Agricultural Science Commons^™

Better Dairy Farm Management Increases The Economic Return From Phosphorus, J. D. Morton

IGC Proceedings (1977-2023)

Some 60% of New Zealand dairy farms on allophanic and sedimentary soils have soil Olsen phosphorus (P) levels to 75 mm depth above the target range for near-maximum pasture production of 20-30 µg/ml (Roberts & Morton 1999). For an economic response in milksolids (MS) production from high Olsen P, the pasture needs to be capable of high production, and the extra pasture grown be converted to milk. This paper seeks to justify this contention and outline some of the farm management practices required to achieve it.

The Effect Of Two Magnesium Fertilisers, Kieserite And Mgo, On Herbage Mg Content, M. B. O'Connor, A. H. C. Roberts, R. Haerdter

IGC Proceedings (1977-2023)

Supplementing Mg to dairy cows is widely practised in New Zealand. Various methods are used including drenching, pasture dusting, water trough treatment and adding to hay, silage and other feedstuffs (Young et al., 1979). Fertiliser Mg (calcined magnesite, MgO) is widely used to maintain soil Mg status but research has shown that using fertiliser Mg to achieve good soil, pasture and animal Mg status requires large inputs of Mg (120 kg/ha) and maintaining blood serum Mg status in dairy cows tends to be short-lived without further animal supplementation (O’Connor et al., 1987). The objective of these experiments was …

The Effect Of Closing Date And Type Of Utilisation In Autumn On Grass Yield In Spring, E. Mosimann, M. Lobsiger, C. Hofer, B. Jeangros, A. Lüscher

IGC Proceedings (1977-2023)

Due to the low cost of grazed grass, most dairy farmers extend the grazing period in autumn. However, delaying the closing date may reduce the grass yield in the following spring (Roche et al., 1996; O’Donovan et al., 2002). The objective of this experiment, conducted in the Swiss lowlands, was to quantify the effects of closing date and type of utilisation in autumn on grass yield in the following spring.

Field Testing Of A Turnip Growing Protocol On New Zealand Dairy Farms, J. P. J. Eerens, P. M. S. Lane

IGC Proceedings (1977-2023)

Summer droughts are a regular occurrence in central North Island districts of New Zealand, which causes pastures to wilt, lose their nutritive value and stop growing. The resulting summer feed gap depresses farm productivity (Clark et al., 1996). Turnips optimally sown mid-late October (more often sown in November or even December) are grown to fill this feed gap. Recorded average yields of 7.4 t dry matter (DM)/ha are below the economic breakeven point of 8-10 t DM/ha (Clark et al., 1996). A turnip growing protocol was developed from published data (Eerens & Lane 2004) and tested on commercial …

Effect Of Different Phosphorous Sources And Levels On The Productive Behaviour Of A Lotus Pedunculatus Cv. Grasslands Maku Oversown Pasture, R. E. Bermúdez, W. Ayala

IGC Proceedings (1977-2023)

The organic meat production protocol of Uruguay (INAC, 2003) requires that the animals graze pastures that receive no chemical fertilisers. The oversown legume pastures in Uruguay used to be fertilised with soluble phosphorous (P) sources that are not accepted by the protocol. The relative efficiency of different P sources would be useful data for farmers. This information is not available for the acid soils of the eastern region of Uruguay. Lotus pedunculatus cv. Grasslands Maku is one of the most adapted legumes to be included in this type of pasture, as the sown area has increased in the last few …

Labour Input Associated With Grassland Management On Irish Dairy Farms, B. O'Brien, K. O'Donovan, J. Kinsella, D. Ruane, D. Gleeson

IGC Proceedings (1977-2023)

The issues of labour and work organisation (working hours, working conditions) must be seriously addressed on Irish dairy farms if dairy farming is to have a viable future. The objective of this study was to quantify the annual labour input per cow on Irish dairy farms, with a specific focus on the task of grassland management, and to establish monthly patterns of labour utilisation over a two-year period for a range of herd sizes.

Factors Affecting Italian Ryegrass (Lolium Multiflorum L.) Seed Distribution, R. D. Williams, P. W. Bartholomew

IGC Proceedings (1977-2023)

Italian ryegrass (Lolium multiflorum L.) can be a productive and high-quality cool-season forage in the Southern Great Plains of the U.S.A, if it is managed to produce sufficient seed for effective reestablishment without compromising forage yield. Before the re-seeding dynamics of Italian ryegrass can be modeled an understanding of seed production, seed-shed, and seed dispersal is necessary. Here two factors affecting Italian ryegrass seed dispersal and distribution are examined – wind and cultivation practice (mowing and raking).

