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Disparities In The Utilization Of Nambia's Grassland: A Need For Adjustments In The Beef Industry, Helmke Sartorius Von Bach, Johan Van Zyl

IGC Proceedings (1977-2023)

Extensive beef production, Namibia's life-line in agriculture, depends entirely on natural pastures. Socioeconomic and environmental disparities, namely (a) the· traditional smallholder communal sector versus the commercial sector and (b) areas in the vicinity versus distant from centralised abattoirs, are analysed by' using econometric analysis of time-series data on the regional influence of prices and· access to markets on beef numbers. This is particulary relevant because Namibia is in a process of structural adjustment, and in view of the beef sector's importance in the Namibian economy. The results accentuate the role of access to markets and productive opportunities for beef production …

Comparison Between Fodder Cropping Rotations Carried With Or Without Meadow In The Intensive Farming System Of The Po Valley Plain (Italy), Mario Onofrii, Cesare Tomasoni, Lamberto Borrelli

IGC Proceedings (1977-2023)

Pour fodder cropping rotations were compared at different degrees of crop intensification: (RI) a I-year continuous monoculture of Italian ryegrass (Loll111n multij/orum Lam.) +silage maize (Zea mays L.); (R3) a 3-year rotation of Italian ryegrass+silage maize - barley (Hordeum vulgare L.)+silage mai1:e - grain maize; (R6) a 6-year rotation of Italian ryegrass+silage maize for 3 years followed by meadow for 3 years (Trifolium repe11s L. + Festuca ari111di11acea Schreb,): (PM) a monoculture of permanent meadow. The most efficient rotation for dairy cattle feeding, on sandy-loam soils, was the I-year rotation of Italian ryegrass, followed by silage maize, with 22 9S0 …

Cadmium In Soil, Pasture And Grazing Ruminants, J Lee, N D. Grace, A D. Mackay, M J. Hedley, J R. Rouce

IGC Proceedings (1977-2023)

Cadmium, present in New Zealand hill country pastures rrom Cd­amended phosphatic fertiliser use, is assimilated by grazing ruminants. Concentrations of Cd in plasma from sheep grazing pastures containing low (0.1-0.2µglg dry weight) or high (0.8-1.4 µgig dry weight) levels of Cd were 0.15±0.04 nglg and 0,35:1:0.15 ng/g, respectively (P<0.08). Cadmium in pasture was highly correlated (P<0,001) with soil O.IM HCl-extractable Cd (log10 Soiled= -0.98+0.26 Plantcd).

Nitrogen Dynamics In Three Contrasting Grassland Systems: Implications For Pasture Productivity And The Potential For Environmental Pollution, B E. Ruz-Jerez, R E. White, P Roger Ball

IGC Proceedings (1977-2023)

Nitrogen (N) dynamics were compared in 3 contrasting grassland systems (2 legume-based and I receiving fertiliser N) in a cool temperate region of New Zealand. The study was concentrated on the various N transfers that occurred during and after grazing. Critical periods for N loss by different processes have been identified, allowing a more comprehensive understanding of the role of N in the productivity of different types of pasture, and the potential for environmental pollution, Calculation of N inputs and outputs for the three pastures indicated that the two legume-based systems were more or less in balance, but in the …

Reduction Of Nutrient Losses For Dairy Farms, With Emphasis On Nitrogen, W Luten, D J. Den Boer

IGC Proceedings (1977-2023)

Recently the Dutch government presented several policy papers in which standards are given for maximum allowed emissions to air, groundwater and surface water. Depending on the farm situation an optimum combination of measures in relation to housing, slurry storage, slurry and fertiliser application, and composition of the ration can be taken. In general a better use of nutrients from animal manure by applying slurry with low emission techniques in the growing season and a reduction of the stocking rate by a higher milk production per cow are the most effective and cheapest measures to reach these targets. There is a …

Use Of Pasture As A Receivers For Swine Lagoon Effluent, J P. Mueller, J C. Barker, J P. Zublena, M H. Poore, R W. Harvey, J T. Green

