Digital Commons Network^™

Grassland Societies In Manitoba, G Bonnefoy

IGC Proceedings (1977-2023)

Farmers with forage and livestock problems were organized into grassland societies and cooperated with extension staff sup­plied by 􀀇anitoba Agriculture. The purpose of the grassland societies is to improve by demonstration the traditional manage­ment practices used by livestock producers for pastures and forage production for beef and dairy herds. Results over 5 years were clearly positive. Significant improvements were noted in both field and animal husbandry practices. The experience confirmed the principles of the diffusion-adoption process and its application to adult extension education.

Pasture Demonstrations For Beef: Agronomic Considerations, N P. Martin, P R. Hasbargen, R L. Arthaud, G J. Sullivan

IGC Proceedings (1977-2023)

Beef cattle supply a major portion of farm income of northern Minnesota, but the major resource supporting this enterprise, forage, is vastly underutilized. A 5-year on-the-farm demonstration was conducted by the Agricultural Extension Service of the University of Minnesota and the Upper Great Lakes Regional Commission to improve income in this area by improving man­agement of the beef enterprise.

We compared one or two improved pasture systems with an unimproved permanent grass pasture composed predominantly of Kentucky bluegrass (Poa pratensis L.), system A, on each of six ranches. Improved systems included use of a cool-season grass fertilized with 138 kg …

Optimizing The Use Of Grazed Dryland Pasture In Western Oregon, T E. Bedell

IGC Proceedings (1977-2023)

When they are properly fertilized, western Oregon dryland pastures of subterranean dover with grasses such as perennial rp:g:rass, tall fescue, and resident annuals produce total annual dry-matter yields averaging 6,500 kg/ha. Some sites are capable of over 9,000 kg/ha. Optimum use of this forage is complicated by its highly seasonal availability. Over 50 % of the total growth occurs from late April to mid-June. Only about 10% takes place during autumn-early winter, and virtually none occurs during summer. Research shows livestock weight gains from 300 to over 700 kg/ha can be expected depending upon pasture mixture and kind of grazing …

Growing Beef Cattle On Native Pasture Oversown With The Legume Fine-Stem Stylo In Subtropical Australia, K G. Rickert, G M. Mckeon, J H. Prinsen

IGC Proceedings (1977-2023)

Fine-stem stylo (FSS), Stylosanthes guianensis var. lntermedia, is a perennial legume suitable for sowing into native Heteropogon contortus pastures on well-drained soils in southeastern Queensland. A grazing system is described that aims to maintain a productive FSS pasture and grow steers to 480 kg live weight at 27 months of age. This goal requires gains of 300 kg/steer in 20 months after weaning. Results from a short-term field study of the system were analyzed for long-term repeatabil­ity using a simple model that predicted animal production from stocking rate and weather records. The system was studied near Gayndah, Queensland, on 11.3 …

Development Of Legume-Based Pastures For Beef Production In Dry Tropical Areas Of Northern Australia, J G. Mcivor, R J. Jones, C J. Gardener, W H. Winter

IGC Proceedings (1977-2023)

A program designed to select pasture legume species suitable for beef cattle grazing in the 500-1,500 mm annual rainfall zone of northern Australia is described. A detailed study of members of the genus Stylosanthes, involving spaced-plant studies and small-scale cutting trials at a number of sites, identified a number of persistent, high-yielding accessions. Animal-production studies have shown that the introduction of a legume into native pasture generally results in an increase in carrying capacity, although production/head may not increase unless superphosphate is applied. The Stylosanthes accessions can produce moderate to high yields without superphosphate, and only small applications of superphosphate …

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 …

Advances In Pasture Research And Development In Santa Cruz, Bolivia, R T. Paterson, C R. Horrell

IGC Proceedings (1977-2023)

