Improvement In Forage Quality Research Articles

Transcriptome analysis identifies differentially expressed genes involved in lignin biosynthesis in barley

Lignin is an essential metabolite for plant growth but negatively affects the quality of forage barley. Genetic modification of quality traits to improve the forage digestibility requires an understanding of the molecular mechanism of lignin biosynthesis. RNA-Seq was used to quantify transcripts differentially expressed among leaf, stem and spike tissues from two barley genotypes. A total of 13,172 differentially expressed genes (DEGs) were identified, of which much more up-regulated DEGs were detected from the contrasting groups of leaf vs spike (L-S) and stem vs spike (S-S), and down-regulated DEGs were dominant in the group of stem vs leaf (S-L). 47 DEGs were successfully annotated to the monolignol pathway and six of them were candidate genes regulating the lignin biosynthesis. The qRT-PCR assay verified the expression profiles of the six candidate genes. Among them, four genes might positively regulate the lignin biosynthesis during forage barley development in terms of the consistency of their expression levels and changes of lignin content among the tissues, while the other two genes may have the reverse effects. These findings provide target genes for further investigations on molecular regulatory mechanisms of lignin biosynthesis and genetic resources for improvement of forage quality in barley molecular breeding programme.

Genome-Wide Association Studies Identifying Multiple Loci Associated With Alfalfa Forage Quality.

Autotetraploid alfalfa is a major hay crop planted all over the world due to its adaptation in different environments and high quality for animal feed. However, the genetic basis of alfalfa quality is not fully understood. In this study, a diverse panel of 200 alfalfa accessions were planted in field trials using augmented experimental design at three locations in 2018 and 2019. Thirty-four quality traits were evaluated by Near Infrared Reflectance Spectroscopy (NIRS). The plants were genotyped using a genotyping by sequencing (GBS) approach and over 46,000 single nucleotide polymorphisms (SNPs) were obtained after variant calling and filtering. Genome-wide association studies (GWAS) identified 28 SNP markers associated with 16 quality traits. Among them, most of the markers were associated with fiber digestibility and protein content. Phenotypic variations were analyzed from three locations and different sets of markers were identified by GWAS when using phenotypic data from different locations, indicating that alfalfa quality traits were also affected by environmental factors. Among different sets of markers identified by location, two markers were associated with nine traits of fiber digestibility. One marker associated with lignin content was identified consistently in multiple environments. Putative candidate genes underlying fiber-related loci were identified and they are involved in the lignin and cell wall biosynthesis. The DNA markers and associated genes identified in this study will be useful for the genetic improvement of forage quality in alfalfa after the validation of the markers.

The Dessau Grassland Experiment—Impact of Fertilization on Forage Quality and Species Assembly in a Species-Rich Alluvial Meadow

Since alluvial meadows of river valleys of the Cnidion dubii are protected by the EU Habitats Directive, reconciling farmers’ demands for forage quality with the objective of maintaining them in good conservation status is an important issue in grassland research. In a long-term experiment from 2010 to 2018, we investigated the impact of fertilizing on forage quality and species assembly on a species-rich and twice-mown alluvial grassland in the Dessau Elbe floodplain (Germany). The experiment was composed of an unfertilized control, PK, N60, N60PK and N120PK applications. A significant improvement in forage quality was achieved by nitrogen fertilization only for crude protein, with higher feeding requirements for sheep met only in individual years. The legume cycle was inhibited by the application of nitrogen and high grass cover was maintained, but not increased, at the highest nitrogen application after an exceptional summer flood. The target forbs persisted in numbers over the study period in all treatments. For cover, the low-competitive target forbs responded neutrally to nitrogen fertilization, whereas detrimental effects were demonstrated for the competitive ones. Thus, we recommend not applying more than 60 kg year−1 of nitrogen and only in combination with phosphorus and potassium.

