at temperature range of 25-55°C.It was found thatthe loss of sulfur dioxide follows first-order kinetics with the range constant varyingfrom 4.3 to 9.9x10-7 s-1; the activation energy for chemical reaction was 60.5 kJ/mol. The rate of diffusion and reaction of sulfur dioxide in corn grain during steeping wassimulated by the diffusion coeficients, were evaluated by fitting of the experimentalabsorption curves of SO2 in corn grain to the model, being the activation for thediffusive process of 39.8 kJ/mol. The relative effectiveness of dehulling, potasiumhydroxide dipping and ethyl oleate spraying aqueous emulsion to increase the rate ofwater absorption by dent and flint corn during steeping was compared with untreatedcorn samples. These pretreatments increased the water absorption rate of both hybridswhen compared to the untreated control samples. Corn grain steeped in SO2 aqueoussolution and variable lactic acid concentration ere performed. For lactic acidconcentrations, about 0.5% higher absorption rates than those steeped only in SO2solution were observed, this effect being more marked for dent than for flint corn. Cornsamples pretreated with potasium hydroxide had lower starch yields than the control. However, the presence of lactic acid in steep water increased the starch yield of dentand flint corn, particularly for the samples treated with alkaline solution. Thisprocedure was particularly beneficial for flint corn; an effective release of the starchgranules was achieved within 24 hr of steeping. Fil: Haros, Claudia Mónica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Six Salers steers, fitted with ruminal and duodenal cannulas, were used in a double 3x3 Latin square design to assess the depressive effect of the nature of wheat, flint corn, and dent corn on fiber digestion in animals fed high-concentrate diets, and to determine the mechanisms involved in these negative digestive effects. Diets were balanced to be equal in starch content (47.7+/-2.3%). The three cereals were characterized by ruminal starch digestibilities of 86.6, 60.8, and 34.8% for the wheat, dent corn, and flint corn, respectively. Ruminal digestion of NDF was lower with wheat- than with corn-based diets (49.4 vs. 55.2%; P.001), and with dent corn than with flint corn (53 vs. 57.3%; P.01). Degradability of hay in nylon bags was not affected by the grain source in the diet (P.1). The mean retention time of forage particles in the rumen was similar between wheat and corn diets (P.1), but it was lower for steers fed dent corn than for those fed flint corn (P.05). Most fibrolytic activities of the solid-associated microorganisms were lower (P.05) in animals fed wheat than in those fed corn. Differences in fibrolytic activities of the solid-associated microorganisms between the two corn genotypes were not statistically significant (P.1), but activities of all fibrolytic enzymes were lower (P.05) with the dent than with the flint corn diet. Protozoal number in ruminal fluid was lower in animals receiving wheat than in those fed corn (177 vs. 789x10(3)/mL; P.001) and was related to the high ruminal acidity (P.01) of the wheat diet. Large modifications in the rumen microbial ecosystem between the two corn genotypes were not visible in protozoal numbers or pH. Total-tract digestion of NDF was the same for wheat and for corn diets, averaging 55% for the three diets. A postruminal compensation of NDF digestion (14% of the total tract NDF digestion) seemed to occur with the wheat diet. The lack of any postruminal NDF digestion (0%) with the two corn diets may suggest negative digestive interactions in the hindgut similar to those in the rumen.

Six cannulated Salers steers (305 +/- 17 kg initial BW) were used in a double 3 x 3 Latin square design to compare the effects of the nature of the cereal (wheat vs corn) and the corn genotype (dent vs flint) on rate, site, and extent of digestion of high-concentrate diets. The cereals were coarsely cracked, and the diets were balanced to have the same percentage of starch (47.7 +/- 2.3%) and CP (14.6 +/- .7%). Differences in ruminal starch digestion were observed between wheat- and corn-based diets (86.6 vs 47.8%; P.001) and between corn genotypes (60.8 vs 34.8% for dent and flint corns; P.001). For flint corn, more than half the starch was digested in the hindgut. Total tract digestion of starch was greater (P.001) by steers fed wheat than by those fed corn and did not differ (P.1) between the two corn genotypes. Ruminal mean pH (P.01) was lower and total VFA concentration (P.1) was higher for wheat- than for corn-based diets. Ruminal acetate:propionate tended to increase with the decrease in the amount of starch degraded in the rumen, but differences were not significant (P.1). When wheat replaced corn, nonammonia, nonmicrobial N duodenal flow decreased (P.01), and microbial duodenal flow increased (P.05), so there were no differences in the duodenal flow of nonammonia N duodenal flow (P.1). The lower nonammonia N duodenal flow for the dent corn- than for the flint corn-based diet (P.05) was related to a lower passage of nonammonia, nonmicrobial N into the duodenum. Efficiency of microbial protein synthesis was inversely correlated with the amount of starch degraded in the rumen. Nature of the cereal, wheat vs corn, and genotype of the corn, dent vs flint, alter the site and extent of starch digestion.

Currently, modified potato and tapioca starches are used as functional additives in formulating reduced- and low-fat frankfurters. However, cornstarches may serve as alternative sources for comminuted meat systems. Meat batters formulated with ground turkey, 2% sodium chloride, 25% distilled-deionized water (ice), and 4% starch, including acid-thinned dent corn (ATDC), cross-linked waxy maize (XLWM), cross-linked dent corn (XLDC), modified potato (MP), acid-thinned dent corn with xanthan gum (ATDCG), or modified tapioca (MT) were compared. Thermal and structural properties of the batters were evaluated using differential scanning calorimetry (DSC) and dynamic rheological testing. Cooking loss, reheating loss, and texture profile analysis (TPA) were determined for cooked turkey batters. The DSC peak temperatures ranged from 57.5 to 74.9 C, which correlated positively to onset temperatures of the storage moduli (G') for XLWM starch. Incorporation of XLWM, XLDC, MT, or MP starch into turkey batters resulted in significant reductions in cooking and reheating losses. The TPA results showed that 9.42, 8.57, and 8.48 kg of force were required for 75% compression of cooked batter segments containing MP, XLDC, and XLWM starches, respectively. Segments prepared with ATDCG starch were the least firm and most springy of all starch-containing segments.