IGC Proceedings (1977-2023)

Swine waste management-cattle grazing systems were monitored on 2 North Carolina farms from 1990-1992, Farmers co-operated directly in the project by furnishing land, labour, equipment and cattle and by maintaining records of grazing and waste applications. Local county agricultural extension agents helped with management decisions, record­keeping and co-ordinating activities among project participants. On a fann where waste was applied to pastures for 5 years, soil N in the upper l m averaged from 230-500 kg/ha, NO3 -N in the forage remained above 10 g/kg for the grazing season and 2 of 4 test wells recorded NO3 levels above 10 mg/I. …

Pastoral Systems Of Central Himalaya: How Long Will They Survive?, K S. Rao, K G. Saxena

IGC Proceedings (1977-2023)

Pastoral systems of Central Himalaya are very old and until recent time were in balance with environment, Recent changes in socio­political setup have drastically altered the status of these systems. The change of political power in trans-Himalayan Tibetean plateau has resulted in closure of international boarders, thus taking away the mercantile aspects of pastoralists and reducing pastoral area. Increased human disturbances on fragile Himalayan marginal lands and excessive onslaught on forests for fuel and fodder by the sedentary population has resulted in degradation and non-productive grasslands which do not help pastoralists sustain existing systems. Changes in relations between migratory pastoralists …

A Preliminary Discussion Of The Management And Administration Of Yunwu Mountain Natural Grassland Reserve In China, Zhao Zhiyi, Yang Ailian

IGC Proceedings (1977-2023)

The advantages and problems encountered in the establishment of a grassland reserve are described. The conflicts between local farmers' requirement to feed and water livestock and the conservation strategy of natural grassland are discussed.

Effect Of Sewage Sludge On The Mineral Composition Of Corn, Arthur E. Peterson, P E. Speth, P L. Schlecht

IGC Proceedings (1977-2023)

For the past 12 years, digested sewage sludge from the Milwaukee Metropolitan Sewerage District has been applied to a Plano silt loam (prairie) soil near Elkhorn, Wisconsin, and corn raised as the indicator crop. The corn has been harvested as silage and fed to dairy cnttle. The amounts of macro-, micro-, and heavy metals contained in this forage were compared with the amounts contained in the untreated areas, and in the forage produced by a sustainable agriculture study on the same experimental station. None of the heavy metals have moved out of the plough layer (lop 25 cm). The uptake …

Sustainable Direction For Resource Management An Assessment Of The Regional Council Role, Allan Lohrey

IGC Proceedings (1977-2023)

The 1980s has seen an increased world awareness of the concept of sustainability. In 1991 New Zealand enacted the Resource Management Act (RMA) which reflected society's concern for a need to consider future generations when making decisions relating to the use of natural resources. Regional councils have been allocated the role within the Act to promote sustainable management at the regional level. The short term challenge to regional councils is to manage resources in manner which strikes a pragmatic balance between the ongoing needs of society and the need to provide resources for future generations. Regional councils will know they …

Application Of Dairy Manure On Alfalfa, Stephen J. Herbert, Jayarm Daliparthy, P L.M Veneman

IGC Proceedings (1977-2023)

Applying dairy manure to alfalfa (Medicago sativa L.) as ,in alternative 10 excess application to· corn (Zea mays L.) may reduce nitrate pollution of groundwater. Field experiments were conducted at 2 sites in Massachusetts, USA, lo study the impact or dairy manure application to alfalfa on forage yield, weed infestation· and nitrate movement. Treatments were an unfertilized (no N) check.· plot, low and high manure (112 and 336 kg N/ha/year equivalerit), and low and high N fertiliser (112 and 336 kg N/ha/year from NH4NO3),'. Liquid dairy manure was applied 10 • alfalfa immediately· after 1st· cutting during spring …

Roly Poly And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Roly poly, also known as prickly saltwort or tumbleweed (Salsola australis), is a native species found throughout Australia. The dead plants can break off at ground level, forming the ‘tumbleweeds’ seen in movies.