Nitrogen fertilizer needs of first‐year small grain forages following alfalfa

AbstractSmall grain forages are commonly grown following alfalfa (Medicago sativa L.) in Utah and the Intermountain West, especially during drought years as small grains require less irrigation than corn (Zea mays L.). Several studies have shown that corn following alfalfa rarely needs nitrogen (N) fertilizer, yet few have evaluated N needs of small grains grown for forage. Objectives of this research were to determine whether N fertilizer is needed to economically optimize the yield and quality of first‐year small grain forages following alfalfa, and whether spring soil nitrate tests can predict N responsiveness. Fertilizer trials (four replications of six N rates) were conducted on 11 first‐year small grain forage sites in Utah during 2018 and 2019. Results indicated that N fertilizer was not needed to economically increase small grain forage yield at most (91%) site‐years. The one responsive site‐year followed an old and thinning alfalfa stand (9‐yr old) and required only 67 kg N ha−1. In contrast, forage quality improved with average N fertilizer applications ranging from 101 to 142 kg N ha−1 at all but one site‐year. Soil nitrate concentration was able to separate yield and forage quality response to N in 73 and 53% of the cases, respectively, suggesting it may be a viable prediction test for yield and some aspects of quality response in this rotation. Results indicate that growers often do not need to apply fertilizer N to first‐year small grain forages unless compensation for forage quality improvement outweighs fertilizer costs.

Using Si-rich materials for increasing fodder grass quality and quantity

Improvement of forage quality is one of the essential issues to enhance livestock productivity. Bahiagrass is a popular fodder plant used as pasture species and for hay production, but it lacks the nutritional quality. In greenhouse experiment, the effect of silicon (Si) (calcium silicate and amorphous silicon dioxide) and nitrogen (ammonium nitrate) supplementation on bahiagrass growth and protein content was evaluated. Both types of fertilizers significantly increased the biomass and crude protein content in leaves of bahiagrass. Higher effect was obtained when Si was applied together with nitrogen. The increases were 78 to 100% for biomass and 57 to 59% for crude protein content. Considering that improved plant Si nutrition mitigates the negative effects of biotic and abiotic stresses, the Si involvement into fertilizer management strategy in fodder crops could be efficient for maintaining productivity and quality.

ПРОДУКТИВНОСТЬ И КАЧЕСТВО КОРМА СЕНОКОСНЫХ УГОДИЙ В ЗАВИСИМОСТИ ОТ СОВМЕСТНОГО ВНЕСЕНИЯ АММОФОСА И АММИАЧНОЙ СЕЛИТРЫ

This paper discusses the effect of a multiple-nutrient fertilizer and a mixture of simple mineral fertilizers on yield increase and forage quality improvement of hayfields under the conditions of the mid-mountain zone of the Republic of Altai. The natural forage lands of the mid-mountain zone of the Republic of Altai are characterized by the predomi-nance of the motley grass-grasses type of vegetation. The soils are deficient in available phosphorus and have in-creased exchangeable potassium content, so it is advisa-ble to apply mineral fertilizers containing nitrogen and phosphorus. The research was conducted from 2018 through 2020 on the farm of the KFK “Yegarmina M.M.” in the Shebalinskiy District of the Republic of Altai. In the var-iants of ammonium phosphate fertilizer application and its combination with ammonium nitrate in the rates of 20 and 40 kg ha (primary nutrient basis), yield increase of 24.1-85.9% (0.72-2.56 t ha) was obtained. The mineral fertilizers not only increase the yields, but also improve the nutritional value and forage quality. Digestible protein content in one fodder unit increased by 15-35 g as compared to that of the control. The maximum value of this indicator (116 g) was recorded in the variant with N12P52. Thus, the application of mineral fertilizers made it possible to obtain forages that met animal nutrition requirements.

