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Development Of A Pasture Research Program For The Tropical Savanna Region Of Brazil, D Thomas, C P. Moore, W Couto, R P. De Andrade, C.M C. Da Rocha, D T. Gomes

IGC Proceedings (1977-2023)

The tropical savannas (cerrados) of west central Brazil contain almost 40% of the nation's cattle population. However, the low productivity and nutritive value of the native pastures is a serious limitation to cattle production. To improve the nutrition of the grazing animal, a research program has been developed with emphasis on the integrated use of cultivated pastures. The program aims (1) to select species adapted to the cerrados, (2) to determine their nutrient requirements, and (3) to develop methods of establishment and utilization. The program is being conducted at the Cerrados Agricultural Research Center (CP AC) at lat 15°S. Rainfall …

Yield And Quality Of Tropical Legumes During The Dry Season: Galactia Striata (Jacq.) Urb., R R. Vera, E A. Pizarro, M Martins, J.A. C. Viana

IGC Proceedings (1977-2023)

A small-plot experiment was conducted during 2 consecutive years in the cerrados of Brazil to evaluate the effect of four dates of deferment (21 February, 7 and 21 March, and 4 April, respectively) on rate of growth, chemical composition, and in-vitro dry-matter digestibility (IVDMD) of a pure stand of Galactia striata, a naturalized legume. The chosen dates of deferment em­braced the last 2 months of the rainy season. Yields were estimated at intervals of 28 days, over an experimental period of 237 days, ending with the beginning of the following rainy season. Asymptotic growth was observed throughout the experimental period. …

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 …

Animal Production With Controlled And Fixed Stocking And Managed Stocking Rates, R E. Blaser, J T. Johnson, F Mcclaughterty, J P. Fontenot, R C. Hammes Jr, H T. Bryant, D D. Wolf, D A. Mays

IGC Proceedings (1977-2023)

Grazing experiments were conducted to implement and improve animal-grazing-management systems. The primary objec­tives were (experiment 1) to investigate animal production with fixed and controlled stocking and (experiment 2) to study animal production and canopy characteristics with three managed stocking rates. Live-weight gains/head for the grazing season were similar for fixed and controlled stocking; during a summer period, gains/head were higher for controlled stocking. Gains/head were not associated with available herbage. The canopies with fixed stocking had 28% to 82% more forage than those with controlled stocking, the former being high in dead tissues and stems. Controlled stocking gave 61 % …

Use Of Principal-Component Analysis In Summarizing Nutritive And Analytical Characteristics Of Forages, O T. Stallcup, C J. Brown, Z B. Johnson, D L. Kreider, J O. York

IGC Proceedings (1977-2023)

Principal component analysis and other multivariate analyses have not been used extensively to analyze forage data. Our objective was the synthesis and summary of 98 digestion trials on forages using a principal-component analysis. The ten variables studied in all trials were dry matter (DM), crude protein (CP), digestible protein (DP), crude fiber (CF), ether extract (EE), nitrogen-free extract (NFE), ash (A), gross energy (GE), total digestible nutrients (TDN), and digestible energy (DE). Acid detergent fiber (ADF), acid detergent lignin (ADL), and cellulose (C) were summarized, in addition, for some forages. When data on thirteen variables in 24 hays were summarized, …

Yield And Forage Quality Of Panicum Virgatum, J L. Griffin, G A. Jung

IGC Proceedings (1977-2023)

In the temperate areas of the U.S.A., high temperatures and low soil moisture in summer limit the production of cool-season grasses and, consequently, the size of most beef cow-calf herds. Warm-season grasses, most productive in midsummer, may serve as a supplement to cool-season grasses for grazing and hay. Switchgrass (Panicum virgatum L. ), a warm-season species native to the Great Plains of the U.S.A., was grown on soils low in available phosphorus at two locations in Pennsylvania to determine changes in forage dry-matter yields, leaf (leaf blade): stem (sheath+ stem) ratios, and quality of leaf and stem fractions associated …

Effect Of Experimental Methods On Results Of Voluntary Intake Experiments With Grass Cultivars, U Simon, P Daniel

IGC Proceedings (1977-2023)

The amount of forage eaten by farm animals when forage is offered ad libitum is a major factor in the nutritive value of forage grasses. It is influenced by a number of internal and external factors. Experimental results of studies on the subject :reported in the literature are often contradictory, partially because, perhaps, of the methods of evaluation employed. We studied whether and to what extent different experimental procedures influenced the results of intake experiments in grass cultivars. Four cultivars of Lolium perenne differing in ploidy level and precocity were fed to sheep ad libitum, and voluntary intake was assessed …