Like most summer weeds, roly poly uses soil moisture and nutrients that would otherwise be available to the following crop. The time taken to clear uncontrolled plants can delay seeding.

Livestock will graze the young plants; however, they will not eat the mature plants and are injured by the prickly leaves.

Windmill Grass And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Windmill grass is a native species and the tenth most common summer weed species in the Western Australian (WA) grainbelt. It hosts pests and diseases and utilises stored soil moisture that would otherwise be available to the following crop.

Capeweed And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Grains and other field crops factsheets

Capeweed (Arctotheca calendula) is a prostrate, stemless, sprawling annual herb that germinates during autumn and winter. In Western Australia (WA), competition from 7 to 90 capeweed plants per square metre in a wheat crop can reduce crop yield by 28 to 44% and net return by 25 to 76%.

Tar Vine And Its Management, Department Of Primary Industries And Regional Development, Western Australia

Biosecurity factsheets

Tar vine (Boerhavia coccinea) is a common summer weed species that depletes soil moisture and nutrients, reducing the yield potential of the subsequent crop. It also acts as a green bridge for crop pests and disease.

How Much Green To Keep The Garden Clean? An Analysis Of The Willingness To Pay (Wtp) Of Home Gardeners For Biowrap Technology, Gengchen Cai, Kanij Fatema, Karina A. Schoengold

Cornhusker Economics

A research team from the University of Nebraska-Lincoln, Kansas State University, and South Dakota School of Mines are working on creating an alternative product that would use locally available materials to create a spray-on, biodegradable polymer that can suppress weeds and will biodegrade in a timeframe that is amenable to crop production. We broadly refer to this technology as BioWRAP (Bioplastics with Regenerative Agricultural Properties).

Our results show that the home garden market is potentially a significant one for a BioWRAP product. Continued work in the development of the BioWRAP technology is necessary to determine what the cost of a …

Foraging Strategies Of Ruminant Livestock On Intensively Managed Grasslands: Potential And Constraints, I J. Gordon, C Lascano

IGC Proceedings (1977-2023)

All grazed swards exhibit heterogeneity in the spatial (horizontal and vertical) dispersion of species/biomass. A herbivore foraging at random within such a heterogeneous environment would ingest less nutrients than wou Id one which exploited the heterogeneity on offer through selective grazing. The suite of decision-making processes involved in the selective grazing we observe is termed the animal's foraging strategy. On first observation, intensively managed sown swards appear to offer little opportunity for a herbivore to exhibit a foraging strategy; however, opporlunities do exist and there is empirical evidence that herbivores foraging on sown swards tend to have a diet higher …

Comparative Foraging Strategies Of Grazing Ungulates In African Savanna Grasslands, N Owen-Smith, D H.M Cumming

IGC Proceedings (1977-2023)

We review the evolutionary (species-specific) and ecological (individual behavioural) strategies of African grazing ungulates. The contexts considered are free-ranging wild ungulates, traditional livestock pastoralism and extensive commercial ranching. Particularly successful are (1) buffalo, able to digest grass fibre effectively in mesic grasslands; (2) wildebeest, exploiting semi-arid grasslands through migration; (3) megaherbivores (elephant, hippopotamus and white rhinoceros) utilising a wide range of vegetation components. Species-specific adaptations include body size and metabolic rate, digestive efficiency and passage rate, oral and dental anatomy, water dependence and detoxification capacity. Species overlap in grass species se'lected, with dietary differences apparent in grass height favoured, and …

Comparison Of Animal Gains Using Perennial Pastures Exclusively Or Combined With Chicory-Oats-Clover Temporary Winter Pastures, J A. Josifovich

IGC Proceedings (1977-2023)

The increment of winter forage availability using short-rotation pastures could be an interesting way to increase winter carrying capacity. The producer could make good use of higher spring grass production. Sowing oats, rye or chicory alone is quite common in the Argentine Pampa. to evaluate the efficiency of these short-rotation winter pastures a 3 year trial was carried out at Pergamino Experiment Station. The treatments were: a) perennial pastures, 100% of the surface, b) perennial pastures 75%, and chicory-clover 25%, with 2 replications of 3 ha each. The pastures were, for. class II soils, fescue (Festrlca aru11dinacea Schreb.) cv. El …

