Agricultural Science Commons^™

Studies On Feeding Value For Five Psammophyte Shrubs In Ningxia Region, Dongmei X., Weixian C., Sijia G., Xiangyun X.

IGC Proceedings (1977-2023)

A trial was conducted on five psammophyte shrubs -Caragana intermedia, C. korshinskii, Hedysarum scoparium, H. laeve, Salix psammophylla in the post-fruit period in Ningxia, China. Chemical composition, palatability and in vitro digestibility were studied systematically. The feeding value was evaluated through Fuzzy multifactorial model. According to chemical composition, palatability and in vitro digestibility, C. intermedia, had the highest feeding value and C .korshinskii the lowest.

In Situ Dry Matter Ruminal Degradation Kinetics Of Prairie Grass And Annual Ryegrass Forage, J. R. Carrete, I. Ceconi

IGC Proceedings (1977-2023)

The objective of this study was to evaluate dry matter ruminal degradation kinetics, of prairie grass (Bromus catharticus Vahl.) and annual ryegrass (Lolium multiflorum), by using in sacco technique, on seven different harvesting dates. The forage was incubated in nylon bags, suspended in the rumen of four Hereford steers with a rumen fistula. The dry matter ruminal degradation was calculated through the exponential model P=a+b(1-exp(-ct)). Potential degradabilities (PD) were high and reduced across a temporal trend, ranging between 92,31 and 81,79g 100g ^-1 of dry matter (DM) for prairie grass (PG) and 95,06 and 77,44g 100g ^{-1 …}

Application Of Near Infrared Reflectance Spectroscopy (Nirs) To Forage Evaluation In Uruguay, D. Cozzolino, Y. Acosta, J. Garcia

IGC Proceedings (1977-2023)

Near infrared reflectance spectroscopy (NIRS) were used to assess the chemical composition of a wide range of forages. Nearly five hundred herbage samples covering a wide range of temperate pastures species and mixtures, previously analysed by conventional wet chemistry were scanned in reflectance with a NIRS 6500 (NIRSystems, Silver Spring, USA). The coefficients of determination in calibration (R² ) and the errors in cross validation (SECV) were 0.98 (5.8), 0.94 (22.2), 0.97 (5.6), 0.94 (6.9) and 0.89 (19.7) for crude protein, in vitro organic matter digestibility, dry matter, ash and acid detergent fiber, in g kg ^–1 on a …

Seasonal Variation Of Brachiaria Spp. Quality In The Pantanal Of Mato Grosso Do Sul, Brazil, S. M. A. Crispim, E. L. Cardoso, F. Fernandes

IGC Proceedings (1977-2023)

This study aims to evaluate the dry matter yield and the crude protein (CP) of Brachiaria decumbens and Brachiaria humidicola and soil covering by these species, considering stand lasting age and hydrologic cycle periods in the Pantanal, from November 1996 to November 1997. Dry matter yield presented differences between hydrologic cycle periods and age, and their interactions. B. decumbens and B. humidicola over 10 years comparison yielded the largest amount of dry matter yield, observed in February. B. humidicola growth rate was slower than B. decumbens. Pastures stand ages did not cause differences in crude protein, but differences have …

Continuous Digestibility Assessment Of Tropical Grasses, A. Chudy, T. Schmidt, A. Glatzle

IGC Proceedings (1977-2023)

The feed value for cattle of three tropical grasses, Gatton (Panicum maximum cv. Gatton), Estrella (Cynodon plectostachyus) and Tifton-85 (Cynodon sp. cv. Tifton-85) was investigated during the growing period, using the method of “continuous digestibility estimation”. Results indicate that feed value is hardly influenced by the growth stage from the 90th day on. Common European in-vitro feed evaluation procedures are not to be recommended for tropical grasses as they presented consistently lower values than did in-vivo measurements.

