Agronomy and Crop Sciences Commons^™

A Simulation Model Of The Seasonal Pattern Of Herbage Digestibility And Its Interaction With Intensity Of Defoliation, A W. Illius

IGC Proceedings (1977-2023)

Despite the considerable efforts expended in studying the seasonal changes in the digestibility of herbage under different harvesting regimes, there has only been slow progress in the modelling of these processes. In this paper, a quantitative description of the factors underlying seasonal changes in herbage digestibility is developed and applied to sets of data from S24 and S23 perennial ryegrass. A new variable, relative maturity, is used to describe the effect of defoliation in interrupting the process of tiller maturation which leads to the decline in digestibility. For S24, the model explained 95.5% of variation in digestibility decline, allowing accurate …

The Effect Of Silage Quality And Level Of Concentrate On The Dry Matter Intake And Milk Production Of British Friesian Heifers, R H. Phipps, J A. Bines, J Thomas, A Cooper, R J. Wilkins

IGC Proceedings (1977-2023)

Trials have shown that both silage quality and level of concentrate are major factors influencing dry matter (DM) intake and milk production with adult dairy cows but there are few data relating to heifers.Seventy-two British Friesian heifers were divided into two groups during weeks 3-12 of lactation and received ad Iibitum either good quality (G) or poor quality (P) grass silage. The in vitro digestible organic matter in the dry matter was 68 and 60 for silages G and P, respectively. In addition, the heifers in each group consumed concentrate at either a low (4.3 kg DM/day), medium (6.4 kg …

Intake Of Grassland - Hay By Dairy Cows And Its Potential Meet Requirements Of Maintenance And Milk Production, J P. Dulphy, C Beranger, D Micol

IGC Proceedings (1977-2023)

There have been few recent studies on the use of grass-hays by dairy cows, probably as a result of the importance given to studies on silage. Therefore 9 grass-hays, harvested in good conditions, were prepared and fed to dairy cows. With a CP content of 133 g/kg DM and an O.M. digestibility of 64.4%, the intake of these hays was 2.07 % of live weight (12.65 kgDM/animal/day). Their energy supply was sufficient to cover the maintenance needs of the cows, and a mean theoretical daily production of 8.1 kg of milk. The real production was 20.1 kg, and the difference …

Barley And Protected Protein Concentrate As Supplements To Timothy Silage For Growing Bulls, H S. Hakkola

IGC Proceedings (1977-2023)

The objective of the experiment was to study the utilization of grass silage by growing bulls. Between the age of 68-434 days, 63 bulls took part in an experiment in which as supplements to timothy silage were 1) barley 2) barley+ protected protein concentrate and 3) protected protein concentrate only. The effects on· silage intake and live weight gain of the bulls were measured. In each feeding group there were 21 bulls. The concentrate contained 30% digestable crude protein of which 72% from soya-bean meal, 18% from rapeseed meal and 10% from milk powder. The protein of the concentrate was …

Evaluation Of Forage At The Level Of Voluntary Intake, M Okamoto, K I. Sung, N Hasegawa, N Yoshida

IGC Proceedings (1977-2023)

To revise the conventional method of forage evaluation, digestion trials were conducted at the level of voluntary intake. Dry matter (DM), crude protein and Neutral Detergent Fibre (NDF) contents in offered and residual feeds were measured, using suffolk wethers which were fed with grass silage and hay. A lower content of crude protein and a higher content ofNDF in residual feeds were detected when compared with those of offered feeds. Then, crude protein and NDF values of intake feeds were calculated from the composition of offered and residual feeds. It was suggested that the reason for different contents of crude …

The Effects Of Heat Treatment And Ruminal Degradation On Digestibility Of Rumen- Bypassed Protein And Total Digestibility, Y Maeda, T Masuko, K Awaya, K Sugimura

IGC Proceedings (1977-2023)

