Italian Ryegrass Silage Research Articles

Faba bean-rapeseed silage as substitute for Italian ryegrass silage: effects on performance and milk quality of grazing dairy cows

Three trials were conducted to study the effect of including in the ration of dairy cows the intercrop faba bean-rapeseed or Italian ryegrass silages on feed intake, milk quality and enteric methane emissions. Ten lactating Holstein cows, randomly allocated in two groups, were used in each trial in a crossover design. Dry matter intake and milk yield were recorded daily for each data period. Milk was sampled for analyses three times per period. Enteric methane emission was estimated applying a model that includes bodyweight, dry matter intake, nutritional values of feeds and milk composition. Concentrate and grass intake did not differ between treatments, while total mixed ration intake was higher with Italian ryegrass silage. Milk yield and protein concentration also increased with the Italian ryegrass treatment. The milk urea concentration was higher with the faba bean and rapeseed diet. Fatty acid profiles were affected by feeding strategy. Thereby, t11 18:1, c9 18:1 and total unsaturated fatty acid were higher when the intercrop silage was fed. As consequence, atherogenicity index and thrombogenicity index were lower under that treatment. Estimated enteric methane emissions did not differ between treatments. In conclusion, faba bean-rapeseed intercrop can be an alternative to Italian ryegrass to feed dairy cows. The rations formulated with the intercrop silage have potential to improve the milk fatty acid content, and show healthier profiles for consumers. However, it would be useful to study the protein content of these crops to avoid possible excess urea in milk and to maintain sustainable milk yield and milk protein content.

Lactic Acid Bacteria Mixture as Inoculants on Low Moisture Italian Ryegrass Silage Fermentation

The effects of lactic acid bacteria (LAB) mixtures on low moisture Italian ryegrass (IRG) silage fermentation was evaluated in field conditions. The experiment was categorized into two groups: Un-inoculated (Control) and Inoculated with LAB mixture for four storage periods (45, 90, 180, and 365 days, respectively). Silage inoculated with the LAB mixture had the lowest pH with highest lactic acid production than the control from beginning at 45-365 days at all moistures. Higher LAB counts were observed in inoculated silages than the control silages at whole experimental periods. It is a key reason for the rapid acidification and higher lactic acid production in silages during the storage periods. Overall results suggest that an adding of LAB mixture had positive effects on the increasing aerobic stability of silage and preserved its quality for an extended duration.

Microbial community and fermentation characteristic of Italian ryegrass silage prepared with corn stover and lactic acid bacteria

The bacterial community determined via PacBio single molecule, real-time sequencing technology (SMRT) and the fermentation characteristics of Italian ryegrass (IR, 82% moisture) silage prepared with corn stover (CS) were investigated. A selected strain of Lactobacillus plantarum (L694) and a commercial inoculant stain of Lactobacillus plantarum (LP) were used as additives. Lactic acid bacteria (LAB) effectively improved silage quality. After fermentation, Lactobacillus plantarum was the dominant species in IR + LP and IR + L694 treatments, which led to higher (P < 0.05) lactic acid and lower (P < 0.05) butyric acid production. Lactobacillus plantarum, Lactobacillus hammesii, Lactobacillus brevis, and Lactobacillus coryniformis were abundantly present in IR + CS + LP and IR + CS + L694 treatments, and acetic acid contents of these were higher (P < 0.05) than those of other silages. This study demonstrated that addition of CS and LAB can change the microbial community and influence the silage fermentation of IR, and PacBio SMRT reveals more specific microbial information.

The Effect of Adding Some Lactic Acid Bacteria Containing Lactobacillus diolivorans on Fermentation Quality and Inhibit Mould Growth in Wilted Italian Ryegrass Silage

The Effect of Adding Some Lactic Acid Bacteria Containing <i>Lactobacillus diolivorans</i> on Fermentation Quality and Inhibit Mould Growth in Wilted Italian Ryegrass Silage

Effects of nitrogen fertilizer and harvesting stage on photosynthetic pigments and phytol contents of Italian ryegrass silage.