Influence Of Climatic Factors On Animal Production In The Humid Pampa Of Argentina, J D. Josifovich, E Frutos

IGC Proceedings (1977-2023)

For any' pasture grazing area it is important lo know the relationship among the climatic parameters, rainfall and temperature, with carrying capacity and minimal gains. The availability of pasture to adjust stocking rates and make provisions for hay or supplementary feed needed for periods of shortage can be estimated from these data. Seven years of monthly rainfall and medium average temperature; and 25 years of forage digestibility and average daily gains were related to cattle i: carrying capacity; Analysis was made using the stepwise regression method. Carrying capacity was evaluated considering animal units (AU) for a 400 kg head gaining …

A New Theory Of Feed Intake Regulation In Ruminants And Its Implications For Forage Quality Research, J.J M.H Ketelaars, B J. Tolkamp

IGC Proceedings (1977-2023)

The low voluntary intake of many roughages is commonly explained by a limited physical capacity of ruminants to process fibrous feeds. Recently, we developed a new theory of feed intake regulation assuming feed consumption to create both benefits for the animal (represented by the intake of net energy for maintenance and gain) and costs (represented by the total oxygen consumption of the feeding animal). For non­reproducing ruminants we have shown that voluntary intake of roughages is close to the optimum feed intake level, i.e., the level at which for the animal the ratio between benefits and costs becomes maximum. According …

Botanical Composition Of Forage Samples Selected By Grazing Sheep On The Mountain Rangeland Of Northern China, Han Jianguo, Liu Fuyuan

IGC Proceedings (1977-2023)

Oesophagus fistulae and microscopic examination were used to determine the botanical composition of forage samples selected by grazing sheep on the mountain rangeland in the Hc-Bci Province of northern China during the growing seasons of 1989 and 1990. Results show a clear preference of sheep for some forage species over others. Sheep selected Cleistogenes squarrosa, Koeleria cristata, Potentilla cihinensis, Lespedeza hedysoroides and Scabiosa comosa in each type of rangeland and from early spring to late autumn. The selection ratio of forbs was more than I , and that of grasses less than 1. Sheep showed strong preference for …

The Independent Effects Of Sward Height And Bulk Density On The Bite Parameters Of Romney Ewes And Red Deer Hinds, R J. Mitchell, J Hodgson, D A. Clark

IGC Proceedings (1977-2023)

The independenl effects of sward height (I, 2, 3, 5 and 8 cm) x bulk density (0.65, 1.30, 2.90 mg DM/cm3) variation on the ingestive behaviour of Romney ewes and Red deer hinds were examined in seedling swards which simulated a leafy grass sward of low shear strength. Depth of penetration, horizontal area of herbage severed per bite, weight of each bite and the rate of intake all increased with increasing height, while the rate of biting decreased (P

Relationships Between Milk Yield, Pasture On Offer And Diet Selection In Tropical Grass Pastures, T M. Davison, W N. Orr, V J. Doogan, K Lowe

IGC Proceedings (1977-2023)

A 7-year study was conducted with Holstein-Friesian cows to determine responses to different levels of nitrogen and phosphorus fertiliser applied to Gatton panic (Panicum maximum cv. Gatton) pastures. This study was used to develop relationships between milk yield, pasture and diet botanical components. Multiple regression analysis revealed there was: a negative relation between stem yield (SI) on offer in summer (S) and milk yield but a positive association with leaf yield (L) on offer in summer and green dry matter .GDM in autumn (A),, MY = 2279.0+0.529 LS-0.246 StS+0.324 GDMA _(R2 = 0.66; P

A New Ambulatory Data-Logging System For A Long Term Determination Of Grazing And Rumination Behavior On Free Ranging Cattle, Kanji Matsui, Tadakatu Okubo

IGC Proceedings (1977-2023)