Cattle production is important in Santa Cruz but is low in productivity, due in part to low grazing value of natural pastures, particularly in the dry season. Other constraints to cattle production include low land values, poor management, high cost of in­puts, and relatively low product prices. This program is aimed at providing higher-quality, low-cost pastures for complemen­tary use within traditional grazing systems. Improved introduced species were identified for five agro-ecological zones, and commercial seed production of the following was encouraged: Petri guineagrass (Panicum maximum), Brachiaria decumbens, buf­felgrass (Cenchrus ciliaris), glycine (Neonotonia wightii, formerly Grycine wightii), Archer axillaris (Macroryloma axillare), …

Pasture Research Results In The Brazilian Amazon, E.A S. Serrao

IGC Proceedings (1977-2023)

Natural upland savanna grasslands are represented mainly by well-drained savannas, with the cerrado type predominant, and by poorly drained savannas with the campo alto-type being the most common. The main limitations are low forage­production potential and, especially, low forage quality. About 3 million ha of rain forest has been replaced by improved pastures of guineagrass (Panicum maximum, 80% ), jaraguagrass (Hyparrhenia rufa, 10% ), and Brachiaria spp. and other grasses (10% ). During the first few years after establish­ment, pastures are productive. However, with time, a gradual decline of productivity occurs, especially in P. maximum pastures. About 0.5 million ha …

Pasture Research Project In The Brazilian Amazon, H M. Saito, H W. Koster, E.J A. Khan, D F. Winslow, A M. Hollick, P M. Paollichi, A C. Costa, F A. Rolim

IGC Proceedings (1977-2023)

The procedure for pasture establishment in the Brazilian Amazon has been to cut down and burn forest and then to seed guineagrass (Panicum maximum L.). Under normal management, animal production has dropped significantly as pastures have deteriorated and have been invaded by weeds. A dearth of knowledge of climate, soils, and plant species; the manner in which pastures have been planted and managed; and a complete absence of fertilization have led to overgrazing and complete degrada­tion of the pastures. This study was undertaken to identify soil problems, adapted forage species, pasture-management practices, and ways of regenerating pastures. Two regions …

Animal Production From Brazilian Tropical Pastures, G L. Rocha, V.B G. Alcantara, P B. Alcantara

IGC Proceedings (1977-2023)

This review deals with the potential for beef production from nitrogen- and legume-based pastures in tropical Brazil. Possibilities for impr􀀞ving the beef industry supported by grass-legume pastures are very promising. According to the literature examined, legume-based pastures produced an annual average of 329 kg gain/ha, and nitrogen (N) fertilization resulted in 4.56 kg gain/ha. Phosphorus (P) was the main fertilizer utilized in addition to N, followed by potassium (K), lime, and micronutrients. An­nual rainfall averaged 1430 mm. Grasses used were of the genera Melinis, Hyparrhenia, Panicum, Cenchrus, Digitaria, Cynodon, Brachiaria, and Pennisetum, and the legumes were of the genera Macroptilium, …

Hemarthria Altissima: A Pasture Grass For The Tropics, K H. Quesenberry, W R. Ocumpaugh, O C. Ruelke

IGC Proceedings (1977-2023)

Limpograss (Hemarthria altissima [Poir] Stapf. et C.E. Hubb), introduced into the U.S. in 1964, has been evaluated for use as a pasture grass. Under Florida conditions it has shown yield potential equal to or greater than other tropical pasture grasses. The cultivar Bigalta has higher in-vitro organic-matter digestion (IVOMD) than other tropical grasses at comparable growth stages. Early evaluations of limpograss involved only three clones, but additional genotypes were collected and introduced during the late 1960s and early 1970s, and an evaluation scheme for this germ plasm was undertaken. Our objectives were to evaluate rapidly the available germ plasm of …

A Comparative Evaluation Of Six Ryegrass Cultivars Under Grazing And Conservation Managements, M Ryan

IGC Proceedings (1977-2023)

