Grass MCQ 2 Flashcards
- What % of seed sale in Ireland are PRG?
o 95%
- Nodules on white clover roots containing Rhizobia bacteria capable of supplying how many units N/acre in the soil each year?
o 120 units N/acre (150kg/ha)
- What form of N does rhizobia bacteria provide the legume plant?
o Ammonium
- White Clover vs Red Clover identification?
o White clover - Leaf margin toothed, No hairs
o Red clover - Leaf margin not toothed, Usually has hairs
- Fixation rate of N in red clover?
o 200-300 kg N/ha/year
- Lifespan of red clover?
o 3-4 years
- PRG/RC pastures can yield how many t/DM/year?
o 11-16 t/DM/year
- Seeding rate of grass seed and red clover?
o 20-22 kg/ha of grass seed and 7-10kg/ha red clover
- PPO meaning and function?
o Polyphenol oxidase
o Protects plant proteins and reduces their solubility, and reduces rumen ammonia-N release and increase the partitioning of N to faeces
- An average annual sward white clover content of approx. what % is desirable for animal and sward production benefits?
o 20-25%
- Most common legume in Ireland?
o White clover
- Permanent pasture in Ireland rarely contains > what % WC on a DM basis?
o >5%
- White clover can fix how much N?
o 100-150kg N/ha/year
- Reseed what % of white clover per year?
o 10%
- Over sow what % of white clover per year?
o 15%
- Max. productivity on what type of soils?
o Medium to free-draining loam soils
- What % reduction in GHG emissions by 2030?
o 25%
- Festulolium are what species combined?
o Fescue x PRG
- Milk production effects from MSS?
o +1.2kg per day
- +1t grass utilised can increase profitability by how much €/ha in drystock and dairy farms respectively?
o €105/ha drystock and €181/ha dairy farms
- A 10% increase in grazed grass in the diet, reduces the cost of production by…
o 2.5c/L
- Profit per cow can be increased by how much per cow per day when the herd has access to grass earlier in the spring?
o €2.70
- Dairy cow spends approx. how long grazing everyday?
o 9-10 hours
- Demand of DM for dairy cows post calving, peak intake, mid-late lactation, and dry cow period?
o Post calving – 10-14kg DM
o Peak intake – 16-20kg DM
o Mid-late lactation – 17kg DM
o Dry cow – 11kg DM
- Demand of DM for dry ewe/hogget and a weaned lamb?
o Dry ewe/hogget – 1.2 to 1.6kg DM/day
o Weaned lamb – 1.2 kg DM/day
- Yield (kg DM/ha) calculation
o Yield (kg DM/ha) = Fresh wgt (g) x DM % x 0.4
- Target pre-grazing cover?
o 1,400kg DM/ha
- Total cover calculation
o Total cover = Paddock DM yield (kg DM/ha) X Paddock area (ha)
- Farm cover calculation
o Farm cover = sum total cover* (kg DM)/ Area available for grazing (ha)
- Target pre-grazing yield kg DM calculation
o Target pre-grazing yield kg DM = stocking rate (cows/ha) * allowance (kg DM/cow/day) * rotation length (days) + residual
- Nutritive value of grazed grass – energy (UFL/kg DM), Protein % and NDF %
o Energy – 0.85-1.05 UFL/kg DM
o Protein – 16-28%
o NDF – 35-50%
- DM% of grass
o 17%
- Chemical composition of grazed grass (g/kg DM) for Crude protein, NDF, ADF and WSC?
o CP – 180-250 g/kg DM
o NDF – 350-400g/kg DM
o ADF – 180-250g/kg DM
o WSC – 150-200g/kg DM
- Crude protein content of autumn grass?
o 21-23%
- Components in a grazing sward:
o Pseudostem, Leaf, Dead material, True stem
- PRG true stem length?
o 3cm
- Rotation length should be increased from how many days mid/late August to how many days in late Sept?
o 21 days in mid/late August to 30-35 days in late September
- The final grazing rotation of the year should be how many days in length?