This study aimed to investigate the effects of nitrogen (N) fertilizer application and harvesting stage on the contents of chlorophyll, phytol and carotenoids (β-carotene and lutein) in Italian ryegrass herbage before and after ensiling, and the extent of phytol preservation after ensiling. Three rates of N fertilizer (0, 60 and 120kg N/ha) were applied by top-dressing as an additional fertilizer. The herbage harvested at booting stage (27weeks of age) or heading stage (29weeks of age) were wilted for 1day, then ensiled for 60days using a small-scale pouch system. In the pre-ensiled herbages, increasing N fertilizer application increased the contents of crude protein and photosynthetic pigments, and these contents were also higher at the booting stage compared with the heading stage. In the silage, increasing N fertilizer application also increased the contents of crude protein, the photosynthetic pigments and their derivatives (pheophytin and pheophorbide), while harvesting stage did not affect the contents of β-carotene, chlorophylls or pheophorbide. Nitrogen fertilizer application and early harvesting of herbage increased lutein and phytol contents in Italian ryegrass silage. Lutein and phytol in Italian ryegrass herbage are indicated to be well preserved during ensiling.

Effects of Different Microbial Culture Supplements on In vitro and In situ Ruminal Fermentation Characteristics of Italian ryegrass Silage

Effects of Different Microbial Culture Supplements on In vitro and In situ Ruminal Fermentation Characteristics of Italian ryegrass Silage

이탈리안 라이그라스 사일리지 급여가 한우 경산우의 번식 성적에 미치는 영향

이탈리안 라이그라스 사일리지 급여가 한우 경산우의 번식 성적에 미치는 영향

Comparative microbiota assessment of wilted Italian ryegrass, whole crop corn, and wilted alfalfa silage using denaturing gradient gel electrophoresis and next-generation sequencing.

The microbiota of pre-ensiled crop and silage were examined using denaturing gradient gel electrophoresis (DGGE) and next-generation sequencing (NGS). Wilted Italian ryegrass (IR), whole crop corn (WC), and wilted alfalfa (AL) silages stored for 2months were examined. All silages contained lactic acid as a predominant fermentation product. Across the three crop species, DGGE detected 36 and 28 bands, and NGS identified 253 and 259 genera in the pre-ensiled crops and silages, respectively. The NGS demonstrated that, although lactic acid bacteria (LAB) became prevalent in all silages after 2months of storage, the major groups were different between crops: Leuconostoc spp. and Pediococcus spp. for IR silage, Lactobacillus spp. for WC silage, and Enterococcus spp. for AL silage. The predominant silage LAB genera were also detected by DGGE, but the presence of diverse non-LAB species in pre-ensiled crops was far better detected by NGS. Likewise, good survival of Agrobacterium spp., Methylobacterium spp., and Sphingomonas spp. in IR and AL silages was demonstrated by NGS. The diversity of the microbiota described by principal coordinate analysis was similar between DGGE and NGS. Our finding that analysis of pre-ensiled crop microbiota did not help predict silage microbiota was true for both DGGE and NGS.

Addition of Novel Lactobacillus plantarum KCC-10 and KCC-19 to Improve Fermentation Quality and Characterization of Italian Ryegrass Silage

An investigation was carried out to evaluate the potential role of Lactobacillus Plantarum KCC-10 and KCC-19 on the quality and fermentation characterization of Italian ryegrass (IRG) silages. The physiochemical properties of IRG silage such as crude protein content, neutral detergent fiber, acid detergent fiber, total digestible nutrient and in vitro dry matter digestibility were not affected by KCC-10 and KCC-19. The pH of IRG silage in KCC-10 and KCC-19 treatments decreased compared to the control (p<0.05), while the lactic acid content in KCC-10 and KCC-19 treatments increased compared to the control (p<0.05). In addition, the number of lactic acid bacteria (LAB) in the KCC-10 treatment increased compared to the control (p<0.05). The number of lactic acid bacteria in KCC-19 increased, but there was no significant difference in all treatments. Therefore, we recommend L. plantarum KCC-10 and KCC-19 as potential additive candidates in IRG silage with lots of advantages.

