• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.4
• /
• pp.526-532
• /
• 2006

The aim of this study was to evaluate the chemical composition, in vitro DM degradability, ME and OMD of alfalfa-maize silage mixtures in comparison to pure maize and alfalfa silages, and to test the existence of associative effects of ensiling alfalfa forage with whole-crop maize using the in vitro gas production technique. Ensiling alfalfa with whole-crop maize had a significant (p<0.001) effect on chemical composition, pH, in vitro DM degradability, OMD and estimated ME values of mixtures. DM content of the resultant silages significantly increased with increasing proportion of whole-crop maize in the mixtures, whereas the pH value, crude protein (CP), acid detergent fibre (ADF) and ash contents of mixtures decreased due to the dilution effect of whole-crop maize which was low in CP, ADF and ash. The pH values of all alfalfa-maize silage mixtures were at the desired level for quality silage. Gas production of alfalfa-maize silage mixtures at all incubation times except 12 h increased with increasing proportion of whole-crop maize. When alfalfa was mixed with whole-crop maize in the ratio 40:60, ME and OMD values were significantly (p<0.001) higher than other silages. Maximum gas production ($A_{gas}$) ranged from 65.7 to 78.1 with alfalfa silage showing the lowest maximum gas production. The results obtained in this study clearly showed that maximum gas production increased with increased percentage of whole-crop maize in the silage mixtures (r = 0.940, p<0.001). It was concluded that ensiling alfalfa with whole-crop maize improved the pH, OMD and ME values. However, trials with animals are required to see how these differences in silage mixtures affect animal performance.

• Korean Journal of Breeding Science
• /
• v.51 no.4
• /
• pp.318-325
• /
• 2019

Salt stress is a significant factor limiting growth and productivity in crops. However, little is known about the response and resistance mechanism to salt stress in maize. The objective of this research was to develop an enhanced salt-tolerant silage maize by mutagenesis with gamma radiation. To generate gamma radiation-induced salt-tolerant silage maize, we irradiated a KS140 inbred line with 100 Gy gamma rays. Salt tolerance was determined by evaluating plant growth, morphological changes, and gene expression under NaCl stress. We screened 10 salt-tolerant maize inbred lines from 2,248 M₂ mutant populations and selected a line showing better growth under salt stress conditions. The selected 140RS516 mutant exhibited improved seed germination and plant growth when compared with the wild-type under salt stress conditions. Enhanced salt tolerance of the 140RS516 mutant was attributed to higher stomatal conductance and proline content. Using whole-genome re-sequencing analysis, a total of 328 single nucleotide polymorphisms and insertions or deletions were identified in the 140RS516 mutant. We found that the expression of the genes involved in salt stress tolerance, ABP9, CIPK21, and CIPK31, was increased by salt stress in the 140RS516 mutant. Our results suggest that the 140RS516 mutant induced by gamma rays could be a good material for developing cultivars with salt tolerance in maize.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.9
• /
• pp.1304-1312
• /
• 2013

The effects of storage period and aerobic deterioration on the bacterial community were examined in Italian ryegrass (IR), guinea grass (GG), and whole-crop maize (WM) silages. Direct-cut forages were stored in a laboratory silo for 3, 7, 14, 28, 56, and 120 d without any additives; live counts, content of fermentation products, and characteristics of the bacterial community were determined. 2,3-Butanediol, acetic acid, and lactic acid were the dominant fermentation products in the IR, GG, and WM silages, respectively. The acetic acid content increased as a result of prolonged ensiling, regardless of the type of silage crop, and the changes were distinctively visible from the beginning of GG ensiling. Pantoea agglomerans, Rahnella aquatilis, and Enterobacter sp. were the major bacteria in the IR silage, indicating that alcoholic fermentation may be due to the activity of enterobacteria. Staphylococcus sciuri and Bacillus pumilus were detected when IR silage was spoiled, whereas between aerobically stable and unstable silages, no differences were seen in the bacterial community at silo opening. Lactococcus lactis was a representative bacterium, although acetic acid was the major fermentation product in the GG silage. Lactobacillus plantarum, Lactobacillus brevis, and Morganella morganii were suggested to be associated with the increase in acetic acid due to prolonged storage. Enterobacter cloacae appeared when the GG silage was spoiled. In the WM silage, no distinctive changes due to prolonged ensiling were seen in the bacterial community. Throughout the ensiling, Weissella paramesenteroides, Weissella confusa, and Klebsiella pneumoniae were present in addition to L. plantarum, L. brevis, and L. lactis. Upon deterioration, Acetobacter pasteurianus, Klebsiella variicola, Enterobacter hormaechei, and Bacillus gibsonii were detected. These results demonstrate the diverse bacterial community that evolves during ensiling and aerobic spoilage of IR, GG, and WM silages.

