Weed Science Commons^™

Economic Analysis Of The Impact Of Management Decisions On Production And Use Of Silage For A Dairy Enterprise, A J. Corrall, H D. St. C Neal, I M. Wilkinson

IGC Proceedings (1977-2023)

The aim of this work was to examine the influence of variations in grass management and methods of ensiling on the economics of milk production for autumn-calving cows. A simulation model was developed to combine knowledge of plant and animal responses and their interactions in order to calculate the effects of management options on economic balances. Input data were compiled for herbage production from cut­ting strategies that gave herbage at four digestibilities, at two levels of applied nitrogen, and in three climates. Experimental evidence was also collated to construct matrices of loss of dry matter and changes in digestibility and …

Changes In Quality And Composition Of Alfalfa During Autumn, S C. Fleming, M Collins, N A. Jorgensen

IGC Proceedings (1977-2023)

Autumn harvest of alfalfa (Medicago sativa L.) offers a potential for obtaining additional forage production during a particular season. Little is known about the quality or changes in the chemical composition of this forage. The objective of this research was to examine changes in chemical composition, dry-matter intake (DMI), and apparent digestibility of alfalfa during autumn in Wisconsin. An established stand of Vernal alfalfa, early bud to midbud, was harvested using a flail harvester on 5 and 20 October and 5 and 18 November 1979. The forage was dried at 55°C for 72 to 96 hours in burlap bags. A …

Maximum Production From Irrigated Rhodesgrass And Green Panic In A Mediterranean Environment, A Dovrat, T Kipnis

IGC Proceedings (1977-2023)

Aspects of the production of rhodesgrass (Chloris gayana Kunth) and green panic (Panicum maximum var. trichoglume) as roughage for high-grade dairy cattle when land and water resources are limited are described. Results from some 10 years of research are highlighted. The height of the canopy to which grasses should be allowed to regrow for maximum production is above the height that can be utilized efficiently when harvested in situ by cattle. Mechanical harvesting and indoor feeding provided 20%-25% more digestible dry matter/unit area of land (with a parallel increase in water-use efficiency) than strip grazing, almost without affect­ing …

Structural Characteristics Limiting Digestion Of Forage Fiber, D E. Akin

IGC Proceedings (1977-2023)

Cell walls of forage were studied for structural and chemical factors that limit digestion by rumen microorganisms. Tech­niques used to investigate digestion were histochemistry, electron microscopy, and anaerobic culturing of rumen populations on specific substrates. Certain tissues, such as the xylem cells, totally resisted degradation by rumen microorganisms; these tissues stained positive for lignin with acid phloroglucinol (Weisner test). Other supportive tissues, such as the sclerenchyma in blades, stained positive for lignin with chlorine-sulfite (and also the Maule test) and were also generally resistant to microbial digestion. Microscopic studies revealed that certain living tissues (i.e., those having cytoplasm and organelles …

Relationship Of Forage-Evaluation Techniques To The Intake And Digestibility Of Tropical Grasses, S M. Abrams, H Hartadi, C M. Chaves, J E. Moore, W R. Ocumpaugh

IGC Proceedings (1977-2023)

Seventy-six grass hays, harvested at 2, 4, 6, and 8 weeks of regrowth, were fed ad libitum to wethers in a digestibility and in­take trial. Range of organic-matter digestibility (OMD) was 54.l % to 72.3% and that of organic-matter intake (OMI) 17.3 to 27.4 g/kg. Lignin was the chemical component most highly related to OMD (r = - 0.72). Neutral detergent fiber (NDF) was bet­ter than acid detergent fiber (ADF) as a predictor of OMD (r = - 0.66 vs. - 0.45). In-vitro NDF digestibility (IVNDFD) was superior to in-vitro organic-matter digestibility (IVOMD) and all other analyses as a predictor …

Bulk Volume: A Parameter For Measuring Forage Quality And Its Influence On Voluntary Intake, P J. Van Der Aar, H Boer, G Hof

IGC Proceedings (1977-2023)

The experiment evaluated bulk volume (ml/g meal) as a method of estimating forage quality. Samples of Lolium perenne (Lp) and Festuca arundinaea, and hay samples of Lp were collected at different stages of growth. Voluntary intakes of these forages by dairy cattle had been measured previously. Volumes of samples and volumes of cell-wall residues after 0, 6, 12, 24, and 48 hours in vitro digestion were determined.