Quantifying the value proposition for white clover persistence on a New Zealand summer-dry hill-country farm

The improvement in forage quality and quantity of summer-dry hill country pasture resulting from the introduction of clover is well recognised. However, ensuring the persistence of the commonly availablecultivars is challenging, in the face of seasonal moisture stress, intensive grazing, competition from established well-adapted pasture species, low soil fertility and low soil pH – conditions typical of the East Coast of the North Island. Here we quantify the value proposition associated with the introduction of white clover into a case study on a Gisborne sheep and beef farm, using a six-step process. A topographically explicit approach is taken, using an understanding of the underlying spatial variability, based on a combination of soil and pasture measurements, APSIM simulation modelling of pasture growth and farm system modelling of enterprise performance. We show that from a baseline of a typical low-fertility, diverse species hill country pasture, white clover introduction can increase spring and summer forage consumption by 17%, enabling inclusion of an additional 6-month bull finishing enterprise generating a 32% greater carcass weight production and leading to a 49% improvement in farm system EBIT. This represents a positive net present value of over $360,000 for the original investment in white clover establishment into existing pastures.

Вплив поверхневого поліпшення гірських і заплавних луків Карпат на їх продуктивність та якість корму

Goal. To determine the features of the formation of efficiency, chemical composition, nutritive value, and energy content of grass forages depending on surface improvement of meadows of the mountain-forest belt of the Carpathians Mountains. Methods. Field, laboratory, mathematical-statistical. Results. It is shown that productivity of dry matter for 1 ha over 3 years of research made on average: for haymaking – 2.15–4.77 t, for perennial mowing — 1.95–4.11 t. For haymaking usage, the highest productivity was at sowing the mixtures of cereal grasses on the background of N60P30K60. For perennial mowing usage, the highest productivity was at sowing white clover on the background of P30K60. It respectively made 12% and 85% more than in the variants without interplanting, and 122% and 111% more than in the variants without surface improvement. The best uniformity of distribution of crop biomass was obtained for perennial mowing with interplanting white clover on the background of P30K60. In this case, the share of the 1st mowing was 39%, 2nd — 33, and 3rd — 28% with the unevenness expressed by the coefficient of variation of 18%. From measures of surface improvement of forage quality as to chemical composition (a primarily, increase of the content of crude protein) they noted the introduction of N60P30K60 or 15 t/ha of manure. For perennial mowing, a similar effect was noted for interplanting white clover on the background P30K60. Regardless of the measures of surface improvement the highest content of crude protein, the best energy content, and the nutritional value of grass fodder had perennial mowing (simulation of pasture meadow). Conclusions. For surface improvement of meadows of the mountain-forest belt of the Carpathians Mountains with natural herbage, the working factors influencing the productivity and improving the quality of grass fodder are the annual introduction of N60P30K60 or 15 t/ha of manure, or N60P30K60 + interplanting of mixtures of grasses of fescue and timothy for haymaking use, or P30K60 + interplanting of white clover for perennial mowing use. The application of mineral fertilizers in combination with the interplanting of perennial grasses ensures the best positive effect.

Heteroexpression of Osa-miR319b improved switchgrass biomass yield and feedstock quality by repression of PvPCF5

BackgroundSwitchgrass (Panicum virgatum L.), a C4 perennial grass, has been recognized as one of the most potentially important lignocellulose biofuel crops. MicroRNA319 (miR319) plays a key role in plant development, abiotic resistance, and cell wall biosynthesis by repressing expression of its target TCP genes. We hypothesized miR319–TCP pathway could play important roles in switchgrass feedstock characteristics for biofuel production, and produced switchgrass transgenic plants overexpressing miR319 (by ectopic expressing Osa-MIR319b gene), blocking miR319 (by overexpressing a target mimicry of miR319/MIM319) and repression of miR319 target gene PvPCF5. Plant phenotype, biomass yield, and feedstock quality of transgenic plants were analyzed.ResultsOverexpression of miR319 in switchgrass promoted leaf elongation and expansion of transgenic plants, increased plant height, stem diameter, and resulted in a significant increase in plant biomass yield. Transgenic plants overexpressing of miR319 reduced lignin content, showed significantly higher enzymatic hydrolysis efficiency compared to the wild type plant. However, opposite results were observed in the MIM319 plants. Furthermore, suppression of miR319 target gene PvPCF5 activity also reduced lignin content, increased lignin monomer S/G ratio and the proportion of β-O-4 linkages, while significantly improving the sugar production per plant. Quantitative real-time (qRT-PCR) analysis indicated that expression of PvMYB58/63B and PvHCT with predicted TCP binding sites in their promoter regions was negatively regulated by miR319–PvPCF5 module.ConclusionsMiR319–PvPCF5 module plays positive roles in regulating biomass yield and quality of switchgrass. It can be utilized as a candidate molecular tool in regulating biomass yield and feedstock quality. The finding could also be transferred to other grasses for forage quality improvement through genetic manipulation.