• Asian-Australasian Journal of Animal Sciences
• /
• v.16 no.12
• /
• pp.1738-1742
• /
• 2003

The whole plant of crop maize was chopped and ensiled in double-layered polyethylene bags to determine the influence of residual sugar on the fermentation of lactic acid and aerobic stability by L. buchneri in whole crop maize silage made in airstress condition. There were a total of six treatments used in this experiment as follow: added 25 g de-mineralised water per kg chopped maize serving as control (con), 37.5 g glucose solution containing 12.5 g glucose ($g_1$), 75 g glucose solution containing 25 g glucose ($g_2$), 25 g, L,.buchneri suspension intended for $10^6$ cfu $g^{-1}$ (L.b.), $g_1$+L.b. and $g_2$+L.b. All silos were opened at day 91 after ensiling for measuring the pH values, microbiological enumeration, fermentative products and aerobic stability. The dry matter loss increased significantly (p<0.01) due to inclusion of sugar or L. buchneri. The lower lactic acid concentrations were observed (p<0.01) in silages inoculated with L. buchneri only or in combination with sugar addition than the correspondent uninoculated silages. Compared with control silage, ethanol production was about 3 or 6-fold higher due to addition 12.5 or 25 g glucose per kg chopped maize at ensiling. The silages added with sugar contained less acetic acid concentration (p<0.01) than control, but silages inoculated with L. buchneri showed the contrary effects (p<0.01) at different sugar levels. No butyric acid was found in uninoculated silages, silages inoculated with L. buchneri. producted more propionic acid, 1-propanol and butyric acid. Lactic acid bacteria counts increased markedly (p<0.01) due to inoculation with L. buchneri, whereas it was reduced (p<0.01) by added sugar. No significant difference was observed in count of yeast, but inoculation with L. buchneri shows a decreasing trend. Mould count in all silages was less than 2 (log cfu $g^{-1}$). The added sugar had negative effects on aerobic stability of maize silage made under air-stress conditions, whereas inoculation with L. buchneri improves (p<0.01) the aerobic stability.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.8
• /
• pp.1128-1133
• /
• 2002