In order to investigate the protein digestibility of heated roughage, the effects of the extent of heat treatment and ruminal degradation on the post-ruminal digestibility of the rumen-bypassed protein and the total digestibility from rumen to post-ruminal tracts were studied. First cutting Italian ryegrass dried at four levels of temperature (freeze, 40, 80 and 120°C) were prepared. Materials were put into the rumen by nylon bag technique for 0, 2 and 6 hr., after rumen exposure, the residual protein was incubated by pepsin-pancreatin artificial digestion method. The total protein was partitioned using three fractions based on ruminal and pepsin-pan-creatin (P-P)degestibility. …

An Expert Nirs Forage System, John S. Shenk, M O. Westerhaus

IGC Proceedings (1977-2023)

Near infrared spectroscopy (NIRS) has become an accepted technique to analyze the nutritive value of forage and feedstuffs. Recent advancements have been made in developing universal calibration equations that can be transferred from instrument to instrument. This advancement has made it possible to use NIRS as the analytical component of expert system software in conjunction with livestock feeding models. The software is flexible to provide information for research, extension, and industry applications. The incorporation of NIRS into an expert system promises to make possible new advancements in efficiency of livestock production.

Near Infrared Reflectance Spectroscopy Analysis Of Quality Of Farm- Grown Alfalfa, N P. Martin, G C. Marten, D A. Schriever, J L. Halgerson, F R. Ehle

IGC Proceedings (1977-2023)

Successful use of near infrared reflectance spectroscopy (NIRS) analysis of crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of farm-grown alfalfa (Medicago sativa) is described. Calibration equations for CP, ADF, and NDF using the BEST/NeoTech 6100 IR spectro-computer system1 were developed from windrow alfalfa samples collected throughout Minnesota over three seasons. Standard errors of calibration were 0.57, 1.56 and 1.83 dag/kg for CP, ADF and NDF, respectively. Coefficients of multiple determination (R2) were 0.97, 0. 91 and 0. 93, respectively. Standard errors of NIRS analysis for CP, ADF, and NDF were 0.58, 1.48 and …

Development Of A National Alfalfa Quality Assessment Procedure In The United States, V L. Marble, W C. Templeton

IGC Proceedings (1977-2023)

Only a small fraction of the U.S. hay crop is evaluated for nutritive properties. Various states have developed alfalfa hay quality prediction systems based on chemical analysis. Confusion among users has resulted from nonuniformity among systems. Additional factors causing concern include: increased awareness among producers of higher income from the sale of high quality hay; increased demand among dairymen for a prediction system compatible with ration formulation; recognition of the inadequacy and nonuse of U.S. federal hay grades; increased movement of alfalfa hay across state borders; and lack of agreement on duplicate samples sent to different laboratories. After formation of …

The Cultivation And Feeding Value Of Persian Clover, P C. Flinn, K.F M. Reed, G R. Saul, G N. Ward, J G. Graham

IGC Proceedings (1977-2023)

Research with Persian clover (Trifolium resupinatum, ssp. majus) cv. Mara!, in south eastern Australia shows it to be productive and well adapted to waterlogged soils. It is particularly productive in spring when compared with other clovers. Winter production can be increased by sowing Persian clover with Westerwolds ryegrass or oats but the yield of clover in the spring is therby reduced. Persian clover conserved as hay was found to have a low neutral detergent fibre content (28.1 % ). In a 60 day feeding trial, lambs were fed Persian clover hay (78.5% digestible dry matter), lucerne hay (63.0% …

Voluntary Intake And Digestibility Of Two Selected Tropical Grasses By Swamp Buffaloes, M Wanapat, A Topark-Ngarm

IGC Proceedings (1977-2023)

