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Kentucky Traffic Collision Facts Calendar Year 2023 Report, Paul Ross, Eric Green, Chris Blackden, Kenneth R. Agent, Chris Van Dyke Oct 2024

Kentucky Traffic Collision Facts Calendar Year 2023 Report, Paul Ross, Eric Green, Chris Blackden, Kenneth R. Agent, Chris Van Dyke

Kentucky Transportation Center Research Report

No abstract provided.


Impact Of Maternal Moringa Oleifera Leaf Supplementation On Milk And Serum Vitamin A And Carotenoid Concentrations In A Cohort Of Breastfeeding Kenyan Women And Their Infants, Suzanna Labib Attia, Silvia A. Odhiambo, Jerusha N. Mogaka, Raphael Ondondo, Aric Schadler, Kristen Mcquerry, George J. Fuchs, Janet E. Williams, Michelle K. Mcguire, Carrie Waterman, Kerry Schulze, Patrick M. Owuor Oct 2024

Impact Of Maternal Moringa Oleifera Leaf Supplementation On Milk And Serum Vitamin A And Carotenoid Concentrations In A Cohort Of Breastfeeding Kenyan Women And Their Infants, Suzanna Labib Attia, Silvia A. Odhiambo, Jerusha N. Mogaka, Raphael Ondondo, Aric Schadler, Kristen Mcquerry, George J. Fuchs, Janet E. Williams, Michelle K. Mcguire, Carrie Waterman, Kerry Schulze, Patrick M. Owuor

Biostatistics Faculty Publications

Background: Childhood vitamin A deficiency leads to increased morbidity and mortality. Human milk is the only source of vitamin A for exclusively breastfed infants. Dried Moringa oleifera leaf powder (moringa) is a good food source of provitamin A and other carotenoids. Its effect during lactation on human milk vitamin A and carotenoid content is unclear. Objectives: Our objective was to investigate the effect of maternal moringa consumption on human milk retinol and carotenoid concentrations and maternal and infant vitamin A status. Methods: We conducted a 3-month pilot single-blinded cluster-randomized controlled trial in breastfeeding mother–infant pairs (n = 50) in Kenya. …


Bacillus Thuringiensis Cry14a Family Proteins As Novel Anthelmintics Against Gastrointestinal Nematode Parasites, Duy Hoang, Kelly Flanagan, Qian Ding, Nicholas R. Cazeault, Hanchen Li, Stefani Díaz-Valerio, Florentina Rus, Esther A. Darfour, Elizabeth Kass, Katherine H. Petersson, Martin Krarup Nielsen, Heiko Liesegang, Gary R. Ostroff, Raffi V. Aroian Oct 2024

Bacillus Thuringiensis Cry14a Family Proteins As Novel Anthelmintics Against Gastrointestinal Nematode Parasites, Duy Hoang, Kelly Flanagan, Qian Ding, Nicholas R. Cazeault, Hanchen Li, Stefani Díaz-Valerio, Florentina Rus, Esther A. Darfour, Elizabeth Kass, Katherine H. Petersson, Martin Krarup Nielsen, Heiko Liesegang, Gary R. Ostroff, Raffi V. Aroian

Veterinary Science Faculty Publications

Bacillus thuringiensis crystal (Cry) proteins have been expressed in commercial transgenic crops for nearly 30 years, providing safe and effective control of insect pests and significantly reducing the application of hazardous chemical pesticides. B. thuringiensis crystal proteins have also been shown to target parasitic nematodes, including plant parasitic nematodes. Recently, transgenic soybean crops expressing Cry14Ab have been shown to provide control against the soybean cyst nematode Heterodera glycines, marking the first time a crystal protein is being commercialized in transgenic crops for control of a nematode pest. However, apart from H. glycines and the free-living nematode, Caenorhabditis elegans, the breadth …


Arthropod Arbiters: Natural Enemy Communities Mediate The Effects Of Landscape And Local-Scale Complexity On Lygus-Induced Crop Loss In Organic Strawberries, Adrian Lu, David J. Gonthier, Amber Sciligo, Karina Garcia, Taiki Chiba, Gila Juárez, Claire Kremen Oct 2024

