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The Effect Of Stocking Rate And Lamb Grazing System On Sward Performance Of Trifolium Repens And Lotus Corniculatus In Uruguay, F. Montossi, R. San Julián, M. Nolla, M. Camesasca, F. Preve

IGC Proceedings (1977-2023)

Lambs have a great potential to diversify and stimulate meat and wool production and economical returns within the industry. The main objective of this study was to evaluate different feeding and management alternatives for the production of high quality wool and meat as well as their effects on sward characteristics in the Basaltic region of Uruguay.

Pasture Intake And Milksolids Production Of Different Strains Of Holstein-Friesian Dairy Cows, J. L. Rossi, K. A. Macdonald, B. S. Thorrold, C. Holmes

IGC Proceedings (1977-2023)

Cows of high yield potential require high daily dry matter intakes (DMI) to meet their increased energy demand. For this reason, DMI may be constrained in a pasture-based system. Daily milksolids yield and DMI of three strains of Holstein-Friesian dairy cows farmed at low and high feeding level during season 2002- 2003 are reported.

Does The Feeding Behaviour Of Dairy Cows Differ When Fed Ryegrass Indoors Vs. Grazing?, A. V. Chaves, A. Boudon, J. L. Peyraud, R. Delagarde

IGC Proceedings (1977-2023)

Dairy cows eating ryegrass ingest smaller boli when grazing than when fed indoors (93 vs. 142 g; Boudon et al., 2004). To investigate whether this difference in bolus affects feeding behaviour of the cows, an automated system (chewing halters) was used to monitor feeding behaviour of cows given ad libitum access to perennial ryegrass in individual feed troughs (indoor feeding, IF) or at pasture (grazing, GR).

Modelling The Effect Of Breakeven Date In Spring Rotation Planner On Production And Profit Of A Pasture-Based Dairy System, P. C. Beukes, B. S. Thorrold, M. E. Wastney, C. C. Palliser, G. Levy, X. Chardon

IGC Proceedings (1977-2023)

The breakeven date is the expected date when pasture supply exceeds cow demand. This date is used to plan the rotation rates, slow during the winter, when pasture growth is low and cows are dry, to a fast rotation in spring, when growth is accelerating and most cows lactating. This date is influenced by regional climate, mainly rainfall and soil temperature, which affects timing and rate of growth acceleration. The objective of this modeling exercise was to explore the effect of the breakeven date on milksolids (MS), grass silage, farm cover and economic farm surplus (EFS) over different climate years …

Development Of A Model Simulating The Impact Of Management Strategies On Production From Beef Cattle Farming Systems Based On Permanent Pasture, M. Jouven, R. Baumont

IGC Proceedings (1977-2023)

Grazing systems in Europe increasingly have to meet environmental objectives, which influence management strategies. A deterministic model describing farming system dynamics is being developed in order to elucidate interactions between nature-friendly management practices, as for example late (after flowering) hay harvest or moderate stocking rate, and agricultural output.

Intake By Lactating Goats Browsing On Mediterranean Shrubland, M. Decandia, G. Pinna, A. Cabiddu, G. Molle

IGC Proceedings (1977-2023)

In Mediterranean regions goat feeding systems are mainly based on shrubland that contain a wide variety of species. There are only a few equations for predicting feed intake of stall-fed goats (Luo et al., 2004). The objective of this study was to develop a model for predicting the intake of lactating goats browsing on Mediterranean shrubland.

The Impact Of Concentrate Price On The Utilization Of Grazed And Conserved Grass, P. Crosson, P. O'Kiely, F. P. O'Mara, M. J. Drennan, M. Wallace

IGC Proceedings (1977-2023)

A linear programming model was designed and constructed to facilitate the identification of optimal beef production systems under varying technical and policy scenarios. The model operates at a systems level and most activities that could occur in Irish spring-calving, suckler beef production systems are included. In this paper, the components of the model are described together with a simple application of the model involving changing concentrate prices.

Modelling Urine Nitrogen Production And Leaching Losses For Pasture-Based Dairying Systems, I. M. Brookes, D. J. Horne

IGC Proceedings (1977-2023)

Urine from dairy cattle grazing pastures with high crude protein (CP) concentrations is a major source of N lost in drainage water from New Zealand farms. This paper provides predictions of urinary N leaching losses for a range of stocking rates and levels of supplementation.

