1
Q
- What is the function of PPO (polyphenol oxidase)?
A
Inhibition of post-harvest proteolysis by inhibiting activity of the plants proteases in the silo
2
Q
- How much white clover should be included per hectare?
A
4.63 kg/ha
3
Q
How much grass is sown per ha?
A
14kg/ha for diploid
16kg/ha for tetraploid
4
Q
- If a plant has a caespitose growth habit, what does this mean?
A
Grows in tufts
5
Q
- How much N can White Clover fix annually?
A
100-150 kgN/ha
6
Q
What are characteristics of varieties with large leaves?
A
- Longer petioles and fewer stolons
- Suitable for lax, rotational grazing
7
Q
- When does white clover have a lower leaf photosynthesis rate than grasses?
A
- Spring
8
Q
- When does white clover have a higher leaf photosynthesis rate than grasses?
A
- Summer
9
Q
- When does white clover rebuild its stolon/root reserves?
A
- Autumn
10
Q
- Over the summer period, which animals should be grazed on white clover ground?
A
- Priority Stock
11
Q
- What would the crude protein content of a white clover/PRG sward be?
A
- 21%
12
Q
- How many seeds does an adult dock produce per year?
A
- 60,000
13
Q
- In a high sward density, how many tillers will be present?
A
- 30,000/m²
14
Q
- During periods of continuous rain, what should you estimate grass DM as?
A
- 12-15%
15
Q
- During the first rotation in the spring or in periods of drier weather, what should you estimate grass DM as?
A
- 18-19%
16
Q
- During drought conditions, what should you estimate grass DM as?
A
- 22-23
17
Q
- A post-grazing sward height of 3.5-4cm represents a post-grazing residual of:
A
- 0-50kg DM/ha
18
Q
- What is grass Organic Matter Digestibility used to calculate?
A
- Energy content/ UFL,UFV value
19
Q
- Grazing swards with medium pre-grazing yields instead of high pre-grazing yields should result in:
A
- Higher grass utilisation
- Better sward quality
- Higher leaf content
20
Q
- Target Average Farm Cover during main grazing season:
A
- 450-600kg DM/ha
21
Q
- Stocking rate for adequate feeding of cows at pasture at required allowance:
A
- 4.5 cows/ha
22
Q
- What % of live leaf should you aim to maintain in the sward immediately ahead of the cows?
A
- ˃65%
23
Q
- At a stocking rate of 2.6 cows/ha, how much of the grazing area can be closed off for first cut silage?
A
- 45-50%
24
Q
- For each kg of grass silage fed as supplement, how much grass DM is replaced in the diet?
A
- 0.9 kg DM
25
79. What is the maximum ratio of field sides in grazing systems?
* 4:1
26
82. In early grazing, which animals should be let out first?
* Lighter cattle
27
85. What is the target number of days ahead at different stages of the season?
* April-June: 12-14 days
* July-August: 16-18 days
* September-Closing: ˃25 days
28
90. What is the usual amount of grass DM that a lactating ewe will eat daily?
* 2.4kg DM
29
92. Forward creep grazing of lambs can increase weaning weight by:
* 2kg
30
93. What is the target weight gain of a lamb on grass post weaning?
* 150g/day
31
99. How much of long established horse pasture is grazed?
* 10%
32
100. After rejuvenation, how much of a horse pasture will be grazed?
* 20-30%
33
With horses, when should grazing occur?
* Just before the rate of grass leaf growth declines
34
110. Why should hay be made from paddocks that have been previously grazed by horses?
* Parasite control
35
116. What depth does shallow compaction go down to?
* 10cm
36
120. What is the normal seeding rate for horse psature?
* 11-15kg/acre
37
125. In laminitis, what causes endotoxins and exotoxins to be absorbed into the bloodstream?
* Increased gut permeability, caused by irritation of the gut lining by increased acidity
38
126. What is the consequence of endotoxaemia?
* Impaired circulation, particularly in the feet
39
129. What does ragwort poisoning cause in the liver?
* Inhibition of the organs normal repair and regeneration process
40
What are the 2 phases of feed-out?
* Degradation of preserving organic acids
* Rise in pH/ activity of spoilage organisms
41
What are the primary fermentable substrates in temperate grasses?