Arthropod Arbiters: Natural Enemy Communities Mediate The Effects Of Landscape And Local-Scale Complexity On Lygus-Induced Crop Loss In Organic Strawberries, Adrian Lu, David J. Gonthier, Amber Sciligo, Karina Garcia, Taiki Chiba, Gila Juárez, Claire Kremen

Entomology Faculty Publications

Sustainable pest management requires growers and regional land managers to consider the relationships among pest management practices, pest and natural enemy communities, crop loss, and multi-scalar habitat complexity. However, the causal links among these variables, in particular potential interactions between landscape and local-scale habitat complexity, remain underexplored. In the context of organically managed strawberry crops in California’s Central Coast, we tested the independent effects of landscape and local habitat complexity gradients on arthropod communities and crop loss using a piecewise structural equation model (PSEM). We found that landscape-scale woody habitat proportion indirectly decreased crop loss through its positive effect on …


Upregulation Of Fatty Acid Synthase Increases Activity Of Β-Catenin And Expression Of Notum To Enhance Stem-Like Properties Of Colorectal Cancer Cells, Courtney O. Kelson, Josiane Weber Tessmann, Mariah E. Geisen, Daheng He, Chi Wang, Tianyan Gao, B. Mark Evers, Yekaterina Y. Zaytseva Oct 2024

Upregulation Of Fatty Acid Synthase Increases Activity Of Β-Catenin And Expression Of Notum To Enhance Stem-Like Properties Of Colorectal Cancer Cells, Courtney O. Kelson, Josiane Weber Tessmann, Mariah E. Geisen, Daheng He, Chi Wang, Tianyan Gao, B. Mark Evers, Yekaterina Y. Zaytseva

Markey Cancer Center Faculty Publications

Dysregulated fatty acid metabolism is an attractive therapeutic target for colorectal cancer (CRC). We previously reported that fatty acid synthase (FASN), a key enzyme of de novo synthesis, promotes the initiation and progression of CRC. However, the mechanisms of how upregulation of FASN promotes the initiation and progression of CRC are not completely understood. Here, using Apc/VillinCre and ApcMin mouse models, we show that upregulation of FASN is associated with an increase in activity of β-catenin and expression of multiple stem cell markers, including Notum. Genetic and pharmacological downregulation of FASN in mouse adenoma organoids decreases the activation of β-catenin …


The Absence Of Cxcl10 Activity Does Not Affect The Capability Of Cd8+ T Cells To Migrate And Eliminate The Tissue Cysts Of Toxoplasma Gondii From The Brains Of Chronically Infected Mice, Rajesh Mani, Yasuhiro Suzuki Oct 2024

The Absence Of Cxcl10 Activity Does Not Affect The Capability Of Cd8+ T Cells To Migrate And Eliminate The Tissue Cysts Of Toxoplasma Gondii From The Brains Of Chronically Infected Mice, Rajesh Mani, Yasuhiro Suzuki

Markey Cancer Center Faculty Publications

Toxoplasma gondii forms tissue cysts in neurons and astrocytes in the brain to establish chronic infection, and astrocytes express the CXCL10 chemokine in chronically infected mice. Since chemokines mediate the migration of T cells to attack their targets, and since CXCL10 plays key roles in T cell-mediated control of the proliferation of tachyzoites (the acute stage form) of T. gondii during the acute stage of infection, we examined whether CXCL10 is involved in recruiting anti-cyst CD8+ cytotoxic T cells to eliminate the cysts in their brains. We employed adoptive transfer of CD8+ immune T cells to infected, T cell-deficient SCID …


The Impact Of Pdcd4, A Translation Inhibitor, On Drug Resistance, Qing Wang, Hsin-Sheng Yang Oct 2024

The Impact Of Pdcd4, A Translation Inhibitor, On Drug Resistance, Qing Wang, Hsin-Sheng Yang

Markey Cancer Center Faculty Publications

Programmed cell death 4 (Pdcd4) is a tumor suppressor, which has been demonstrated to efficiently suppress tumorigenesis. Biochemically, Pdcd4 binds with translation initiation factor 4A and represses protein translation. Beyond its role in tumor suppression, growing evidence suggests that Pdcd4 enhances the chemosensitivity of several anticancer drugs. To date, numerous translational targets of Pdcd4 have been identified. These targets govern important signal transduction pathways, and their attenuation may improve chemosensitivity or overcome drug resistance. This review will discuss the signal transduction pathways regulated by Pdcd4 and the potential mechanisms through which Pdcd4 enhances chemosensitivity or counteracts drug resistance.


Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath Sep 2024

Development Of Intensive Grassland Systems: From Science To Practice, D G. Mccall, G W. Sheath

IGC Proceedings (1977-2023)

Level of nnimal production from grassland is determined by the amount of pasture grown, pasture utilisation and animal conversion efficiency. The key components affecting production are pasture growth and animal conversion efficiency. These arc mainly influenced by environment, genetics and through inputs to maintain soil fertility or animal health. Systems development aims to link pasture growth and animal conversion through efficient strategies for pasture utilisation. The means of influencing pasture utilisation is through adjustments to animal feed demand, feed supply or grazing management. Stock policies that adjust the pattern and level of feed demand are of greatest significance in developing …


The Ecology Of Grazing Management, R K. Heitschmidt Sep 2024

The Ecology Of Grazing Management, R K. Heitschmidt

IGC Proceedings (1977-2023)

The broad objective of this paper is to review the fundamental principles of grazing management as a means of assessing the inherent value of intensive and extensive grazing systems. Conceptual analyses of intensive and extensive grazing systems reveal that the fundamental differences between intensive and extensive grazing systems are related to differences in non-grazing rather than grazing tactics. Intensive grazing systems employ a wide array of non-grazing tactics in an attempt to overcome the inherent ecological constraints that limit secondary (i.e., livestock) productivity in extensively grazed systems. Moreover, analyses of the ecological or true efficiency of various agricultural production systems …


Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis Sep 2024

Intensive Grazing Of Alfalfa By Beef Steers, M Rasnake, W R. Burris, G D. Lacefield, J Randolph, N Gay, L Davis

IGC Proceedings (1977-2023)

In the temperate region of North America, high temperature and moisture deficit cause low forage growth during the summer of most years, making it difficult to grow beef (Bos taurus), calves through summer grazing. Alfalfa (Medicago sativa), offers some potential to provide high dry matter production during summer if an effective system of grazing can be developed. The objective of this study was to test a system of intensive grazing of beef steers on alfalfa to maximise live-weight gains/ha and maintain plant population. Alfalfa was no-till seeded into a 6.5 ha field in autumn 1988 after …


Use Of Brassica Forage Crops To Extend The Grazing Season In The North-East Usa, G A. Jung, H W. Harpster, M G. Lambert, K T. Leath, R A. Byers Sep 2024

Use Of Brassica Forage Crops To Extend The Grazing Season In The North-East Usa, G A. Jung, H W. Harpster, M G. Lambert, K T. Leath, R A. Byers

IGC Proceedings (1977-2023)

Forage turnip (Brassica rapa L,) can be made available for animal utilisation in late summer or In late autumn-early winter, when cool­season grass pastures have a low animal carrying capacity. field trials were conducted to identify and quantify factors that influence turnip yield in December or January and to determine whether these factors affect turnip cultivars similarly. Different levels of production in late autumn-winter were attributed to summer drought, foliar diseases, freezing temperatures and rate of leaf senescence. In all instances, the effects of these factors varied with turnip cultivar. However, cultivar ranking generally was the same whether mean …


Interactions Of Rotational And Continuous Grazing With Stocking Rate On Warm And Cool-Season Pastures, David I. Bransby Sep 2024

Interactions Of Rotational And Continuous Grazing With Stocking Rate On Warm And Cool-Season Pastures, David I. Bransby

IGC Proceedings (1977-2023)

With more intense commercialisation of electric fencing many production and economic advantages have been claimed for rotational grazing compared with continuous grazing. However, very little research data are available from the south-eastern USA to verify these claims, Therefore, the objective of this study was to evaluate animal performance under conditions of continuous and IO-paddock rotational grazing on cool- and warm-season pastures commonly used in this region. Three 2-year grazing experiments were conducted, one each on a mixed rye-annual ryegrass (Secale cereale-Lolium multiflorum) pasture, Coastal bermudagrass ( Cynodon hybrid) and Pensacola bahiagrass (Paspalum notatum). In each experiment continuous …


