• Asian-Australasian Journal of Animal Sciences
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• 제16권11호
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• pp.1619-1624
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• 2003

The effect of maize hybrid (Suco and Dekalb 765, DK 765), maturity stage (milk, $R_3$ and 1/2 milk line, $R_5$) and animal diet (Diet 1: 70% lucerne hay+30% maize silage; Diet 2: 50% maize silage+20% sunflower meal+30% maize grain) on ruminal stover dry matter (DM) degradability was studied. Additionally, morphological and chemical plant composition was evaluated. Fodder samples ground at 2 mm were incubated in three Holstein steers (400 kg body weight) using the in situ technique. Ruminal degradation kinetics was studied and the effective degradability (ED) was estimated for an assumed kp of 5%/h. The in situ data was analyzed in a complete randomized block design with the animals as blocks. Significant interactions between hybrid${\times}$diet and maturity${\times}$diet on kinetic digestion parameters were detected. In Diet 1, hybrids did not differ in degradable fraction, kd or ED, although a minor difference (p<0.05) in the soluble fraction was found (25.5 and 23.2% for Suco and DK 765, respectively). In Diet 2, the DK 765 had greater degradable fraction (p<0.001) but smaller (p<0.01) kd than Suco, without differences in the soluble fraction or in ED. Anticipating the harvest increased ED of stover from 37.5% in $R_5$ to 44.6% in $R_3$ (average values across hybrids and diets) due to the increase (p<0.001) in the soluble fraction ($R_5$: 22.6%, $R_3$: 28.8%). It is concluded that hybrids had similar stover in situ DM degradability and that soluble fraction represent the main proportion of degradable substrates. Advancing the date of harvesting may not improve the in situ DM degradability of whole maize plant silage since the increase in stover quality is counteracted by the depression in the grain-to-stover ratio. The diet of the animal consuming silage might not improve stover utilization either.

• 한국근적외분광분석학회:학술대회논문집
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• 한국근적외분광분석학회 2001년도 NIR-2001
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• pp.1610-1610
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• 2001

Microbiological examination of silage is of little value in gauging the outcome of silage, and so chemical analysis is more reliable and meaningful indicator of quality. On the other hand chemical assessments of the principal fermentation products provide an unequivocal basis on which to judge quality. Livestock require energy, protein, minerals and vitamins from their food. While fresh forages provide these essential items, conserved forages on the other hand may be deficient in one or more of them. The aim of the conservation process is to preserve as many of the original nutrients as possible, particularly energy and protein components (Woolford, 1984). Silage fermentation is important to preservation of forage with respect of feeding value and animal performance. Chemical and bacteriological changes in the silo during the fermentation process can affect adversely nutrient yield and quality (Moe and Carr, 1984). Many of the important chemical components of silage must be assayed in fresh or by extraction of the fresh material, since drying either by heat or lyophilisation, volatilises components such as acids or nitrogenous components, or effects conversion to other compounds (Abrams et al., 1987). Maize silage dorms the basis of winter rations for the vast majority of dairy and beef cattle production in Uruguay. Since nutrient intake, particularly energy, from forages is influenced by both voluntary dry matter intake and digestibility; there is a need for a rapid technique for predicting these parameters in farm advisory systems. Near Infrared Reflectance Spectroscopy (NIRS) is increasingly used as a rapid, accurate method of evaluating chemical constituents in cereals and dried forages. For many years NIRS was applied to assess chemical composition in dry materials (Norris et al., 1976, Flinn et al., 1992; Murray, 1993, De Boever et al., 1996, De la Roza et al., 1998). The objectives of this study were (1) to determine the potential of NIRS to assess the chemical composition of dried maize samples and (2) to attempt calibrations on undried samples either for farm advisory systems or for animal nutrition research purposes in Uruguay. NIRS were used to assess the chemical composition of whole - plant maize silage samples (Zea mays, L). A representative population of samples (n = 350) covering a wide distribution in chemical characteristics were used. Samples were scanned at 2 nm intervals over the wavelength range 400-2500 nm in a NIRS 6500 (NIRSystems, Silver Spring, MD, USA) in reflectance mode. Cross validation was used to avoid overfitting of the equations. The optimum calibrations were selected on the basis of minimizing the standard error of cross validation (SECV). The calibration statistics were R$^2$ 0. 86 (SECV: 11.4), 0.90 (SECV: 5.7), 0.90 (SECV: 16.9) for dry matter (DM), crude protein (CP), acid detergent fiber (ADF) in g kg$\^$-1/ on dry matter, respectively for maize silage samples. This work demonstrates the potential of NIRS to analyse whole - maize silage in a wide range of chemical characteristics for both advisory farm and nutritive evaluation.

