High-moisture Maize Research Articles

Hermetic Bags: A Short-Term Solution to Preserve High-Moisture Maize during Grain Drying.

Maintaining maize quality while drying during a rainy season is a major challenge for smallholder farmers in developing countries. We conducted a study to evaluate the impact of temporarily storing wet maize of 18, 21, and 24% moisture content (m.c.) in hermetic Purdue Improved Crop Storage (PICS) and polypropylene (PP) woven (control) bags for 21 days. Oxygen and carbon dioxide concentrations were monitored, and m.c., germination, and visual mold were assessed. In PICS bags, oxygen dropped below 1% within 7, 11.5, and 21 days for maize at 24, 21, and 18% m.c., respectively. After 21 days, the m.c. of maize stored in PICS bags remained constant, but decreased in PP bags. Germination of maize in PICS bags decreased by 0.5, 6.2, and 95.5 percentage points for 18, 21, and 24% m.c., respectively. In PP bags, germination decreased by 17.5, 15.2, and 39.5 percentage points for the respective moisture levels. After 21 days of storage, visible mold was present on maize stored in PP bags at both 21 and 24% m.c. No mold was observed on maize stored in PICS bags, but a fermentation smell was released from maize at 21 and 24% m.c. The results indicate that maize can be effectively stored in PICS bags at 21% m.c. or below for 21 days with minimal germination loss or mold growth. These findings highlight the potential of using hermetic bags for short-term grain quality preservation just before and during drying. This new utility adds to the current use of hermetic bags for protection against pests during long-term storage. Hermetic bags' dual functionality could significantly improve postharvest management on smallholder farms, thereby enhancing food and nutritional security and safety. Field testing is required in order to integrate this approach under smallholder farmers' conditions (e.g., temperature, m.c., drying practices, etc.).

Impacts of two-stage drying techniques on drying characteristics, physical and nutritional quality of maize

This research aimed to evaluate the effect of two-stage drying techniques on drying characteristics and selected physical parameters, colour, and nutritional qualities of dried maize. To execute this study, the maize sample was dried by (i) fluidized bed drying at 120–160 °C temperatures followed by sun drying at 32 °C (Technique 1), (ii) fluidized bed drying using higher temperatures (120, 140, and 160 °C) at first stage followed by lower temperature (65±2 °C) at the second-stage (Technique 2), and (iii) sun drying method (∼32 °C) (control). Results signposted that lower drying time was attained in the second approach (1.5 h) compared to the drying Technique 1 (4.5 h) while the sun drying method took 10 h for plummeting high moisture (25.43%, wb) to a safe level (<14%, wb). Data analysis revealed that the dried product's bulk density and porosity diverged between two-stage drying and sun drying techniques. The colour properties of the dried products changed significantly (P ≤ 0.05) with the drying arrangements. The results of nutritional values of the dried product did not change significantly with the first-stage drying temperature but did change significantly with the drying techniques. Even though both techniques yielded almost the same quality dried product, Technique 2 is superior for rapid drying. Therefore, the proposed two-stage drying techniques can be familiarized as alternative drying for high-moisture maize in a commercial drying complex.

Changes in chemical composition and fermentation profile in silages from rehydrated grains of maize hybrids during prolonged air exposure

Most studies investigated the effects of air exposure during the ensiling of whole maize silage and high-moisture maize grains on the chemical composition and fermentation profile, but not of rehydrated grain. The aim of the present study was to investigate the effect of the hybrid and the duration of air exposure on the pH and the content of moisture, main nutrients, fermentation products and nitrogen fractions in silages from three commercial maize hybrids. The grains were rehydrated to 32 % of moisture and ensiled for 63 days with the addition of an inoculant (BIO-SIL®, Dr Pieper Technologie und Produktentwicklung GmbH). After opening, the silages were stored at room temperature for 10 days and samples were taken after 0, 1, 3, 5 and 10 days of air exposure. With increasing duration of air exposure, the content of moisture, lactic and acetic acid and ethanol decreased, while the pH value and the content of water-soluble carbohydrates and ammonia increased. The hybrid affected all the determined properties of the silages except the pH and the ethanol content. There were distinct differences in the contents of moisture, total sugars, water-soluble carbohydrates, lactic, acetic, propionic and isobutyric acids, methanol and ammonia, suggesting that some hybrids may be more susceptible to aerobic spoilage. The majority of the properties remained similar until the fifth day of air exposure, suggesting that the silages of all three hybrids were stable during this period. The only property that increased immediately after air exposure was the content of nitrogen fractions suggesting that proteolysis was occurring, even though pH and lactic acid content remained unchanged. Overall, the results of the study indicate that the behaviour of rehydrated maize silage after exposure to air should be taken into account when selecting maize hybrids.