Photosynthesis And Water Relations Of Two Savanna Grasses As Influenced By Shade And Water Stress, M J. Trlica, J I. Kinyamario Sep 2024

Photosynthesis And Water Relations Of Two Savanna Grasses As Influenced By Shade And Water Stress, M J. Trlica, J I. Kinyamario

IGC Proceedings (1977-2023)

Net CO2 assimilation and plant water relations of the African savanna grasses Panicum maximum Jacq. and Tliemeda triandra Porrsk. were measured under controlled conditions. We hypothesised that 1; triandra would be better adapted to higher light and temperature conditions and could withstand greater moisture stress than could P. maximum, as T. tria11dra is commonly found in open areas, whereas P. maximum dominates in the shade of trees. Plants of both species were transplanted into a common soil in large pots and placed under shade (approximately 150 µrnoVm1/s photon flux density (PFD)) or high light (approximately 1200 µmoVm1/s PFD) conditions, with …


Defoliation Of Young Branch And Parent Stolons Of White Clover In Rotationally Grazed Pastures, M.J M. Hay, M Kim, R W. Mclean, A Gonzalez-Rodriguez Sep 2024

Defoliation Of Young Branch And Parent Stolons Of White Clover In Rotationally Grazed Pastures, M.J M. Hay, M Kim, R W. Mclean, A Gonzalez-Rodriguez

IGC Proceedings (1977-2023)

This study was undertaken to examine the relative severity of defoliation of young branches (those comprising <4 nodes) and parent stolons of white clover (Trifolium repens L.) in rotationally grazed pastures stocked al either 2.5, 5.0 or 7.5 bulls/ha. On 7 occasions over a year, the defoliation of expanded leaves of parenl and branch stolons was assessed using tagged stolons. Petiole length of leaves ,vas measured before grazing. Leaves of young branch stolons (43% of the total number of leaves defoliated) were less severely defoliated than leaves of parent stolons (64%). Defoliation of branch stolon leaves was relatively greater at the higher stocking rates which had lower residual …


Improving Germination And Seedling Establishment Of Chicory, S N. Hur, W F. Hunt Sep 2024

Improving Germination And Seedling Establishment Of Chicory, S N. Hur, W F. Hunt

IGC Proceedings (1977-2023)

Chicory (Cichorium intybus L.) seeds were treated before sowing with polyethylene glycol (PEG 6000) under different PEG concentrations, treatment period and temperatures, and tested for uniformity of germination, establishment and drought tolerance. Suitable seed coating materials were found that improved emergence, establishment and seedling growth when surface sown on established swards. The best primed or coated seeds in germination tests were surface sown in growth cabinet and field.Osmotic priming with PEG accelerated germination of chicory and significantly reduced time taken for germination compared with coated seeds in Petri-dishes, but not in the field. In contrast, coated seeds germinated more slowly …


Growth Of Temperate Perennial Legumes Over Three Cycles Of Defoliation At Different Temperatures, M A.P Duarsa, M J. Hill, J V. Lovett Sep 2024

Growth Of Temperate Perennial Legumes Over Three Cycles Of Defoliation At Different Temperatures, M A.P Duarsa, M J. Hill, J V. Lovett

IGC Proceedings (1977-2023)

Summer-active legumes such as big trefoil (Lollis ped11nc11lat11s), birdsfool trefoil (Lot11s comic11la111s), crownvelch (Coronilla varia) and cicer milkvetch (Astraga/11s cicer) are needed for summer rainfall areas of the perennial pasture zone in eastern Australia where soil conditions and grazing management do not suit lucerne (Medicago sativa). The growth of these species was compared at 4 temperatures regimens (14/10, 18/14, 22/18, 26/22°C, 12:12 h) for 3 cycles of regrowth where soil moisture was serially changed from field capacity (FC) to 50% PC and back to PC in a growth cabinet pot experiment. Growth rates in lucerne always exceeded those of the …


Nutrient Cycling In Semi-Arid Grasslands And Savannas: Its Influence On Pattern, Productivity And Stability, Robert J. Scholes Sep 2024

Nutrient Cycling In Semi-Arid Grasslands And Savannas: Its Influence On Pattern, Productivity And Stability, Robert J. Scholes