Profile of Hanwoo Steer Carcass Characteristics, Meat Quality and Fatty Acid Composition after Feeding Italian Ryegrass Silage.

The objective of this work was to evaluate the growth performance, feed intake, slaughter characteristics, meat quantity and quality characteristics of Hanwoo steers fed with Italian ryegrass (IRG) silage (TRT). IRG silage consisted 11.70% protein, 2.84% ether extract, 53.50% dry matter digestibility and 63.34% total digestible nutrients. The daily weight gain and feed conversion ratio of TRT were significantly (p<0.01) higher than that of control diet (CON; fed rice straw) in the whole periods. However, the slaughter weight, dressing percentage, quantity grade and quantity traits (marbling score, meat color, fat color, and quality grade) of either TRT or CON were similar. Meat fed TRT diet showed higher crude fat and lightness (L*) value and lower moisture content and pH value compared with the CON diet (p<0.05). Overall the carcass yield was 12.5% higher than CON diet.

Hetero 발효 유산균주 첨가가 사일리지용 이탈리안 라이그라스와 총체보리의 품질에 미치는 효과

본 연구에서는 hetero 발효유산균 첨가가 이탈리안 라이그라스 및 총체보리 사일리지의 사료가치 및 발효품질에 미치는 영향을 조사하였다. 사일리지 접종균주를 선발하기 위해 유산균 6종(L. plantarum IMAU 70164, L. acidophilus KACC 12419, L. casei KACC 12413, L. reuteri KCTC 3594, L. buchneri KACC 12416 and L. diolivorans KACC 12385)을 이용하였으며, 젖산 함량이 높은 L. casei KACC 12416와 프로피온산 함량이 높은 L. reuteri KCTC 3594을 최종 선택하여 사일리지를 제조하였다. 처리구는 대조구, L. casei 첨가구, L. reuteri 첨가구 및 L. casei, L. reuteri 혼합첨가구로 하여 30일, 45일 및 60일간 저장하였다. pH는 IRG 사일리지의 경우 유산균 첨가구가 대조구에 비해 낮았으며(p<0.05), 수분함량, 젖산 및 초산함량 또한 유산균을 첨가한 처리구에서 낮은 것으로 나타났다(p<0.05). 수용성 탄수화물의 함량은 L. casei KACC 12416와 L. reuteri KCTC 3594를 혼합배양한 처리구에서 가장 낮았다(p<0.05). 프로피온산은 유산균을 접종한 총체보리에서 전 기간동안 높게 나타났으며, 반면에 사일리지 품질을 저해시키는 butyrate는 발효 60일의 대조구에서 측정되었다. 사일리지의 미생물 측정결과 IRG 사일리지 배양 60일에 유산균 첨가구에서 곰팡이가 억제되었으며, WCB 사일리지는 유산균을 첨가한 처리구에서 곰팡이가 검출되지 않았다. 이상의 연구 결과들로 볼 때, 단일 균주를 접종한 사일리지에 비해 co-culture (L. casei + L. reuteri)로 접종했을 때 사일리지 저장품질 개선에 보다 효과적이었으며, 혼합배양한 처리구가 청보리 사일리지내 높은 프로피온산을 생성하며 이는 사일리지의 품질개선에 도움을 주는 것으로 조사되었다. This study was conducted to determine the quality of italian ryegrass (IRG) and whole- crop barley (WCB) silage combined with heterofermentative lactic acid bacteria (LAB) during fermentation. Six strains of LAB (L. plantarum IMAU 70164, L. acidophilus KACC 12419, L. casei KACC 12413, L. reuteri KCTC 3594, L. buchneri KACC 12416 and L. diolivorans KACC 12385) were used in this study. L. casei and L. reuteri had the highest propionic acid production and were therefore used for fermenting the forages. The forages were fermented using monoculture and co-culture of L. casei and L. reuteri for 30, 45 and 60 days of ensiling. Addition of LAB lowered the pH of the IRG silage (p<0.05). Moisture content, lactic acid and acetic acid contents were higher (p<0.05) after addition of LAB. Water soluble carbohydrate was significantly lower (p<0.05) in WCB with a co-culture containing L. casei and L. reuteri. Propionic acid production was comparatively higher after addition of LAB to WCB on days 30, 45 and 60 while butyric acid was only detected in the IRG control on day 60. Fungi was not detected within 60 days after addition of LAB in IRG and WCB. Through this experiment, improved forage preservation was achieved using a co-culture containing L. casei and L. reuteri. WCB silage had higher propionic acid concentration and thus, it was a better forage for ensiling using co-culture of L. casei and L. reuteri.