A study on chemical compositions, voluntary feed intake and nutrient digestibility of Panicum maximum cv. Guinea and Brachiaria decumbens cv. Signal at three regrowth cuttings (week 4, 8, 12) by swamp buffalo steers, was conducted. Dry matter, acid detergent lignin contents increased whereby ash, crude protein and neutral detergent fiber contents decreased, as the plants matured. Acid detergent fiber fraction remained similar for all cuttings. Voluntary dry matter intake and digestion coefficients of nutrients were relatively high at week 4 and 8 and markedly low at week 12 for both species. Buffaloes fed with signal grass had higher intakes and …

Research For Selection Criteria For Grass Quality, Based Upon Animal References, M Gillet, J Scehovic, M Lila

IGC Proceedings (1977-2023)

In an effort to find selection criteria for intake and digestibility, based on correlations with the same characters measured on animals, we have compared 4 to 6 grasses of similar heading dates for intake, palatability, digestibility by sheep, intake by goats and many laboratory tests. 1979 results were published for Lexington Congress. Results of 1980 and 1981 springs bear them out in several points :

- palatability was a very precise and stable test

- palatability, digestibility and goat intake were stable and correlated with each other

- soluble phenols were able to predict palatability and part of digestibility

-sheep …

Using Grinding Energy Measurements For Predicting Crude Fibre Content In First Growths Of Permanent Grassland, Chr Paul, U V. Borstel, E Zimmer

IGC Proceedings (1977-2023)

The performance of a grinding energy test for the simple and rapid prediction of crude fibre content in spring growth of grassland was investigated during three successive years and its potential for deriving recommendations on appropriate cutting dates demonstrated. The grinding energy test appeared to achieve a precision comparable to that for near infrared based predictions of crude fibre reported from the literature. Prediction bias consisting in a mean 2% crude fibre underestimation was found to occur in one year presumably due to an anomalous _constellation of environmental conditions. This appeared to have affected the pattern of plant development and …

Cell Wall Composition And Rate Of Digestion Of Brown-Midrib Sorghum Internodes As Influenced By Maturity, J H. Cherney, J J. Volenec, K J. Moore

IGC Proceedings (1977-2023)

More information is needed on the growth of secondary plant cell walls in forage species, and the relationship of cell wall structure to rate and extent of digestion. Our overall objective was to relate changes in cell wall composition with maturation to rate and extent of cell wall digestion. The seventh intemode of normal and brown-midrib ( bmr) sorghum (Sorghum bicolor (L.) Moench.) was harvested at eight maturities beginning with the cessation of intemode elongation. Dry weight per segment was determined for each maturity stage. Lignin accumulation in lntemode 7 increased during maturation, with the rate of lignin synthesis being …

The Effect Of The Species, Stage Of Maturity And Level Of Intake Of Grass On The Efficiency Of Microbial Protein Synthesis In The Rumen Of Cattle, F J. Hart, Jane Leibholz

IGC Proceedings (1977-2023)

This study was undertaken because there is a paucity of information in the literature on the efficiency of microbial protein synthesis in the rumen of cattle when grass is fed as the sole diet. There is also little experimental data available on the factors which affect the efficiency of microbial protein synthesis. The work involved feeding six rumen fistulated Friesian steers with three species of grass which were harvested at various tages of maturity. In addition each maturity of forage was fed at three 15levels of orp5 nic matter ( OM) intake.

as sampled at the omasum and microbial protein …

The Influence Of Aging On Forage Quality Of Individual Switchgrass Leaves And Stems, B Anderson

IGC Proceedings (1977-2023)

Cattle selectrively graze switchgrass (Panicum virgatum L.) tops prior to the boot stage and prefer vegetative culms and new tillers following heading. Therefore, a study was conducted to evaluate the changes in forage composition of individual leaves and stems during growth to determine if grazing selection may be influenced by aging. Plants were cut periodically at ground level from collaring of the first leaf until anthesis. Leaves (leaf blade plus sheath) of different ages, stems, and the whorl were hand separated at each harvest. Crude protein, in vitro dry matter disappearance (IVDMD), neutral and acid detergent fiber, lignin, and …