IGC Proceedings (1977-2023)

The grazing animal carrying capacity of tropical semi-arid rangelands is largely controlled by rainfall, but above about 500 mm per annum, soil nutrient status has an overriding role. On low-nutrient soils, which cover vast areas of the ancient land surfaces of Africa, South America and Australia, it is the amount of grass eaten and digested that controls animal production, not the amount produced. On nutrient­poor soils (particularly those deficient in nitrogen and phosphorus) the primary production continues to increase with increasing rainfall, but the acceptability of the forage to ruminants declines, On the nutrient-rich soils of younger land surfaces, both …


Soil Characteristics And Processes Critical To The Sustainable Use Of Grasslands In Arid, Semi-Arid, And Seasonally Dry Environments, John Williams, Keith R. Helyar, Richard S.B Greene, Rosemary A. Hook Sep 2024

Soil Characteristics And Processes Critical To The Sustainable Use Of Grasslands In Arid, Semi-Arid, And Seasonally Dry Environments, John Williams, Keith R. Helyar, Richard S.B Greene, Rosemary A. Hook

IGC Proceedings (1977-2023)

The focus of this paper is a framework for determining the soil and land properties and processes which are critical to managing grasslands in an ecologically sustainable manner. Essential to the discussion is the development of concepts which allow description of the stability, resilience and sustainability of the agroecosystem as a whole as well as the land resource base. The regions of Australia with arid, semi-arid and seasonally dry environments are defined and related to the dry environments of the world. This provides a background for a brief consideration of major vegetation types and soils within the dry environments of …


Soil Animal Composition And Distribution In The Leymus Chinensis Grassland Region In Central Part Of North-East Of China, Yin Xiuqin, Li Jiandong, Zhu Tingcheng Sep 2024

Soil Animal Composition And Distribution In The Leymus Chinensis Grassland Region In Central Part Of North-East Of China, Yin Xiuqin, Li Jiandong, Zhu Tingcheng

IGC Proceedings (1977-2023)

Since 1990, we have investigated the soil animal composition and distribution in the Leymus chinensis (Aneuro chinensis) grassland region in central part of north-east of Chinn. Soil animals were studied in 20 plant communities in 4 habitats. A total of 15 797 soil animals belonging to 4 phyla, 6 classes, 28 orders and 86 families were obtained. Among them, 26 families and 22 species were new records in norlh-easl of China. The dominant groups were Formicidne, Actinedida, Oribatidn, lsotomidne, Rhnbditidae, Dorylainidae. Sparse woods of Ulmus, and the most animal groups (40) and Puccinellia chinapoesis and Heleochalis intersiIa …


Intensive Grazing Systems And Methods For Beef Cattle, V G. Allen, J P. Fontenot, M A. Cochran, A Brock, W Mcclure, J Wilkins Sep 2024

Intensive Grazing Systems And Methods For Beef Cattle, V G. Allen, J P. Fontenot, M A. Cochran, A Brock, W Mcclure, J Wilkins

IGC Proceedings (1977-2023)

Three experiments were conducted to determine effects of grazing systems and methods on beef production. In experiment 1, cows, calves and stockers grazed tall fescue-clover (Festuca arundinacea-Trifolium repens) in a l 6-paddock system using rotational stocking or a 3-paddock system using continuous stocking as grazing methods. In experiment 2, stocker steers grazed orchardgrass-clover (Dactylis glomerata-Trifolium pratense) using buffer grazing with continuous stocking or a 14-paddock rotational stocking method. In experiment 3, 4 grazing systems were compared using sequence grazing combinations of cool-and warm­seasoo perennial and annual forages. In experiments l and 2, there were no differences in …


Selection Pattern Of Holstein-Zebu Cows Grazing Stoloniferous And Tufted Type Tropical Grasses In A Cafeteria Type Trial, Francise E. Davis Sep 2024

Selection Pattern Of Holstein-Zebu Cows Grazing Stoloniferous And Tufted Type Tropical Grasses In A Cafeteria Type Trial, Francise E. Davis

IGC Proceedings (1977-2023)

