week 4 - 01/10/2024 Flashcards
Multispecies swards for ruminant production
- need to reduce N losses from farm
- most efficient method = reducing N inputs
- nitrogen fertiliser and concentrates feed
- con we reduce the level of N applied to swards, while maintaining biomass and milk production?
what is the main source of nutrient losses in ireland - Nitrogen
pasture
followed by wastewater
in 2018, what was the total tonnes of Nitrogen loss from catchments without N issues
20,000
in 2018, what was the total tonnes of Nitrogen loss from catchments with N issues
45,000
what does multispecies outperform?
Multispecies outperformed PRG only treatments at both low (90kg N/ha) and high (250kg N/ha) rates of N
the effect of swards type annual herbage DM production:
PRG
PRG & WC
6 Species mix
9 species mix
PRG- 10,000 kg DM per ha
PRG & WC - 9,000 kg DM per ha
6 Species mix - 10,500 kg DM per ha
9 species mix - 10,000 kg DM per ha
was more or less nitrate leached from the herbal ley compared to the binary control
less
key benefits of (leys)
- Reduced fertiliser requirement: Legumes – essential component for N fixation
- Nutrient use efficiency – microbial protein: Animal performance = milk production, ADG
- Soil health and biodiversity
what are multispecies forages
forages that contain 2 or more plant species from at least two functional groups
what are the 3 primary functional groups of multispecies forages
- Grasses
- Legumes
- Herbs
Functional groups - Grass (6)
- Nutritious and palatable
- Shallow, fibrous roots and vigorous growth – easy manage
- Ability to persist under adverse conditions and sub-optimal soils
- High energy – 10 – 11 ME
- Sensitive to drought/moisture deficits
- N dependent
name the 4 functional groups of grass and there uses
- perennial ryegrass - grazing and silage
- timothy grass - grazing and silage
- italian ryegrass - silage - 2 year ley
- westerworld ryegrass - silage - annual ley
the characteristics of perennial ryegrass
- very persistent - 5 years +
- flexible and tolerant of grazing
- palatable: high intake
- sensitive to climate - drought
characteristics of timothy grass
- very persistent
- drought and frost tolerant
- better on heavy ground
- 1st year slow to establish
the characteristics of italian ryegrass
- High production – up to 18T
- Highly digestible, reduced after 1st cut
the characteristics of westerworld ryegrass
- High production – up to 18T
- Highly digestible – 68 – 75 DMD.
functional groups: legumes
- Fix high amounts of N – 100 – 200+ kg N/ha annually
- Highly degradable and nutrient rich
milk solids and ADG - Energy rich : Red clover 10 ME, White clover 11 ME
- Can be slow to establish – sensitive to low temps, high moisture
- Needs to be sown with perennial forages: Spring growth, Reduce risk of bloat, Persistency
is functional group important
vital
why are legumes important
support forage growth and biodiversity
- earthworms and bees love WC
name common legumes
- white clover
- red clover
- vetch (annual)
characteristics of Italian ryegrass and red clover
- Good persistence – 3 years+
- Rapid growth
- Drought resistant, can oversow into grazing swards
-Avoid tight grazing, crown 6cm above ground - Cut silage higher.
characteristics of perennial ryegrass and white clover
- Helps ground cover with upright PRG. - Medium leaf best for grazing. Persistent – 4 years+.
- Also suited to timothy but not on heavy soils.
- Under sow with trefoil in crops
characteristics of Westerwold ryegrass and vetch
- Very vigorous growth
- Soil improver
- Annual green crop/ cover crop
- Frost tolerant
- Can sow late into Autumn and harvest in Spring
Functional groups - Herbs
- Chicory, Plantain, Yarrow, Sheep’s parsley, Salad Burnet etc
- Mineral rich, tend to have deep rooting systems
- Highly degradable plants – high energy, low structural fibre, low DM
- High protein plants – 18% - 20%
- Can be sown in grazing ley mixtures or finishing mixes for dry stock
–> Chicory, plantain and white clover for finishing lambs
Characteristics of chicory
- Mineral rich, long taproot.
- Soil improver.
- Persistent when well managed – 3 years+
- Frost and drought tolerant.
- Weeds common when sown but removed once grazed/cut.
- Avoid over-grazing – 5/6 cm+.
- Graze at 7 leaf stage. 10 – 11 ME.
characteristics of plantain
- Mineral rich, long taproot. Soil improver.
- Similar persistency to well managed ryegrass.
- Avoid trampling.
- Frost and drought tolerant.
- Deep roots good for light soils.
- Graze at 6 leaf stage. 11 – 12 ME.
what do herb species =
- what must you do because of this
small seed size!