Comparison on drying characteristic, efficiency, unit drying cost and quality of maize dried by a novel multi-crop mobile dryer, existing industrial dryer and sun drying method

This research aimed to investigate the effects of different drying methods on drying characteristic, drying efficiency, unit drying cost and quality of maize grain dried by newly developed HSTU multi-crop mobile dryer (HMMD) which was operated by alternative heating sources such as LPG and electric heater (EH), existing HSTU multi-crop industrial dryer (HMID) which was operated by rice husk fired cyclonic furnace and sun drying method. The comparative drying experiments were carried out at the drying temperature of 60±5 °C, 70±5 °C and 80 ± 10 °C for HMMD-LPG, HMMD-EH and HMID, respectively, while sun drying was accomplished at 30±5 °C. The results indicated that the HMMD was capable of drying 820 ± 10 kg maize in each batch from 29.8 ± 0.87 % (wb) moisture to 14 ± 0.56 % (wb). Drying time in HMMD-LPG, HMMD-EH, HMID, and sun drying were 8.24 ± 0.18, 7.36 ± 0.17, 10.18 ± 0.16 and 16.14 ± 0.24 h, respectively, indicated that HMMD reduced time significantly for drying of freshly harvested maize. Unit drying cost in BDT/kg for EH and LPG integrated HMMD was 2.64 ± 0.17 and 1.69 ± 0.10, respectively, while lesser unit cost was found in HMID and sun drying methods. However, drying efficiency of HMMD-LPG was the highest (64.79 ± 1.21 %) while HMID exhibited the lowest drying efficiency (49.42 ± 1.63 %). Mechanically dried grain especially by HMMD-LPG was better or comparable in terms of nutritional quality than sun dried maize. HMMD-LPG and HMMD-EH dried grain exhibited a lower ΔE value than HMID and sun dried samples which indicated that the color properties were not affected so much by the drying method. Furthermore, maize samples dried in HMMD had lower microbial loads than other products. Therefore, the HSTU multi-crop mobile dryer with alternative heating source is recommended as an alternative drying technique for quick and safe management of high moisture maize at farm level in Bangladesh and other subtropical countries in contrast to weather depended sun drying method.

Macroelement Seasonal Variations in Latvian Organic Milk

Abstract Consumer perception of organic milk is associated with the assumption that organic milk differs from conventionally produced milk. The aim of the present study was to analyse calcium, magnesium, and phosphorus concentration in organic milk in the context of the season. The study was conducted from November 2019 to the end of October 2020. Over a year, raw bulk milk samples were collected and analysed. The milk for the study was supplied by two organic farms located in Latvia. Cows received a total mixed ration consisting of high moisture maize silage, grass silage, etc. The chemical composition of the total mixed rations was analysed, as well as fat, protein, lactose, milk solids non-fat, and total solids, calcium, phosphorus, and magnesium content in organic milk were determined. Seasonal variation in milk composition was observed. The average calcium concentration in our study was 107.96 ± 9.61 mg·100 g−1 with a lower average concentration 97 mg·100 g−1 in organic milk in March. The concentration of calcium, phosphorus, and magnesium was higher in organic milk during the spring–summer season. The sale of organic milk is growing in Latvia, and the presence of a favourable level of calcium in organic milk during the whole year should be reached, providing calcium concentration in cow’s milk around 120 mg·100 g−1 throughout the lactation period. Milk and milk products are an important part of daily nutrition, recommended to every consumer due to their wholesomeness and calcium concentration. Evaluating the bone health data of the Latvian population, 100 ml of milk consumption should provide at least 15% of the recommended daily intake of calcium.