The whole plant of crop maize was chopped and ensiled in airtight 1-L capacity glass jars to determine the influence of residual sugar on anaerobic yeast growth and on the fermentation of lactic acid by L. buchneri in whole crop maize silage. There were a total of six treatments used in this experiment as follow: added 25 g de-mineralised water per kg chopped maize serving as control (con), 37.5 g glucose solution containing 12.5 g glucose ($g_1$), 75 g glucose solution containing 25 g glucose ($g_2$), 25 g L. buchneri suspension intended for $10^6$ cfu $g^{-1}$ (L.b.), $g_1+L.b.$ and $g_2+L.b.$ All silos were stored in the dark at $20^{\circ}C$ until end of experiment. Jars were opened on duplicates at day 2, 7, 14, 28, 56 or triplicates at day 91 after ensiling for measuring the pH, microbiological enumeration and fermentative products. Results indicated that acidification rates for all silages were very fast, no difference occurred among treatments before day 28. After day 28 the pH values for silages inoculated by L. buchneri. with or without sugar tended to increase especially for treated only with L. buchneri, resulting in higher (p<0.01) finial pH than uninoculated silages. Compared with control silage, the added sugar significantly (p<0.01) increased dry matter (DM) loss, L. buchneri enhanced (p<0.01) DM loss further at different sugar existence. Silages inoculated by L. buchneri only or in combination with sugar addition contained less (p<0.01) lactic acid than the correspondent silages without inoculation with L. buchneri. In comparison with control, ethanol production is about 3 or 6 fold higher due to addition 12.5 or 25 g glucose per kg chopped maize at ensiling. The added sugar resulted in less acetic acid concentration (p<0.01) than control, but inoculation with L. buchneri increased (p<0.01) acetic acid than correspondent uninoculated silages at different sugar levels. No butyric acid and propionic acid were found in uninoculted silages, silages inoculated with L. buchneri. produced more propionic acid, 1-propanol and butyric acid. Lactobacilli counts were not influenced by added sugar, but increased (p<0.01) with inoculation of L. buchneri. The added sugar increased significantly (p<0.01) the yeast count, whereas L. buchneri showed the contrary effect. No differences were found in the aerobic stability among all treatments. In conclusions, 1) the added sugars encourage the growth of yeast and yeasts convert extra sugar into ethanol in maize silages. 2) The added sugars and L. buchneri do not influence the aerobic stability of silages stored in anaerobic silos.

• Journal of Animal Science and Technology
• /
• v.63 no.2
• /
• pp.339-353
• /
• 2021

This study aimed to assess the causality of different climate variables on the production of whole crop maize (Zea mays L.; WCM) in the central inland region of the Korea. Furthermore, the effect of these climate variables was also determined by looking at direct and indirect pathways during the stages before and after silking. The WCM metadata (n = 640) were collected from the Rural Development Administration's reports of new variety adaptability from 1985-2011 (27 years). The climate data was collected based on year and location from the Korean Meteorology Administration's weather information system. Causality, in this study, was defined by various cause-and-effect relationships between climatic factors, such as temperature, rainfall amount, sunshine duration, wind speed and relative humidity in the seeding to silking stage and the silking to harvesting stage. All climate variables except wind speed were different before and after the silking stage, which indicates the silking occurred during the period when the Korean season changed from spring to summer. Therefore, the structure of causality was constructed by taking account of the climate variables that were divided by the silking stage. In particular, the indirect effect of rainfall through the appropriate temperature range was different before and after the silking stage. The damage caused by heat-humidity was having effect before the silking stage while the damage caused by night-heat was not affecting WCM production. There was a large variation in soil surface temperature and rainfall before and after the silking stage. Over 350 mm of rainfall affected dry matter yield (DMY) when soil surface temperatures were less than 22℃ before the silking stage. Over 900 mm of rainfall also affected DMY when soil surface temperatures were over 27℃ after the silking stage. For the longitudinal effects of soil surface temperature and rainfall amount, less than 22℃ soil surface temperature and over 300 mm of rainfall before the silking stage affected yield through over 26℃ soil surface temperature and less than 900 mm rainfall after the silking stage, respectively.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.3
• /
• pp.378-384
• /
• 2007

