Ruminal Metabolism Flashcards
(94 cards)
1
Q
Acidosis two types
A
SARA pH
2
Q
What causes rumen pH to fall
A
Excess starch hence shift towards amylolytic flora
3
Q
Process of acidosis
A
Increase of starch causes incr in VFA and decr in pH
Increase in lactate producing bacteria S.Bovis so incr in lactate
pH
4
Q
Which VFA supports gluconeogenesis
A
Proprionate
5
Q
How can you control pH
A
Yeast supplements - scavenge O2 giving anaerobic environment for bacterial growth
6
Q
Which is main VFA produced
A
Acetate
7
Q
Solutions to lack of glucose eg at lactation
A
Utilise oxaloacetate from KA
Burn fat releasing acetyl CoA
BUT
Reduced efficiency of KCA if less oxaloacetate Nx too much acetyl CoA
Acetyl CoA metabolised to ketone bodies in liver and supplies tissues instead of glucose and builds up toxic level
8
Q
Signs of ketosis
A
Pear drops
Lethargic
Loss in body weight
9
Q
Treatment of ketosis
A
Dextrose (500ml 50%) IV
propylene glycol and glycerol drench
Glucocorticoids
10
Q
Prevention of ketosis
A
Balanced ration
Maintain BCS
11
Q
Cause of hepatic lipidosis
A
Excess energy intake during dry period
Negative energy balance at calving
Body fat mobilised faster than it is used up
NEFA in blood and stored by liver
12
Q
What does fatty liver occur with
A
Metritis
Mastitis
DA
Hypocalcaemia
13
Q
Prevention of fatty liver
A
Monitor BCS in dry period, don’t let >3.5
minimise NEB so less fat mobilisation
Minimise stress
14
Q
DA causes
A
Hypo motility of abomasum
Incr concentrates and decr roughage
15
Q
Signs of LDA
A
Decr milk Gas production Decr appetite/anorexia Alkalosis and hypokalaemia Secondary ketosis common
16
Q
Signs of RDA
A
LDA PLUS
ischaemia
Blood supply to GIT compromised
Necrosis
17
Q
DA treatment
A
Surgical
Manipulation
Roll
18
Q
Prevention of DA
A
promote DMI and rumen fill immediately after calving Feed TMR avoid rapid dietary changes Feed enough roughage Treat ketosis
19
Q
Causes of retained placenta
A
Dystocia Twins Stillbirth Abortion Low Se Hypocalcaemia Old age Previous history
20
Q
Treatment of retained placenta
A
Trimming of excess tissue don’t manually remove
21
Q
Prevention of retained placenta
A
Se supplementation
Cull repeat offenders
22
Q
Hypocalcemia/ mikl fever causes
A
Too much calcium in dry period
Not enough vit D or Mg in dry period
Ca:P ratio too low (excess P)
Jersey cow is prone
23
Q
Milk fever signs
Three stages
A
1
24
Q
How do vit D and Mg prevent milk fever
A
Regulate calcium reabsorptiom
25
Milk fever prevention
Low calcium diet in dry period
DCAD diet- low pH improves calcium absorption
- promotes parathyroid gland to use bone calcium
-use low K diet S it blocks Mg
Vit D in feed
26
Cause of twin lamb disease
Poor rationing in pregnancy
Sheep outdoors in poor weather
Ketosis
27
Signs of twin lamb disease
Don't want to move
Ketone bodies
Disturbed vision
28
Treatment of twin lamb disease
Dextrose IV bonus (500mg 50%)
Propylene glycol and glycerol drench
Glucocorticoids
29
Prevention of twin lamb disease
Good nutrition in last 8w pregnancy
| Concentrate supplementation
30
Cause of hypo magnesaemia
Pasture low in Mg
| Fertiliser use reduces pasture uptake of Mg
31
Signs of hypo magnesaemia
Frothing at mouth
Muscle twitching and teeth grinding
Dead stock at pasture
32
Treatment of hypo magnesaemia
```
Mg sulphate (200ml 50%) SC
Hay treated 60g Mg oxide daily
```
33
Prevention of hypo magnesaemia
Her age dusted with Mg oxide (500g a cow)
Herbage sprayed with 2% Mg sulphate
Mineral licks
Boluses
34
Causes of cerebrocortical necrosis
Vit b1 deficiency /thiamine deficiency
Carb rich and roughage poor ration causes SUBCLINICAL lactic acidosis
Destruction of thiamine in GI tract
35
Signs of CCN
circle collapse leg-kicking
36
Treatment of CCN
early thiamine may cure but not if lesion advanced
37
Prevention of CCN
Diet ensuring no SARA
| Prophylactic vitamins
38
Causes of swayback
Low Cu causes underdevelopment of myelin sheaths in lambs
| Poor absorption of Cu due to copper thhiomolybdate formation
39
Prevention of swayback
CoSeCure boluses
| Supplement copper but with CARE as sheep accumulate copper in liver and toxicity occurs at 25mg/kg
40
Cause of pine
Lack of Co
| Inability to make vit B12 in rumen
41
Signs of pine
Unthrifty
Dull fleece
No appetite
42
Treatment of pine
IM injection of vit B12
| Drenching up to 1ml/kg cobalt sulphide
43
Prevention of pine
CoSeCure boluses
44
Cause of white muscle disease
Se and vit E deficiency
Low bioavailability of inorganic Se
Se incorporated into organic form on pasture
45
What does Se do
Cofactor for reduction of antioxidant enzymes
Cofactor for thyroid hormone deiodinases
Removes reactive oxygen species
Controls metabolic rate
46
Signs of white muscle disease
Acute and rapid wasting of skeletal muscle
| Unable to stand
47
Treatment of white muscle disease
IM or SC injection of young lambs with 0.75-1.5mg Se as potassium selenate