Assessment of Fermentative Quality of Ensiled High-Moisture Maize Grains by a Multivariate Modelling Approach

The study aimed to define a grain-adapted quality score (GQS) to assess the fermentative pattern of ensiled high-moisture maize grain (EMG) based on organic acids, ammonia, and ethanol data of a lab-scale dataset. The GQS was validated by comparison with both the Flieg-Zimmer’s quality score (FQS) and a standardized quality score (SQS) by a received operating analysis. Compared with FQS and SQS, the cut-offs of poor/good samples for the proposed GQS were 47 (accuracy of 0.94) and 71 points (accuracy of 0.88) over 100, respectively. The relationship among indices was also tested in a farm-derived dataset by arranging a confusion matrix, which showed the higher predictive performance considering the lower cut-off. On the lab-scale dataset, a factorial discriminant analysis (FDA) assessed the most predictive chemical post-ensiled traits able to segregate EMG samples according to three fermentative quality classes of GQS. High-quality samples were accurately determined as having a positive correlation with lactate, while low- and middle-quality ones were partially overlapped and correlated with NH3-N, butyrate, and propionate. The validation of the FDA model in the blind farm-derived dataset confirms the effectiveness of the proposed GMS to rank between poorly- or well-preserved EMG.

Effects of Apple Vinegar Addition on Aerobic Deterioration of Fermented High Moisture Maize Using Infrared Thermography as an Indicator.

This study was carried out to determine the effects of apple vinegar and sodium diacetate addition on the aerobic stability of fermented high moisture maize grain (HMM) silage after opening. In the study, the effect of three different levels (0%, 0.5% and 1%) of apple vinegar (AV) and sodium diacetate (SDA) supplementation to fermented HMM at two different storage conditions (27–29 °C, 48% Humidity; 35–37 °C, 26% Humidity) were investigated. The material of the study was fermented rolled maize grain with 62% moisture content stored for about 120 days. Silage samples were subjected to aerobic stability test with three replicates for each treatment group. Wendee and microbiological analyses were made at 0, 2, 4, 7, and 12 days. Meanwhile, samples were displayed in the T200 IR brand thermal camera. According to the thermogram results, 1% SDA addition positively affected HMM silages at the second and fourth days of aerobic stability at both storage conditions (p < 0.05). Aerobic stability and infrared thermography analysis indicated that 1% AV, 0.5%, and 1% SDA additions to HMM silages had promising effects. Due to our results, we concluded that thermal camera images might be used as an alternative quality indicator for silages in laboratory conditions.

Comprehensive exergy transfer analysis of a cyclonic furnace integrated recirculating mixed flow grain dryer

Investigation of exergy transfer is an important aspect for all grain drying industry. Exergy transfer of rice husk fired cyclonic furnace assisted recirculating mixed flow dryer (MFD) equipped with a heat exchanger, was sought in this study. A cyclonic furnace (CF) having capacity 0.5 MW and recirculating MFD were designed and developed to investigate exergy transfer during grain drying. Efficiency of furnace was determined to quantify performance of CF for industrial grain drying system. Exergetic efficiency was also thoroughfare performed for the developed CF, air mixing chamber (heat exchanger) and MFD. Thermal efficiency of the CF varied from 68.96 to 87.01% during drying of high moisture maize grain. Exergy efficiency of the CF, heat exchanger and drying chamber marked between 58.8 and 63.5%, 74.6–93.29%, and 3.03–21.9%, respectively. Exploration of exergy inflow persist between 53.32 and 60.51 kJ/s and 7.58 to 9.81 kJ/s while exergy outflow ranged between 7.58 and 9.81 kJ/s and 1.52 to 3.10 kJ/s, respectively for heat exchanger and drying chamber. Results based on exergy losses indicates that 44.01–51.54 kJ/s and 5.87–7.50 kJ/s of exergy is just loss through heat exchanger and drying chamber, respectively. Exergy improvement potential and sustainability index varied between 1.02 and 1.80 kJ/s and 1.17–1.40 kJ/s, respectively. Quality of final product is in acceptable range as color difference of dehydrated maize kernel varied from 9.19 ± 0.46 to 17.05 ± 0.13. Exergy results indicate that CF can aptly be applied for grain drying industry in commercial scale.

