Agronomy and Crop Sciences Commons^™

Particulate And Fluid Retention Times In Sheep As Influenced By Forage Morphological Composition And Intake, D J.R Cherney, D R. Mertens

IGC Proceedings (1977-2023)

Production by ruminants on high forage diets is often limited by intake. If fill limits intake, residue must escape the rumen through digestion or passage for further intake to occur. Resistance to escape of forage residues from the rumen is a function of physical and morphological characteristics of the forage, although the nature of the relationship is not fully understood (Moseley and Jones, 1984). Understanding of factors affecting passage of undigested residue is important to ensure maximum forage utilization in ruminant diets. It was hypothesized that differences in forage morphological composition, particle length and rates of passage of morpho­logical components …

Responses In Ingestive Behavior By Sheep Changes In Sward Structure, P D. Penning, A J. Parsons, G E. Hooper, R J. Orr

IGC Proceedings (1977-2023)

Recent work has shown how herbage growth, ingestive behaviour and herbage intake may be related to sward height under continuous stocking (Parsons et al., 1986; Penning, 1986). However, the application of these relationships to other grazing managements, where differences in herbage mass, tiller number and leaf to stem ratio at the same sward heights occur, have not been considered. The objective of this study was to determine the major factors affecting ingestive behaviour and intake of herbage by sheep grazing swards differing in structure and morphology but with similar heights.

Factor Affecting The Eating Rate Of Forage Feeds, G Moseley, A Antuna Manendez

IGC Proceedings (1977-2023)

The total amount of a forage feed eaten by an animal may be regarded as the product of rate of eating and time spent eating. Balch and Campling (1962) suggested that it is controlled largely by the rate at which the forage can be broken down phy­sically and passed through the foregut. Differences in voluntary

intake between forage feeds may, however, be due to the effects of extrinsic factors such as environment, animal condition and feed presentation, or to inherent feed characteristics which con­trol the rate and extent of breakdown and digestion. The degree to which physical plant characteristics may …

Influence Of The Nature Of Hay On Its Ingestibility And The Kinetics Of Intake During Large Meals In Sheep And Cows, R Baumont, J P. Brun, J P. Dulphy

IGC Proceedings (1977-2023)

Ingestibility is the quantity of a forage that can be eaten by a standard animal when it is fed ad libitum as the sole feed (INRA, 1978). The eating pattern of ruminants reflects the way in which intake is controlled. The animal eats a large meal when a new batch of forage is distributed ; meals thereafter are small until the next distribution (Dulphy & Faverdin, 1987). To make a closer study of forage ingestibility, it seemed interesting to record the daily pattern of intake and to analyse in detail the large meals, which are 60 to 90 % of …

Relative Palatability Of Some Little-Known Tropical Forage Legumes, R Schultze-Kraft, C Lascano, G Benavides, J M. Gomez

IGC Proceedings (1977-2023)

In preliminary agronomic evaluations some of the little­know legumes recently selected in Southeast Asia have shown good adaptation to an acid, low-fertility Ultisol (CIAT, 1984, 1985). It is recognized that early evaluation of forage species should include an assessment of relative palatability (Joblin, 1962), particularly for tropical legumes where some species have been found to be highly unpalatable to cattle (Warmke et al., 1952). This paper reports on two cafeteria grazing trials conducted to assess the relative palatability of some new Southeast Asian legume germplasm as well as some South American species and ecotypes assumed to be of low palatability.

Fiber Composition Of Successive Cuts Of Lucerne, D Kolarski, J Pavesic-Popovic,, O Krstic, K Koljajic

IGC Proceedings (1977-2023)

The plant cell walls contain lignin, cellulose, hemicellulose, fiber bound protein and fiber bound minerals. Their nutritive value is limited by their degree of lignification, while cell con­tents is not limited (Barton et al., 1977). Type and extent oflig­nin-polysaccharide bounding could affect digestion more than amount of lignin (Jung et Fahey, 1983). The purpose of these studies was to determine chemical and fiber composition of four cuts of lucerne (Medicago sativa, CV Kl).

Relationship Between The Mineral Content In Pastures And The Content Of These Elements In Blood Serum In Dairy Cows, A Lachowski, I Kuczynska, W Wojciechowski

IGC Proceedings (1977-2023)

Grass tetany, a conditioned Mg deficiency of improper K: (Ca + Mg) ratio is a nutritional problem in various parts of Poland. The aim of the investigations was to determine to what degree the mineral content of grasses in the pastures influenced the mineral content in blood serum in dairy cows. This is very important when the animals are grazing and when cattle slurry is used on grasslands. In the literature we can find opinion con­sidering hypomagnaesemia as a metabolic disorder of rumin­ants typified by low blood serum Mg and generally accompanied by hypocalcemia. It has been related to low …