Prediction Of Intake Of Hay Differing In Species And Maturity By Goats, S. W. Coleman, S. P. Hart, T. Sahlu

IGC Proceedings (1977-2023)

Eight species of forage, a cool-season perennial (Festuca arundinacea) and annual grass (Triticum aestivum), four warm-season perennial grasses (Bothriochloa caucasica, B. ischaemum, Cynodon dactylon, and Tripsacum dactyloides), a warm season annual (Digitaria sanguinalis) and a perennial legume (Medicago sativa), were cut at two or three maturities to provide a wide array of quality difference (n=20). Twenty wether goats (Capra hicus) were fed the hays in four different trials using an incomplete block so that each hay was fed to four different goats. Alfalfa produced the highest DM, …

Climatic Factors, Acid Detergent Fiber, Neutral Detergent Fiber And Crude Protein Contents In Digitgrass, C. S. Chen, S. M. Wang, Y. K. Chang

IGC Proceedings (1977-2023)

Digitgrass (Digitaria Xumifolia) was treated according to a set of programmed harvest cycles to study the impact of climatic factors on the quality of the grass. It is found that seasonal changes have greater effect on the quality of the grass than does the length of the harvest cycle. The highest correlation coefficient (0.81) between the ADF content and accumulated temperature is attained when the base temperature is set to 15.5 , while the highest correlation coefficient (0.88) between CP and is attained at a base temperature of 15.0 . The determination coefficient of regression (R² ) …

Effect Of Level Of Surface Spoilage On The Nutritive Value Of Maize Silage Diets, K. K. Bolsen, L. A. Whitlock, G. L. Huck, M. K. Siefers, T. E. Schmidt, R. V. Pope, M. E. Uriarte

IGC Proceedings (1977-2023)

This study determined the effect of surface spoilage in the diet on feed intake and nutrient digestibilities using growing steers fed whole-plant maize silage-based diets. A bunker silo, 0.9 m in depth, and a 2.7 m diameter AgBag were filled with alternating loads of chopped forage. After 90 days, the bunker was sealed with a sheet of polyethylene, and this silage was designated “spoiled”. The silage in the AgBag was designated “normal”. The four diets contained 90% silage and 10% supplement (dry matter basis), and the proportions of silage in the diets were A) 100% normal, B) 75% normal: 25% …

Selenium And Sulphur Concentrations In Primary Growths Of Different Plant Communities, W. Opitz Von Boberfeld

IGC Proceedings (1977-2023)

The factorised evaluated data of seven different grassland swards and two harvest dates of primary growths led to following results: Regarding the concentrations of selenium and sulphur, a selenium antagonist, and the N/S ratio, there were no significant plant community x harvest date, plant community x year, and harvest date x year interactions. The selenium concentrations, which never met the requirements of ruminants, were the highest in young herbage of a Bromion racemosi community reaching 49 µg kg^-1 DM. The average of all swards and treatments was 33 µg kg^-1 DM of selenium. Apparently, repeated application of selenate-bearing …

Canopy Characteristics, Ingestive Behaviour And Herbage Intake In Cultivated Tropical Grasslands, Lynn E. Sollenberger, J. C. Burns

IGC Proceedings (1977-2023)

Compared to temperate systems, there have been few detailed assessments of canopy characteristics and associated grazing behavior in planted tropical grasslands. Reasons include the large number of forage species used in warm climates, the diversity of their morphology, research priorities emphasizing germplasm evaluation and management, and limited resources. This review describes canopy attributes of C₄ grass pastures, highlights the most important relationships between grazing behavior and these canopy characteristics, and discusses the implications of canopy characteristics and grazing behavior for long-term intake and animal performance. It is suggested that the largest differences in canopy characteristics between tropical and temperate …

Foraging Behaviour And Intake In Temperate Cultivated Grasslands, S. Prache, J. L. Peyraud

IGC Proceedings (1977-2023)

In temperate areas, grazing provides a large part of the nutrient requirements of ruminants and may be an important form of land use. In Europe, grassland occupies some 150 million hectares, and grazing provides about 60 to 75% of the nutrient requirements of cattle (Wilkins and Vidrih 2000). From the end of the 80’s, agricultural surpluses in Europe have led to production quotas and increased interest in more extensive systems. At the beginning of the 90’s, the emergence of the notion of sustainable agriculture combining economic, social (concerns in dereliction of less-favoured rural areas), and environmental issues (pollution, loss of …

