Voluntary Feed Intake Flashcards
1
Q
How to Measure Feed Intake?
A
- Difficuty of metabolic weight is that cows will all be a different weight
2
Q
Mixer Wagon
A
- To properly cut the straw and other rations until they are of appropriate size
- they won’t eat it if it is too long!!
Need to increase the roation and leave in for longer for shorter straw
3
Q
Why is Feed Intake Imp?
A
- having a lower maxiumum feed intake and having a better utilization?
- we don’t want our dry cows to gain much weight
- we need to look after their weight and feed intake for the animals to thrive to best potential
4
Q
Distension Feedback
A
- the idea that when you are full you stop eating, but is not always true
5
Q
Other Factors affecting VFI
A
- effects of Feed Intake
6
Q
Distension or Fill Feedback
A
- Try to fill the rumen to reach that stretch factor..
- Distension will stop the feed intake at some point even though there may be weight loss
7
Q
Water in Rumen
A
- 2 types of water
- water with dry food will not have much affect on VFI
- but the water within plants will- the bulk is still there
8
Q
Water Holding Capacity
A
- essentially osmosis
- slower transit through the guts, which is good for absorption of nutrients, but also means lower food intake
- chopping of the feed will have the opposite effect: make the transit time faster and increase VFI (fiber is shorter, will pass through rumen faster)
9
Q
DMI and retention time
A
- Low DMI in the trial will have a lower passage through the gut, will affect how this matter is digested
- proteins will go quicker and be absorbed less efficently
- farmers try and balance this
10
Q
Maintenance Level
A
- Intake of food will heavily affect the production level
11
Q
Inert Fill
A
- happens to cows and sheep in late pregnancy
- nutrients will be in the gut for shorter
- means we need to feed more nutritious or digestible feed, need to optimize increased flow rate
- ex: twin lamb or triplets
12
Q
Rumen Outfow Rate
A
- a bout of rumen acidosis will lead to more pressure in the rumen due to the stasis
13
Q
VFA’s
A
- another chemical reason that we have an effect on the feed intake
- the more fermentation there is, the lower feed intake?
- Poorly fermentated silages produce a lot of butyrate and lead to poor intake
14
Q
Thermostatic theory
A
- ruminal process is actually exothermic, they get warm by eating
- they will start eating more at -15C to keep themselves warm
- so more of an issue for chickens in cold than cows
15
Q
Cows and Heat Stress
A
- Cows have more of an issue with overheating as the rumination is exothermic
16
Q
Post Digestive Feedback
A
- If you have a low glucose level in your blood, you want to go feeding
17
Q
Glucose: how about Farm Animals?
A
- have less glucose dependance than other species
- hgiher proprionic acid will reduce feed intakes
- all the glucose preferentially goes into our production cows for milk and that is the way we have bred them
18
Q
Lipostatic Theory
A
- Higher the fat store, the lower the appetite
- theory is not very effective in cows
19
Q
Hepatic Oxidation Theory (HOT)
A
- Idea that there is plenty of E in the liver which should decrease need to feed?
- resources for ATP are plentiful in liver and that is why they don’t eat more since liver is saying that is enough
20
Q
Leptin
A
- We have been breeding cows for high growth route
- It is developed in the fat tissue
21
Q
Dairy Cows and Negative E Balance
A
- Negative E balance is what we refer to as the lag phase
22
Q
So How much Do animals eat?
A
23
Q
Factors for feed intakes
(Dairy, Beef, Dog)
A
- demand for production in cows will mainly outweigh all the others
24
Q
Nutrient Needs
A
*
25
Maintenance
26
Feed Intake and Maintenance
* the more milk she makes the more she will need for production
* pregnancy equates to about an 8L milk yield
27
High E diets
* apples can be too digestible and lead to acidosis
28
Body Weight Loss
29
Two Sources for E in Forages
* cell wall is good for bulk but not necessarily the E req.
30
Plant Composition
* higher the lignin factor the lower the digestibility
* The more bulky the plant is the " "
* The older the plant the higher the lignin
31
NEutral Detergent Fiber
| (NDF)
32
Forage NDF vs. Intake
| (NDF intake graph)
* curved linear relationship
33
Acid Detergent Fiber
* ADF is a good indicator of the digestibility
34
Silage Quality
* silage pH is highly dependent on the dry matter quality of that silage
* Amount of protein that has been degraded (ammonia N) will have a massive impact on the intake of that ration by the cow
35
Anti-Nutritional Factors
* tannins will have a large impact on the ........
* Tannins are quite casutic to the gut lining and this can be a major consequence: oak poisoning --\> especially after a stormy day
* GI ulcerations will allow tannins and toxins to be absorbed
36
Anti Nutritional Factors
| (Lectins, Glucosinolates, Saponin)
* Farmers can only include a certain amount of oilseed rape as they are restricted by anti-nutritional factors
* Saponins can negatively affect the ruminal flora
37
Other Factors on Feed Intake
*
38