Etude D'Un Facteur Antinutritionnel De La Luzerne: Les Saponines, M Lila, G Genier, W Pietraszek

IGC Proceedings (1977-2023)

Les proteines de luzerne (Medicago sativa) extraites par des procedes industriels ne peuvent etre incorporees qu'en faible proportion dans les rations pour monogastriques a cause d'un effet antinutritionnel du essentiellement a la presence de sapo­nines et plus particulierement d'acide medicagenique (Pie­traszek, 1985). La technologie d'extraction ne permettant pas d'eliminer ces molecules, il a ete envisage d'ameliorer la qualite de ces proteines extraites par la diminution de la teneur dans la plante par voie genetique. Pour cela il fallait etudier la variabilite genetique disponible au sein de l'espece Medicago sativa et definir un test rapide per­mettant de discriminer en grande serie …

Mineral Composition Of Grasses Grown On Peat Soils In Northwestern Hungary And Fertilization Experiments. Manganese, R Schmidt, J Varga, G Tolgyesi

IGC Proceedings (1977-2023)

The main goal of these experiments which were carried out for four years was to study the mineral composition of grasses grown on peat soil, where preliminary studies indicated manga­nese, copper and zinc deficiency. We tried to eliminate these deficiences by agrochemical methods, because in our opinion, intervening in the first part of the foodchain - in the soil - we can contribute to solving of the deficiency problems more fund­amentaly (Ti:ilgyesi et al., 1983).

Characterization Of Biological Properties Of Fodder Value Of Dandelion, Taraxacum Officinale Web., M Falkowski, I Kukulka, S Kozlowski

IGC Proceedings (1977-2023)

In recent years the quantities of dandelion appearing on newly established grasslands has increased quite significantly. In such conditions it can no longer be treated as a meadow herb whose fodder value, according to European literature, equals half of that of valuable fodder plants. Becoming a weed, dan­delion has been the object of investigations on ways of elimina­ting it from the sward by means of herbicides (Schlotter et al., 1988). At the same time, experiments are under way on biologi­cal properties of dandelion with the aim to explain the causes of its expansion. It was found that there is an …

Location Of Polyphenols In Leaves Of Serciea Lespedeza, C O'H Mosjidis, C M. Peterson, J A. Mosjidis

IGC Proceedings (1977-2023)

Preliminary studies in sericea lespedeza, a nonbloating for­age legume, indicated that its palatability and digestibility were reduced by high levels of phenolics (Clarke el al., 1939). Another study suggested that younger parts of the shoots are more palatable than older leaves and stems (Donnelly el al., 1971). Nevertheless, younger leaves have been reported to con­tain higher levels of phenolics (Burns, 1966). Polyphenols have been thought to play a role as growth regulators and in protection against insects and diseases. Also they seem to be associated with lignification (Salatino el al., 1988). The present study was performed to determine whether his­tological …

Effect Of Endophytic Fungus Infection, Water Stress And Genotype On K, Ca And Mg Concentration Of Fescue, S R. Wilkinson, D P. Belesky, W C. Stringer

IGC Proceedings (1977-2023)

Replacement of endophyte infected tall fescue with endo­phyte free tall fescue is recommended to avoid tall fescue toxi­cosis. Fribourg et al. (1988) suggest that the endophyte may enhance tolerance of tall fescue to environmental stresses, including drought. This controlled environment study was undertaken to determine the effect of water stress on the K, Ca and Mg concentration of four genotypic selections of tall fescue with and without fungal endophytes. This paper emphasizes water stress and endophyte effects. The growth characteristics are reported elsewhere (Belesky et al. 1989).

Effect Of Fertilizers On Cutting On Time On Chemical Composition Of Sward From Permanent Meadow, A Golob, Zdenka Berloznik, M Leskosek, Vekoslava Stibilj

IGC Proceedings (1977-2023)

Ecological problems and surpluses of milk and meat have given rise to less intensive systems of grassland utilisation. One of such system is utilisation of air nitrogen via legume sym­biosis with nitrogen fixing bacteria. In Slovenia, where conditions for legume growth are more favourable than in NW Europe, natural meadows fertilized with P and K only give reasonable yields - on average around 7 t DM per ha (Leskosek, 1981). Most legumes suffer after fre­quent defoliation so such meadows should be defoliated only 2- 3 times during the growing season. Under less frequent cutting regime nutritive value of forage is …

The Effect Of N And K Fertilizers On The No3 Content Of Different Grass Species And Mixtures, A Szodfridt, J Varga

IGC Proceedings (1977-2023)

The major quantity of the annual grassland vegetation comes from the first cut in Hungary because of the continental climate of the country. Next to the energy content of grasses it is important to have informations about the amount of some possible toxic components such as nitrate. The critical NO3- value is considered to be 0.25-0.31 % in DM (Andreev, 1981), NO3 content higher than 0.6 % in DM is toxic (Kemp et al., 1977). Ebert et al. (1977) showed that 120 kg/ha N given for the 1st cut did not raise NO3 content higher than the critical value. K …