A Comparative Grazing Study Of Sheep And Cattle Diet Selection On Native Pastures In Uruguay, Fabio Montossi, G. Pigurina, E. J. Berretta, I. Santamarina

IGC Proceedings (1977-2023)

An experiment was carried out during winter, spring and summer 1997, on native pastures of the basaltic region of Uruguay to evaluate the effects of different herbage mass levels (high, medium and low) on sward characteristics and on sheep and cattle diet selection and grazing behaviour. Higher herbage masses resulted in increments in herbage accumulation and sheep bite weight: winter (1880, 1513 and 610 kg DM ha-1, P < 0.01; 199, 148 and 128 mg DM/bite, P < 0.01), and summer (3046, 2175 and 1172 kg DM ha-1, P < 0.01; 214, 175 and 143 mg DM/bite, P < 0.01) for high, medium and low herbage mass levels respectively. The nutritive value of diet selected by sheep and cattle was higher than that of the herbage on offer, and higher in sheep than in cattle: winter (10.2, 15.9 and 12.5% crude protein, CP, P < 0.05; 49.2, 32.4 and 38.1% acid detergent fiber, ADF, P < 0.01, and summer (7.4, 10 and 9.5% CP, P < 0.05; 51.1, 36.8 and 43% ADF, P < 0.01) for herbage on offer, sheep and cattle diets respectively. These contrasting results found in the nutritive value were closely associated with differences in the proportions of the botanical components recorded, particularly the differential contribution of dead material. This experiment quantified the importance of diet selection in determining the nutritive value of the forage eaten by sheep and cattle on the native pastures of the basaltic region of Uruguay and established some relationships between diet selection and grazing management, involving animal selectivity ability differences (sheep versus cattle) and seasonal effects.

A Sheep And Catlle Diet Selection Study On A Fertilized Native Sward In Uruguay, Fabio Montossi, E. J. Berretta, G. Pigurina, I. Santamarina

IGC Proceedings (1977-2023)

This study was undertaken during winter, spring and summer 1997, located in the basaltic region of Uruguay to evaluate the effects of stocking rate (SR) and N and P fertilizer application on sward characteristics and on sheep and cattle diet selection and grazing behaviour. The treatments applied were: a) control (C; without fertilizer application using a SR of 0.9 stock units (SU)/ha), b) T1 (with N and P fertilizer application using a SR of 0.9 SU/ha), c) T2 (with N and P fertilizer application using a SR of 1.2 SU/ha) and d) T3 (with N and P fertilizer application using …

Ingestive Behavior Of Beef Cattle Fed Either Protein Or Energy Supplements Under A Rotational Grazing System, R. P. Manzano, Luiz Gustavo Nussio, M. P. Andreucci, K. Z. Veiga, R. Z. M. Costa

IGC Proceedings (1977-2023)

Eight Nellore bullocks were assigned to a Tanzânia grass pasture (Panicum maximum Jacq.) under a rotational grazing system, to evaluate the ingestive behavior under two different grazing residues. Stocking rate intensity was used to reach either 1000 kg DM.ha^-1 (R1) or 4000 kg DM.ha^-1 (R2) as residual targets. Three grazing days followed by 33 days resting period, composed a 36 day grazing cycle. Each grazing plot supported four animals, in a 4x4 Latin square design, within the following supplementation rates and sources: S1 = no supplement; S2 = 2,0 kg DM.day^-1 coarsely ground corn - 8 …

Changes In Pasture Growth Rate Due To Fertiliser And Grazing Management, P. Quigley, D. Chapman, J. Lamb, G. Kearney

IGC Proceedings (1977-2023)

It is imperative that sheep production systems in southern Australia continue to be refined so producers remain financially viable but at the same time the environment is not degraded. As part of a national thrust for development and promotion of better production systems, one research site has been established in Victoria where pastures and animal production are measured together with water and nutrient movement. Results for pasture growth rates over two years are presented here and will be used to develop best industry practice at completion of the project.