* Glucose, fructose, sucrose, fructans
42
What are the weather effects on DM and WSC?
* Increasing light intensity increases DM and WSC
* Increasing temperature increases DM and reduces WSC
* Increasing water supply reduces DM and WSC
43
146. What is the typical Buffering Capacity in grass?
* 250 -350 mEq/kg DM
44
147. What is the typical Buffering Capacity in grass silage?
* 1200-1500 mEq/kg DM
45
150. Which sugars are fermented by most lactic acid bacteria?
* Sucrose, hexose, pentose
46
151. Which sugars are fermented by few lactic acid bacteria?
* Fructans
47
152. What action is carried out by Saccharolytic clostridia?
* Fermentation of sugars and Lactic Acid to produce Butyric Acid
48
153. What action is carried out by Proteolytic clostridia?
* Ferment amino acids producing amines and ammonia
49
What action is carried out by Enterobacteria spp.?
* Ferment carbohydrates to short chain organic acids eg acetic acid, ethanol, hydrogen
50
What do Enterobacteria spp produce?
* Ammonia and nitrous oxide
51
2 High moisture grains:
crimped grain 60-70%
urea treated grain 65-72%
52
What is SMCO?
S-methyl cysteine sulphoxide
High levels cause red water in ruminants (haemoglobinuria) ***
Results in depressed DMI and anaemia
53
What are the causes of nitrate accumulation in the plant?
Periods of rapid growth following periods of stress
High use of N fertilisers
***>2% DM is unsafe/ toxic <1% safe to feed
54
Effect of winter feed on dry cow performance at parturition?
Kale: 3.27 (8kg and 4kg DM grass silage)
Swedes: 3.20 ( 8 kg and 4 kg DM grass silage)
Grass in situ: 2.85 (12kg)
Silage indoors: 3.58 (grass and silage ad lib)
***66%
55
White clover growth
Red clover nitrogen fixation rate:
Roots
How much dry matter/ year is yielded by a PRG X RC sward?
How much dry matter yielded from 0kg N/ha chemical fertiliser?
200 kg N/ha (2-4 year lifespan)
Deep tap root for drought resistance and silage sward
11-13 tonne DM/year
15 tonne DM/ha
56
Shape of clover leaves
57
Characteristics of white vs red clover
Red
Not toothed
Has hairs
White
Toothed
No hairs
58
When cutting RC silage what is the process?
Avoid condition mower – leaves prone to shattering
Cut silage crop to residual 7-8cm
Wilt for 24-48 hours
DM% 25-35%
59
Factors affecting nitrogen fixation
Drought,
low temperature,
N fertiliser application,
clover sward content,
solar radiation,
soil aeration,
nutrient availability,
disease/
weed infestation.
60
Clover seed mix high establishment?
Inclusion level is 3-6kg/ha
61
White clover growth habit :
Stoloniferous growth habit makes it capable of colonising bare spaces in swards
62
Nitrogen applied to horse pasture?
25-30 kg N/ ha applied in spring time
63
What helps accelerate the loss of water from plants?
Conditioning – disruption of the cuticle as the cuticle limits the rate of water loss from the plant after mowing
64
Type of bacteria that dominates the fermentation process?
Epiphytic lactic acid bacteria ***
Homofermentative lactic acid bacteria
Heterofermentative lactic acid bacteria
65
Silage additives
***
Acid based, sugar-based, enzymes, enzyme + salt mix, inoculants and absorbents
3 CLASSES
Fermentation promoters/ stimulants
Fermentation inhibitors
‘Shelf life’ enhancers
66
What are the WSC contents of silage measured in?
g/L aqueous extract
67
What is the buffering capacity?
The equivalents of acid per unit DM required to lower crop pH from 6 to 4
68
What is the typical BC rang in grass?
250-340 mEw/kg DM
69
unction of homofermentative lactic acid bacteria?
Ferment 1 mole of glucose/ fructosw to 2 moles of lactic acid
70
Function of heterofermentative lactic acid bacteria?
Produce lactic acid plus acetic acid ethanol or mannitol
71
When is the best time to sample silage?
At least 6 weeks post-harvest **
Representative sample
Core samples or feed face samples
GFP :0
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