Determination Of Condensed Tannins In Tropical Legume Forages, L Telek

IGC Proceedings (1977-2023)

The effect of condensed tannins (proanthocyanidins) in ruminant nutrition is complex and needs further interdiscipli­nary reinvestigations with improved analytical methods. With the « cell rupture » theory of legume pasture bloat (Howarth et al., 1978), the role of condensed tannins seems to be secondary; they are acting as protein precipitants (Goplen et al., 1980) and inhibiting microbiological proliferation in cell­ular spaces (Howarth et al., 1982). Their assumed interference with digesting enzymes in vivo is doubtful (Mole and Water­man, 1985). On the importance of condensed tannins in nutrition, several reviews were published (McLeod, 1974; Tempel, 1982; Kumar and Singh, 1984 and …

Screening Sericea Lespedeza Germplasm For Tannin Concentration In The Leaves And Herbage Palatability, J C. Petersen, J A. Mosjidis, N S. Hill

IGC Proceedings (1977-2023)

Several million hectares in the subtropical world are currently used as grazing land for beef and dairy cattle, how­ever, in many cases animal production is very low. To improve animal nutrition, cultivated legume species can be introduced. Sericea lespedeza has potential and could be utilized in the acid soils of the· subtropics. Generally, sericea is low in palatability and nutritive value because its leaves contain tannins, which have long been associ­ated with low intake and reduced digestibility. Tannins are responsible for an astringent or bitter taste caused by the pre­cipitation of salivary glycoprotein (Goldstein and Swain, 1963). Chopping or macerating …

The Effect Of Selenium Fertilizer On The Selenium Status Of Sheep Grazing Annual Pasture In South-Western Australia, B R. Whelan, D W. Peter, N J. Barrow, D J. Buscall, V C. Cox

IGC Proceedings (1977-2023)

White muscle disease was first reported in grazing livestock in Western Australia by Gardiner (1961). Sheep affected by the disease could be divided into two categories : young suckling lambs in winter and early spring, and weaners and hoggets in summer (Gardiner et al., 1962). Subsequent investigations showed that, while there were few clinical symptoms of sel­enium deficiency, there were probably many sheep suffering from ill-thrift. This sub-clinical deficiency caused reduced liveweight gains, reduced wool production and lowered ewe fertility. It was most noticeable in areas of greater than 600 mm of annual rainfall on the lighter sandy soils with …

Synthesis Of Cell Wall Components In Maize Internodes, J H. Cherney, J J. Volenec, G A. Brown

IGC Proceedings (1977-2023)

Cell wall structure affects intake and digestibility of forages by rummants. Before microbial degradation of cell walls can be understood, it will be necessary to have a better understanding of cell wall formation. Internodes of grasses elongate in a_cropetal succession, with two internodes usually elongating s1multaneously. Elongating internodes consist of three regions : 1) a zone of cell division, 2) a zone of cell elongation, and 3) a zone of secondary cell wall deposition. This tissue provides an excellent system for studying cell wall changes in rapidly developing tissues. Our objectives were to : 1) examine changes in cell wall …

Natural And Artificial Drying Effects On Condensed Tannins Of Sericea Lespedeza, T H. University Of Georgia, W R. Windham, J J. Evans, C S. Hoveland

IGC Proceedings (1977-2023)

Sericea lespedeza [Lespedeza cuneata (Dumont-Cours.) G. Don.] is well adapted to acid soils and low fertility but has generally been considered a low-quality forage due to high levels of tannin and indigestible fiber. Tannin levels increase during midsummer (Windham et al. 1988). The most com­monly used assay for tannin in sericea is the vanillin-HCl pro­cedure (Burns, 1963) on oven-dried samples. Oven-drying has been reported to cause increased polymerization or oxidative changes in tannins (Goldstein and Swain, 1963). Fresh-frozen sericea contained higher amounts of extract­able tannin than field-dried forage and fiber digestibility of high-tannin sericea by sheep was much lower …

International Rice Outlook: International Rice Baseline Projections 2024–2034, A. Durand-Morat, W. Mulimbi

AAES Research Reports and Research Bulletins

• Global rice consumption is projected to exceed global rice production for most of the coming decade, with stocks playing a crucial role in balancing the global market over the projected period.

• The projected growth in production is almost exclusively due to productivity gains.

• The projected global rice consumption is growing, driven mainly by population growth. However, the average global per capita rice consumption is estimated to increase slowly in the coming decade due to a regain in per capita consumption in Asia, the largest rice-consuming region worldwide.

• The international prices of long-grain and medium-grain rice are …