Seven stoloniferous and 7 tufted grasses are being evaluated in a long­term trial on an acid ultisol in Trinidad in duplicate 3x3 m plots. The grasses were cut at five weekly intervals and nitrogen at 40 kg/ha applied after every harvest. A basal dressing of 125 kg P20��, and 100 kg '½O and a trace element mix was applied twice annually. After culling in May 4 milking cows were allowed to graze the area. There was no significant difference in dry matter yield between the stoloniferous and tufted grasses, but there were significant differences within each type of grass in …


Effect Of Percentages Calluna Vulgaris Cover And Cow And Ewe Physiological Status On Animal Production On Mountain Pastures, K Osoro, R Celaya, Mamen Olivan Sep 2024

Effect Of Percentages Calluna Vulgaris Cover And Cow And Ewe Physiological Status On Animal Production On Mountain Pastures, K Osoro, R Celaya, Mamen Olivan

IGC Proceedings (1977-2023)

The effect percentage cover of Calluna vulgaris (30 or 70%) on performance of dry and lactating ewes and cows with their lambs and calves was studied during 1990 and 1991. Lactating cows had greater body weight losses than dry ones, the difference being 0.3 and 0.S kg/day for 1990 and 1991 respectively. Percentage C.vulgaris cover (30 or 70%) caused differences in body-weight losses· similar to those caused by physiological status. Milk production from the cows, and therefore calf live-weight gain, were significantly higher in the group grazing on the plot with 30% Calluna (0.62 and 0.71 kg/day for 1990 …


Adaptation Of Some Grass Species To Grazing, Marc Ghesquiere, J C. Emile, X Charrier, R Traineau Sep 2024

Adaptation Of Some Grass Species To Grazing, Marc Ghesquiere, J C. Emile, X Charrier, R Traineau

IGC Proceedings (1977-2023)

To examine the grazing behaviour of some grass species, 2 linked trials were set up in Lusignan (France), Dry matter yields of 10 species were recorded by frequent mechanical cuts (every 15 days) and compared with the ability to feed sheep under continuous grazing management. The dry matter yield of the genotypes ranged from 5600 to 8600 kg DM/ha and the grazing yield from 86 to 183 days x animal. The well-known species, such as Bromus siIchensis L., 8. caIhar1ic11s L. and Dactylis glomerata L. usually used in farms allowed high dry matter and grazing yields, but some secondary species …


Crop Processing And Fractionation As A Commercial Proposition To Forage-Based Animal Systems, H T. Ostrowski-Meissner Sep 2024

Crop Processing And Fractionation As A Commercial Proposition To Forage-Based Animal Systems, H T. Ostrowski-Meissner

IGC Proceedings (1977-2023)

The paper outlines crop processing and fractionation technology as it applies to an intensive forage-based operation with beef cattle, The benefits of forage processing prior to its feeding to cattle are described with an emphasis not only on the uniformity of the nutritive quality of the processed product but also on the extra financial benefits resulting from the wet fractionation process. The value-added primary products from the fractionation process ensure extra return to the. forage producers, crop processing installation and the feedlot operation. The characteristics of the fractionation products derived from lucerne and other crops are described.


Integrated Grazing Of Goats With Sheep Or Cattle On Continuously Grazed Pasture, A M. Nicol, A.J F. Russel, I A. Wright Sep 2024

Integrated Grazing Of Goats With Sheep Or Cattle On Continuously Grazed Pasture, A M. Nicol, A.J F. Russel, I A. Wright

IGC Proceedings (1977-2023)

Oroups of ewes (10) and their twin lambs were grazed on sown ryegrass• white clover (Lolium perenne L.-Trifollum repens L.) pastures maintained at a sward surface height of 4 or 8 cm and a further group grazed with yearling goats (in a proportion of 1/3 ewe plus lamb live weight) also at fi cm. A second concurrent experiment consisted of 3 similar treatments using young cattle with sward surface heights of 8 and 12 cm. Results over the 140-day grazing period showed that allhough the diet selected by sheep and cattle grazed with goats contained more green grass …


Herbage And Animal Production From Tall Fescue- And Ryegrass-Based Pastures In A Summer-Dry Environment, D E. Hume, R.J M. Hay, T B. Lyons Sep 2024

Herbage And Animal Production From Tall Fescue- And Ryegrass-Based Pastures In A Summer-Dry Environment, D E. Hume, R.J M. Hay, T B. Lyons