o 40-45 days
- The closing farm grass cover in late November should be how many kg DM/ha @ how many LU/ha?
o 550-600kg DM/ha @ 2.5 LU/ha
- Aim for a max residual grass yield of how many kg DM/ha in paddocks as they are closed?
o 100kg DM/ha (4.5cm)
- Aim to have what % farm closed by the end of the first week of November?
o 60% (1-2 weeks earlier in wet areas)
- When should paddocks start to be closed for winter?
o From 10th October onwards (1-2 weeks earlier in wet areas)
- How many kg DM/ha on first grazed paddocks in early April?
o 12-1400kg DM/ha
- Spring rotation planner for dry farms:
o Turnout early to mid February
o 30% of farm grazed by 1st March
o 60% of farm grazed by 17th March
o 100% grazed by end of first week of April
o Heavy farms approx. 7-14 days behind the targets for dry farms
- Stocking rate per ha from mid-April to early June?
o 4.5 cows/ha
- Pre-grazing yields in main grazing season?
o 1300-1500kg DM/ha
- Mid season grazing match grass supply and stock requirements by what % BW?
o 2% BW
- Days Ahead Concept
o Total amount of grass available on farm (kg DM)/Herd demand on grazing area (kg Dm per day)
o The number of days grazing ahead if growth were to cease on the farm
- Mid-season pre-grazing yields for beef?
o 1300-1600kg DM/ha
- Concentrates per ewe cost?
o €39 per ewe
- Total variable costs per ewe?
o €98
- To supply enough herbage for 1 ewe and twin lambs we must grow __t and utilise __kg?
o Grow 1tonne ad utilise 850kg (85% utilisation)
- DM requirements for a lactating ewe and 5 weeks post-lambing?
o Lactating ewe - 2.4 kg DM/head/day
o 5 weeks post-lambing - 3.2 kg DM/head/day
- Early/mid March lambing flock an opening farm cover of…
o 600-700 kg grass DM/ha or 20-25 days ahead
- Target ADG on grass post weaning for lambs is…
o 150g/day
- How much grassland used in Western Europe for silage?
o 10 million ha (25% is baled)
- Ensiling process:
o Aerobic phase, fermentation phase, stable phase, feed-out phase
- 2 phases of feed-out phase:
o Degradation of preserving organic acids
o Rise in pH and activity of spoilage organisms such as bacilli, moulds and enterobacteria
- Conditioning definition:
o After mowing crops close stomata and the cuticle limits the rate of water loss. Disruption of the cuticle helps accelerate the loss of water
- Primary fermentable substrates in temperate grasses:
o Glucose, Fructose, Sucrose, Fructans
- AM or PM cutting preferrable and why?
o PM – better fermentation characteristics, less fibrous components, increased DMI, milk solids production and nitrogen use efficiency
- Typical Buffering Capacity in grass range:
o 250 to 350 mEq/kg DM
- Buffering Capacity definition
o The equivalents of acid per unit DM required to lower crop pH from 6 to 4
o BC is higher in legumes and lower in maize than grass
- Homofermentative lactic acid bacteria
o Ferment 1 mole of glucose or fructose to 2 moles of lactic acid
- Heterofermentative lactic acid bacteria
o Produce lactic acid plus acetic acid, ethanol or mannitol
- Saccharolytic clostridia
o Ferment sugars and LA to produce butyric acid
- Proteolytic clostridia
o Ferment amino acids producing amines and ammonia
- Typical loss of DM in silage well preserved and wilted, direct harvested poorly, and direct harvested well?
o Well preserved and wilted – 23%
o Direct harvested poorly – 30%
o Direct harvested well – 19%
- Silage sampling when?
o 6 weeks post harvest
- pH of silage
o 3.8-4.2
- How much forage should a horse consume in 1 day?
o Range of 1.5-3.5% of body weight (2.5%)
- Stocking rate for horses
o 1.5 horses per ha
- 450kg horse will consume
o ~ 2.5-3-plus tons of forage DM during 6 to 7 months
- Horses spend up to how many hours a day eating?
o 16 hours
- Why no clover in horse pasture sward?
o Causes colic – abdominal pain/ GIT issues
- Laminitis definition?
o Inflammation and weakening of the laminae that bonds the hoof wall to the pedal bone in the hoof.