Injection of 34-68mg vit E
48
Prevention of white muscle disease
Supplement dams ration in late gestation
Injection of newborn lambs with Se and vit E prep
CoSeCure bolus
SelPlex
49
Aphosphorosis cause
Phosphorus deficiency due to poor diet or grazing soil low in P
50
Signs of aphosphorosis
```
Rickets
Stiff joints
Poor fertility
Decr milk
Chew strange things
```
51
Treatment of a phosphorosis
Oral P supplementation (won't work on vomiting or diarrhoea)
| Sodium phosphate salts
52
Prevention of aphosphorosis
P fertiliser on depleted soil
| 0.42% DM P conc for high yielders
53
Signs of vit a deficiency
```
Night blindness
Infertility
Rough coat
Impaired immunity
Weak/dead lambs
Xerophthalmia (dry conjunctiva)
```
54
Treatment of vit a deficiency
Retinol injection and vit a supplement in feed
55
Goitre causes
Iodine deficiency causing decr thyroxine
| Goitrogens reduce T3 and or T4 production and release
56
Signs of goitre
Enlarged thyroid gland
| Weak or hailess young
57
Treatment of goitre
Potassium iodide oral dosing
| Intra ruminal boluses provide slow release of iodine
58
Prevention of goitre
Add iodine to conc rations
| Rapeseed treated to eliminate goitrogens
59
Clover disease causes
Phytoestrogens produced in clover gives infertility as cysts form in uterus and cervix and uterus doesn't contract normally
60
What conditions In Rumen support microbial growth
Temp/moisture /pH
Supply of nutrients
Removal of products of digestion and fermentation
61
How are VFA produced
From pyruvate by fermentation
62
What are the three VFAs
Acetate butyrate propionate
63
Why drive towards propionate production
So less methane produced as acts as hydrogen sink
64
What diet produces acetate
High fibre
65
What is the fate of acetate
Converted to acetyl CoA in liver, used in kerbs
| Milk fat precursor
66
What diet favours propionate
High concentrate
67
What is fate of propionate
20% to lactate during absorption across rumen wall, enters gluconeogenic pathway via PEP
80% to glucose VIA OXALOACETATE
68
What favours butyrate
High fibre
69
What is destiny of butyrate
B hydroxybutyrate in absorption, passed to liver and converted to acetyl CoA , or used as energy source
70
How is methane formed
Reduction of co2, h2 from acetate and butyrate production
71
What should be pH of rumen
6.7+/- 0.5
72
What provides buffer
Saliva- 180L a day produced
73
What is dietary protein made up of
Microbial protein DMTP (from non-protein N)
| dietary Undegraded protein RUP
74
What uses amino acids as energy
Low energy FME diets, form branched VFAs
75
What is the fate of urea
Converted to ammonia by bacterial urease in the rumen, excreted in urine
76
What causes low ammonia levels
Low dietary protein
77
What causes high ammonia levels
More protein degraded than microbial protein formed
78
What is optimal rumen ammonia conc
8mM
79
Efficiency of dietary N utilisation and reason
20% retention in rumen
Different rates of degradation of carbs and protein gives low efficiency of microbial protein syn
BALANCE OF RDP AND FME IMPROVES EFFICIENCY
80
Glycerol base lipids
Neutral triacylglycerol
| Structural glycolipids and phospholipids
81
Non glycerol base lipids
Steroids
Vitamins
PGs
Waxes
82
How much energy per mole lipid
409 mole ATP
83
PUFA:SUFA
>0.45 for healthy cell function and membrane fluidity
84
Lipid recommendations
Omega 6: omega 3
85
Where does most of lipid in diet come from
Chloroplast of plants- thylakoids has membrane lipid (omega 3 mainly)
86
Fatty acids in beef
MUFA>>SUFA>PUFA
87
Process of bio hydrogenation
Protozoa act on cells causing lipolysis to FFAs (incr by red clover)
FFAs undergo bio hydrogenation, PUFA (92% omega 3 and 86% omega 6) lost
Fish oil decr sat fat 18:0 and incr trans Fat 18:1
88
Role of PPO in red clover
Oxidises phenols to quinones in presence of oxygen which bind to proteins
89
What causes milk fat depression (fat lowered up to 50%)
Highly polyunsaturated fats- plant oils, oil seeds
Low roughage and high conc
High 18:1 trans fat
90
What does SREBP1 do
Up regulates de novo synthesis, esterification and desaturation
91
What drives metabolic disorders
Losing control of rumen pH
92
Unsustainability of the Holstein
Yield requires energy and protein beyond levels available from pasture
Consumes more than body weight of cereals per lactation- using human resources
Producing cereals uses polluting fertiliser
Ill equipped to digest a grain rich diet- SARA, DA
93
Proposed solutions to global food security
International network of 'model farms
Global network of 'farm platforms'
Critical zone observations
94
How do PUFAS affect butterfat
Toxic to rumen bacteria, have to be converted from 18:2 and 18:3 to 18:0 by biohydrogenation
A low rumen pH will cause 18:2 or 18:3 to create intermediate c10-t12 TFA which causes milk fat depression as down regulates SREBP1 reducing de novo synthesis of c4-c14 FAs