The optimal plant density of maize for dairy cow forage production

AbstractWhole maize (Zea mays L.) plant (WMP) silage is an important feed for dairy cows. In northern China, yields and feed quality are adjusted by modifying the planting density. This paper is the result of a 2‐yr field study aimed at determining the effects of plant density on maize silage yield and quality. Five planting densities (52,500, 60,000, 67,500, 75,000, and 82,500 plants ha−1) were used. The results showed that plant height and leaf area increased, while stem diameter, chlorophyll, and leaf area per plant decreased with increasing plant density. Both the biomass yield, expressed as the dry matter (DM) per ha, and the utilizable energy yield improved when the density was increased from 67,500 to 75,000 plants ha−1, but increasing the density further reduced these values. The highest observed DM were 17,734 kg ha−1 and 17,055 kg ha−1, and total net energy for lactation (NEL) were 104.1 GJ ha−1 and 97.0 GJ ha−1 in 2017 and 2018, respectively. Feeding quality generally decreased with increasing plant density. The plant density which obtained the highest biomass yield was not the same as the plant density for optimizing feeding production. Compared with the highest predicted DM yields, the highest predicted total NEL yields increased the grading index by 4–9%, which indicated an improvement in forage quality. Total NEL yield is more efficient for the purpose of evaluating the productivity of WMP forage than biomass yield.

Intensification of dairy production can increase the GHG mitigation potential of the land use sector in East Africa.

Sub‐Saharan Africa (SSA) could face food shortages in the future because of its growing population. Agricultural expansion causes forest degradation in SSA through livestock grazing, reducing forest carbon (C) sinks and increasing greenhouse gas (GHG) emissions. Therefore, intensification should produce more food while reducing pressure on forests. This study assessed the potential for the dairy sector in Kenya to contribute to low‐emissions development by exploring three feeding scenarios. The analyses used empirical spatially explicit data, and a simulation model to quantify milk production, agricultural emissions and forest C loss due to grazing. The scenarios explored improvements in forage quality (Fo), feed conservation (Fe) and concentrate supplementation (Co): FoCo fed high‐quality Napier grass (Pennisetum purpureum), FeCo supplemented maize silage and FoFeCo a combination of Napier, silage and concentrates. Land shortages and forest C loss due to grazing were quantified with land requirements and feed availability around forests. All scenarios increased milk yields by 44%–51%, FoCo reduced GHG emission intensity from 2.4 ± 0.1 to 1.6 ± 0.1 kg CO2eq per kg milk, FeCo reduced it to 2.2 ± 0.1, whereas FoFeCo increased it to 2.7 ± 0.2 kg CO2eq per kg milk because of land use change emissions. Closing the yield gap of maize by increasing N fertilizer use reduced emission intensities by 17% due to reduced emissions from conversion of grazing land. FoCo was the only scenario that mitigated agricultural and forest emissions by reducing emission intensity by 33% and overall emissions by 2.5% showing that intensification of dairy in a low‐income country can increase milk yields without increasing emissions. There are, however, risks of C leakage if agricultural and forest policies are not aligned leading to loss of forest to produce concentrates. This approach will aid the assessment of the climate‐smartness of livestock production practices at the national level in East Africa.