Metabolic and Productive Response and Grazing Behavior of Lactating Dairy Cows Supplemented with High Moisture Maize or Cracked Wheat Grazing at Two Herbage Allowances in Spring.

Simple SummaryEnergy supplements such as high moisture maize or cracked wheat increase total dry matter intake (DMI) and dairy cow performance compared to pasture-only diets. However, the effectiveness of such a feeding strategy depends upon the level of herbage allowance (HA). In this study, increasing HA from 20 to 30 kg DM/cow had no effect on milk production but increased the concentration of urea in milk and plasma regardless of the type of energy supplement offered to grazing dairy cows. These results demonstrate that in high-quality pasture, low HA is appropriate to improve milk production performance per cow and per hectare.The aim was to determine the effect of the herbage allowance (HA) and supplement type (ST) on dry matter intake (DMI), milk production and composition, grazing behavior, rumen function, and blood metabolites of grazing dairy cows in the spring season. Experiment I: 64 Holstein Friesian dairy cows were distributed in a factorial design that tested two levels of daily HA (20 and 30 kg of dry matter (DM) per cow) and two ST (high moisture maize (HMM) and cracked wheat (CW)) distributed in two daily rations (3.5 kg DM/cow/day). Experiment II: four mid-lactation rumen cannulated cows, supplemented with either HMM or CW and managed with the two HAs, were distributed in a Latin square design of 4 × 4, for four 14-d periods to assess ruminal fermentation parameters. HA had no effect on milk production (averaging 23.6 kg/day) or milk fat and protein production (823 g/day and 800 g/day, respectively). Cows supplemented with CW had greater protein concentration (+1.2 g/kg). Herbage DMI averaged 14.17 kg DM/cow.day and total DMI averaged 17.67 kg DM/cow.day and did not differ between treatments. Grazing behavior activities (grazing, rumination, and idling times) and body condition score (BCS) were not affected by HA or ST. Milk and plasma urea concentration increased under the high HA (+0.68 mmol/L and +0.90 mmol/L, respectively). Cows supplemented with HMM had lower milk and plasma urea concentrations (0.72 mmol/L and 0.76 mmol/L less, respectively) and tended (p = 0.054) to have higher plasma β-hydroxybutyrate. Ruminal parameters did not differ between treatments.

In situ techniques to predict in vivo digestibility and to evaluate the impact of flint maize processing methods on degradation parameters

AbstractThis study aimed to (1) evaluate the effects of flint maize processing methods on the estimation of the readily soluble fraction (a), the potentially degradable fraction (b) and the rate of degradation of b (c) for dry matter (DM), organic matter (OM) and starch in the rumen; and (2) verify whether two different applications of in situ technique can be used to estimate in vivo DM, OM and starch digestibilities. Five ruminally cannulated Nellore bulls (265 ± 18.2 kg; 8 ± 1.0 mo) were distributed in a 5 × 5 Latin square. Three experimental diets were composed of 0.30 whole-plant maize silage, 0.10 supplement and 0.60 of one of the following processing methods: dry ground maize grain (DMG); high-moisture maize (HMM); reconstituted maize grain silage (RMG). Two additional diets were composed of 0.10 supplement, 0.80 snaplage and 0.10 stalklage (SNAP-80); or 0.10 supplement and 0.90 snaplage (SNAP-90). Digestibilities were estimated using in vivo procedure or predicted from in situ technique using a single 24 h incubation point or an equation proposed in previous literature. Diets based on ensiled grains presented greater (P &lt; 0.05) fraction a and c and lower (P &lt; 0.05) fraction b of DM, OM and starch compared to DMG. Both alternative use of in situ technique accurately estimated (P &gt; 0.05) in vivo DM, OM and starch digestibilities. The results suggest that ensilage process may increase the availability of nutrients. The two different applications of in situ technique showed precision and accuracy to estimate in vivo digestibility.

