Final Exam Flashcards

(71 cards)

1
Q

What are at least 2 biological advantages that the ruminant gastrointestinal tract provides compared to the non-ruminant digestive system

A

VFA production
Digest more materials than a nonruminant can- can use stuff monogastrics cannot

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2
Q

Provide at least 4 defining characteristics of ruminant animals

A

split hooves
herbivores
different teeth- no upper incisors
have a rumen/ pre-gastric stomach

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3
Q

What are the 5 sacs of the rumen and what biological advantage do they provide compared to if the rumen was a single continuous compartment

A

Ventral
Ventral blind
dorsal
dorsal blind
cranial
these sacs allow for better digestion as they increase the time food is caught in the rumen

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4
Q

What are 2 factors that influence digestion of feed in ruminants

A

rate of passage
rate of fermentation

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5
Q

What are 2 examples of fermentation end products that are not directly useful to ruminant animals

A

methane
carbon dioxide

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6
Q

Ruminant species have different grazing strategies and differences in grazing strategies often related to body size. Why?

A

The smaller the animal is, the smaller their rumen will be. This means they will have to eat certain foods that can be digested quicker since there is less room for it to hang out

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7
Q

What are the 3 different grazing strategies utlilized by ruminant species and describe how they differ from each other

A

Browse- leaves and berries- goat
Grazing- less picky- eating the grass and forage- cattle
Intermediate- eat a bit of both, leaves, berries, grass, etc.- sheep

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8
Q

List 3 short-chain fatty acids produced in the rumen that account for almost all organic acids produced from ruminal fermentation. Which short-chain fatty acid is typically found in the greatest amount

A

Butyrate
propionate
Acetate- found in the greatest amount

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9
Q

What nutrients can be metabolized from food to provide energy to ruminants

A

proteins
lipids
carbohydrates

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10
Q

What is the standard unit of energy used in the United States in reference to dietary energy concentrations in cattle diets

A

Mcal- because cows require so many more calories it is easier to use this larger unit

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11
Q

What fraction of energy in a food represents the heat of combustion

A

gross energy

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12
Q

What energy losses describe the difference in metabolizable energy and the heat of combustion

A

fecal
gaseous
urinary

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13
Q

What form of energy loss represents the difference between net energy and metabolizable energy

A

heat losses

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14
Q

Illustrate the partial efficiency of energy use from fasting (no food intake) to ad libitum for a rapidly growing beef steer. Identify there maintenance energy requirements are met

A

Graph 1 on Notability document

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15
Q

Explain why energy is of increasing importance for growth in cattle after the typical age for weaning

A

After weaning their main energy source is through fats/lipids given to them in feed. This is important for growth/performance

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16
Q

How are energy values derived in most feed libraries

A

TDN

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17
Q

What do measures of TDN reflect

A

energy

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18
Q

How can TDN be calculated if one knows the digestible nutrients in a feed

A

digestible carbohydrates+ digestible protein+ digestible fats times 2.25=TDN

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19
Q

What is the inherent flaw in calculations of TDN

A

It assumes that carbs and protein are equal

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20
Q

What is an example of an inaccuracy that results from the flaw in calculations of TDN

A

TDN being more than 100%

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21
Q

If TDN is flawed, then why is it still commonly used in reference to feed ingredients for ruminants

A

It is easy to use
can do it in a lab with calculations and no animals

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22
Q

How is energy related to predictions of dry matter intake

A

Energy drives dry matter intake

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23
Q

Empty body weight gain (EWG) can be predicted using the below model equation. In this model equation what is EQEBW and what does it reflect

A

Equivalent empty body weight
shows physiological maturity

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24
Q

what dietary components contributes the most to determining predictions of body weight gains in cattle be specific