Meat and dairy products command overriding importance in the Irish agricultural economy. They are derived primarily from Irish grasslands, which occupy 89% of the arable land area. Use of improved grass cultivars is probably the best means of increasing grassland output once the basics, optimal fertilizer use, and high stocking rates have been met. Objective identification of superior cultivars is the responsibility of state agencies. A recommended list, published annually in Ireland, presently contains 47 ryegrass (Lolium perenne) cultivars. There is some doubt, however, that results from small-plot cutting trials can be extrapolated to equivalent performance by grazing …

Potential Grass Production In Ireland, A J. Breeton

IGC Proceedings (1977-2023)

Variation in weather geographically and between years can have a significant impact on intensive animal production systems dependent on grass as feed. This work was undertaken to quantify the effect of weather variations on grass production. The first objective was to relate grass growth quantitatively to radiation and temperature. These relationships are obscured by large changes in sward growth potential within the season, which are related to changes in the physiological status of the crop. Therefore, it was necessary to quantify this physiological effect. Production data were drawn from production experiments, and weather data were drawn from the published records …

Production Of Big Trefoil On Acid, Low-Fertility Soils In New Zealand, R S. Scott

IGC Proceedings (1977-2023)

On undeveloped, acid (pH< 5.0) soils in New Zealand, growth of the conventional legumes white clover (Trifolium repens L.), red clover (T. pratense L.), and alsike clover (T. hybridum L.) is limited by acidity. The objective of this research was to identify an alternative legume species better adapted to both acidity and low inputs of phosphorus (P) and to examine grazing management. Big trefoil (Lotus pedunculatus Cav.) cv. Grasslands Maku and birdsfoot trefoil (L. rorniculatus L.) cv. Maitland were examined. Seed was inoculated with appropriate strains of rhizobia and sown into undisturbed tussock grasslands on acid soils of low P status at altitudes of 550-880 m. Lime and phosphorus …

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 % …

Influence Of Sward Structure Upon Herbage Intake Of Cattle Grazing A Perennial Ryegrass Sward, M H. Wade, Y.L P. Le Du

IGC Proceedings (1977-2023)

To examine the influence of structural distribution of herbage within a sward on intake by grazing animals, two swards of contrasting structure were established at two periods in the grazing season by either infrequent mowing (C) or hard sheep graz­ing (G) of a perennial ryegrass (Lolium perenne) pasture. The plots were then allowed to grow undisturbed for about 5 weeks before being grazed by young cattle for periods of 2 weeks at two levels of herbage allowance, 30 and 60 g dry matter/kg live weight/day, in July (1) and in September (2). Detailed measurements of sward structure were …

A Mathematically And Conceptually Unified Approach To Grazing-Management Terminology, D L. Scarnecchia, M M. Kothmann

IGC Proceedings (1977-2023)

Expressions such as "stocking density," "stocking rate," "grazing pressure," "herbage allowance," "grazing intensity," "stock­ing intensity," and "stocking pressure" have long been used to describe animal-pasture systems. In general, these expressions describe relationships among the basic variables of animal demand, forage quantity, pasture area, and grazing duration. Our objective was to develop a conceptually dynamic mathematical framework of expressions summarizing all of the meaningful relationships among these variables. Elementary differential and integral calculus were used to develop this dynamic approach. The resulting expressions are dimensionally valid and are capable of accurately describing dynamic animal-pasture systems. Adoption of this system would standardize …

Screening Perennial Forages By Mob-Grazing Technique, P Mislevy, G O. Mott, F G. Martin

IGC Proceedings (1977-2023)

Mob-grazing allows the study of forage response to severe defoliation by grazing animals on a limited land area. This tech­nique was used to evaluate two Digi,taria spp., one Paspalum sp., and 13 Cynodon spp. at grazing frequencies of 2, 3, 4, 5, and 7 weeks. Average dry-matter (DM) yield generally increased as grazing frequency decreased from 2 to 7 weeks. Decreasing the grazing frequency from 4 to 7 weeks resulted in a DM yield increase of 50% to 75% for most entries. Grazing at 4-and 5-week intervals resulted in the highest (42%) and lowest (22%) weed contamination, respectively, when compared …