Effects of ruminal and post-ruminal protein supplementation in cattle fed tropical forages on insoluble fiber degradation, activity of fibrolytic enzymes, and the ruminal microbial community profile

The aim of this study was to evaluate the effects of ruminal and abomasum protein supplementation in cattle consuming tropical forages on nutritional characteristics, fibrolytic enzymatic activity, in vitro degradation of insoluble fiber, and the ruminal microbial community profile. Two experiments were sequentially conducted and differed only in the forage quality that was offered: medium-quality forage (MQF, 78.4g of crude protein, CP/kg of dry matter, DM) and high-quality forage (HQF, 98.6g CP/kg DM). Four Nellore young bulls fitted with rumen and abomasum cannulas were utilized, and the following supplementation schemes were evaluated: control (only forage), daily supply of 230g of additional CP (casein) into the rumen, daily supply of 230g of additional CP into the abomasum, and supply of 115g of additional CP into the rumen and 115g of additional CP into the abomasum. Experiments were conducted using a 4×4 Latin square design where two sequential squares were used, one for MQF and other for HQF. The improvement in forage quality increased (P<0.05) intake, fiber digestibility, and nitrogen retention. Supplementation, independently of site (rumen, abomasum or both), increased (P<0.05) nitrogen balance in the rumen and in the animal’s body. Ruminal supplementation increased (P<0.05) rumen ammonia nitrogen concentration and consequently in vitro degradation rate of neutral detergent fiber. Enzymatic activity was not affected (P>0.05) by forage quality. However, in disagreement with data of degradation and digestibility, decreases in enzymatic activity were observed mainly for post-ruminal supplementation. The improvement of forage quality increased (P<0.05) the richness and diversity associated with liquid fractions from ruminal fluid, although there was no effect on solid fractions. The improvement in forage quality and protein supplementation increases nitrogen accretion in the animal body. Well-defined associations cannot be established between production characteristics and enzymatic activities, and rumen microbial diversity in cattle fed tropical forages and receiving protein supplementation.

Chemical composition and in vitro ruminal digestibility of hand-plucked samples of Xaraes palisade grass fertilized with incremental levels of nitrogen

Improvements in the nutritional quality of tropical grasses depend on the proper use of grazing management and nitrogen fertilization as well as climatic conditions. The aim of this study was to evaluate the effect of nitrogen (0, 125, 250, 375, 500 or 625kg/ha, applied as urea), grazing cycles (GCs) and growing degree days (GDD) on the chemical composition and in vitro digestibility of dry matter (IVDMD), organic matter (IVOMD) and neutral detergent fibre (NDFD) of hand-plucked samples of Xaraes palisade grass (Urochloa brizantha cv. Xaraes). A total of 24 plots of 112m2 each were cultivated with Xaraes palisade grass was evaluated and carried with repeated measures (GCs) and one treatment factor (N rate) in completely randomized block design, with four replications. Grass samples were collected after 26 days of regrowth from plots that were managed under rotational stocking (26 days of rest and 2 days of occupation) in six GCs (1–6). To achieve the target height of post-grazing residues (24–27cm), dry Holstein cows were used with a body weight (BW) of 527kg (SD 36kg), considering a consumption of 2.5% of BW and 40% estimated mass loss of pre-grazing forage. All of the nutrient concentrations were affected by N fertilization and GCs. The crude protein (CP) content increased linearly with the N rate in each grazing cycle (P<0.05). NDF decreased linearly with the N rate in each grazing cycle (P<0.05). N fertilization increased the IVDMD, IVOMD and NDFD with a linear or quadratic response depending on the GC (P<0.05). The average maximum point that was obtained in GC4 in the regression equations for IVDMD, IVOMD and NDFD as a function of N fertilization was 533kgN/ha/year. The GDD had a quadratic effect on the chemical composition and digestibility of Xaraes palisade grass with distinct N doses. N fertilization stimulated the formation of cell walls with better-quality fibre and resulted in a higher forage digestibility according to the climatic conditions and GDD. The greatest improvements in forage quality were obtained, with N rates greater than 382kg/ha/year.