IGC Proceedings (1977-2023)

Herbage production and animal performance were measured over 3 years In Hawkes Bay, a summer-dry region of New Z'.ealand. Tall rescue (Festuca arundinacea) (3 cultivars, all endophyte free) was compared with high endophyte perennial ryegrass (Lolium perenne). All pastures were sown with white clover (Trifolium repens). Herbage production and composition were determined for all seasons while cattle were monitored for live-weight gains from spring through to autumn. Tall fescue pastures produced 27% more total dry matter/ year than the ryegrass pasture, primarily in autumn. In summer­autumn, ryegrass pastures had up to 76% dead matter …


Climate Change: Adapting Tropical And Subtropical Grasslands, G M. Mckeon, S M. Howden, N.O J. Abel, J M. King Sep 2024

Climate Change: Adapting Tropical And Subtropical Grasslands, G M. Mckeon, S M. Howden, N.O J. Abel, J M. King

IGC Proceedings (1977-2023)

Climate change as a result of increasing greenhouse gas concentrations or lhe repetition of historical climale variability will affect the management and production of tropical and subtropical grasslands that support about half the world's domestic herbivores. Previous studies of the regional impact of climate change and climate variability on intensive agriculture have shown lhat such evaluation should include the known and expected abilities of managers and governments to respond by reducing the negative impacts and taking advantage of positive opportunities, A high priority for grassland scientists is the development of similar evaluation capabilities for grassland systems, which are more complex …


Methane Production By New Zealand Ruminants, K Betteridge, M J. Ulyatt, J Knapp, R L. Baldwin Sep 2024

Methane Production By New Zealand Ruminants, K Betteridge, M J. Ulyatt, J Knapp, R L. Baldwin

IGC Proceedings (1977-2023)

Methane production by ruminants in New Zealand was estimated using a ma1hema1ical model of rumen digestion interfaced with census livestock numbers. New Zealand was divided into 4 climatic regions with each classified into improved, unimproved and tussock grasslands, and livestock were allocated to each class at appropriate stocking rates. Models of changing livestock numbers within n year were developed for each animal and land class. Food dry matter intake for each class of livestock was calculated from estimates of feed requirements and diet quality. Total methane production was estimated to be 1.50 Tg per year: 58.4% sheep, 20.7%, beef cattle, …


Nitrous Oxide Emissions From Grassland In Manawatu, New Zealand, R A. Carran, J P. Evans Sep 2024

Nitrous Oxide Emissions From Grassland In Manawatu, New Zealand, R A. Carran, J P. Evans

IGC Proceedings (1977-2023)

Nitrous oxide (Np) is a minor component of the atmosphere which acts as a potent greenhouse gas and also causes ozone depletion. Soil bacteria are the most important agents of N2O production, but both the New Zealand and the international data on N2O emission rates from soils are very poor at present. In order to help define the possible range of emission ranges from pasture soils· we selected sites with characteristics that would make then "high" or "low" emitters of N2O. The "high" emission site was a fine-textured, fertile but poorly drained flood plain soil. The "low" emission site was …


Development Of Plants Resistant To Insect Pests Using Gene Manipulation, D.W R. White, D R. Biggs, M T. Mcmanus, C R. Voisey, J T. Christeller, A H. Broadwell, E.P J. Burgess, C N. Chilcott, P J. Wigley, P G. Mcgregor Sep 2024

Development Of Plants Resistant To Insect Pests Using Gene Manipulation, D.W R. White, D R. Biggs, M T. Mcmanus, C R. Voisey, J T. Christeller, A H. Broadwell, E.P J. Burgess, C N. Chilcott, P J. Wigley, P G. Mcgregor

IGC Proceedings (1977-2023)

Damage to pasture plants caused by insect pests reduces the supply of feed for grassland animal production. In addition, the use of chemical insecticides for the control of pasture pests is undesirable for reasons of high cost and possible damage to the environment. One way to overcome these limitations is 10 utilize a recent development. in plant molecular biology which has seen the incorporation of cloned genes that confer insect _pest resistance into crop plants. To date, the most widely used genes for this purpose are those coding for insecticidal proteins from the bacterium Bacillus thuringiensis, and for inhibitors …