Grazing Techniques For Evaluating Quality Of Forage Cultivars In Small Pastures, A G. Matches, F A. Martz, D A. Sleeper, R L. Belyea

IGC Proceedings (1977-2023)

Because plant beeders have few laboratory analyses of forage quality that are good predictors of animal performance when grazing pasture, • we studied the feasibility of grazing small pastures with cattle in order to detect possible forage-quality dif­ferences among cultivars of tall fescue (Festuca anmdinacea Schreb). Kentucky 31, Kenmont, Fawn, and Missouri 96 tall fescue cultivars and Kenhy, a Lolium-Festuca derivative, were grown in 0.47-ha pastures and grazed in separate periods ranging from 35 to 68 days during the spring, summer, and autumn of 1974-1976. Between grazing periods, cattle grazed a reserve pasture of the same cultivar. All test pastures …

Using A Dynamic Model Of Fiber Digestion And Passage To Evaluate Forage Quality, D R. Mertens, L O. Ely

IGC Proceedings (1977-2023)

Assessing forage quality depends not only upon the characteristics of the plant and animal, but also upon the dynamic interac­tion of the forage, rumen microorganisms, and animal. Although static variables, such as composition or 48-hour in-vitro fermentation, are important for characterizing feeds and predicting in-vivo responses under standard conditions, they provide little information that can be used to assess forage quality in dynamic situations. Dynamic properties, such as rates of digestion and passage, can be used to predict digestion under varied circumstances but require an appropriate mathematical model. Our objectives were to describe a dynamic model of fiber digestion and …

Methodology For Determining Pasture And Animal Response Differences In Unbalanced Experiments With Intercorrelations Among Treatments, J C. Burns, R W. Harvey, F G. Giesbrecht

IGC Proceedings (1977-2023)

Conventional statistical analyses require balanced data sets. Unbalanced data can be analyzed using regression procedures, but excessive adjustments may be needed for some treatment means. The objective of this paper is to evaluate an analysis of grazing-trial data using generalized least squares. The data was obtained from a 6-year study involving 12 treatments with not all treatments being made in all years. The analyses involved estimating variance components due to years, fields, and random error and then using these estimates to obtain adjusted treatment means. Variance-component estimates for the complete data set were similar to estimates from two balanced subsets …

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 …

Review Of Mechanisms Of Toxicity Of 3-Nitropropanoic Acid In Nonruminant Animals, D L. Bustine, B G. Moyer

IGC Proceedings (1977-2023)

Crownvetch (Coronilla varia L.) now has limited use in the U.S.A. as a forage crop for ruminant animals. Even though crown vetch forage can contain high amounts of nutrients, intake by ruminants may be reduced. Toxicity problems upon feeding crownvetch to nonmminants have been traced to 3-nitropropanoic acid (NPA), which occurs esterified to glucose in the plant. Understanding mechanisms of toxicity in nonruminants will be helpful in avoiding livstock losses and in treating poisoned animals. Symptoms of NPA toxicity are similar in rats, mice, meadow voles, chickens, and rabbits and probably reflect central nervous system disorders and oxygen deprivation. …

Beef Production From Tall Fescue Treated With Mefluidide A Chemical Plant-Growth Regulator, T W. Robb, D G. Ely, C E. Rieck, S Glenn, L Kitchen, B P. Glenn, R J. Thomas

IGC Proceedings (1977-2023)

Mefluidide treatment of Kentucky 31 tall fescue (Festuca arundinacea Schreb.) in the spring will inhibit seed-head formation, maintain the forage in an immature and vegetative stage, and increase forage N and soluble-sugar content and in-vivo nutrient utilization in the ovine. Productivity of animals grazing mefluidide-treated tall fescue, however, has not been determined. The objective of this study was to evaluate agronomic characteristics of forage and productivity of yearling beef steers and heifers grazing mefluidide-treated (T) and nontreated control (C) pastures of Kentucky 31 tall fescue. Experimental pastures of Kentucky 31 tall fescue ( 4 replications at location I and one …