Experimental study on the key factors of low-loss threshing of high-moisture maize

The rates of maize breakage and entrainment loss are high in the harvest of high-moisture maize, which remains an issue with the development of agricultural mechanization. In order to reduce the maize breakage and entrainment loss rates, the correlations among key factors, such as the threshing cylinder speed, concave clearance and feeding rate, and the rates of breakage and entrainment loss during high-moisture maize harvesting were studied in this paper. A single-factor experiment was carried out using a single-longitudinal-axial flow maize harvester, and an orthogonal experiment was carried out using single- and double-longitudinal-axial flow maize harvesters with the Taguchi experimental design method. The single-factor experiment revealed that when the cylinder speed increased, the breakage rate of maize decreased first and then increased, while the entrainment loss rate decreased. The breakage rate of maize decreased as the concave clearance increased, while the entrainment loss rate decreased first and then increased. The optimum value of the concave clearance was positively correlated with the ear diameter of maize; Additionally, the minimum breakage rate of maize occurred when the feeding rate was at the rated value, and the entrainment loss rate increased as the feeding rate increased. The orthogonal experiments revealed that the importance of cylinder speed, feeding rate, concave clearance on the maize breakage and entrainment loss rates were in descending order. The optimum values of parameters for the single-longitudinal-axial flow maize harvester were 370 r/min cylinder speed, 40 mm concave clearance and 10 kg/s feeding rate. The optimum values of parameters the double-longitudinal-axial flow maize harvester were 550 r/min cylinder speed, 35 mm concave clearance and 10 kg/s feeding rate. The research can provide a reference for parameter configuration and control strategy for the longitudinal-axial flow maize harvester with high-moisture maize. Keywords: high-moisture maize, maize harvester, parameter configuration, Taguchi experiment DOI: 10.25165/j.ijabe.20201305.5653 Citation: Zhu X L, Chi R J, Du Y F, Qin J H, Xiong Z X, Zhang W T, et al. Experimental study on the key factors of low-loss threshing of high-moisture maize. Int J Agric & Biol Eng, 2020; 13(5): 23–31.

Experimental study on the key factors of low-loss threshing of high-moisture maize

The rates of maize breakage and entrainment loss are high in the harvest of high-moisture maize, which remains an issue with the development of agricultural mechanization. In order to reduce the maize breakage and entrainment loss rates, the correlations among key factors, such as the threshing cylinder speed, concave clearance and feeding rate, and the rates of breakage and entrainment loss during high-moisture maize harvesting were studied in this paper. A single-factor experiment was carried out using a single-longitudinal-axial flow maize harvester, and an orthogonal experiment was carried out using single- and double-longitudinal-axial flow maize harvesters with the Taguchi experimental design method. The single-factor experiment revealed that when the cylinder speed increased, the breakage rate of maize decreased first and then increased, while the entrainment loss rate decreased. The breakage rate of maize decreased as the concave clearance increased, while the entrainment loss rate decreased first and then increased. The optimum value of the concave clearance was positively correlated with the ear diameter of maize; Additionally, the minimum breakage rate of maize occurred when the feeding rate was at the rated value, and the entrainment loss rate increased as the feeding rate increased. The orthogonal experiments revealed that the importance of cylinder speed, feeding rate, concave clearance on the maize breakage and entrainment loss rates were in descending order. The optimum values of parameters for the single-longitudinal-axial flow maize harvester were 370 r/min cylinder speed, 40 mm concave clearance and 10 kg/s feeding rate. The optimum values of parameters the double-longitudinal-axial flow maize harvester were 550 r/min cylinder speed, 35 mm concave clearance and 10 kg/s feeding rate. The research can provide a reference for parameter configuration and control strategy for the longitudinal-axial flow maize harvester with high-moisture maize. Keywords: high-moisture maize, maize harvester, parameter configuration, Taguchi experiment DOI: 10.25165/j.ijabe.20201305.5653 Citation: Zhu X L, Chi R J, Du Y F, Qin J H, Xiong Z X, Zhang W T, et al. Experimental study on the key factors of low-loss threshing of high-moisture maize. Int J Agric & Biol Eng, 2020; 13(5): 23–31.