Identification of bacteria in total mixed ration silage produced with and without crop silage as an ingredient.

As a forage source for total mixed ration (TMR) silage production, locally produced crop silage is now used in addition to imported hay. This type of TMR ensiling is regarded as a two-step fermentation process; hence, a survey was carried out to determine whether the bacteria in crop silage affect the subsequent TMR ensiling. Fermentation product contents and bacterial community were determined for TMR silage and its ingredient silages collected in August, October and November. August product contained corn, sorghum and Italian ryegrass silages, October product had wheat silage exclusively and November product did not include any crop silages. Acetic acid, lactic acid, 2,3-butanediol and ethanol were predominant fermentation products in corn, sorghum, Italian ryegrass and wheat silages, respectively. Robust lactic acid fermentation was seen in TMR silage, even if acetate-type and alcohol-type silages were mixed as ingredients. The finding that bacterial community of the TMR silage appeared unrelated to those of ingredient silage supported this. Silages of various fermentation types can therefore be formulated without interfering with lactate-type fermentation in TMR silage.

Enhancing Nutritional Quality of Silage by Fermentation with Lactobacillus plantarum.

The present study was aimed to investigate the nutritive profiles, microbial counts and fermentation metabolites in rye, Italian rye-grass (IRG) and barley supplemented with Lactobacillus plantarum under the field condition, and its probiotic properties. After preparation of silage, the content of crude protein (CP), crude ash, acid detergent fiber (ADF), and neutral detergent fiber (NDF), microbes such as lactic acid bacteria (LAB), yeast and fungi counts, and fermentation metabolites lactic acid, acetic acid and butyric acid was assessed. Results indicated that the content of ADF and NDF were significantly varied between rye, IRG and barley mediated silages. The content of CP was increased in L. plantarum supplemented with IRG, but slightly decreased in rye and barley mediated silages. The maximum LAB count was recorded at 53.10 × 10(7) cfu/g in rye, 16.18 × 10(7) cfu/g in IRG and 2.63 × 10(7) cfu/g in barley silages respectively. A considerable number of the yeasts were observed in the IRG silages than the rye silages (P<0.05). The amount of lactic acid production is higher in L. plantarum supplemented silages as compared with control samples (P<0.05). It was confirmed that higher amount of lactic acid produced only due to more number of LAB found in the silages. L. plantarum was able to survive at low pH and bile salt and the duodenum passage with the highest percentage of hydrophobicity. Furthermore, the strain was sensitive towards the antibiotics commonly used to maintain the microbes in food industrial setups. In conclusion, supplementation of L. plantarum is most beneficial in rye, IRG and barley silage preparations and probiotic characteristics of L. plantarum was an intrinsic feature for the application in the preparation of animal feeds and functional foods.