Role Of Alkaloids And Toxic Compounds In The Utilization Of Tall Fescue By Ruminants, J A. Boling, R W. Hemken, L P. Bush, R C. Buckner, J A. Jackson Jr, S G. Yates

IGC Proceedings (1977-2023)

Tall fescue (Festuca arundinacea Schreb.) contains several alkaloids. Studies in our laboratory showed that perloline is a prin­cipal alkaloid in tall fescue during the summer and that concentration peaks at a time when cattle grazing tall fescue pastures fre­quently have severely reduced performance (summer syndrome or summer fescue toxicosis). The objectives of the following studies were (1) to determine the influence of perloline on in-vitro fermentation and in-vivo ruminant metabolism and (2) to determine the effects of two tall fescue strains selected for perloline concentration on performance of growing cattle and lactating dairy cows and on interrelationships with environmental …

Feeding Value Of The Legume Component In Pasture And Silage, K.F M. Reed, P T. Kenny

IGC Proceedings (1977-2023)

Grazing experiments were conducted to examine the feeding value of various pastures for grazing sheep and, in some cases, as silage. Recently, the use of legumes for improving the growth of weaned lambs during the dry summer and early autumn was in­vestigated at Hamilton, Victoria. Studies in Australia showed that the fleeceweights of weaner sheep grazed on eight pasture mixtures of varying grass species increased as the amount of clover in the pasture increased (r -0.88 • *). In a separate study, young sheep grew faster on lucerne· grass pasture than on grass-subtenanean dover pasture. Most recently, live-weight gains of …

Increasing Productivity And Extending Grazing Season Of Cynodon Pastures For Steers With N And Overseedings Of Trifolium And Festuca In The Southeastern U.S.A, H A. Fribourg, J B. Mclaren, R J. Carlisle

IGC Proceedings (1977-2023)

A series of grazing experiments has been conducted 80 km east of Memphis, Tennessee, since 1969 on fine-silty, mixed, ther­ mic, Typic Hapludalfs soils to evaluate productivity and quality of Cynodon pastures grown with N fertilizer or in combination with Festuca arundinacea and/or Ladino, TnJolium repens, and sometimes with T. pmtense, for growing beef steers. Pastures were grazed by the put-and-take system, and forage growth and consumption were determined by the cage-and-strip method. These experiments have shown that bermudagrass pastures can support many young beef animals for 5 months/yr if they are fertilized with N, can produce rapid gains in …

Simulation Of Complementary Forage Cropping By Feeding Oat Grain To Ewes, J L. Wheeler, D A. Hedges, C Mulcahy

IGC Proceedings (1977-2023)

In many parts of the world where year-round grazing is feasible, complementary forages such as oats or sorghum are sown to impove the quantity and quality of the forage available at specific periods. Experiments in which these crops complement well­fertilized grassland have generally not shown an increase in animal production compared with all-grassland systems. The pres­ent experiment aimed to determine the effects of a simulated complementary forage crop on pasture yield and on the production of breeding ewes. Eight groups of 10 sheep grazed 0.6-ha plots of Phalaris aquo.tica L.-Trifolium repens L., and eight groups of 10 sheep grazed 0.8-ha …

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 …

Effect Of Supplements On The Live-Weight Gain Of Beef Cattle Given Forage During The Dry Season, C Thomas, P N. Mbugua

IGC Proceedings (1977-2023)

The low quality of standing pasture grasses in the dry seasons presents a major problem in the intensification of beef produc­tion in the tropics. The objective of this research was to examine the role of maize and grass silage or standing napiergrass (Pen­nisetum purpureum) as sources of forage when given alone or with supplements to beef cattle. In the first of three trials conducted at the National Agricultural Research Station, Kitale, Kenya, 36 Friesian castrates, initially 249 kg live weight (LW), were given silage of whole-crop maize either alone or supplemented with corn-and-cob meal. Each of these two basal diets …