Ruminant Nutrition Final

What are the defining characteristics of ruminants

• pre gastric fermentation

• herbivores

• ungulates

The rumen is composed of 5 sacs. Which one is NOT considered a sac of the rumen?

Reticulum

Why should a prey species have a ruminant gastrointestinal tract?

• ruminant digestive system allows for increased time in between means

• ruminants can digest later on in a safe place

Volatile fatty acids are an end product of fermentation. What are the 3 most common VFA's and their total number of carbons?

Acetate C2, Propionate C3, Butyrate C4

The _______ is the main site of pre gastric fermentation, while the reticulum does this but also catches harmful objects. Most water absorption happens in the ________ which may also act as a pump regulating liquid passage. The ______ is the site gastric secretions. Absorbing nutrients within the stomach complex happens most efficiently in the ______

Rumen, Reticulum, Omasum, Abomasum, Rumen

In the abomasum, cheif cells synthesize ____.

Pepsin

Why is it important to know the evolution of the ruminant gastrointestinal tract?

The adaptation of the ruminant GI tract allows diverse species to thrive through symbiosis.

What does the microflora NOT contribute to the symbiosis relationship with a ruminant?

controls the temperature

What is an example of a chemical property that influences digestion?

heat treatment

T/F: Dry matter intake and physical characteristics of feed influence residence time, while rate of fermentation is influenced by concentration of microbes and intrinsic traits of feed. 

True

What type of grazing strategy do sheep exhibit?

Intermediate feeder

What happens in the gastrointestinal tract of a browser?

Lower retention time

The prehensile action of cattle and goats differ. Generally, _______ are the least discriminate when choosing what to eat whereas _________ are the most discriminate because they use their lips and teeth to pick through plant parts easily.

Cattle, goats

Why is it not always a good idea to put sheep and cattle together when interspecies grazing?

They compete for the same resource

Typically, cattle are harvested around 80% of physiological maturity. Which of the following might result in a shift of the ideal time of harvest from 80% of physiological maturity for cattle? Select all that apply.

Change in feed price

change in value of the animal

Where is puberty defined on the composition of gain curve?

more than 50% of caloric intake contributes to adipose gain

Where do animals partition nutrients to before anything else?

Maintenance

Why is it difficult to get dairy cows pregnant during lactation?

They partition nutrients toward lactation over reproduction

Which nutrients provide energy for the body to use? Select all that apply.

Carbs, protein, lipids

The amount of energy to raise the temperature of 1 mL of water by 1 degree Celsius is a _______

calorie

What units of measure are most often used for energy among ruminant nutritionists when evaluating cattle diets?

Mcal

Having a positive retained energy means cattle have enough energy towards development, gain, or lactation. What does it mean when an animal is in a negative energy balance?

Expending more energy than they are getting from food

Immunity, Reproduction, Lactation, Muscle, etc. have a metabolic priority in the body. What happens in the bloodstream regarding delivery of nutrients?

 Changes in nutrient flux depending on the metabolic priority

In the net energy system, there is ______ energy lost between gross energy and digestible energy. Net energy is differentiated from metabolizable energy due to _____ energy losses.

fecal, heat

What does TDN stand for?

Total digestible nutrients

What is the fatal flaw with the TDN calculation?

 The assumption that protein and carbohydrates have the same amount of energy per gram

Animals metabolize protein to use for energy. What happens when an animal consumes more protein than it needs?

Energy is lost through urea

T/F: The energy in 1 kg of corn = the energy in 1 kg of alfalfa

False

Why is the TDN assumption of energy from protein an issue?

• amount of protein consumed is dynamic

• it can depend on the animals need to metabolize protein for energy

• there is not always the same metabolic cost to metabolize protein from animal to animal

Energy is important when formulating cattle diets because we want to add pounds to an animal that will increase its value at market. How can we guess the final shrunk body weight of an animal we are feeding?

• using frame size

• using mother’s body weight at maturity

• using industry averages

It is difficult to measure NEg in growing animals. Why is it much easier to measure energy used by a dairy cow?

Energy can be directly measured trough the milk

The types of glycosidic linkages between monosaccharides have major effects on energy and gain when metabolized in a growing animal.  What type of glycosidic linkage does sucrose have?

alpha

Which is not a function of carbohydrates used by ruminants?

Structural components of muscles fibers

T/F carbohydrates are required for the body each day to function

False

Amylose, Amylopectin, and Glycogen are all forms of starch used by ruminants. What is the structural benefit of these molecules being branched? Select all that apply.