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 …

Nutritive Value Of Cattle Diets On Fertilized And Unfertilized Blue Grama Rangeland, J D. Wallace, F J. Cordova, G B. Donart, R D. Pieper

IGC Proceedings (1977-2023)

Low levels of nitrogen (N) fertilization can substantia1ly increase forage production on native rangeland if adequate precipita­tion is available. The objective of this study was to_ compare nutritive value of diets selected by Hereford steers grazing unfer­tilized and N-fertilized (45 kg N/ha) rangeland in south central New Mexico. The study area consisted of two adjacent pastures of approximately 60 ha each, containing comparable areas ofbottomland, upland, and hillside sites. Stocking rates were 4.8 and 2.4 ha/yearling steer for control and N-fertilized pastures, respectively. Dietary samples were collected from esophageally fistulated steers (average weight 308 kg) during early, middle, and late …

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 …

Combination Range-Pasture Management In South Florida For A Low-Energy Grassland Program, L L. Yarlett

IGC Proceedings (1977-2023)

The semitropical environment of south Florida is favorable for coordinated management of a wide variety of native grass species and improved pasture forages. The decade of the 1980s will emphasize change from forage programs of high energy utilization to those with a low requirement of fossil fuels. For 4 decades, grassland management in south Florida has been primarily pasture establishment created from the rangeland resource. The establishment and management required substantial inputs of fossil fuel. Use and management of rangeland was largely neglected. Ecological concepts as a basis for managing semitropical ranges were not accepted. In recent years practical programs …

Effect Of Herbage Mass And Allowance Upon Herbage Intake By Grazing Dairy Cows, J.A C. Meijs

IGC Proceedings (1977-2023)

An adequate supply of nutrients for grazing animals depends on the intake and nutritive value of herbage. Little information is available on factors affecting herbage intake of grazing cows, particularly for grazing systems that do not involve daily change of animals to a new pasture. Our objectives were to determine the effects of variation in herbage mass ( due to variation in stage of maturity) and of herbage allowance on herbage intake by grazing dairy cows and on efficiency of consumption (herbage con­sumed as a proportion of herbage accumulated). From 1976 to 1979 the herbage intake oflactating cows was determined …

Round Baling From Field Practices Through Storage And Feeding, W L. Kjelgaard, P M. Anderson, L D. Hoffman, L L. Wilson, H W. Harpster

IGC Proceedings (1977-2023)

A model analysis compared labor and fuel requirements for round and rectangular bale systems. Round baling reduced harvesting, transport, and handling labor by one-half but increased fuel use by a factor of 1.6. When data from field studies of all dry matter (DM) losses were included, round baling required 80 % as much labor and 200 % as much fuel as did rectangular bal­ing. Baling losses for round balers and stackers averaged 10 % compared with 3 % for rectangular balers. ·Dry-matter losses from mowing through feeding of field-cured round bales, including 6 months of outdoor storage, totaled 41 % …

Effect Of Formic Acid- Formaldehyde Treatments On The Nitrogenous Constituents In Annual Ryegrass Silage, M L. Fishman, F Mchan, D Burdick

IGC Proceedings (1977-2023)

Prevention of proteolysis during ensiling is important in preserving the nutritive value of silage. Hence, the mechanism by which silage protein is protected against degradation was studied in wilted annual ryegrass (Lolium multiflorium Lam.) silage pretreated with formic acid, formaldehyde, and a formic acid-formaldehyde mixture. Raw-wilted ryegrass, control ryegrass silage, and treated ryegrass silage were extracted and fractionated under conditions previously found to maximize yield of nitrogenous constituents and minimize proteolysis during the extraction of fresh grass. Extractions were by boric acid-borate buffer at pH 8.0 with and without detergent (1 % sodium dodecyl sulfate). Sodium metabisulfite, an antioxidant, was …

Marker-Assisted Identification Of Hybrids In Polyembryonic ‘Carabao’ Mango (Mangifera Indica L.) Breeding In The Philippines, John Edward L. Felipe, Kyla Andrea G. Mendoza, Benjamin Christian J. Esguerra, Carolyn E. Alcasid, Gino R. Hernandez, Eureka Teresa M. Ocampo

The Philippine Agricultural Scientist

Varietal improvement of the Philippine ‘Carabao’ mango (Mangifera indica L.) through conventional breeding is constrained by polyembryony, which makes it difficult to distinguish zygotic hybrids from nucellar seedlings at early developmental stages. This study evaluated the utility of simple sequence repeat (SSR) markers for early and accurate identification of hybrids in polyembryonic ‘Carabao’ mango crosses. Genomic DNA was isolated from 24 parental accessions and 61 putative hybrid seedlings using a modified CTAB protocol that yielded DNA suitable for PCR-based marker analysis. Eighty-one SSR markers were screened across 29 parental combinations, of which 64 markers (79.0%) were polymorphic in at …