2022 Western Australian Crop Sowing Guide, B. Shackley, B. Paynter, J. Bucat, M. Seymour, S. Power

Bulletins 4000 -

Welcome to the 2022 edition of the Crop Sowing Guide for WA, which introduces 27 new variety releases: three wheat, nine barley (three recently accredited for malt and six currently under malt evaluation), twelve canola, two field pea and a lentil.

The Crop Sowing Guide for WA has been compiled by officers in the Department of Primary Industries and Regional Development. It provides information to support variety decisions for each of the major crops for the upcoming season.

In this edition, lupin agzones have been reduced from 8 agzones to 6 so that all varieties for each of the major …

Response Of Mixed C4 Grasses To Various Multiple Paddock Grazing Strategies, B. E. Anderson, W. H. Schacht

IGC Proceedings (1977-2023)

The botanical composition of mixed grass pastures may change during grazing due to the various grazing period/recovery period lengths associated with multiple-paddock grazing strategies. This 4-year study compared changes in relative species composition and basal plant cover of a C₄ grass mixture grazed using a nested paddock design to simulate 2, 4, 6 and 12- paddock grazing cells in eastern Nebraska. Total basal plant cover declined from 11.6% prior to grazing to 7.3% after one year of grazing and then remained nearly constant thereafter. Neither relative species composition nor basal density were affected greatly by grazing strategy. Within grazing …

Spatial And Time Distribution Of Dairy Cattle Manure In An Intensive Pasture System, S. L. White, S. P. Washburn, L. D. King, R. E. Sheffield, J. T. Green Jr.

IGC Proceedings (1977-2023)

This study determined distribution of feces and urine from dairy cattle managed in a rotationally grazed pasture. Lactating Holsteins (n=18) and Jerseys (n=18) were grazed on a .74 ha endophyte-free fescue (Festuca arundinacea)/white clover (Trifolium repens) pasture. All cows were constantly observed for 24 h 6 times over 12 mo. Cows had access to about 54% of the paddock during the first grazing period (12 h) and had access to the entire paddock during the second grazing period (8 h). Data included: (1) all feces and urine events from eight cows, observed while in the pasture, …

Test Of A Conversion Equation To Increase The Accuracy Of Microhistological Analysis Of Herbivore Diets In The Pantanal, S. A. Santos, C. Costa, A. Pott, J. M. Alvarez

IGC Proceedings (1977-2023)

Forty forage species samples were collected in September 1999, including grass, sedges, forbs, shrubs and trees. Seven hand-compounded mixtures of known botanical composition and dry weight were prepared. Five slides of each mixture were made and 20 frequency observations were recorded per slide. Two procedures were used to determine percent composition on a dry weight basis and their values were converted to correct the proportion of the unidentifiable fragments amongst species. Estimated and actual values differed significantly (P < 0.05) in 31.7%, 34.1%, 12.2% and 12.2% of the species for frequency addition (FA), density convertion (DC), frequency addition converted (FAC) and density convertion converted (DCC), respectively. The average similarity values between estimated and observed mixture were 90.2, 86.0, 94.2 and 93.3 for FA, DC, FAC and DCC, respectively. In conclusion, food habits by microscopic analysis may be described using any of the procedures tested because they rank important forage species for herbivores.

Effects Of Herbage Allowance Upon Animal Performance And Grazing Behavior Of Strip-Grazed Heifers, Claudio F. Machado, F. Di Croce, F. Gonzalez, H. Zeballos, N. J. Auza, M. H. Wade, S. T. Morris, J. Hodgson

IGC Proceedings (1977-2023)

A trial was designed to test the effect of herbage allowance (HA) on live-weight gain (LWG) and grazing behavior of heifers during spring as part of a combined field-modeling research programme. Low HA (L) and high HA (H) of 2.5 and 5.0 kg DM herbage mass 100 kg animal LW^-1day^-1 were fed respectively. H animals grazed longer and achieved a higher LWG than L (P < 0.05). H animals left a higher residual pasture (P < 0.051) with a significantly (P < 0.05) higher content of green, clover, non-lamina and petiole of a higher digestibility and NSC, with a lower NDF content. The significance of some factors involved in these results on intake and diet selection are discussed in relation to the predictability of animal performance.