Effect Of Nitrogen On The Radiation Use Efficiency For Modelling Grass Growth, R. Lambert, A. Peeters

IGC Proceedings (1977-2023)

When nitrogen (N) is not at a sufficient level to permit maximum growth rate, dry matter production is reduced. Models of plant growth in relation to solar radiation intercepted by the crop have been largely used. According to these models, N deficiency can act on the leaf extension and thus on the quantity of radiation intercepted by the crop, but also by reducing the radiation use efficiency of the crop (RUE) (Bélanger, 1990). The effect of N on the RUE of ryegrass swards is determined and discussed.

The Meal Criterion Estimated In Grazing Dairy Cattle: Evaluation Of Different Methods, P. A. Abrahamse, D. Reynaud, J. Dijkstra, S. Tamminga

IGC Proceedings (1977-2023)

The meal criterion (MC) has been found a useful tool to pre-treat intake behaviour data in dairy cows. It was defined as the longest interval between bouts that belong to the same meal (Tolkamp & Kyriazakis, 1999), necessary to cluster bouts to meals. The method of Yeates et al. (2001) calculating the log_e-transformed intervals between bouts and using the Gaussian-Gaussian-Weibull (GGW) model to calculate the MC was found to provide the best estimation of the MC in biological as well as statistical terms. However, in grazing dairy cattle the MC-estimation has only been carried out by Rook …

Radiation Use Efficiency Of Ryegrass: Determination With Non Cumulative Data, R. Lambert, A. Peeters

IGC Proceedings (1977-2023)

The growth of a crop is generally described as biomass accumulation per unit time. Monteith (1977) developed a model of growth where biomass accumulation is related to solar radiation intercepted by the crop. This model has been largely used for different crops. The conversion factor between radiation absorbed or intercepted by the crop and the biomass production is called “radiation use efficiency” or “dry matter radiation quotient”. Radiation use efficiency (RUE) is usually calculated as the regression coefficient of the linear relationship between crop biomass measured repeatedly during growth and cumulated intercepted or absorbed solar radiation. Demetriades-Shah et al. …

Modelling The Digestibility Decrease Of Three Grass Species During Spring Growth According To The Age Of The Grass, The Thermal Age And The Yield, M. E. Salamanca, R. Lambert, M. Gomez, A. Peeters

IGC Proceedings (1977-2023)

The nutritive value of forage changes during growth. For the protein content, a general evolution curve was found with the yield increase (Salette & Lemaire, 1984). The digestibility of the organic matter decreases during growth as cellulose and lignin content increase. Regrowth age is the main factor, which explains the digestibility decrease (Demarquilly & Jarrige, 1981). The crop age can be expressed in number of growth days but also in thermal age (cumulated temperature). We compared the digestibility change of three grass species during spring growth for two years as a function of yield increase, thermal age or number of …

Pâtur’In: A User-Friendly Software Tool To Assist Dairy Cow Grazing Management, L. Delaby, J. L. Peyraud, P. Faverdin

IGC Proceedings (1977-2023)

The feeding of dairy cows at pasture presents many technical, economic and environmental advantages, while benefiting from a very favourable image. However, the management of grazed land is a complex game of strategy in which the farmer applies decisions in order to manage two unstable and uncertain fluxes of change: growth of grass and intake of the herd. Many tools (platemeter, etc.) and overall methods (local stocking rate references, farm cover, etc.) have been developed as aids to grazing management. Nevertheless, few decision-support systems are currently available that make it possible to anticipate and assess the consequences of a given …

Enhancing Grasslands Education With Decision Support Tools, H. G. Daily, J. M. Scott, J. M. Reid

IGC Proceedings (1977-2023)

We have successfully used Decision Support Tools (DST) relevant to the management of grazing enterprises to enhance problem solving skills of undergraduates in Australia. Tools such as GrassGro™ (Moore et al., 1997) and GrazFeed™ (Freer et al., 1997) are accessed from a central server by authorised users at many widely dispersed Universities across Australia using remote access to thin-client technology via an Internet portal. This has been supplemented with training for lecturers. Experience in developing appropriate teaching and learning materials and the reliable delivery of simulation software to many clients has enhanced learning outcomes at tertiary level. We …