Effects Of Irrigation And Nitrogen Management On Yield And Leaching Risk In Organic And Conventional Broccoli Fields, Shane Egerstrom

Master's Theses

Under regulatory pressures to reduce groundwater contamination by nitrate from fertilizer, such as those posed by the Central Coast Regional Water Quality Control Board’s Agricultural Order 4.0, a need exists to better understand interactions between irrigation and nitrogen (N) management. To increase N use efficiency (NUE), growers are encouraged to account for additional sources of N in their management plans, such as irrigation water N and preplant soil N. The availability of these N sources for plant uptake and how it is affected by other management conditions is not yet well documented. We conducted 6 field trials, 3 organic and …

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 …

A Descriptive Scheme For Stages Of Development In Perennial Forage Grasses, U Simon, B H. Park

IGC Proceedings (1977-2023)

A descriptive scheme of morphological stages of development in forage grasses is urgently needed for scientific investigations as well as for practical purposes. It could be used for precise timing of management measures, such as application of fertilizers and herbicides, and in harvesting with respect to a certain level of forage yield and/or quality. Existing schemes, like the Feekes scale and its modifications, were devised for cereals. They do not adequately consider the peculiar stages of development of perennial grasses grown for forage. We propose a scheme that consists of consecutive stages of the following phases of plant development: number …

Pasture Evaluation In The Desertic Zone Of Venezuela For The Development Of Goat Production, A Gallardo, A Leone

IGC Proceedings (1977-2023)

The desertic zone of Venezuela is an area of approximately 4.1 million ha that represents 4.8 % of the total national territory, on which there are two million goats. Goats represent the main, if not the only, income source for 60,000 rural families. According to UNESCO (1973), the desertic zone of the country comprises two vegetation types, evergreen scrub and deciduous scrub. In each of these zones the plant species consumed by goats were collected and, for those plant parts consumed by the animals, chemically analyzed to determine nutritive value. Forage plants from other tropical countries were also in­troduced and …

Nutritional Quality Of Leaf Proteins Prepared From Crops Containing Phenolic Compounds And Polyphenolase, T Horigome, S Uchida

IGC Proceedings (1977-2023)

Many studies have indicated that leaf protein prepared by green crop fractionation affords good potential as a protein supple­ment. It has been noted, however, that there were some marked differences between crops in the nutritional quality ofleaf pro­tein in spite of a similarity in amino-acid composition between leaf proteins made from different crops. We previously showed that brown casein, which was produced by the interaction of milk casein with phenolics undergoing enzymic oxidation, had lower nutritional value than original casein. In addition, it has been suggested that leaf proteins prepared from crops containing phenolics and polyphenolase were brown after extraction …

Physiological And Morphological Advances For Forage Improvement, J P. Cooper

IGC Proceedings (1977-2023)

Forage production basically involves the conversion of environmental inputs to provide digestible energy and other nutrients for ruminant livestock. The plant breeder needs to consider the seasonal inputs or constraints in his particular environment, the efficiency of the crop in responding to these factors, those features of the plant that contribute to this efficiency, and the degree to which those features can be modified by selection and breeding. Forage production basically involves the conversion of environmental inputs to provide digestible energy and other nutrients for ruminant livestock. The plant breeder needs to consider the seasonal inputs or constraints in his …

Potential Productivity Of Temperate And Tropical Grassland Systems, G O. Mott

IGC Proceedings (1977-2023)

Grasses of temperate regions of the world belong primarily to the subfamily Festucoideae, whereas tropical regions are populated by tribes of the Panicoideae subfamily. Temperate grasses have a C3 biochemical pathway of photosynthesis in con­trast to tropical grasses, which have a C4 photosynthetic mechan-ism. Both tropical and temperate legumes are C3 plants. Com­patible mixtures of legumes and grasses have long been successful in many temperate regions, but combining C4 grasses and C3 legumes as mixtures in the tropics has been only moderately successful. Maximum net primary productions of temperate and tropical grasslands are in the order of 25 and 80 …

Forage Quality: Assessing The Plant-Animal Complex, D J. Minson

IGC Proceedings (1977-2023)

At the VI International Grassland Congress held at Pennsylvania State College in 1952, the late Dr. C.P. McMeekan re­viewed the many problems associated with the plant-animal complex. Great stress was placed on the need to measure forage in­take accurately as a prerequisite to an under-standing of the plant-animal complex. Progress in the development of more accurate :methods of estimating the forage intake of grazing animals is reviewed, in­cluding the introduction of different methods of administering chromic oxide, the esophageal fistula for obtaining samples of selectively grazed material, the in-vitro technique for estimating the digestibility of the forage eaten, and the …