Heterosis for protein, digestibility, fiber, and water soluble carbohydrates in nine sources of orchardgrass germplasm

Orchardgrass, or cocksfoot, (Dactylis glomerata L.) is one of the most important forage grasses used in temperate agriculture. Yet, genetic gains are slow and complicated owing to the perennial and autotetraploid nature of orchardgrass. The development of orchardgrass population hybrids may be a way to more efficiently make genetic gains through heterosis. In the study reported herein, we describe the results of a 3 year study of the effect of heterosis on the forage quality of orchardgrass population hybrids managed with supplemental irrigation at a Cache County, UT, USA field site. The population hybrids derived from the orchardgrass cultivars Latar, Paiute, and Potomac; and from six additional germplasm sources from Asia, Europe, and North America. Data reflected July and August harvests from 2008 to 2010 and included crude protein (CP), in vitro true digestibility (IVTD), neutral detergent fiber (NDF), and water soluble carbohydrates (WSC). There were differences (P < 0.05) among the population hybrids and the included check cultivars for each of the traits at both harvest points. Mid-parent heterosis was relatively common and there were several instances of high-parent heterosis and reciprocal effects. Additionally, the population hybrids possessed better mean phenotypic values than the cultivars for July CP (2 g kg−1), and August CP (4 g kg−1), IVTD (7 g kg−1), NDF (−9 g kg−1), and WSC (4 g kg−1). Overall, the results suggest that population hybrids may prove a feasible approach for orchardgrass forage quality improvement.

Digestibility-related histological attributes of vegetative organs of barrel medic (Medicago truncatula Gaertn.) cultivars

An anatomical analysis of vegetative organs of barrel medic (Medicago truncatula Gaertn.) cultivars was performed using anatomical and stereological methods. The aim was to determine histological bases of the genotypic differences for digestibility, calculate tissue volume densities (Vv), examine the variability and assess tissue proportions along the stem maturity gradient. As the cultivars showed similar proportions of leaf tissues, potential variations in digestibility should be assigned to structural differences observed for the stems. Phloem and xylem Vv increased linearly with stem maturation, whilst Vv of epidermis, mechanical and parenchyma tissue significantly decreased. Secondary xylem was the tissue with the highest potential impact on digestibility. Cultivars ‘Mogul’ and ‘Jemalong’ had low proportion of lignified stem tissues, whilst ‘Parabinga’ and ‘Caliph’ did not show favourable anatomical characteristics. More advantageous proportions of thick-walled and thin-walled cells were recorded in M. truncatula stems, compared to alfalfa (M. sativa). Therefore, examined cultivars are comparable in anatomical quality parameters to this wellknown forage crop. Leaf parameters did not provide variability necessary for the improvement of forage quality. Stem parameters showed higher within-cultivar variability, which could be useful as a starting point in breeding towards improvement of digestibility. As the secondary xylem was the lignified stem tissue with the highest Vv, we recommend the improvement of M. truncatula digestibility through the reduction of its proportion.

Sparse‐Flowering Orchardgrass Represents an Improvement in Forage Quality During Reproductive Growth

ABSTRACTOrchardgrass (Dactylis glomerata L.) is a major component of many pastures in temperate North America. Early and profuse flowering in pastures is problematic, because livestock refuse to consume flowering stems, prompting many graziers to simply avoid using this species. The objective of this research was to determine the impact of reduced flowering on the quality of harvested forage under two harvest managements of orchardgrass. Six cultivars, three normal cultivars and three sparse‐flowering cultivars (mean panicle density of 141 vs. 61 panicles m⁻2, respectively), were evaluated in field experiments at 21 locations in North America under a 3‐cut harvest management. These cultivars were also evaluated at seven locations under a 5‐cut harvest management. Sparse‐flowering cultivars averaged 9% greater crude protein (CP), 3% lower neutral detergent fiber (NDF), 2% greater NDF digestibility, and 2% greater in vitro dry matter digestibility (IVDMD) than normal cultivars. For the two digestibility measures, differential panicle density between the cultivar groups explained a significant portion of variability, indicating that the increase in forage quality was proportional to the decrease in panicle density below a threshold of about 50 panicles m⁻2. Lastly, differences in regrowth forage quality between cultivar groups were smaller, less consistent, and of lesser statistical significance than for first harvest. While selection for sparse flowering in orchardgrass resulted in significant cause‐and‐effect increases in first‐harvest forage quality, these effects were too small to offset the reduced forage yield associated with the sparse‐flowering trait.

Breeding and improvement of quality traits in alfalfa (Medicago sativa ssp. sativa L.)