Effect Of Feeding Level And Forage: Concentrate Ratio On The Digestibility Of Pelleted Diets By Sheep And Cattle, G.M J. Horton, M J. Farmer, B E. Melton, S Sklane

IGC Proceedings (1977-2023)

Sheep are frequently used to determine the nutritive value of cattle feeds. However, there is some evidence that digestion coef­ficients for cattle and sheep may differ and that digestibility may be influenced by feeding level. The purpose of this study was to investigate the effects of feeding level and animal species on the digestibility of pelleted diets containing different ratios of alfalfa hay to barley grain. Five 4O-kg yearling crossbred lambs and four 35O-kg yearling steers were used to evaluate each diet. The six diets were isonitrogenous, containing the following proportions of barley grain and alfalfa hay (percentage as fed …

Seasonal Changes In Botanical And Chemical Composition And Digestibility Of Diets Of Large Herbivores On Shortgrass Prairie, G M. Van Dyne, J D. Hanson, R C. Jump

IGC Proceedings (1977-2023)

Studies were conducted from 1969 through 1974 on northeastern Colorado shortgrass prairie during different grazing seasons and under different grazing intensities to evaluate bison, cattle, sheep, and pronghorn antelope diets. The purpose was to ex­amine seasonal changes in chemical and botanical composition and digestibility of diets of large herbivores. Bison, cattle, and sheep diets were obtained from esophageal fistula samples. Fistula samples were analyzed microscopically to determine botanical composition. Pronghorn antelope diets were obtained by bite-count methodology. Data, presented for im­portant plant species and species groups, were averaged for 28-day intervals to show typical seasonal trends in diets. During all …

Diet Selection By Cattle On Tropical Pastures In Northern Australia, B Walker, M T. Rutherford, P C. Whiteman

IGC Proceedings (1977-2023)

Diet selection by steers in northern Australia on a continuously grazed pasture of Setaria sphacelata var. sericea (Kazungula), Macroptilium atropurpureum (siratro), and Stylosanthes guianensis var. guianensis (Schofield) was studied. The pasture treatment that supported the highest annual weight gains (254 kg/steer) in a stocking-rate experiment had 1.7 steers/ha. Mean annual rain-fall was 1,490 mm, with 70 % falling from December to March. Monthly average temperatures are highest in December (30 .1 °C) and lowest in July (11. 9°C). Pastures were sampled in 1973 (seven 3-day periods) and 1975-1976 (six 3-day periods) with three esophageal fistulated steers. Extrusa samples were analyzed …

Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel

IGC Proceedings (1977-2023)

Experiments were conducted to determine the effect of hay ammoniation on hay consumption and weight gain by steers when the hay was fed unsupplemented and supplemented with energy and protein. Mature orchardgrass (Dacrylis glomerata L.) hay was baled in early June 1979 and treated with anhydrous ammonia at 30 g/kg of hay. Seven weeks after treatment the hay was uncovered and allowed to aerate for 3 days. It was then fed to weanling steer calves weighing approximately 225 kg each. Similar hay baled from the same field but not ammoniated was fed to separate groups of steers. Both the treated …

Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar

IGC Proceedings (1977-2023)

Large improvements in the feeding value of low-quality roughages have resulted from treatment of them with various chemicals. Chemical treatment of grains may also be a potentially useful practice. The research reported here was designed (1) to determine how Chelating Metal Caustic Swelling (CMCS), a nontoxic, alkaline, aqueous reagent, compares with sodium hydroxide (NaOH) in enhancing in-vitro cellulose digestion (IVCD) of cornstalks (CS) (Zea mays) and soybean residues (SBR) (G!),cine max.), and (2) to evaluate the effects of NaOH and CMCS treatments of fibrous grains using in-situ techniques. CMCS or 7.5% NaOH solutions were added to CS or SBR at …

Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg

IGC Proceedings (1977-2023)

Treatment of crop residues with low levels of sodium hydroxide has been shown to improve organic-matter digestibility and animal performance. One objective of these experiments was to evaluate the effects of three treatments -water, sodium hydrox­ide, and chelating metal cellulose-swelling solution-on solubilization of cell-wall components in corn (Zea m£rys) stover. The two latter treatments were balanced for level of sodium hydroxide application, which was .3 .2 % of stover dry matter. The second objective was to determine the effects of these treatments on in-vitro and in-vivo digestibility as well as on consumption of corn stover. Twelve growing ram lambs were …

Effects Of Water Stress On Herbage Quality, J R. Wilson

IGC Proceedings (1977-2023)