Growth And Development Of Two Echinochloa Millet Species In A Warm Temperate Climate, D K. Muldoon

IGC Proceedings (1977-2023)

Most summer forage crops fall into either the sorghum or the millet species group. Included in the millet group are two species, Echinochloa utilis and Echinochloa frumentacea, commonly known as Japanese barnyard millet and Indian barnyard millet, respectively. These species have a negligible HCN potential and higher nutritive value than Sorghum species. However, they generally flower early, yield less than forage sorghum , and lack vigor in regrowth. In this study the pattern of growth and development of two Echinochloa millets was examined as part of a larger program of improving the production of these forage species. E. utilis …

Test Adaptation And Evaluation Trials Of Forage Plants In Major Ecological Regions Of Ethiopia And Kenya, K M. Ibrahim, A Orodho

IGC Proceedings (1977-2023)

Kenyan and Ethiopian natural grazing Ian.cl. support more than 20% of the cattle population of the African continent. Many of the natural pastures of these countries are severely overgrazed, as unfavorable grazing conditions prevail for over half the year. Objectives of adaptation trials were to evaluate and identify introduced or indigenous forage and fodder species or ecotypes having genetic potential for high production of digestible dry matter for direct pasture and range improvement and for future use in breeding programs. Over 4,000 indigenous and 3,000 introduced ecotypes were evaluated for 24 vegetative characters in six ecological regions between 1971 and …

Neutral Detergent Fiber And Protein Levels In Diploid And Tetraploid Ryegrass Forage, L R. Nelson, F M. Rouquette Jr

IGC Proceedings (1977-2023)

Nutritive value of 18 ryegrass (Lolium multifloriumLam.) cultivars was studied at Overton, Te1

0.42-mm screen. Plots were harvested four times during each of the first 2 years and five times in the third year. In 1977-1978 and 1978-1979, NDF and protein analyses were run on samples from 2 replications. All forage samples were analyzed for pro­tein via the micro-Kjeldahl technique. Percentages of NDF were obtained via Van Soest extraction procedures. A seasonal increase in neutral detergent fiber (NDF) content and a decrease in protein percentage was observed. Differences in NDF were observed among cultivars and were most apparent during …

Forage Quality Of Barley Straw As Influenced By Genotype, D W. Meyer, D O. Erickson, A E. Foster

IGC Proceedings (1977-2023)

Cereal straw is an untapped carbohydrate source for ruminant animal feeds, but little information is available on genotypic differences in the feeding value of barleys (Hordeum vulgare L.) commonly grown in the northern Great Plains of the U.S.A. Our objective was to determine if barley genotypes differ in straw forage quality and if straw-quality parameters are associated with agronomic characters. Straw from 37 and 31 barley genotypes was sampled in 1977 and 1978, respectively. Straw from 10 barley genotypes grown at four locations was sampled in 1979. Standard laboratory procedures were used to determine the quality parameters measured. Correlations …

Evolution Of Selection Techniques In Breeding For Bloat-Safe Alfalfa, B P. Goplen, R E. Howarth, G L. Lees, W Majak, J P. Fay, K J. Cheng

IGC Proceedings (1977-2023)

This report summarizes the Canadian breeding program to develop a bloat-safe alfalfa (Medicago sativa L.). This program has experienced an evolution of selection methods in attempting to identify bloat-safe alfalfa genotypes. In chronological order, the methods involved selection for fraction I (18S) protein, soluble proteins, foam volume, tannins (flavolans), saponins, initial rate of digestion (IRD), sonication, purified enzymes, gas production, and leaching. Although soluble herbage protein is correlated with the occurrence of pasture bloat, we have experienced slow progress in a selection program to reduce soluble-protein concentration in alfalfa. We have found that foam volume is not correlated with …

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.

Hedysarum Mongolicum Turcz.: An Important Protein Resource Legume On Dry Sandy Land, Li Min, A W. Hovin

IGC Proceedings (1977-2023)

In searching for plants that can both increase the protein production and improve the sandy-soil conservation of the grassland in the arid, windy regions of North China, so far, from among many native plants, we have identified Hedysarum mongolicum Turcz. as the best species to fulfill our dual purposes. We investigated its distribution, planted its native seeds in the Maowusu desert, and studied it under its native and cultivated growing conditions from 1957 to 1964. Chinese farmers call this perennial subbrush legume of the sweetvetcb genus "Yang Cai," meaning "sheep like to eat." It can thrive in the stable or …