A new ambulatory apparatus (named "jaw recorder") has been developed. The apparatus has a large data storage capacity (32 768 data points), and enables data to be recorded every minute for a minimum of 22 days in one recording session. A Holstein heifer was fitted with the apparatus and was grazed with 4 other heifers for 13 days on a pasture of 0.36 ha of Italian ryegrass (Lolium nmltiflorum Lam.). Grazing and rumination period could be distinguished by a combination of jaw movements and pauses between jaw movements longer than 3 sec/min. Grazing and rumination time distinctly increased with …

Field Test Of Optimal Foraging With Cattle: The Marginal Value Theorem Predicts Patch Selection And Utilization, Emilio A. Laca, R A. Distel, T C. Griggs, G Deo, M W. Demment

IGC Proceedings (1977-2023)

Grazers selectively forage within heterogeneous vegetation. Prediction of intake rate necessitates theoretical developments to understand site selection. We tested III optimal foraging model to predict patch selection by cattle in the field, Nine "grazing environments" (GB) consisting of 16 0.36 m2 patches each were created by mowing. Treatments were a factorial of 3 distances between patches and 3 sets of patch heights. Patch residence time (T,) was accurately predicted (r2=0.89), and increased linearly whh patch distance (P

A Conceptual Model To Explain Variation In Ingestive Behavior Within A Feeding Patch, Emilio M. Laca, M W. Demment, R A. Distel, T C. Griggs

IGC Proceedings (1977-2023)

A conceptual model is presented that links the mechanics of bite formation to the characteristics of the sward to explain variation in bite weight, bite area, bite depth and biting rate measured in a series of experiments with hand-constructed swards. Bite area is determined by the behaviour used by the animal to collect and grasp the tillers, and the length and stiffness of the sward, Bite depth is affected by height and the degree of vertical heterogeneity in stiffness. Time per bite is controlled by bite weight. These mechanisms of bite formation and time per bite ex.plain many observed effects, …

Selective Behaviour Of Cattle Grazing Ryegrass Swards With Horizontal Heterogeneity In Patch Height And Bulk Density, Montague W. Demment, R A. Distel, T C. Griggs, E A. Laca, G P. Deo

IGC Proceedings (1977-2023)

Patches of different height and/or bulk density were created in ryegrass pasture to study selective responses of steers to horizontal variability in patch structure. The experiment involved 3 heterogeneity treatments with 2 patch types each. Steers encountered and entered both patch types available in each treatment with the same frequency. In contrast, they grazed for a longer time (T,) at; and removed more bites (B) from the patch type that yielded greater intake rates. While T, and B varied for a patch type depending on the alternative patch, bite rate and likely bite size were constant for a given patch …

Computer Recording Of The Variation In Intake Of Supplements Provided To Grazing Cattler, R M. Tait, L J. Fisher

IGC Proceedings (1977-2023)

A computer system has been developed to record the consumption of' supplements provided free choice to grazing cattle. The system is based on electronic animal identification and one or more weatherproof electronic scales located in simple feed stations connected by telephone cable to a computer at a distance of up to 1 km. The software program identifies and records individual animals, • time and duration of visits, and the quantity of supplement consumed. The system has been tested in the field using 40 kg molasses-based feed blocks with up to 20 steers per feed station in paddocks of approximately 4 …

Diet Selection By Lambs In Ryegrass-White Clover Swards Differing In The Horizontal Distribution Of Clover, R H. Armstrong, E Robertson, C S. Lamb, I J. Gordon, D A. Elston

IGC Proceedings (1977-2023)

Weaned 5-month-old lambs grazed 2 series of perennial ryegrass (Lolium perenne L.) plots containing patches of mixed perennial ryegrass and white clover (Trifolium repens L.) varying in either a) the size of patches or b) the distance between patches. Both series embraced the same range of percentages (1-25) of ryegrass-clover patches in each plot. Diet composition was estimated from the pattern of naturAI alkanes in faeces collected between days 6 to 15 after allocation of the lambs to the treatments. The percentage of clover in the diet declined markedly from days 6 to 11 and thereafter increased slightly. Dietary …