An important objective in alfalfa breeding is the improvement of forage quality. The aim of this experiment was to determine the genetic control of the most important quality traits in whole plant leaves and stems of alfalfa genotypes. Quantitative genetic parameters were estimated for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) content. A 5x5 diallel design with reciprocals among parents from geographically different populations were studied. In the diallel study, effects due to general combining ability (GCA) were higher than those due to specific combining ability (SCA) for majority of the tested characters in analyses of whole plant. The F1 progeny effect was significant for almost all characters (except ADF content). The highest values of narrow sense heritability?s were found for NDF (h =0.19) and CP (h =0.17) in whole plant, and in leaves (0.11 and 0.08), while in stems most heritable traits are ADF (h = 0.29) and ADL (h = 0.16) content. As a consequence, CP, NDF and ADF content would be more efficient selection criteria in whole plant analyses, while ADF and ADL content would be more interesting to investigate in stems, in a breeding program for improved nutritive value of alfalfa.

Produção forrageira e composição bromatológica de combinações genômicas de capim-elefante e milheto

Objetivou-se com este trabalho, avaliar o comportamento agronômico de combinações genômicas oriundas do cruzamento entre capim-elefante (Pennisetum purpureum Schum.) e milheto (Pennisetum glaucum (E.) Leek), visando determinar o potencial de Pennisetum glaucum para o melhoramento da qualidade forrageira do capim-elefante. Três cultivares de capim-elefante e 11 combinações genômicas foram avaliadas para produção de matéria verde total (PMV), produção de matéria seca total (PMS), percentagem de matéria seca (%MS), produção de matéria seca de folhas (PMSF), produção de matéria seca de caule (PMSC), relação caule/folha (RFC), altura (ALT), vigor fenotípico (VF), número de perfilhos (NP), fibra em detergente ácido (FDA), fibra em detergente neutro (FDN), proteína bruta (PB) e digestibilidade in vitro de matéria seca (DIVMS). Excetuando RFC e NP, todas as demais características apresentaram diferenças significativas para os genótipos (p < 0,05), indicando variabilidade genética entre os genótipos avaliados. A combinação genômica HCM-5x-2 destacou-se entre os pentaploides quanto à produção de matéria seca de forragem e a combinação genômica HCM-4x-2 destacou-se entre os tetraploides para a mesma característica. O efeito na melhoria da qualidade forrageira em Pennisetum através da introgressão de características favoráveis do milheto foi evidenciado pelo melhor desempenho das combinações genômicas pentaploides para características bromatológicas, mostrando o potencial das mesmas para inclusão em programas de melhoramento genético.