Bu araştırma, mısırda bazı karakterlerin birbirleri ile olan ilişkileri ve aynı karakterlerin path analizi ile dekara tane verimi üzerine doğrudan ve do/aylı etkilerinin belirlenmesi amacıyla yapılmıştır. Deneme, Bursa sulu koşullarında 1997 ve 1998 yıllarında 13 at dişi melez mısır çeşidi ile yürütülmüştür. İncelenen özellikler arasındaki ilişkilerde, tane verimi ile koçan uzunluğu, koçan çapr, koçanda tane sayısı, bitkide koçan sayısı ve koçanda tane ağırlığı arasında pozitif yönde önemli ilişki bulunmuştur. Path analizi sonucuna göre, dekara tane verimine olumlu yönde en yüksek doğrudan etkiye sahip özellikler koçanda tane sayısı, koçanda tane ağırlığı, bitkide koçan sayısı ve bitki boyudur. This research was conducted to determine the correlations among the some c haracıers and the direct and indirect effect of these characters on the seed yield per decade in com. The experiment was conducted with 13 hybrid corn varieties in 1997 and 1998 under irrigated conditions of Bursa Region. According to the results from relations among the characters investigated, signifıcant and positive correlations were found between seed yield and ear length, ear diameter, seed number per ear, ear number per plant, seed weight per ear. In results of path analysis, the seed number per ear, seed weight per ear, ear number perplantand plant height such as characters have positive and highest-direct effect on the seed yield per decare.

Bursa sulanabilir koşullarında üç aldişi hibrit mısır çeşidinde azot dozlarının verim ve verim öğelerine etkisini belirlemek için yapılan bu çalışmada bitki boyu, koçan yüksekliği, koçan boyu, koçan çapı, koçanda tane sayısı, 1000 tane ağırlığı, bitkide koçan sayısı ve dekara tane verimi belirlenmeye çalışılmıştır. Denemeler, TTM-815, P-3163 ve Se/e çeşitleri kullanılarak 1997 ve 1998 yıllarında kurulmuştur. Üç tekerrürlü tesadüf bloklarında yapılan bu araştırmada dört farklı azot dozu (0, 12.5, 25 ve 37.5 kg N/da) kullanılmıştır. Azot dozu arttıkça koçan boyu, koçanda tane sayısı ve tane verimi de artmıştır. Yüksek tane verimi için en uygun azot dozunun 25 kg N/da olduğu saptanmıştır. In order to determine the effects of nitrogen doses on the yield and yield components of three dent corn varieties, this study was carried out under irrigated cnditions in Bursa in 1997 and 1998. The plant height, ear height, ear length, ear diameter, seed numberlear, 1000 seed weıght, earl plant and seed yield lda were investigated. The field experiments were set up according to randomized black design witlı three replicated. Three varieties were used (TTM-815, P-3163 and Sele) and four rate of nitrogen (0, 12.5, 25 and 37.5 kg N/da) were applied. When the nitrogen levels increased, the ear Length, seed numberlear and seed yield increased. lt was determined that 25 kg N/da was suitable for high seed yield.

Two years field experiments were conducted to evaluate the effects of placement and supplying patterns of soluble or controlled availability fertilizers (CAFs) on the N recoveries, growth and yield of dent corn (Zea mays L.). Grain yield of co-situs CAFs treatments were about 20% greater than that of conventional urea treatment in 1995, while there was no difference between these treatments in 1994, reflecting the differences in rainfall between the two years. The controlled N supply synchronizing with the N demands of dent corn increased the recovery of N fertilizer in any climatic conditions. Therefore single co-situs placement of suitable CAFs can increase fertilizer efficiency and achieve stable yield.

Maize (Zea mays L.) is a cross-pollinating species, with the male (tassel) flowers at the top and female (ear) flowers at lower nodes on the stalk. The grains, developed in ears or cobs, are the part mainly harvested. There are a number of grain types distinguished by differences in chemical compounds deposited or stored in the kernel: flint corn, dent corn, floury corn, waxy corn, sweetcorn, popcorn, sweet floury corn, and pod corn. Maize provides nutrients for human and animals, and serves as a basic raw materials for industry such as in starch, oil, protein, alcoholic beverages, food sweeteners, seasonings, fuel, etc. The green or dried plant has been used with much success as feed for livestock. Maize is one of the world’s leading cereal crops with 129 million hectares of havesting area in the world, producing 478 million tons in 1991 (FAO 1991).

U.S. No. 2 yellow dent corn was randomly probe-sampled from rail cars being shipped to a wet-milling plant from a Corn Belt local elevator. The probe samples were blended together and kernels were sorted into four levels of stress cracks (0, 1, 2, or multiple). Each level of stress cracking was then laboratory wet-milled in triplicate. The only statistically observed differences were in total fiber and in protein content of the gluten meal fraction. The starch yield difference between zero stress cracked corn and multiple stress cracked corn was smaller (0.8%) than would be expected if stress cracking were an indicator of damage to the wet-milling characteristics of the corn.