Identification and phylogenetic characterization of novel Lactobacillus plantarum species and their metabolite profiles in grass silage

Italian ryegrass (IRG), barley, and rye are types of forage that are difficult to ensile with an assurance of good quality. Therefore, the addition of lactic acid bacteria (LAB) is the best way to enhance the preservation of this silage. However, applications of LAB have been impeded due to its poor growth characteristics, the sudden decline in pH, and other non-beneficial microbial growth associated with its presence. To overcome these limitations, a new Lactobacillus sp. KCC-10 and KCC-19 strain was isolated from well-fermented IRG silage samples. Biochemical and physiological studies revealed that the strains were Gram-positive, catalase-negative, and produced gas from glucose, and produced more lactic acid in fermentation. The 16S rRNA gene-based phylogenetic affiliation was determined by using bioinformatic tools that identified Lactobacillus sp. KCC-10 and KCC-19 with 100 % sequence similarity to Lactobacillus plantarum. Novel L. plantarum strains were deposited in the Korean Collection for Type Cultures under the accession numbers KACC 91785P and KACC 91758P, respectively. The shake-flask cultivation of these new strains under aerobic, microaerobic, and anaerobic conditions showed a higher specific growth rate than that achieved using the well-studied L. plantarum KACC 91016 and KACC 91096 on MRS broth and grass juice. Lactic acid was detected as the dominant organic acid in IRG (78.45 mM), barley (51.28 mM), corn (16.28 mM), and rice paddy (11.05 mM), followed by acetic acid and succinic acid. The KCC-10 in the silage was observed to increase from 2.4 × 105 CFU/g per sample at day 0 to 0.58, 0.60, and 0.59 × 109 CFU/g at day 5 for IRG, barley, and rye, respectively. The growth of KCC-10 and KCC-19 in all the silages decreased, as the storage period increased from 5 to 50 days. Whereas, KCC-19 was noted to increase from 2.7 × 105 CFU/g per sample at day 0 to 0.71, 0.72, and 0.711 × 109 CFU/g at day 5 for IRG, barley, and rye. Among the total organic acids, lactic acid was detected as the dominant acid present in IRG, barley, and rye silages. From these results, we concluded that strains KCC-10 and KCC-19 can be used as appropriate inoculants to prolong the stability of silage and fermentation quality.

Effects of Ensiling Fermentation and Aerobic Deterioration on the Bacterial Community in Italian Ryegrass, Guinea Grass, and Whole-crop Maize Silages Stored at High Moisture Content.

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.

Maize silage and Italian ryegrass silage as high-energy forages in organic dairy cow diets: Differences in feed intake, milk yield and quality, and nitrogen efficiency

AbstractDuring the winter feeding period in organic dairy production systems in the alpine and pre-alpine regions of Austria and its neighboring countries, maize silage is an energy-rich forage that is regularly included in grass-silage-based diets to improve the energy supply of the cows. Italian ryegrass (Lolium multiflorumLam.) is also a high-energy fodder grass popular as forage for dairy cows, but it is rarely cultivated in Austrian organic agriculture. The two crops differ in their cultivation demands and characteristics. Italian ryegrass establishes rapidly and may reduce the risk of soil erosion. Italian ryegrass would be a beneficial addition to crop rotation, which is an essential tool in successful organic farming. In a 15-week feeding trial, Italian ryegrass silage and maize silage were fed to 22 lactating Holstein dairy cows. Organically produced Italian ryegrass silage and maize silage were included at a rate of 40% [of dry matter (DM)] in grass-silage-based mixed basal diets. The mixed basal diets were supplemented with modest amounts of additional concentrates (2.7–3.0 kg DM day−1). Owing to the higher energy content of maize silage as compared to Italian ryegrass silage, the maize diet provided more energy [6.3 MJ net energy for lactation (NEL) kg−1DM] than the ryegrass diet (6.15 MJ NEL kg−1DM). The protein supply of the maize diet and the ryegrass diet was intended to be equal, but in fact the protein content of the maize diet was significantly lower (122 g crude protein kg−1DM) than that of the ryegrass diet (141 g kg−1DM). When the maize diet was fed, feed intake, milk yield and milk protein content were significantly higher as compared to the ryegrass diet. Also, intake of crude protein was significantly lower when feeding the maize diet, and in combination with the higher milk protein yield, this enabled an efficiency of gross nitrogen (N) utilization as high as 0.304. This level of N efficiency can be considered as above average and was significantly and considerably higher than the level of 0.259 observed when the ryegrass diet was fed. Therefore, maize silage upholds its reputation as an ideal energy-rich component in grass-silage-based dairy cow diets.