수확시기, 예건 및 싸라기 처리가 유기 청보리의 사초 생산성 및 사일리지 품질에 미치는 영향

최근에 청보리 사일리지는 국내에서 가장 많이 이용하는 조사료이지만 유기축산을 위한 유기조사료의 생산과 품질에 관한 연구는 미흡한 실정이다. 따라서 본 시험은 유기 청보리 사일리지의 적정 수확시기를 구명하고, 사일리지 품질 향상을 위하여 예건과 싸라기를 첨가하여 사일리지를 평가하였다. 시험구 배치는 12처리 3반복의 분할구 배치법으로 주구는 수확시기로 출수기, 유숙기 및 황숙기를 두었으며, 세구는 무처리, 예건, 싸라기 10%, 싸라기 15%를 두었다. 수확시 건물함량은 출수기, 유숙기 및 황숙기가 각각 12.8%, 21.9% 및 29.8%로 증가하였다. 청보리의 건물수량은 출수기, 유숙기 및 황숙기가 각각 10,346, 15,819 및 18,336 kg/ha였으며, TDN 수량은 6,288, 9,550 및 10,178 kg/ha였다. 유기 사일리지의 pH는 출수기, 유숙기 및 황숙기가 각각 4.70, 4.03 및 5.37로 유숙기가 가장 낮았다. 청보리의 수확시기가 늦어짐에 따라 조단백질, 조지방, NFC 및 TDN 함량은 감소하였으나, NDF 및 ADF 함량은 증가하였다. 그러나 조회분 함량은 유숙기가 가장 낮았다. 사일리지의 예건과 싸라기의 첨가는 조회분, NDF 및 ADF 함량을 감소시키고, NFC와 TDN 함량은 증가시켰다. 사일리지의 건물소화율은 수확시기가 늦어짐에 따라 감소하였으며, 예건과 싸라기 첨가에 의하여 건물소화율이 증가하였다. 유숙기가 다른 수확시기보다 젖산과 총유기산 함량은 높고 낙산 함량이 낮아 총유기산 중 젖산함량이 가장 높았다. 예건과 싸라기 첨가에 의한 젖산 함량 증가 효과는 출수기가 다른 수확기보다 효과가 있었다. 이상의 결과를 종합해 볼 때 유기 청보리 사일리지 제조를 위한 수확적기는 유숙기 이었으며, 예건과 싸라기 첨가에 의하여 청보리 사일리지의 품질을 향상시킬 수 있었다. Although whole crop barley (Hordeum vulgare L.) is now widely grown as a silage crop in Korea, forage production and silage quality of that for organic farm have not been published. Therefore, this experiment was conducted to evaluate the effect of harvest stage on forage production and quality of organic barley, and effect of field wilting and crushed rice for shortening of harvest date and improvement of forage quality. The experiment was split-plot design with three replications. Main plots were heading, milking and yellow stages, and sub-plot were field wilting for I day, crushed rice 10% (CR10%) and 15% (CR15%) treatments. The dry matter (DM) contents of heading, milking and yellow stages were 12.8%, 21.9% and 29.8%, respectively. The DM yields of heading, milking and yellow stages were 10,346, 15,819 and 18,336 kg/ha, respectively, and the total digestible nutrients (TDN) of these were 6,288, 9,550 and 10,178 kg/ha, respectively. The pH of milking stage showed low 4.00 pH values. The crude protein, ether extract, crude ash, non-fiber carbohydrate (NFC) and TDN contents were decreased as harvest stage progressed, while neutral detergent fiber (NDF) and acid detergent fiber (ADF) were increased. The crude ash (CA) of milking stage showed the lowest among harvest stages. Field wilting and crushed rice treatments decreased CA, NDF and ADF contents, and increased NFC and TDN contents. In vitro dry matter digestibility (IVDMD) decreased with progressed harvest stage, while field wilting and crushed rice treatments increased that of barley silage. Lactic acid and total organic acid contents of milking stage were the highest, and butyric acid of milking stage was the lowest among harvest stage. The good effect of field wilting and crushed rice was observed in heading stage. The experiment results indicate that optimum harvest stage of barley silage for organic was milking stage. The field wilting and crushed rice additive could be recommended as effective method for shortening harvest date and increasing forage quality of organic barley silage

Adubação nitrogenada em sistema silvipastoril álamo: pastagens de inverno

O álamo (Populus spp.) apresenta rápido crescimento e vem sendo empregado comercialmente no Sul do Brasil desde meados dos anos de 1990. Pelo espaçamento utilizado em seu plantio, é consorciado com a pastagem, contribuindo para o melhor uso do solo e abatimento do custo da madeira. Visando potencializar o crescimento de culturas de inverno e do álamo em sistema integrado, foi testada a adubação nitrogenada no Município de São Mateus do Sul, PR. O experimento foi instalado em um solo orgânico, testando-se cinco doses de N (0, 20, 40, 80 e 160 kg ha-1) repetidas quatro vezes, na forma de uréia aplicada na cultura consorciada de inverno, que foi a aveia-preta (Avena strigosa Schreb) e o azevém (Lolium multiflorum Lam.), em delineamento inteiramente casualizado. Os resultados indicaram que, após dois períodos de crescimento, as árvores não apresentaram diferenças significativas quanto às variáveis circunferência à altura do peito (cap) e altura total. Para a matéria seca de aveia e azevém, houve acréscimo linear na produtividade em função das doses de N. Pode-se concluir que na idade de 8 anos a fertilização antecipada não traz benefícios, pelo menos nos primeiros anos de sua aplicação.