Uncertainty exists about whether drought is detrimental to the nutritive quality of herbage. This paper tries to resolve this uncertainty by examining the influence of soil moisture on some herbage-quality characteristics. Unpublished data from my own work and review of published literature are presented. Field plots of three tropical grasses, green panic (Panicum maximum var. trichoglume), buffelgrass (Cenchrus ciliaris), and speargrass (Heteropogon contortus), were subjected to perioqs of controlled drought, and herbage from these plots was compared with that from well-watered plots. Leaf and stem dry-matter ?igestibility of water-stressed herbage was either similar to or higher than that of unstressed …

Value Of White Sweet Lupin In Production Of Protein Fodder And Feeding Of Animals, O Saric, I Ramosevac

IGC Proceedings (1977-2023)

The potential of white sweet lupin (Lupinus albus L.) as a grain or forage feed for livestock was investigated in a series of ex­periments. Grain yield of lupin was greater than or equal to that of soybeans (Glycine max [L.] Merrill) in most evaluations. The quality of lupin seed compared favorably with that of soybean meal and fishmeal. Lupin is capable of producing large amounts of forage in a short period, making it a good prospect for forage production in regions that have a short growing season.

Effects Of Sample Drying Method On Estimates Of Nutritive Value Value, S Uchida, H Hayashi, T Horigome

IGC Proceedings (1977-2023)

The influence of different drying methods for the sample used for analysis on the estimates of the nutritive value of silage was investigated. The silages and hay were made from the same grass and fed to three wethers to determine digestibilities. The samples for analytical use of silages and hay fed, and feces excreted, were prepared by three drying techniques of freeze drying (F), oven drying at 60 C (L) and oven drying at 100 C (H) and then each dried sample was ground in a Wiley mill to pass a 0.5 mm screen. The residual moisture in prepared samples …

Effect Of Stage Growth And Chopping Length On Ensiling Characteristics, Digestibility And Palatability Of Guinea-'A', S Panditharatne, J P. Fontenot, V G. Allen, M.C N. Jayasuriya

IGC Proceedings (1977-2023)

Ensiling of forages is a common practice in temperate areas, but is not used extensively in tropical countries. Preservation of excess forage during rainy seasons would provide a more even distribution of feed during the year. Experiments were conducted to investigate fermentation characteristics, and digestibility and palatability of Guinea-'A' (Panicum maximum, ecotype A) silage by sheep. Guinea-'A' grass was harvested after 2- and 3-week growth periods, and ensiled chopped or unchopped in 210 liter metal drums, double lined with polyethylene. Cutting grass at 2 weeks decreased pH and increased lactic acid of silage, compared to cutting at 3 weeks. Chopping …

Use Of Leaf Protein As Human Food, R P. Devadas, P Vijayalaks

IGC Proceedings (1977-2023)

Leaf protein obtained from lucerne was fed to pre-school children, for a period of three years. These children who were on leaf protein were compared against those who received milk in the place of leaf protein, leaf protein + 300 calories, 300 calories alone and control group who did not get any supplement. The results indicated that 100 grams of leaf protein provides 397 calories, 60 g of protein, 800 mg of calcium, 50 mg of iron and 1.4 µg of B carotene. Leaf protein is acceptable for pre-school children from poor socio-economic groups. Adults need more persuasion. Leaf Protein …

Evaluation Of Orchardgrass And Alfalfa For Its Nutritive Value And Voluntary Intake By Neutral Detergent Analysis, T Ishiguri

IGC Proceedings (1977-2023)

A series of trials has been carried out over a ten-year period to determine the ad lib. intake and digestibility of clipped orchardgrass and alfalfa fed at several growth stages to wethers. Forage and feces were fractionated into cell wall (CW) and cell content (CC) with neutral detergent solution, moreover the digestibility and the digestible amount of CW, CC were determined. The changing amount of digestible dry matter (D DM) in grass and legume related to the amount of digestible CC and indigestible CW, whereas digestible CW was observed to have little relation.

orchardgrass varied little between the first cut …

The Digestibility, Intake And Rumen Fermentation By Sheep Of Some Tropical Grasses In Japan, O Kawamura, S Tanaka, T Miaki

IGC Proceedings (1977-2023)