• Asian-Australasian Journal of Animal Sciences
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• 제16권12호
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• pp.1738-1742
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• 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
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• 제31권9호
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• pp.1464-1473
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• 2018

Objective: To describe in-depth sequencing, the bacterial community diversity and its succession during ensiling of whole-plant maize and subsequent exposure to air. Methods: The microbial community dynamics of fermented whole-plant maize for 60 days (sampled on day 5, 10, 20, 40, 60) and subsequent aerobic exposure (sampled on day 63 after exposure to air for 3 days) were explored using Illumina Miseq sequence platform. Results: A total of 227,220 effective reads were obtained. At the genus level, there were 12 genera with relative abundance >1%, Lactobacillus, Klebsiella, Sporolactobacillus, Norank-c-cyanobacteria, Pantoea, Pediococcus, Rahnella, Sphingomonas, Serratia, Chryseobacterium, Sphingobacterium, and Lactococcus. Lactobacillus consistently dominated the bacterial communities with relative abundance from 49.56% to 64.17% during the ensiling process. Klebsiella was also an important succession bacterium with a decrease tendency from 15.20% to 6.41% during the ensiling process. The genus Sporolactobacillus appeared in late-ensiling stages with 7.70% abundance on day 40 and 5.32% on day 60. After aerobic exposure, the Lactobacillus decreased its abundance from 63.2% on day 60 to 45.03% on d 63, and Klebsiella from 5.51% to 5.64%, while Sporolactobacillus greatly increased its abundance to 28.15%. These bacterial genera belong to 5 phyla: Firmicutes (relative abundance: 56.38% to 78.43%) was dominant, others were Proteobacteria, Bacteroidetes, Cyanobacteria, and Actinobacteria. The bacterial communities clearly clustered into early-ensiling (d 5), medium-ensiling (d 10, d 20), late-ensiling (d 40, d 60), and aerobic exposure (d 63) clusters, with early- and late-ensiling communities more like each other than to the aerobic exposure communities. Conclusion: High-throughput sequencing based on 16S rRNA genes proved to be a useful method to explore bacterial communities of silage. The results indicated that the bacterial communities varied during fermentation and more dramatically during aerobic exposure. The study is valuable for understanding the mechanism of population change and the relationship between bacteria and ensilage characteristics.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1128-1133
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• 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.

• 한국육종학회지
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• 제51권4호
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• pp.318-325
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• 2019

식물은 다양한 환경 스트레스에 적응하기 위해 스트레스 내성 유전자의 발현과 자연 돌연변이를 통해 외부 환경 및 자극에 대한 반응 특성을 강화시켜 왔다 본 연구는 사료용 옥수수를 대상으로 감마선을 이용하여 돌연변이 집단을 구축하고 내염성이 증대된 계통을 개발하고자 수행되었다. 140RS516은 NaCl 처리 조건에서 대조군인 KS140과 비교하여 증가된 염 스트레스 내성을 보였다. 감마선에 의한 다양한 유전변이를 보인 140RS516 식물체는 염 스트레스 조건에서 대조군보다 높은 발아율과 생장, 기공전도도 그리고 proline함량을 나타냈으며, 내염성에 관여하는 유전자들의 발현이 증가하였다. 따라서 본 연구를 통해 개발된 140RS516 옥수수는 간척지 염화토양과 같이 불량한 환경에서 작물 재배 및 생산이 가능한 내염성 품종을 개발하기 위한 육종 소재로 활용될 수 있을 것이다.

• 한국작물학회지
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• 제65권4호
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• pp.406-415
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• 2020

본 연구는 간척지 내 재배 가능한 내염성 사료용 옥수수를 선발하기 위해 EMS를 이용하여 돌연변이 집단을 구축하고 기내 선발 방법을 통해 내염성 증진 계통을 선발하였고, 연구결과는 다음과 같다. 1. 사료용 옥수수 모본인 KS140에 다양한 조건으로 EMS를 처리하여 발아율 및 식물의 생육 상태를 조사하였고, 발아율에는 영향을 미치지 않으면서 생육에 큰 영향을 주지않는 0.5% EMS를 돌연변이 유도 적정 농도로 선정하였다. 2. 기내 선발 방법을 통해 선발된 내염성 증진 계통 140ES91 계통을 이용하여 0.5% 염분 스트레스 처리 후 표현형을 조사한 결과, 대조군인 KS140 대비 식물의 초장 및 근장의 생육이 양호하였으며, 높은 proline 함량과 기공전도도를 보였다. 따라서 염분 스트레스 시 높은 proline 함량과 기공전도도가 140ES91 계통의 증가된 내염성과 관련이 있을 것으로 판단된다. 3. 내염성 증진 140ES91 계통의 유전변이 분석을 통해 유전자 기능에 영향을 미칠 수 있는 아미노산 변이를 유발하는 39개의 변이 유전자를 확인하였고, 변이 유전자와 내염성의 관계를 증명하기 위한 유전자 기능 분석이 요구된다. 4. 기 보고된 내염성 관련 유전자들의 발현 양상을 조사한 결과 ABP9과 CIPK31 유전자는 대조군 대비 염분 스트레스 처리 전후 140ES91 계통에서 높은 발현율을 보였으며, CIPK21 유전자는 염분 스트레스 처리 후 대조군에는 발현이 감소하나 140ES91 계통에서는 발현이 유지됨을 확인하였다. 따라서 140ES91 계통에서 보이는 내염성 관련 유전자들의 높은 발현율이 140ES91 계통의 내염성에 관여할 것으로 판단된다. 5. 이상의 결과 기내 선발 방법을 통해 선발한 내염성 증진 계통은 간척지와 같은 염류집적 토양에서 작물의 안정적인 재배와 생산이 가능한 내염성 증진 품종 개발의 육종소재로 활용될 수 있을 것으로 판단된다.