Changes in the bacterial community and composition of fermentation products during ensiling of wiltedItalian ryegrass and wilted guinea grass silages

To gain further insights into temperate and tropical grass ensiling, fermentation products and bacterial communities were examined at both the initial and late stages of ensiling of wilted Italian ryegrass and wilted guinea grass silages. 2,3-Butanediol and ethanol fermentation were observed in wilted Italian ryegrass silage. Enterobacteria such as Rahnella sp. and Enterobacter sp. may have been involved in fermentation; however, alcohol production was intensified after the silage enterobacterial community overwhelmed the pre-ensiled enterobacterial community. Pediococcus spp. appeared in silage stored for 4 months, when a significant increase in lactic acid content was seen compared with that at 2 months. Prolonged storage enhanced acetic acid fermentation in wilted guinea grass silage. The disappearance of Enterococcus sulfureus and appearance of Lactobacillus plantarum may have been associated with the increased acetic acid content. Although many species of enterobacteria were found in common between the pre-ensiled crop and silages of Italian ryegrass and guinea grass, marked differences were seen in the type of fermentation from the initial stages. These results indicate that the bacterial community of pre-ensiled crops may be immediately replaced by one that is adapted to ensiling environments, although metabolic changes may continue over the course of ensiling.

Effect of Different Silages for TMR on In vitro Rumen Simulative Fermentation

In this study, the in vitro fermentation parameters of whole crop barley (WCBS-TMR) and Italian ryegrass (IRGS-TMR) silage total mixed rations were compared. A rice straw based diet (RSBD), which was a mixture of rice straw and concentrate (60:40), was used as the control. The feeds were incubated in buffered rumen fluid for 3, 6, 9, 12, 24, 48 and 72 hours at 39°C. At the end of each incubation period the following parameters were determined, total gas, pH, ammonia nitrogen (NH₃-N), volatile fatty acids (VFA) and then the acetate to propionate ratio (A/P) was calculated. The dietary treatments did not affect (p>0.05) the overall production of NH3-N, gas, total VFA and all the individual VFA, with the exception of n-butyrate (p<0.001). The treatment diets significantly affected the A/P ratio (p<0.01). The control diet resulted in the lowest A/P ratios, followed by WCBS-TMR and lastly IRGS-TMR had the highest ratios. Gas production was not different between treatments, suggesting a probable similar level of digestibility when treatments are fed to animals. It can therefore be concluded from the present study that WCBS and IRGS are of almost an equivalent nutritional value when incubated in a TMR form. WCBS-TMR however resulted in lower A/P ratios than IRGS-TMR, which is indicative of a more energy efficient diet.

Characteristics of lactic acid bacteria isolates and their inoculating effects on the silage fermentation at high temperature

Thermotolerant strains of lactic acid bacteria (LAB) were screened for their suitability for silage making at high temperatures. Four selected strains were identified by 16S rRNA sequencing analyses and added to unwilted and wilted Italian ryegrass for ensiling at 45°C. All four strains (HT1, HT2, HT3 and HT4) grew at 50°C and pH 4·0. Strains HT1 and HT2 were identified as Lactobacillus rhamnosus; HT3 and HT4 were identified as Lact. fermentum. Strains HT1 and HT2 were the most effective at improving the fermentation quality of Italian ryegrass silage, irrespective of wilting, as indicated by lower pH values, less NH(3) -N, and more lactic acid. In contrast, strains HT3, HT4 and a commercial inoculant consisting of Lact. plantarum and Pediococcus acidilactici conferred no or reduced benefits. Wilting alone did not improve the fermentation quality of Italian ryegrass at 45°C. Inoculating with thermotolerant Lact. rhamnosus HT1 and HT2 could improve the fermentation quality of silage at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics and could play an important role in developing silage production in such regions. Grasses are often difficult to ensile in the tropics and subtropics because of the high temperatures there. To solve this problem, we screened for thermotolerant lactic acid bacteria and obtained two valuable strains of Lactobacillus rhamnosus, HT1 and HT2, which proved to be beneficial to silage fermentation at high temperatures. Lactobacillus rhamnosus HT1 and HT2 can be used as inoculants for silage making in the tropics and subtropics, and will play an important role in developing silage production in such regions.