The cultivation of tropical grasses is gradually becoming widespread in southwest Japan. In this research, the digestibility, voluntary intake and rumen fermentation of the tropical grasses (green panic, Rhodes grass, Sudan grass and African millet) were compared with Italian ryegrass. The crude protein contents of all tropical grasses tested were over 10% in the dry matter, and were not so much different from the Italian ryegrass. The tropical grasses, in general, had higher contents of cell wall materials and lower content of total non-structural carbohydrate than the Italian ryegrass. In the dry matter digestibility and digestible nutrient contents, the tropical …

Influence Of Supplementation On Herbage Digestibility And On Faeces Characteristics With Sheep, M Chenost, Elisabeth Grenet, C Demarquilly, C Beranger

IGC Proceedings (1977-2023)

The objective of this study is to determine whether or not supplements e.g. concentrates, added at pasture modify the relationship between organic matter digestibility (OMD) of grazed herbage and faecal crude protein content (FCP). This would provide an answer whether or not the OMD of the fraction of herbage in the ration can be predicted from the FCP content of the faeces corresponding to the ration. We have utilized results of 2 digestibility measurements trials in which sheep were fed ad libitum herbage alone or supplemented either with barley (trial 1) or with a concentrate (trial 2). The supplementation leads …

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 …

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 …

Influence Of Reduced Intensity Of Grassland Management On Herbage Yield, Forage Quality, Sod Density And Botanical Composition, P Dahmen, W Kuhbauch, U Thome

IGC Proceedings (1977-2023)

In the Federal State of Northrhine Westfalia, a number of programs have been initiated to reduce intensity of land use with respect to unwanted environmental effects presumably coming from conventional agricultural systems. On grassland most of the programs require delayed first cuttings for hay and silage, reduced fertilization and/or less grazing pressure on pastures. Field experiments were established in order to evalu­ate consequences of these programs for practical farming and grassland ecology. Treatments include conventional grassland management systems with intensive fertilization and utilization as well as intermediate and low intensity systems.

Chemical And Nutritive Values Of Three Ensiled Residues (Broad Beans, Peas And Soybean) In Comparison With Yellow Lupin Silage, J Efe Serrano

IGC Proceedings (1977-2023)

The agro-industrial residues of legumes in Portugal has increased recently in animal feeding, but with little information about the nutritive values of these diets. The few values from literature (Economides and Had­jidemetriou, 1974; Boza and Guerreiro, 1981 ; Escandon et al., 1983) or in Tables of Food Composition are quite different. In south of Portugal, the yellow lupin is an expanding forage used in sheep diets as hay or silage. The purpose of this work, and others in progress, was to compare the feeding value of silages made from three important residues with the yellow lupin silage.

Evaluation Of Tree Legumes Species At Different Agroclimatic Zones Of Indonesia, Mas'ud Panjaitan, R Jessop, W W. Stur

IGC Proceedings (1977-2023)

The population of Indonesia is over 145 million and more than 56 % of them earn their living from agriculture (Bi. Stat. Ind., 1983). A major problem in the development of improved animal production has been the shortage of feed and the generally low nutritive value of tropical forages which limit livestock pro­duction in Indonesia (Asian Agriculture Survey, 1969). The production of feed of adequate quality for ruminants is an important consideration particularly for small holders. In many situations, nitrogen fixing legume trees can be used as a high protein feed supplement which improves the utilization of grasses and crop …

Utilization Of Native Mediterranean Fodder Trees By Dairy Goats, M Meuret

IGC Proceedings (1977-2023)

Few data are available on utilization of fodder trees and shrubs by lactating goats. In most cases, predictions of animal performances on the basis of recommendations obtained from standard reference trials, do not correspond with production results achieved on the farm. Using measurements in digesti­bility cages and on rangelands (chromic oxide marker), we recorded intake, apparent digestibility of diets and perform­ances of goats well used to rangelands and browsing fresh oak foliage (Quercus ilex and Quercus pubescens).

Phenols As Defensive Compounds In Birch (Betula Spp.) Metabolism Of Platyphylloside In Goats, Rabbits And Hares, R T. Palo, G Iason, P G. Knutsonn

IGC Proceedings (1977-2023)

Herbivores of the boreal forest like moose (Alces alces), hares (Lepus spp.) and birds (Tetranoidae) use birch as a major feed source. The tree is of medium preference to the animals and is low in available nutrients for most of the year. Apart from a high amount of lignified cell walls it also contains con­siderable amounts oflow molecular phenolic substances (Palo, 1984). A herbivore feeding on birch could thus be excepted to ingest large amounts of phenols. These are in general enough fat soluble to enter animal cells expected to ingest large amounts of …