Using The Grassgro Decision Support Tool To Evaluate The Response In Grazing Systems To Pasture Legume Or A Grass Cultivar With Improved Nutritive Value, H. Dove, J. R. Donnelly

IGC Proceedings (1977-2023)

Decision support tools (DST) based on models of grazing systems allow the evaluation of changes in enterprise management on productivity and profitability. The Grassgro DST (Moore et al., 1997) uses historical weather data on a daily time step to simulate pasture growth and the resultant productivity of either grazing sheep or cattle. Different pasture species are represented within a parameter set that describes the response of pasture species to their environment. Manipulation of these parameters provides a means of evaluating, a priori, the likely responses of livestock production to ‘improved cultivars’. We report the results of simulations conducted …

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 …

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 …

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 …

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 …

Aerobic Stability And Nutritive Value Of Low Dry Matter Maize Silage Treated With A Formic Acid-Based Preservative, I. Filya, E. Sucu, A. Karabulut

IGC Proceedings (1977-2023)

Aerobic stability is one of the major problems of the ensiling process, especially in warm climates. Ashbell et al. (2002) have shown that at 30°C, the development of aerobic yeast and moulds in silages is most intensive. In Turkey all silages are susceptible to air penetration during storage and unloading with a large proportion of the silage spoiled and in extreme cases all the silage is spoiled. The purpose of the present work was to study the effects of formic acid-based preservative (FAB; Kemisile® 2000, Kemira Oyj-Industrial Chemicals, Finland) on the aerobic stability and nutritive value of maize silage.

The Effects Of The Growth Stage And Inoculant On Fermentation And Aerobic Stability Of Whole-Plant Grain Sorghum Silage, E. Tabacco, G. Borreani

IGC Proceedings (1977-2023)

Grain sorghum (Sorghum bicolor) is well adapted to environments with limited rainfall and low soil fertility. Today, on dry land, improved grain sorghum hybrids may be a valid alternative to maize silage and they may give DM yields and digestible energy that are comparable to maize, but at lower production costs (Legarto, 2000). Harvesting crops for silage at an early stage of maturity (low DM content) may result in silage with a higher acid content and low nutritional quality, while harvesting crops at a later stage of maturity may make the forage more difficult to chop and pack. …

Perennial Ryegrasses Bred For Contrasting Sugar Contents: Manipulating Fermentation And Aerobic Stability Using Wilting And Additives (1) (Eu Fp V -Project ‘Sweetgrass’), P. O'Kiely, H. Howard, G. Pahlow, R. J. Merry, F. P. O'Mara

IGC Proceedings (1977-2023)

Higher concentrations of water-soluble carbohydrate (WSC) in silage offer ruminant nutrition and environmental attractions. Both successful field wilting and alternative silage additives provide the opportunity to manipulate silage WSC by modifying fermentation and/or improving aerobic stability. This experiment evaluated the fermentation and aerobic stability of silages made from perennial ryegrass cultivars of high or normal WSC genotype that differed in field wilting or additive use.

Perennial Ryegrasses Bred For Contrasting Sugar Contents: Manipulating Fermentation And Aerobic Stability Of Unwilted Silage Using Additives (2) (Eu-Project ‘Sweetgrass’), H. Howard, P. O'Kiely, G. Pahlow, F. P. O'Mara

IGC Proceedings (1977-2023)

Grass cultivars bred for elevated concentrations of water-soluble carbohydrate (WSC) could have improved silage preservation but possibly disimproved aerobic stability. Additives can be used to manipulate fermentation and thereby increase silage WSC. They can also influence aerobic stability. This experiment evaluated the fermentation and aerobic stability of unwilted silages made from perennial ryegrass cultivars of high or normal WSC genotype that differed in additive use.

Perennial Ryegrasses Bred For Contrasting Sugar Contents: Manipulating Fermentation And Aerobic Stability Of Wilted Silage Using Additives (3) (Eu-Project ‘Sweetgrass’), H. Howard, P. O'Kiely, G. Pahlow, F. P. O'Mara

IGC Proceedings (1977-2023)

Rapid field-drying of grass prior to successful ensilage restricts fermentation and can assist preservation, but can consequently result in silages that are prone to aerobic deterioration at feedout. Additives that directly (e.g. potassium sorbate or sodium benzoate) or indirectly (e.g. formic acid or Lactobacillus plantarum, via manipulation of fermentation) alter yeast activity at feedout could modify silage aerobic stability. This experiment evaluated the fermentation and aerobic stability of wilted silages made from perennial ryegrass cultivars of high or normal water soluble carbohydrate (WSC) genotype that differed in additive use.