Harvesting Alyceclover For Maximum Dry Matter Yield And Nutrient Value, D D. Baltensperger, W G. Blue, W H. Anderson

IGC Proceedings (1977-2023)

Limited information is available on the quality of alyceclover (Alysicarpus vaginalis) in relation to plant stress. This study was undertaken to clarify the relationship between plant maturity and forage yield, quality and mineral composition in order to optimize each at harvest. Alyceclover was grown for two summers and new plots were harvested weekly through the pod-fill stage of development beginning eight weeks after planting. Samples were analyzed for dry matter, organic matter, In vitro dry matter digestibility, nitrogen, phosphorus, potassium, calcium, magnesium, manganese, copper, iron and zinc. Dry matter yields increased through the flowering stage of development except …

Adaptation Of The Inra System Of Determination And Expression Of The Nutritive Value Of Forages To The Tropical Conditions In The Caribbean Island, A Xande, R Garcia-Trujillo

IGC Proceedings (1977-2023)

This program have undertaken a series of trials of systematic measure of nu tritive value on the tropical forages. The choice of the calculation and of the way of expression of energetic and nitrogen values required comparation measures in different systems as well as attempts in alimentation before adopting the new french INRA system of energy (UFL-UFV) and of the protein value (POI). The general results of this study is a preamble to the diffusion of the table of nutritive value of the tropical forages. For this purpose 450 samples of forages have been analysed on sheep in cage of …

Hemp Cultivation Under Off-Season High Tunnel Growth Chamber Environments In South Louisiana, Gabriel Lococo

LSU Master's Theses

Industrial hemp (Cannabis sativa) production in Louisiana began in 2020 with 932 acres cultivated for fiber and cannabidiol (CBD) extraction. By 2024, production had declined to just 58.4 acres (Louisiana Department of Agriculture and Forestry, personal communication). During the 2020–2021 season, over 40% of field-grown hemp was lost due to tropical storms, insect pressure, and diseases associated with warm, wet conditions. To mitigate these challenges, hemp was planted and harvested between November and January, a cooler period with reduced environmental stress.

‘Sour Citron’, a day-neutral cultivar, was selected for its insensitivity to photoperiod, enabling flowering during shorter days. …

Effect Of Rainfall Reduction And Competition On The Phenology Of The Mediterranean Forage Perennial Legume Bituminaria Bituminosa Var. Albomarginata Cv. Lanza, Jesus Fernandez-Habas, Daniel Real, Tom Vanwalleghem, Jose Ramon Leal-Murillo, Jesus Fernandez-Rebollo

Grain and Other Field Crops Research Articles

Tedera (Bituminaria bituminosa (L.) C.H. Stirt.) is a Mediterranean drought-tolerant species that shows potential as a forage perennial legume for Mediterranean livestock systems. This three-year study investigated the phenology of the newly developed variety of tedera (Lanza) in response to an annual 24% rainfall reduction and competition compared to alfalfa (Medicago sativa L.) in a typical Mediterranean environment of the Iberian Peninsula. Tedera showed early phenology for the reproductive stages from inflorescence emergence to ripening compared to alfalfa, with a long flowering period from early April to mid-May, overlapping with mature fruits. In general, tedera responded to a …

Soil Health In Nebraska: Exploring Practitioners' Needs And Insights From A Long-Term Organic Farm, Ingrids Isabel Mata Vigil

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Soil health is foundational to sustainable agriculture, environmental resilience, and long-term food security. Yet, the adoption of soil health assessments remains limited, often perceived as too technical, costly, or difficult to implement in real-world contexts. To better understand these challenges, the first chapter presents findings from a statewide survey of 41 soil health practitioners in Nebraska, including farmers, extension educators, NRCS staff, and conservation professionals. Respondents highlighted the need for simpler, more accessible, and context-specific tools for soil health assessment that help practitioners make informed decisions aligned with their management goals. Complementing these insights, the second chapter includes an independent, …