근적외선 분광법을 이용한 이탈리안 라이그라스 사일리지의 품질 평가

본 연구는 근적외선분광법의 현장 이용성 및 이탈리안 라이그라스 원물 사일리지의 신속한 품질평가를 위한 근적외선 검량식을 개발하기 위하여 전국에서 이탈리안 라이그라스 사일리지 약 450여 점을 수집하였다. 각각의 시료는 근적외선 분광기를 이용하여 스펙트럼을 측정한 후 측정된 스펙트럼과 실험실 분석값 간에 상관관계를 이용한 다변량회귀분석법을 통하여 검량식을 유도한 다음 각 성분별로 예측 정확성을 평가하였다. 이탈리안 라이그라스 원물 사일리지의 수분 함량에 대한 검량식 개발 결과는 검량식 작성시 표준오차(SEC)가 0.94% (<TEX>$R^2$</TEX>=0.99)로 매우 우수한 정확성을 보였으며 개발된 검량식의 상호검증(SECV) 결과는 1.27% (<TEX>$R^2$</TEX>=0.98)로 나타났다. ADF, NDF 및 조단백질 함량 평가를 위해 개발된 검량식의 상호검증(SECV) 결과는 각각 1.26% (<TEX>$R^2$</TEX>=0.88), 2.0% (<TEX>$R^2$</TEX>=0.84) 및 0.96% (<TEX>$R^2$</TEX>=0.93)으로 나타났으며 조회분함량 평가에 대한 검량식 개발 결과는 다소 낮은 정확성(SECV 0.72%, <TEX>$R^2$</TEX>=0.62)을 나타내었다. 사일리지의 발효품질의 주요 평가항목인 pH와 젖산함량 평가에 대한 검량식 개발결과(SEC)는 각각 0.41 (<TEX>$R^2$</TEX>=0.85), 0.18% (<TEX>$R^2$</TEX>=0.92)로 나타났으며 개발된 검량식의 상호검증 결과(SECV)는 각각 0.56 (<TEX>$R^2$</TEX>=0.78), 0.31%(0.81)로 나타났다. Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid and accurate method of evaluating some chemical compositions in forages. This study was carried out to explore the accuracy of near infrared spectroscopy (NIRS) for the prediction of chemical parameters of Italian ryegrass silages. A population of 267 Italian ryegrass silages representing a wide range in chemical parameters and fermentative characteristics was used in this investigation. Samples of silage were scanned at 2 nm intervals over the wavelength range 680~2,500 nm and the optical data recorded as log 1/Reflectance (log 1/R) and scanned in intact fresh condition. The spectral data were regressed against a range of chemical parameters using partial least squares (PLS) multivariate analysis in conjunction with spectral math treatments to reduced the effect of extraneous noise. The optimum calibrations were selected on the basis of the highest coefficients of determination in cross validation (<TEX>$R^2$</TEX>) and the lowest standard error of cross validation (SECV). The results of this study showed that NIRS predicted the chemical parameters with very high degree of accuracy. The <TEX>$R^2$</TEX> and SECV were 0.98 (SECV 1.27%) for moisture, 0.88 (SECV 1.26%) for ADF, 0.84 (SECV 2.0%), 0.93 (SECV 0.96%) for CP and 0.78 (SECV 0.56), 0.81 (SECV 0.31%), 0.88 (SECV 1.26%) and 0.82 (SECV 4.46) for pH, lactic acid, TDN and RFV on a dry matter (%), respectively. Results of this experiment showed the possibility of NIRS method to predict the chemical composition and fermentation quality of Italian ryegrass silages as routine analysis method in feeding value evaluation and for farmer advice.