The Effect Of Additive Containing Formic Acid On Quality And Aerobic Stability Of Silages Made Of Endophyte-Infected Green Forage, L. Podkówka, J. Mikołajczak, E. Staszak, P. Dorszewski

IGC Proceedings (1977-2023)

Festuca species grasses are very often infected with endophytic fungi Neothypodium, that produce ergotic alkaloids, peramins etc. (Podkówka et al., 2003). Produced green forage can be dangerous to animals. The basic preservation method of such green forages is ensiling, especially with organic acids addition. Organic acids demonstrate destructive action on fungal organisms, as well as influence the quality and aerobic stability of forage. The objective of this study was to determine if the preservation of endophyte-infected green forage by ensiling with formic acid affects quality and aerobic stability of produced fodder.

Recent Developments In Methods To Characterise The Chemical And Biological Parameters Of Grass Silage, R. S. Park, R. E. Agnew, M. G. Porter

IGC Proceedings (1977-2023)

Key points

1. Chemical analysis of forages is expensive, time consuming, environmentally unfriendly and relates poorly to the feed value for production purposes.
2. In vivo characterisation of animal feed is not a feasible option in terms of cost and analysis time.
3. NIRS is a rapid, non destructive, environmentally friendly, multi-analytical technique which can estimate the nutritive value of the feed.
4. NIRS predictive equations developed on a master instrument can be transferred to local and international sites.
5. Future assessment of forages necessitates rapid, stable, instrumentation for ‘in field’ studies.

The Effect Of Chop Length And Additive On Silage Intake And Milk Production In Cows, V. Toivonen, T. Heikkilä

IGC Proceedings (1977-2023)

Effects of reduced silage chop length on silage intake and milk production by dairy cows have been variable. Chopping of grass at harvest generally improves silage fermentation quality and consequently intake. The objective of this study was to assess the effect of chopping flail harvested silage ensiled with acid or biological additive prior to feeding on intake, milk yield and milk composition in dairy cows.

Effect Of Additives At Harvest On The Digestibility In Lambs Of Whole Crop Barley Or Wheat Silage, S. Muhonen, I. Olsson, P. Lingvall

IGC Proceedings (1977-2023)

There are very few published articles about how silage additives affect digestibility of whole crop silage. In this experiment, male lambs were given whole crop barley or wheat silage harvested at dough stage with a number of different acid-based and bacterial additives.

Use Of Silage Additives In Ensiling Of Whole-Crop Barley And Wheat - A Comparison Of Round Big Bales And Precision Chopped Silages, M. Knický, P. Lingvall

IGC Proceedings (1977-2023)

An increasing use of whole-crop cereals, as supplementary feed, has increased interest in development of efficient ways of preserving these forages to achieve a high hygienic quality. It is known that ensiling of whole-cereals often results in silages with high concentrations of butyric acid (Weissbach & Haacker, 1988). Furthermore, problems with poor aerobic stability still persist despite the use of lactic acid bacteria (Filya et al., 2000). Therefore, the objective of this study was to examine the effect of different types of additive mixtures on the fermentation process and aerobic stability of precision chopped and baled silages.

Effects Of Varying Dietary Ratios Of Lucerne To Maize Silage On Production And Microbial Protein Synthesis In Lactating Dairy Cows, G. A. Broderick, A. F. Brito

IGC Proceedings (1977-2023)

Lucerne silage (LS) is high in total CP and rumen degraded protein (RDP) but low in fermentable energy, while maize silage (MS) is a good source of fermentable energy but low in RDP. Thus, these silages are complementary and feeding them at optimum ratio should increase nutrient efficiency in lactating cows. Dhiman & Satter (1997) observed greater milk yield when the dietary forage was 2/3 LS and 1/3 MS. The objective of this experiment was to optimise the dietary LS:MS ratio for production, microbial protein and N utilisation.