Practical Application Of A One-Parameter Approach To Assess The Accuracy Of Two Different Estimates Of Diet Composition In Sheep, C. Elwert, M. Rodehutscord

IGC Proceedings (1977-2023)

The composition of ingested herbage mixtures can be estimated using the alkane technique (Dove & Moore, 1995). Until now, the accuracy of the estimates is assessed by linear regression of estimated and actual proportions of the dietary components. The authors presented an approach to compare actual and estimated diet compositions using only one parameter named Distance (D; Elwert & Rodehutscord, 2005), thus enabling a statement regarding the similarity of estimated and known diet composition. In a feeding trial with sheep, diet composition was estimated using two different levels of information. The accuracy of the two estimates was assessed and compared …

Use Of Alkanes To Estimate Dry Matter Intake Of Beef Steers Grazing High Quality Pastures, G. Scaglia, H. T. Boland, I. Lopez-Guerrero, R. K. Shanklin, J. P. Fontenot

IGC Proceedings (1977-2023)

Pastures remain the most important source of nutrients for ruminant livestock and nutrition is critical to optimize animal production. The daily quantity of dry matter that is consumed by an animal is a critical measurement to make nutritional inferences about feed and subsequent animal response. Researchers are facing the dilemma that, while estimates of individual animal performance are readily obtained, it is still difficult to estimate the herbage intake of individual animals. The objectives of this experiment were to estimate forage intake in beef steers grazing tall fescue (Festuca arundinacea Schreb.) and alfalfa (Medicago sativa)/tall fescue pastures …

Effects Of Rumen Fill On Intake And Milk Production In Dairy Cows Fed Perennial Ryegrass, A. V. Chaves, A. Boudon

IGC Proceedings (1977-2023)

Physical limitation often limits dry matter intake (DMI) of high producing cows or cows fed high forage diets. The extent to which DMI is regulated by distention in the rumen depends upon the cow’s energy requirement and filling effects of the diet offered (Allen, 2000). The objective here was to challenge middle lactation dairy cows with rumen fill (rumen inert bulk – RIB) feeding ryegrass fresh cut (indoors) or grazed to determine whether RIB affects intake and milk production.

Detection And Capture Of Nitrogen Fixing Bacteria From Soil And Roots Using Plant Specific Lectins, Alana Horton

Natural Sciences and Mathematics | Biological Sciences Master's Theses

Diazotrophs increase plant productivity by providing ammonia directly to plants in the rhizosphere or through association with the roots (Sun et al., 2021). Leveraging diazotrophs can aid in the reduction or application of harmful synthetic nitrogen fertilizers. This thesis aims to use plant root proteins, or lectins, to more rapidly recover viable diazotrophs that are likely to associate with crops. In this study, lectins, are used to recover bacteria from bulk soil by taking advantage of the binding relationship between lectins and bacterial cell surface polysaccharides. When commercially-available lectins were used with a magnetic pulldown to separate the lectin, bacterial …

Objectives And Benefits Of Molecular Breeding In Forage Species, T. Lübberstedt

IGC Proceedings (1977-2023)

1. The amount of resources and information provided by forage crop genomic programs has dramatically increased during the past few years.
2. Trait-based forward genetic procedures such as mapping and expression profiling have successfully provided new candidate genes or genome regions affecting forage quality. Respective information can easily be transferred across related forage species.
3. Since several genes in major biochemical pathways related to forage traits have been isolated, gene-based reverse genetic approaches (transformation, association studies) are promising.
4. Most genetic experiments are conducted under simplified "artificial" conditions such as on single-spaced plants. Therefore, transferability of respective genetic information to breeding practice needs to …

Both Grass Development Stage And Grazing Management Influence Milk Terpene Content, G. Tornambé, A. Cornu, N. Kondjoyan, P. Pradel, M. Petit, B. Martin

IGC Proceedings (1977-2023)

Terpenes are a wide group of molecules originating from plants’ secondary metabolism. Forage terpenes vary according to the botanical composition and in particular to the proportion of plants such as Apiaceae, Lamiaceae or Asteraceae. These molecules are considered effective milk markers for the presence of diversified forages in dairy cow diets. The variation in terpene content in the milk of grazing cows would depend on the period of development of terpene-rich plants and on the grazing management, whereby cows do or do not have the opportunity to choose and to modify the botanical composition of the ingested grass. The aim …

Supplementation Under Intensive Grazing, Silage- Or Grain-Based Diets For Beef Production On Steer Performance And Meat Fatty Acid Composition, J. Martínez Ferrer, E. Ustarroz, C. G. Ferrayoli, A. R. Castillo, D. Alomar

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) is the main cultivated pasture in Argentina. In beef production enhanced productivity and profit depend on high stocking rates and pasture utilisation, with grain supplementation necessary to maintain high individual live weight gains (LWG) and to increase production per ha (Ustarroz, 1999). Substitution of grazed grass by concentrate can affect meat fatty acid (FA) composition (French et al., 2000). The objective of this study was to evaluate the effects of intensifying an alfalfa-based grazing system and two confinement dietary regimens for beef steer finishing on animal performance and meat FA composition.