Factors Influencing The Yield Proportions Of Plantago Lanceolata L. And Taraxacum Officinale Web. In Lolium Perenne L. Swards, Harald Laser

IGC Proceedings (1977-2023)

Diaspores of Plantago lanceolata and Taraxacum officinale respectively were sown in established Lolium perenne swards to determine the dynamics of their yield proportions during five years. The experimental factors were forb species, variety of the grass species (= early or late flowering), N-fertilization, and sward density. The amount of nitrogen fertilizer had the most important effect on yield proportions of the forb species and also on the total dry-matter (= DM) yield. The single creation of gaps in grass swards before sowing forbs had a lasting positive effect on the Plantago lanceolata and Taraxacum officinale proportions. Peak proportions of Taraxacum …

Dynamic Of Native Pasture Influenced By Deferment Of Grazing And Fertilization, K. E. Gomes, G. E. Maraschin, J. Riboldi

IGC Proceedings (1977-2023)

Native pastures of southern Brazil cover 12 million ha and are the main forage feed resource for most domestic livestock. However, their heavy and continuous use has reduced standing biomass and the presence of good forage species, reducing animal performance and jeopardizing the ecosystem sustainability. An alternative for better use of these pastures and their preservation is grazing deferment that allow natural reseeding. The objective of this research was evaluate native pasture dynamic after six years of grazing deferments (GD) periods and soil fertilization effects by point-quadrat method every season. All pasture components were affected by GD, with prostrate grasses …

Evaluation Of Plant Functional Types Response To Grazing And Fertilizer Levels In Natural Grassland, Zélia M. S. Castilhos, V. D. Pillar

IGC Proceedings (1977-2023)

We report a study on a natural grassland experiment with the objective of finding optimal plant functional types (PFTs) for the description of vegetation response to levels of grazing (ungrazed, grazed) and fertilizer (with, without). The experiment was a split-plot design in randomized blocks, with three replications and the grazing levels in the main plots. Vegetation description was based on species composition and on 12 plant morphology attributes (life-form, growth-form, stem tissue type, leaf cross section, leaf texture, leaf dorsal epidermal surface, leaf ventral epidermal surface, spininess, leaf resistance, leaf width, plant height). Cover-abundance of species was visually estimated. By …

Mountain Pastures Structure And Its Relationship With Grazing, I. Albizu, S. Mendarte, G. Besga, I. Amezaga, M. Onaindia

IGC Proceedings (1977-2023)

The present work aims toward an approach to mountain pastures as a system of relationships in which it is needed to point out those environmental factors that reflect more clearly their structure and potential productivity. This initial step of pasture tipification is important as a previous activity before the planning and management of protected areas because these areas support an intensive pastoral activity. In order to achieve this objective a field study was conducted in two areas in the Gorbeia Natural Park (Bizkaia): Arraba and Aldamiñape, located at 900-1100 masl. In each pasture four plots were selected according to orientation …

Structure And Function Vegetation Conditions By Grazing Processes In A Humid Pampean Grassland (Argentina), O. E. Ansín, Estrella M. Oyhamburu, E. A. Hoffmann, M. A. Eirin

IGC Proceedings (1977-2023)

Expressed changes were evaluated as consequence of the cattle grazing, or their exclusion, in the structure of plant communities of the Flooding Pampa. We center our interest in the species numbers, plant cover, species diversity and forage availability. The treatments were: a) continuous grazing, b) enclosure grazing and c) controlled grazing. The enclosure grazing area was installed two years before starting the measurements. In the continuous grazing St. Augustine grass (Stenotaphrum secundatum Walt.) holds its initial cover of 64 % and dallis grass (Paspalum dilatatum Poir.) the 15 %. In the enclosure grazing S. secundatum decreased its cover …