- Maize silage €/t utilisable DM 2024?
o €142/t
- Tassel definition
o Male part of the corn plant that contains the pollen. The tassel is on top of the corn plant.
- Silk definition
o A hollow tube that comes from the female part (ovary) on the ear. The silk grows outside of the husk until the pollen lands on the silk and then moves down silk tube to fertilize the ovary to form the seed. Each ear has one silk strand for each kernel on the ear.
- Ear definition
o The structure that contains the kernels that are forming after fertilization. The female part of the corn plant.
- Husk definition
o Leaf like structure that wraps around the ear for protection.
- Brace roots definition
o Develop from aerial stem nodes and can remain aerial or grow into the ground. Function of these roots is to brace the plant
- Amount of maize worldwide?
o 141million ha worldwide
- Maize production in tonnes?
o 238million tonnes
- Maize is a main food source for what regions?
o Mexico, Latin America, Africa and Asia
- Maize is produced for what in Ireland?
o Forage maize - Whole crop harvested and converted to silage
- Area (ha) of Forage Maize Grown in Ireland 2017-2024?
o 15000ha
- Maize sowing recommendations:
o Recommended to sow when soil temperature reaches 10oC at 10 cm depth
- Plastic on maize increases soil temp by what in May/June and in July?
o 3oC in May/June and 1.5oC in July
- When to start weed control of maize?
o Between 2-5 leaf stage of maize growth
- Target DM% and Starch % for harvesting maize silage?
o 30% DM and 30% Starch
- Nutrient Value Slurry calculation
o Units of either N, P, or K and x 1.25 to get _kg N/ha
- Crimped grain DM%
o 60-70%
- Urea treated grain DM%
o 65-72%
- What is the primary function of Rhizobium bacteria in legume plants?
o To fix atmospheric nitrogen for plant growth
- Environmental factors that affect N fixation in legumes?
o Soil structure, nutrient availability, and sunlight exposure
- Which type of clover has an erect growth habit and is often used for silage?
o Red clover
- What nutrient is primarily fixed by legumes, aiding in their growth and surrounding soil fertility?
o Nitrogen
- Red clover is NOT suitable for:
o Intensive grazing
- Disadvantage of using Red Clover in forage systems?
o Short lifespan
- What is a unique characteristic of the white clover (Trifolium repens)?
o Trifoliate leaves with minutely serrate margins
- Which leaf size of white clover is recommended for sheep grazing?
o Small
- What is the optimal inclusion rate of white clover in permanent pastures in Ireland to achieve desired sward benefits?
o 3-6kg/ha
- What is one of the main challenges associated with clover-based pastures?
o Risk of bloat in animals
- How does white clover in swards impact the nutritional profile of the herbage?
o Increases mineral content and crude protein
- What factor is essential to avoid when attempting to increase the white clover content in a pasture?
o Applying nitrogen fertiliser from mid-late April onwards
- Which plant characteristic of plantain (Plantago lanceolata) can reduce nitrogen excretion in animals?
o High mineral content
- Which functional group in multispecies swards contributes to reducing nitrogen losses and improving soil structure?
o Forbs (herbs)
- Why might multispecies swards be preferred over perennial ryegrass monocultures?
o Increased biodiversity and lower nitrogen inputs
- What is the primary financial benefit of effective grazing management for dairy farmers?
o Longer grazing season with low-cost, high-quality feed
- In a continuous stocking system, what is a significant disadvantage?
o Potential for under- or overgrazing
- What is the objective of rotational grazing?
o To allow paddocks to rest after grazing
- In the leader-follower system, which group of animals typically gets access to the pasture first?
o Calves or younger stock
- What is the main goal of grass budgeting in grazing management?
o To synchronize grass supply with animal demand
- Tools in PBI tool kit for grazing management?