Pasture condition and milk production by grazing dairy cows as affected by daily herbage-allowance restriction

Daily herbage allowance is recognised as the main tool to control pasture utilisation and milk production per cow. The aim of the present study was to evaluate the long-term effects of daily herbage allowance (DHA) on pasture characteristics and milk production of dairy cows. Forty-four dairy cows were randomly assigned to one of four treatments in a 2 × 2 factorial design by considering two levels of DHA (20 and 30 kg DM/cow.day) and two types of supplements (high-moisture maize and maize silage) over a 77-day period. Pre- and post-grazing herbage masses, vertical distribution of herbage mass, species density, botanical and chemical composition, sward depletion and changes in morphological components of the pasture were measured. The effect of DHA on soil compaction was evaluated on the basis of the penetration resistance. Milk production and composition levels, bodyweights and body condition scores were recorded. Post-grazing residual declined as the level of DHA decreased, while grazing efficiency increased from 39.8% to 44.8%. We found no effects of DHA on any pasture characteristics, pasture regrowth or soil compaction. Low-DHA conditions induced a faster sward-height reduction, while the herbage mass remained unaffected. Individual milk production decreased with DHA. However, milk outputs per hectare increased by 2772 L/ha. Milk composition, bodyweight and body condition score were not affected by DHA. The results showed that DHA restriction decreases milk production per cow while increasing both herbage utilisation and milk production per hectare, without affecting long-term pasture condition.

Determination of safe storage moisture content of commercial maize (Zea mays) seeds during hermetic storage: Presentation

Germination declines during storage and meeting official standards (90% limit) can be challenging for the seed industry. Hermetic storage, through the establishment of self-modified atmospheres has shown to preserve germination in high-moisture maize seeds, but in the range of the low-moisture contents (m.c.) used by the seed industry, the relationship between hermetic storage and seed quality has not been fully studied. The aim of this work was to determine the safe storage m.c. of commercial maize seeds during hermetic storage considering both germination and microbiological aspects. Maize seeds with 95% initial germination were conditioned to m.c.s. between 11.5 and 14.5% and stored hermetically at 25oC for 6 months. Germination, % oxygen, % infected grains, and colony forming units (CFU) were evaluated. Germination declined with increasing m.c.s, dropping to 50% at 14.5% m.c. Microflora respiration started to be detected at 13.5% m.c. and an anaerobic self-modified atmosphere was reached at 14.5% m.c. Despite the higher relative humidity, % infected grains and CFU count at 14.5% m.c. were lower than at 13.5%, probably due to the suppressive effect of the anaerobic atmosphere. In conclusion, 11.5% was a safe storage m.c. as it preserved germination above marketing requirements without microbiological risk. Hermetic storage was useful to generate self-modified atmospheres for m.c.s above 13.5%, but these self-modified atmospheres were not effective to protect germination. Further research on the effects of controlled and self-modified atmospheres on the quality of different maize genotypes is needed to evaluate the benefit of hermetic storage of commercial seeds.

Yeast and bacteria from ensiled high moisture maize grains as potential mitigation agents of fumonisin B1.

Fumonisin B1 (FB1 ) is a mycotoxin produced by several Fusarium species and is a very common contaminant of maize-based food and feed throughout the world. The selection and use of FB1 -degrading microorganisms appears as a promising alternative to cope with the problem of toxicity towards humans and livestock. High moisture maize grain silage, which is based on natural maize fermentation, could be an interesting reservoir of such microorganisms. Using an in vitro simulated silage model with FB1 naturally contaminated grains, we demonstrated a significant raw decrease in FB1 during ensiling process ascribed to biodegradation mechanisms. A panel of 98 bacteria and yeasts were isolated from this matrix and selected for their ability to use FB1 as the sole source of C and N. For nine of them, the ability to degrade FB1 in vitro was evidenced. Notably, two bacteria identified as Lactobacillus sp. were highlighted for their efficient FB1 -degrading capacity and production of hydrolysed FB1 as intermediate degradation metabolite. Fermentation of high moisture maize grain contaminated with FB1 leads to a significant reduction of the toxin and allows the isolation of FB1 -degrading microorganisms that could further be used as FB1 decontaminating agents. © 2016 Society of Chemical Industry.