Three microorganisms and one chemical preservative were tested for their effects on the fermentation and aerobic stability of whole-crop wheat, sorghum and maize silages. Wheat at the early dough stage, sorghum at the late milk stage and maize at the one-third milk line stage were harvested and ensiled in 1.5-l anaerobic jars untreated or after the following treatments: control (no additives); Lactobacillus plantarum (LP) at $1.0{\times}10^6$ colony-forming units (CFU)/g of fresh forage; L. buchneri (LB) at $1.0{\times}10^6$ CFU/g; Propionibacterium acidipropionici (PA) at $1.0{\times}10^6$ CFU/g; and a formic acid-based preservative (FAP) at 3 ml/kg of fresh forage weight. Three jars per treatment were sampled on d 90 after ensiling, for chemical and microbiological analysis. At the end of the ensiling period, 90 d, the silages were subjected to an aerobic stability test lasting 5 d. In this test, $CO_2$ produced during aerobic exposure was measured along with chemical and microbiological parameters which serve as spoilage indicators. The silages inoculated with LP had higher concentration of lactic acid compared with the controls and the other treated silages (p<0.05). The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages. The controls and LP-inoculated silages spoiled upon aerobic exposure faster than LB, PA and FAP-treated silages due to more $CO_2$ production (p<0.05) in these two groups and development of yeasts unlike the other groups. In the experiment, the silages treated with LB, PA and FAP were stable under aerobic conditions. However, the numbers of yeasts was higher in the LP-inoculated wheat, sorghum and maize silages compared with the LB, PA and FAP-treated silages. The LB, PA and FAP improved the aerobic stability of the silages by causing more extensive heterolactic fermentation that resulted in the silages with high levels of acetic and propionic acid. The use of LB, PA and FAP as silage additives can improve the aerobic stability of whole-crop wheat, sorghum and maize silages by inhibition of yeast activity.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.40 no.1
• /
• pp.66-72
• /
• 2020

This study aimed to discuss the optimal seeding and harvesting dates with growing degree days(GDD) via meta-data of whole crop maize(WCM). The raw data (n=3,152) contains cultivation year, cultivars, location, seeding and harvesting dates collected from various reports such as thesis, science journals and research reports (1982-2012). The processing was: recording, screening and modification of errors; Then, the final dataset (n=121) consists of seeding cases (n=29), and harvesting cases (n=92) which were used to detect the optimum. In addition, the optimal periods considering tolerance range and GDD also were estimated. As a result, the optimum seeding and harvesting periods were 14th April ~ 3rd May and 15th August ~ 4th September, respectively; where, their GDDs were 23.7~99.6℃ and 1,328.7~1,602.1℃, respectively. These GDDs could be used as a judge standard for selecting the seeding and harvesting dates.

• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.287-295
• /
• 2018

A meridic artificial diet, including whole milk powder, wheat bran, maize leaf powder, and sucrose as the main nutrients, was tested for rearing Locusta migratoria (Orthoptera: Acrididae). When locusts were supplied with only the artificial diet over their entire life cycle, a second generation was not produced. The same result was observed when the diet was supplied daily and fresh maize leaves were supplied every other day. However, when the diet and fresh maize leaves were supplied alternately every other day, four generations of L. migratoria were produced. Fecundity in adults reared with the alternating diet was higher than that in adults supplied with both the diet and maize leaves daily. These results indicate that this artificial diet could be used as a supplementary food for rearing of L. migratoria.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.113-113
• /
• 2017

Downy mildew (DM), caused by several species in the Peronosclerospora and Scleropthora genera, is a major maize (Zea mays L.) disease in tropical or subtropical regions. DM is an obligate parasite species in the higher plants and spreads by oospores, wind, and mycelium in seed surface, soil, and living hosts. Owing to its geographical distribution and destructive yield reduction, DM is one of the most severe maize diseases among the maize pathogens. Positional cloning in combination with phenotyping is a general approach to identify disease resistant gene candidates in plants; however, it requires several time-consuming steps including population or fine mapping. Therefore, in the present study, we suggest a new combination strategy to improve the identification of disease resistant gene candidates. Downy mildew (DM) resistant maize was selected from five cultivars using the spreader row technique. Positional cloning and bioinformatics tools identified the DM resistant QTL marker (bnlg1702) and 47 protein coding genes annotations. Eventually, 5 DM resistant gene candidates, including bZIP34, Bak1, and Ppr, were identified by quantitative RT-PCR without fine mapping of the bnlg1702 locus. Specifically, we provided DM resistant gene candidates with our new strategy, including field selection by the spreader row technique without population preparation, the DM resistance region identification by positional cloning using bioinformatics tools, and expression level profiling by quantitative RT-PCR without fine mapping. As whole genome information is available for other crops, we propose applying our novel protocol to other crops or for other diseases with suitable adjustment.