- adjust seeder and management accordingly
because small seed have less starch what do they need
more time to establish roots
which herb was the most consistent to supply nutrients
- chicory
what is the key energy source for ruminants
fibre
what does bacteria in the rumen digest
carbs to VFA’s
- Acetate - increases in forage diets
- Propionate - increased in starch diets
- butyrate - formed from actetate
what is the challenge with fibre fermentation
provide forage which balances rapidly and slowly degradable carbs to maintain rumen function and production
what are the two forms of protein
- rumen degradable protein (RDP)
- rumen undegradable protein (RUP)
how is RDP degraded
degraded largely to ammonia
what does microbial protein equal to
energy + ammonia = microbial protein
what is another name for microbial protein
true protein
what can other measures indicate digestibility
- NDF and ADF – fibre density measures
- DMD = 88.9 – [0.779 × %ADF (on a dry matter basis)]
what is straw made up of
Straw
85% NDF,
55% ADF
6 – 6.5 ME
what is maize meal made up of
Maize meal
10% NDF,
3% ADF
13.5 ME
what is soya hulls made up of
soya hulls
60% NDF,
50% ADF
11.5 ME
what is nutrient availability influenced by
degradability
why is it difficult to manipulate nutrient supply in forage based diets
it is dependent on the plant composition of the forage
what can help improve nutrient supply and animal performance
including alternative species
what is the effect of sward type on lamb weaning weights
- Compared to a perennial ryegrass sward, lambs suckling ewes which grazed the 6 species sward had a 2.4kg higher liveweight at weaning
what is the effect of sward type on number of days required to reach target slaughter weight for a lamb
Compared to a perennial ryegrass sward, lambs fed any mixed sward reached slaughter 2 weeks earlier
what is the effect of sward type on dairy calf to beef
Compared to a perennial ryegrass sward, steers fed any mixed sward turned out and were housed > 40 kg heavier (P < 0.05)
slide 38 - The effect of treatment on dry matter intake (DMI) and milk production in lactating dairy cows.
The percentage of saturated FA
in the milk of cows offered PRG, PRGWC or MULTI
Saturated fat:
PRG - 66.55%
PRGWC - 69.11%
MULTI - 67.14
The percentage of monounsaturated FA in the milk of cows offered PRG, PRGWC or MULTI
Monounsaturated fat:
PRG - 25.67 %
PRGWC - 22.85%
MULTI - 24.64%
The percentage of polyunsaturated FA in the milk of cows offered PRG, PRGWC or MULTI
polyunsaturated fat:
PRG - 2.89 %
PRGWC - 3.74 %
MULTI - 4.21 %
examples of rapidly digestible fibre
- perennial ryegrass: high sugar (WSC)
- herb species - high pectin
what does improved nutrient use efficiency lead to (2)
- Reduces ammonia loss as urea in urine – up to 50%
- Increased milk production and ADG
what is the challenge with nutrient use efficiency
rapidly degradable nature of herb and clover species can impact milk fat production
In sacco effective degradability of DM of PRG, PRGWC and MULTI
and which is it highest in
PRG- 67.43%
PRGWC - 66.37%
MULTI - 76.52%
DM is highest in multi
In sacco effective degradability of crude protein of PRG, PRGWC and MULTI
and which is it highest in
PRG- 81.40%
PRGWC - 78.99%
MULTI - 79.61%
CP is highest in PRG
what sort of a correlation is there between forage DM % and FrWI
A positive correlation existed with forage DM % and FrWI
when is the best time for weed management
year previous if possible
- mid april to late july
list of weeds
Common/greater chickweed
Shepherds purse
Lambsquarters
Field pennycress
Common fumitory
Lady’s thumb
Wall rue
Dead nettle
Lad’s Bedstraw
grazing management
Approx. 8 weeks post sowing
- Chicory 7 fully grown leaves
- Plantain 6 fully grown leaves
what did multispecies forage consistently increase in dairy cows in mid and late lactation
the DMI and milk yield of dairy cows in mid and late lactation
what benefits was there in including clover and herbs species in grazing forages for late lactation cows
altered the milk fatty acid profile in milk from late lactation cows
what does multispecies reduces in dairy cows
the urinary nitrogen concentration of dairy cows and helps reduce N loss via leaching
benefits of multispecies swards (8)
High nutritive value
Increased animal performance
High summer growth rates
Increased drought tolerance
Reduced chemical N
Various levels of root depths
Increased biodiversity
Reduced anthelmintic usage (sheep)
disadvantages of multispecies swards
Poor autumn/early spring growth
Weed control
Increased rotation length
Persistency
Milk fat concentration
PRGWC swards – bloat risk