Nitrogen Dynamics From Decomposing Litter Of Panicum Maximum With Different Nitrogen And Phosphorus Content In Brazilian Alfissol, R. M. Schunke, J. C. Kiehl, Valdinei T. Paulino, S. Urquiaga, R. M. Bodey, B. Alves

IGC Proceedings (1977-2023)

The objective of this study was to measure the dynamics (immobilization and release) of N and to evaluate the effect of the initial chemical composition of four Panicum maximum cultivars grown in a Alfisol and fertilized with different levels of nitrogen (0, 80 e 160 kg ha^-1 de N) and phosphorus (0 e 200 kg ha^-1), on the release of the N from the litter using the litterbags technique. There was an increase in the litter initial concentration of N with time of decomposition. The Aruana and Vencedor cultivars released about 70 and 60% of N; respectively, …

Impact Of Grazing Management Strategies On Carbon Sequestration In A Semi-Arid Rangeland, Usa, J. D. Reeder, G. E. Schuman, J. A. Morgan, D. R. Lecain, R. H. Hart

IGC Proceedings (1977-2023)

The effects of 12 years of grazing management strategies on carbon (C) distribution and sequestration were assessed on a semi-arid mixed-grass prairie in Wyoming, USA. Five grazing treatments were evaluated: non-grazed exclosures; continuous, season-long grazing at a light (22 steer-days ha^-1) stocking rate; and, rotationally-deferred, short-duration rotation, and continuous, season-long grazing, all three at a heavy stocking rate (59 steer-days ha^-1). Non-grazed exclosures exhibited a large buildup of dead plant material (72% of total aboveground plant matter) and forb biomass represented a large component (35%) of the plant community. Stocking rate, but not grazing strategy, changed …

Contribution Of Dairy Cow Manure To Soil Fertility And Nutrient Redistribution In Pastures, S. R. Aarons, C. R. O'Connor, M. Hall, C. J. P. Gourley

IGC Proceedings (1977-2023)

The effects of dairy cow manure on soil fertility were investigated at the site of the long-term phosphorus rate by stocking rate farmlet experiment at the Dairy Research Institute, Ellinbank, in Victoria. Manure increased extractable soil P (Olsen) in the 0 - 5 cm layer after 60 days to 61 mg/kg compared with values of 32 mg/kg in the control soils. Extractable soil K (Colwell) almost doubled under manure pads to 5 cm depth from 642 mg/kg in control soils to 1226 mg/kg in manure treated soils. The effects of grazing management on nutrient redistribution and pasture growth within strip-grazed …

Impact Of Increasing Nitrogen Fertilizer Rates Upon An Irrigated Tanzania Grass Pasture. 1. Dry Matter Yield, F. Queiroz-Neto, G. B. Martha Jr., M. A. Penati, M. Corsi, M. J. T. Menezes

IGC Proceedings (1977-2023)

An experiment was carried out with irrigated Tanzania grass (Panicum maximum, Jacq.) pasture receiving five nitrogen (N) rates of (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) during the growing season. N application increased dry matter yield and Tanzania growth rate linearly (P < 0.05). Responses to nitrogen applications were higher in the first two cuts of the growing season than in the last two cuts. The N fertilizer conversion into herbage dry matter was also higher in the beginning of the growing season.

Short-Term Study On 13Carbon Discrimination On Irrigated Tropical Pasture, G. B. Martha Jr., M. Corsi, P. C. O. Trivelin, F. Queiroz-Neto

IGC Proceedings (1977-2023)

A better understanding of pasture ecosystem can be obtained through the use of ¹³C discrimination technique. In this context, an experiment, assigned in a randomized complete block design with four replicates, was conducted to evaluate the Δ ¹³C (‰) discrimination, nitrogen (N) yield (kg N ha-¹), total nitrogen content (g kg dry matter (DM)-¹) and dry matter yield (kg DM ha-¹) on an irrigated Tanzania grass pasture (Panicum maximum, Jacq.) receiving increasing rates (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) of N fertilizer during the summer. Dry matter yield, N yield and nitrogen …