VLIV SMĚSI ORGANICKÝCH KYSELIN A MIKROBIÁLNÍHO INOKULANTU NA FERMENTAČNÍ PROCES LABORATORNÍCH SILÁŽÍ Z MAČKANÉHO VLHKÉHO ZRNA KUKUŘICE

In the experiment, the effect of chemical (A) and biological (B) additiva on the fermentation quality of climper high moisture maize grain corn was examined, compared with the untreated control (K). The chemical means contained propionic, formic and benzoic acids and ammonium formate as effective substances. As effective substances of bacterial water–soluble inoculants, selected were bacterial strains of Propionibacterium shermanii JS and Lactobacillus casei LC-705. Both conservative preservatives were added equally to the ensilaged material. The addition of chemical additivum under conditions of our experiment increased statistically significantly (P&lt;0.01) the contents of acetic acid (7.66±0.95 g/kg DM), ethanol (11.22±0.65 g/kg DM) and pH values (4.33±0.02) in experimental silages. Simultaneously, a statistically significant (P&lt;0.01) inhibition of lactic acid formation (15.17±2.75 g/kg DM) and of total content of all fermentation acids (22.33±2.38 g/kg DM) occurred. The bacterial inoculant increased significantly (P&lt;0.05) the content of lactic acid (26.78±2.63 g/kg DM) and the total acid content (32.87±2.88 g/kg DM) in inoculated silages. The inoculation positive effect was demonstrated highly significantly (P&lt;0.01) in reduction of ethanol amount (2.14±0.40 g/kg DM) and of totat acidification. The pH value (4.21±0.02) was significantly lower (P&lt;0.05) than that in the control silage (4.24±0.02). The fermentation characteristics in the inoculated silages by us were more favourable. The addition of organic acid mixture in the used concentration of 3.5 L/t did not confirm the positive effect on climper maize grain corn quality as expected.

Assessing Purdue Improved Crop Storage (PICS) bags to mitigate fungal growth and aflatoxin contamination

Storing maize in regions of the world without sufficient drying and storage capacity is challenging due to the potential risk of aflatoxin contamination produced by Aspergillus flavus. This study sought to determine if storage of maize in Purdue Improved Crop Storage (PICS) bags prevents mold growth and aflatoxin accumulation. PICS bags are a three-layer, hermitic bag-system that forms a barrier against the influx of oxygen and the escape of carbon dioxide. Maize conditioned at 12, 15, 18, and 21% grain moisture was inoculated with 50 g of maize kernels infected with fluorescent-marked strain of A. flavus. The grain was stored in either PICS or woven bags at 26 °C, and percent oxygen/carbon dioxide levels, fungal growth, aflatoxin, moisture content, and kernel germination were assessed after 1 and 2 months incubation. Maize stored in woven bags was found to equilibrate with the ambient moisture environment over both storage periods, while PICS bags retained their original moisture levels. Aspergillus flavus growth and aflatoxin accumulation were not observed in maize stored in any PICS bags. No aflatoxin B1 was detected in woven bags containing low-moisture maize (12 and 15%), but detectable levels of aflatoxin were observed in high moisture maize (18 and 21%). The percentage of oxygen and carbon dioxide within PICS bags were dependent on initial grain moisture. Higher carbon dioxide levels were observed in the bags stored for 1 month than for 2 months. High initial moisture and carbon dioxide levels correlated with low kernel germination, with the 18 and 21% treatment groups having no seeds germinate. The results of the study demonstrate that storage of maize in PICS bags is a viable management tool for preventing aflatoxin accumulation in storage.

Impact of silage additives on aerobic stability and characteristics of high-moisture maize during exposure to air, and on fermented liquid feed

To (i) measure the aerobic stability- and describe the characteristics, during aeration, of high-moisture maize (HMM) treated with various additives, and (ii) describe the microbial characteristics of fermented liquid feed (FLF) added HMM. Four treatments were prepared with each of three HMM samples: (i) The HMM as is (CONTROL); and the control added (ii) acids (ACID); (iii) heterofermentative lactic acid bacteria (HETERO); or (iv) homofermentative lactic acid bacteria (HOMO). After ensiling, aerobic stability was measured (Aim 1) and FLF prepared (Aim 2). The ACID treatment improved the aerobic stability of samples 1 and 3 from 9 to 14 h in the CONTROL to 67-115 h. All additives improved aerobic stability of sample 3 from 32 h in the CONTROL to 104-168 h. No proliferation of Enterobacteriacaea was detected during incubation of FLF. The microbial profile during aeration- and impact of additives on the aerobic stability of HMM depended on the characteristics of the samples. No blooming of Enterobacteriaceae was observed in FLF containing c. 20 g HMM 100 g(-1) . The impact of silage additives on aerobic stability of HMM should be tested in samples with varying characteristics. Inclusion of HMM could be a way of improving biosafety of FLF.