Alfalfa In Rotation With Annual Crops Reduced Nitrate Leaching Potential, Arshdeep Singh, Tahseen Afzal, Bryan Woodbury, Charles Wortmann, Javed Iqbal

Department of Agronomy and Horticulture: Faculty Publications

Rotation of perennial alfalfa (Medicago sativa L.) with annual crops has the potential to reduce nitrate-nitrogen (NO₃-N) in the vadose zone and increase soil organic carbon (SOC) sequestration. The objective of this study was to determine the long-term effects on SOC, NO₃-N, ammonium-N (NH₄-N), and soil water in the 7.2 m depth with an alfalfa rotation compared with continuous corn (Zea mays L.). Soils from six pairs of alfalfa rotation versus continuous corn observation points were sampled to 7.2 m depth in 0.3 m increments. The uppermost 0.3 m was divided into …

Soybean Seed Protein Concentration Is Limited By Nitrogen Supply In Tropical And Subtropical Environments In Brazil, E. H. Figueiredo Moura Da Silva, N. Cafaro La Menza, G. G. Munareto, A. J. Zanon, Santos Carvalho, F. R. Marin

Department of Agronomy and Horticulture: Faculty Publications

Soybean production contributes to ca. 60% of global plant-based protein used for food and feed. Brazil is the largest soybean producer and exporter, with 60% from tropical and 40% from subtropical environments. Nitrogen (N) can play an essential role in the storage of proteins in seeds; thus, it could be a key factor in increasing the quantity and quality of seeds in high-yielding soybean crops. Unlike in temperate environments, there is a gap of knowledge on whether soybean grown under tropical and subtropical climates are limited by N-fertilization to sustain the seed yield increase without detriments in seed protein concentration. …

Potential Yield Of Cocksfoot (Dactylis Glomerata) Monocultures In Response To Irrigation And Nitrogen, A. Mills, D. J. Moot, R. L. Lucas, P. D. Jamieson, B. A. Mckenzie

IGC Proceedings (1977-2023)

Cocksfoot is a widely sown grass in temperate pastures. However, while potential yield of cocksfoot can exceed 28 t DM/ha per year, it is often restricted by water, temperature and nitrogen (N). Of these, Peri et al. (2002) showed that N was severely limiting in all seasons. The aim of this study was to confirm the potential yield of cocksfoot and quantify the extent of yield reductions due to environmental constraints.

Diverse Forage Mixtures Effect On Herbage Yield, Sward Composition, And Dairy Cattle Performance, M. A. Sanderson, K. Soder, N. Brzezinski, S. Goslee, H. Skinner, M. Wachendorf, F. Taube, L. Muller

IGC Proceedings (1977-2023)

Managing complex mixtures of plants to take advantage of spatial and temporal variability in land and climate may be one ecological approach to increase productivity of pastures. We tested the hypothesis that complex mixtures of forage species would yield more herbage and reduce weed competition compared with a simple grass-legume mixture in grazed pastures.

Hygienic Value And Mycotoxins Level Of Grass Silage In Bales For Horses, A. Potkański, J. Grajewski, K. Raczkowska-Werwińska, B. Miklaszewska, A. Gubała, M. Selwet, M. Szumacher-Strabel

IGC Proceedings (1977-2023)

Mycotoxins are secondary metabolites of moulds which have adverse effects on humans, animals, and crops and result in illnesses and economic losses. The toxins may occur in storage under conditions favourable for the growth of the toxin-producing fungus or fungi. The highest forage concentration of toxins was found in horizontal storage methods such as bunker silos and feed piles, which were left open to oxygen. In any fermentation storage system, temperature and the presence of moisture is sufficient for toxin production. In a plastic covered storage system, oxygen penetration is slowed but not eliminated. The longer silage is stored, the …

Participatory Approach To Common Use Grazing Management In Dry Area Developing Countries, J. Tiedeman, A. Larbi, F. Ghassali, N. Battikha

IGC Proceedings (1977-2023)

Key points

1. Range restoration technology is available but useless when not followed by management.

2. Institutional mechanisms for grazing management are needed for communal range.

3. Community participatory approaches help pastoralists better manage rangeland grazing.