Evaluating The Effects Of Row Spacing, Legume Intercropping, Fertilizer Source, And Fertilizer Timing On Intermediate Wheatgrass In Eastern Nebraska, Madeline M. Johnston

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Kernza^® is the trademarked name of the perennial crop intermediate wheatgrass (Thinopyrum intermedium). In addition to its potential for dual-use as a grain and forage crop, Kernza is marketed to provide needed environmental services by increasing crop biodiversity, sequestering soil carbon, and reducing nitrate leaching. However, more work is needed in cultivar selection and crop management to increase total grain yields and prevent long-term grain yield decline. Furthermore, research in quantifying and understanding Kernza’s ability to affect soil properties and water dynamics is limited.

Two field experiments were conducted at the Eastern Nebraska Research Extension and Education …

Evaluating Biodegradable Mulch As A Soil Conservation Tool And The Impact On Soil Properties And Yield In Soybean (Glycine Max) Cropping Systems In Eastern Nebraska, Ana Clara Gomes

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This study, conducted during the 2024 growing season, evaluated short-term effects of soil management practices on greenhouse gas (GHG) emissions, soil microclimate, nitrogen dynamics, weed suppression, and soybean (Glycine max) yield. In addition to conventional tillage and no-till, this research included cereal rye (Secale cereale) cover cropping and a novel sprayable biodegradable mulch (BioWRAP®) to assess emerging strategies for sustainable soybean systems under contrasting moisture regimes.

Field trials were established at two eastern Nebraska locations: Havelock (dryland, silty clay loam) and ENREEC (irrigated, clay loam). A strip-block randomized design with four replications tested six soil management …

Response Of Wheat To Phosphorus-Enriched Ironstone Gravel, David Weaver, David Rogers, Ron Master, Peta Richards, Robert Summers, Simon D V Clarendon

Grain and Other Field Crops Research Articles

Context

Gravel fractions ( > 2 mm) in soil are almost always excluded from laboratory analysis and glasshouse experiments as they are considered to be inert; however, the > 2 mm fraction is always present in field experiments. Aims

To determine whether the > 2 mm fraction of ironstone gravel (IG) soil enriched with phosphorus (P) can supply P to wheat (Triticum aestivum L.). Methods

An IG soil was separated into different size fractions ( < 2, 2–4, 4–6, 6–8 and 8–10 mm), and adsorption and desorption experiments, volumetric moisture measurements and glasshouse experiments were conducted. Each of the > 2 mm fractions were enriched with P to different levels and added to a sand culture, or to the enriched < 2 mm fraction in different amounts (25%, 50% and 75% IG). Wheat was grown in pots and growth correlated to P added from enriched soil fractions, weighted Colwell P, soil solution P concentrations and volumetric water content. Key results

The < 2 mm fraction of the IG soil adsorbed more P than the > 2 mm fraction of the IG …

Comparison Of Energy Efficiency And Vegetation In Different Establishment And Management Systems Of Steep Mountainous Grassland In The Aso Area, Japan, K Kabata, C Okamoto, M Shimizu, M Kikuchi

IGC Proceedings (1977-2023)

The Aso area is one of the most important areas for grass­land agriculture in Japan. In this area there exists ca. 44,000 hectares of which ca. 28,700 ha are steep mountainous lands ( a gradient of more than 15 degrees). Additionally, there is much precipitation (ca 2.600 mm/year) in the area. Consequently, there is a problem of grassland destruction due to soil erosion. Therefore, in order to promote the utilization and conser­vation of steep grasslands, the following two experimental grazing were carried out: 1) a two pasture system and 2) a coexistent pasture system with introduced and native grasses. In …

Comparison De La Dynamique De La Vegetation De Deux Ecosystemes Herbagers Mesoxerophiles Apres Deprise Agricole Dans Le Massif Vosgien, S Muller