Mycoflora of high-moisture maize treated with ozone

This study evaluated the effectiveness of ozone to reduce the presence of fungi in stored high-moisture maize. Maize at moisture contents of 18, 22 and 26% (wet basis) were treated with air having ozone concentrations of 0, 50, 500, 1000 and 15,000 ppm for 1 h at a flow rate of 0.5 L min−1. After treatment, maize samples were surface disinfected and fungal species – Aspergillus, Cladosporium, Curvularia, Fusarium, Mucor, Penicillium, and Rhizopus – enumerated in the samples. The response to grain moisture content varied with fungal species. The average fungal infections per 100 kernels of maize for the non-ozone treated samples was 14.0 for Aspergillus, 0.6 for Cladosporium, 0.9 for Curvularia, 28.6 for Fusarium, 11.6 for Mucor, 56.9 for Penicillium, and 3.2 for Rhizopus. Ozone at the median concentrations – 500 and 1000 ppm – was most effective in reducing the presence of Aspergillus (p < 0.0001), Fusarium (p < 0.0001) and Mucor (p < 0.0001). Penicillium infections decreased with ozone concentrations of 1000 and 15,000 ppm (p < 0.0001). An ozone concentration of 15,000 ppm was necessary to reduce Rhizopus infection (p < 0.001). Ozone is capable of penetrating the surface of maize kernels to reduce fungal infections during storage. Ozonation of high-moisture maize is likely most effective in controlling the activity of Aspergillus and Fusarium due to their relatively high occurrence of infection on non-ozone treated maize and the observed reduction in their presence at lower ozone treatment concentrations.

Evaluation of probiotic bacteria for their effects on the growth performance and intestinal microbiota of newly-weaned pigs fed fermented high-moisture maize

The effects of feeding high-moisture maize fermented with Lactobacillus acidophilus or Pediococcus acidilactici on the growth performance and intestinal microflora of newly weaned pigs were investigated. A total of 270 newly weaned pigs (equal numbers of castrated males and females) were allocated to 3 dietary treatments (5 pens per treatment and 18 pigs per pen) in a randomized complete block design on the basis of body weight (BW) and litter. The dietary treatments included a basal diet supplemented with: 1) naturally fermented high-moisture maize without any microbial inoculants (Control); 2) high-moisture maize fermented with L. acidophilus (LA); and 3) high-moisture maize fermented with P. acidilactici (PA). Pigs were fed diets in liquid form for a 5-wk period. Quantitative polymerase chain reaction (QPCR) analysis with PCR primers specific to L. acidophilus or P. acidilactici indicated a well-developed bacterial population of each inoculated bacterium in the fermented high-moisture maize. Lactic acid was the major short-chain fatty acid (SCFA) produced from the fermentation. Among the 3 treatments and on most sampling days, LA-fermented maize had the numerically highest concentration of lactic acid. Dietary treatments over the 5-wk period did not impact pig growth performance. However, during last 3wks of the trial, pigs on the LA treatment had higher BW gains than pigs on PA. Pigs fed LA-fermented high-moisture maize showed fewer coliform bacteria in fecal samples when compared to pigs fed PA-fermented high-moisture maize (P<0.05). The PCR and denaturing gradient gel electrophoresis (DGGE) analysis on the relatedness of bacterial profiles of colonic microbiota revealed 3 bacterial clusters and the microbiota from PA-treated pigs formed 1 cluster. In addition, feeding LA- or PA-fermented maize reduced the diversity and richness of bacterial microbiota in the colon (P<0.05). Both L. acidophilus and P. acidilactici colonized poorly in the intestine of pigs regardless of the dietary treatments. These results indicate that feeding the probiotic-fermented, high-moisture maize can modulate the intestinal microbiota, and LA has the potential to impact pig growth performance.