o Nitrogen Use Efficiency calculator, Autumn Rotation Planner, Farm Mapping Tool
- What grazing strategy involves animals grazing for a limited time before being returned indoors?
o On-off grazing
- What is one of the primary benefits of creep grazing?
o Allows young stock to access higher-quality pasture
- What is the effect of the leader-follower system on the follower group?
o May lead to lower-quality herbage available
- What does “paddock rotation length” refer to in grazing management?
o The time animals spend grazing in a single paddock
- Which grazing system is most commonly associated with higher grass utilisation and reduced waste?
o Strip grazing
- Which grazing system is most commonly associated with higher grass utilisation and reduced waste?
o To manage grazing areas and track fertiliser application
- Which grazing method is commonly used in challenging weather conditions to minimize pasture damage?
o On-off grazing
- Priority measurements in grassland management?
o Paddock cover in kg DM/ha, Farm grass cover per cow, Stocking rate per hectare
- What is the recommended residual height for paddocks after grazing to maintain sward quality?
o 5-6cm
- Which tool in grazing management helps identify high and low-producing paddocks?
o Grass Wedge
- According to the PBI Tool Kit, which of the following is crucial for managing pasture quality during grazing?
o Priority measurements like growth and residuals
- What is the recommended grass dry matter (DM) allowance per day for a weaned lamb?
o 1.2kg DM
- In the leader-follower system, what grazing period is ideal for each paddock to avoid overgrazing?
o 4-5 days
- What is the primary purpose of using a Nitrogen Use Efficiency (NUE) calculator in grazing management?
o To monitor nitrogen input vs. uptake
- Methods used for herbage mass assessment?
o Rising plate meter, Grass shears and quadrat, Wellington boot technique
- Which grass measurement tool shows the highest correlation with actual plot yields?
o Grasshopper plate metre
- The target pre-grazing yield is calculated based on what parameters?
o Stocking rate, allowance, rotation length, and residual
- What does Post-Grazing Sward Height (PGSH) indicate?
o Average height to which a paddock is grazed
- In the Wellington boot technique, which measurement is primarily observed?
o Post-grazing residual
- What is the relationship between Post-Grazing Sward Height (PGSH) and residual grass yield?
o Higher PGSH indicates higher residual yield
- Which factor is associated with high Organic Matter Digestibility (OMD) in pasture quality?
o High energy value (UFL/UFV)
- What does a Priority Measurement in grazing management typically include?
o Target residual, Pre-grazing yield, Stocking rate
- Which technique involves taking grass samples from the sward and drying them to estimate live leaf percentage?
o Quadrat and shears method
- For which grazing severity score would a Post-Grazing Sward Height (PGSH) be categorised as “good grazing”?
o 2 (3.5-4.5 cm)
- How is the target pre-grazing yield impacted by an increase in rotation length?
o It increases
- Influences of pasture nutritional quality?
o Post-Grazing Sward Height (PGSH), Rotation length, Herbage mass
- What does the Rising Plate Meter measure in a grazing system?
o Grass height and estimated yield
- Which is a benefit of using the Grass Wedge tool in grazing management?
o To visually assess pasture supply across paddocks
- What is the typical crude protein (CP) content of autumn grass?
o 21-23%
- Which factor contributes to reduced pasture quality in autumn compared to spring?
o Increased dead material and lignification
- The 60:40 autumn grassland plan is primarily designed to:
o Keep cows grazing until a designated housing date
- In the 60:40 autumn grassland plan, what date is typically targeted to have 60% of the farm grazed?
o 1st November
- What is the recommended Post-Grazing Sward Height (PGSH) for autumn grazing?
o 4.5-5.0 cm
- High Organic Matter Digestibility (OMD) in pasture is associated with:
o Higher energy intake for animals
- What is the target crude protein (CP) level for well-managed spring grass?
o 19-24%
- Which component of the grazing sward generally has the lowest digestibility?
o Dead material
- What effect does grazing pasture older than three leaves per tiller typically have?
o Increases senescent material