A

retained energy

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25
How are energy requirements for lactation determined in ruminants
all of their energy should go into milk so you can measure the components of the milk to determine them
26
Name and describe the 3 forms of starch discussed in class
Amylose- plant starch Amylopectin- plant starch Glycogen- animal starch
27
What are 3 functions of carbohydrates
Provide energy building blocks for other stuff heat production
28
What is the main difference in the chemical structure between starch and cellulose
Their linkage alpha vs. beta animals cannot break down beta linkages
29
What are examples of two heteropolysaccharides
pectin hemicellulose
30
What fiber fraction is included in measurement of NDF but not ADF
hemicellulose
31
What produces VFAs What are 3 common VFAs
Microbes Butyrate, acetate, propionate
32
Describe the differences in VFA production between a stocker calf and a calf in a feed lot
stockers use a forage based system meaning there is more acetate created while feedlots use a grain based system meaning more propionate
33
What are 2 benefits to increasing propionate production
increased production for the animal decrease in methane production
34
Describe how/why VFA production relates to methane
Methane is the byproduct of the fermentation that is used to create VFA H+ into CH4
35
What is the primary impact of grain processing on starch digestion in ruminants
processing allows a higher starch digestion because it breaks the undigestible barrier. This allows the starch to be used
36
What are ionophores
antibiotics that change the ion gradient of microbes by messing with the channels
37
Describe at least 3 impacts ionophores have when fed to cattle
increased propionate production decreased meal size increased efficiency of ruminal fermentation
38
What are at least 4 possible symptoms of lactic acidosis in catle
death lower activity abscessed liver laminitis
39
Rank the following in order from the most rapidly digestible to the slowest ruminally fermented carbohydrate; cellulose, neutral detergent fiber, water soluble carbohydrates, and starch
Water soluble carbs starch neutral detergent fiber cellulose
40
explain why protein is an essential nutrient
the protein is broken down into amino acids that are then used to build the proteins that are needed by the body
41
what is a limiting amino acid
the AA that when it is lacking will limit protein synthesis
42
is hydrolysis of starch by enzymes or transport of glucose form the small intestine most limiting to small intestinal starch digestion in ruminants
hydrolysis of starch by enzymes
43
Name 2 separate strategies used to improve the amino acid profile of diets fed to ruminants
protein complementation synthetic amino acids
44
How does net protein differ from metabolizable protein
Net protein is the protein/ amino acids that are actually used by the body for protein synthesis Metabolizable protein is the protein/ amino acids available for protein synthesis
45
The extent of ruminal digestion is determined by two competing processes (Kd and Kp) What do Kd and Kp stand for
Kd= rate of digestion Kp= rate of passage
46
Write out the extent of digestion equation that was on slide 3 of the 3/13/23 lecture
extent of digestion= rate of digestion over rate of digestion + passage rate
47
Give an example where feed processing would lead to a greater Kp but likely reduce the extent of digestion
grinding down feed particles would lead to greater rate of passage but reduce extent of digestion increasing feed intake
48
If I limited feed intake to 55% of ad libitum, what impacts did it have on passage rate (either solid or liquid) and what impact did it have on dry matter digestion
with less intake the rate of passage was slower, allowing for a greater dry matter digestion
49
what is the primary route of excretion of waste products from nitrogen metabolism
urine
50
what are two different forms of digestion that occur in the gastric phase of postruminal digestion
chemical enzymatic
51
What segment of the large intestine accounts for the majority of postgastric fermentation
cecum
52
why is meal duration important to consider when managing ruminants
a fast rate of consumption can lead to acidosis (HOT)
53
what is the difference between chemo static and physical fill mechanism for regulation of intake in ruminants
physical fill- size of the stomach cheomostatic- reaching the caloric intake needed
54
What 2 fraction of crude protein contribute to metabolizable protein
RUP and MCP
55
Is microbial crude protein estimated to more or less efficient when cattle are fed diets with greater than 3.9% fat
more efficient
56
What is the goal of protein and carbohydrate synchrony
to maximize microbial efficiency/ fermentation efficiency
57
Why do diets that provide synchronous amounts of ruminally degradable protein and fermentable carbohydrates often fail to provide real benefits
the animal does nitrogen recycling
58
Why is metabolizable protein not usually the most limiting nutrient for production in cattle
metabolizable protein is made up of almost always present microbial crude protein and metabolizable protein includes what amino acids are available, rather than actually used by the tissue MCP is produced in excess of the requirements of the animal
59
What role does the liver play in nitrogen use by ruminants
Converts ammonia into urea which is then given to the salivary glands, the kidney, or recycled back to the rumen where it can be used to make skeletal protein (beef)
60
Illustrate ruminal fermentation of protein. clearly identify the different fractions of protein on the chart
Graph 2 on Notability document
61
What are 3 factors that can influence rate of protein disappearance in the rumen
composition of the feed forage: concentrate ratio types of microbes in the rumen protozoa vs bacteria
62
How much metabolizable protein is provided from ruminally degradable protein
RUP+RDP=MP so it is that fraction that RUP does not provide to MP
63
Which hormone is most commonly associated with long-term signaling of satiety when intake is regulated by chemostatic mechanisms
Leptin
64
Generally anabolic implants do what to daily dry matter intake in cattle
increase it
65
Concentration of what is the primary factor that controls daily dry matter intake in cattle when intake is limited by chemostatic mechanisms
Net Energy for Maintenance
66
Generally, cattle require about how many gallons of water per hundred pounds of body weight
1
67
Measures of what are most useful when evaluating water quality for cattle
Total dissolved solutes
68
Why does the caloric requirement for gain increase with increasing body weight in ruminants
because fat makes up an increasing percentage of gain as ruminants mature
69
When is feed conversion to body weight gain most efficient in cattle
When they are less mature, because fat makes up a lesser proportion of body weight gain
70
Generally energy and protein requirements are based on
composition of gain
71
Efficiency of dietary energy is use is most efficient when
fat makes up the greatest proportion of gain