IGC Proceedings (1977-2023)

Les orientations actuelles de !'agriculture europeenne dans le cadre de la Politique Agricole Commune de la Communaute Economique Europeenne devraient conduire a !'abandon dans les decennies a venir de plusieurs millions d'hectares de terres agricoles en France, entrainant des modifications ecologiques et paysageres considerables. Dans le Massif Vosgien la deprise agricole, consecutive a la regression des industries traditionnelles et a !'elevation du niveau de vie, a provoque !'abandon depuis les annees 1950 de nombreux herbages, autrefois entretenus surtout par des pluri­actifs. Ces milieux evoluent alors vers des friches herbacees seboisant plus ou moins rapidement de maniere spontanee.

Massif Vosgien constitue …

Le Role Des Plantes Herbageres Dans La Limitation Des Pertes Des Principaux Elements Nutritifs Par Le Drainage, S Kopec

IGC Proceedings (1977-2023)

Depuis longtemps on connait !'action anti-erosive des plan­tes herbageres qui empechent d'une fa< ;on tres efficace l'affais­sement des particules de sol, en particulier sur des surfaces en pente. Dans ces derniers temps on parle de plus en plus souvent du role des herbages dans la limitation du drainage des elements nutritifs du sol et de nombreuses recherches menees a cet effet dans plusieurs pays le confirment (Jones, 1972; Gachon et Tri­boi, 1967; Kopec, 1985). Dans cette etude on a presente les resultats des recherches lysimetriques Sur la quantite des principaux elements nutritifs draines par les eaux s'evacuant des terrains agricoles couverts d'herbages et d'autres cultures.

Degradation Models And Their Use In Determining The Condition Of Southern African Grasslands, O.J H. Bosch, K Kellner, S.H E. Scheepers

IGC Proceedings (1977-2023)

An understanding of the processes of change is an important prerequisite for the development of techniques for the monitor­ing of condition and trend, and to interpret the ecological sig­nificance of determined condition classes. The approach to develop and use degradation models for determining range condition is illustrated in this paper by means of basic ecological data from the relatively high rainfall zone in the climatic climax grasslands (Mentis and Huntley, 1982) of southern Africa.

An Experiment And Study On A Air-Seeding Astragalus Adsurgens For Soil Conservation On The Loess Plateau Of China, Yimin Liang, Daiqiong Li, Xinhai Cong

IGC Proceedings (1977-2023)

The irrational land utilization has resulted in destruction of original vegetation and serious soil erosion on the Loess Pla­teau in China. At present, 1600 million ton of sediment is disch­arged into the Yell ow River per year. In order to explore effec­tive avenues to speed reestablishing vegetation for controlling soil erosion, we made an experiment in seeding forage and shrubs by airplane for four years, from 1976 to 1979, in semi­arid region on the Loess Plateau. We selected suitable plant species for aerial seeding on semiarid region, determined fit aerial seeding time and seeding rate through manual broadcast and air-seeding. …

Role Potentiel Des Legumineuses Annuelles A Ressemis En France, P Masson, G Gintzburger

IGC Proceedings (1977-2023)

L'interet pour les legumineuses annuelles a ressemis est recent en France malgre !'importance de la zone mediterra­neenne et atlantique dont ces plantes sont originaires. Le trefle souterrain (Trifolium subterraneum) et les luzernes annuelles (Medicago sp.) apparaissent respectivement dans notre littera­ture specialisee a la suite de travaux d'amelioration pastorate en Corse (Etienne, 1977) et des travaux de plusieurs labora­toires de l'Institut National de la Recherche Agronomique a Montpellier (Gintzburger et Prosperi, 1987). Apres 4 ans d'experimentation dans diverses situations des Pyrenees Orientates dans le sud de la France en climat mediter­raneen (pluviometrie moyenne annuelle de 575 mm a …