• Branched molecules have a greater amount of anomeric carbons to increase solubility in water

• braning compacts the molecule requiring less space

In aerobic fermentation, oxygen acts as the final electron acceptor. What does not act as a final electron acceptor in anaerboic fermentation?

Ca+

Ruminant ______  can breakdown starch, cellulose, and hemicellulose into glucose or fructose. Glu and Fru go through      __________ to form pyruvate. Pyruvate creates _______ from fermentation that can further be metabolized and used by the animal. 

microbes, glycolysis, VFAs

Microbes are beneficial when an animal does not have the ability to digest a nutrient itself. What is a cost to the ruminant with the presence of microbes?

Microbes oxidize nutrients the animal could utilize on its own

VFAs are important because they are used for many functions throughout the body. Acetate is used for ________ synthesis.  _________  is used in gluconeogenisis to form glucose. Epithelial fuel sources, like _______ , are other types of energy that allow for glucose sparing by gastrointestinal tissues. 

Lipid, Propionate, Butyrate

What are the benefits of altering the VFA profile to propionate?

Decreased methane production

increases circulating glucose

Feed processing increases rates of digestion and influences changes in VFA's, like greater propionate digestion. Which is not a type of feed processing?

Adding an essential oil

Ionophores, like monensin, are used in more than 90% of cattle diets. What is an effect of adding an ionophore to a ration?

Increased propionate production

Buffers are used in cattle diets to control acidity of the rumen. Typically, a weak base is used. It dissociates and creates an ion in the rumen. The greater amount of ions create a ________ environment that increases body water flow into the rumen. Essentially, flushing the __________ out of the rumen and diluting the ruminal liquid

Hydrophobic, Acid

Lactic acidosis is caused when the pH decreases and lactogenic bacteria take over due to highly fermentable carbohydrates in the diet. What are signs of lactic acidosis? Select all that apply.

Abscessed liver, poor feed intake, diarrhea, laminitis

T/F: Fiber is digested in the small intestine of ruminants

False

Associative effects can be positive or negative depending on the concentrate:forage ratio and bacteria that participate in the fermentation of those feeds for energy. What is an example of a negative associate effect?

Competition within the microflora of the rumen

Amino acids are all structured with an amine group, a carboxyl, and an R group. Which amino acids are used in protein production?

Alpha

From the diet, proteins are used for many metabolic mechanisms. What is not a function of protein?

Formation of triglycerides

The multiple stave hypothesis explains that ruminants can only synthesize as much protein according to the concentration of the limiting amino acid. What can we do to increase protein synthesis?

Increase the concentration of the limiting amino acid

Crude protein is a guess based off of the percent Nitrogen multiplied by a constant. Why do nutritionist use crude protein versus true protein? Select all that apply.

• It is hard to account for microbial crude protein

• nitrogen concentration is easily measurable

In ruminal fermentation of protein, there is a soluble fraction, a potentially fermentable fraction and a non-fermentable by microbes fraction. Which parts make up the equations for ruminally degradable protein and ruminally undegradable protein?

RDP= cA+dB

RUP = c+ uB

The rate of disappearance (Kd) of protein is influenced by what factors? Select all that apply.

Heat, particle size, rumen pH

The concept of asynchrony revolves around the animal rapidly fermenting carbohydrates, but not having enough protein available to the microbes. What is a consequence of this?

Decreased fermentation

Why is it less common to see protein and carbohydrate synchrony?

The urea cycle keeps high amounts of protein cycling for 3-4 days

Why does the liver resynthesize urea from ammonia (NH3) and CO2?

NH3 is a charged molecule

How much metabolizable protein is provided to the ruminant from MCP?

64%

T/F: amino acids fed to an animal are the same amino acids found in the product made from the animal. 

False

Limiting amino acids prevent protein use by livestock. What can we do when feeding production animals to meet their different amino acid requirements? 

Use protein complementation

What are other ways to increase protein utilization in livestock, besides protein complementation? Select all that apply.

Synthetic amino acids

ruminally protected amino acids

_____ AA are not synthesized in the body but are used for protein synthesis. _______ AA are not synthesized in adequate amounts to support an important physiological process.

essential, functional

Which vitamins can be synthesized in the rumen

Vitamin K, Vitamin B

Is water hardness an issue in terms of palatability for ruminants?

No

Calcium should be supplied at _______ % DM from _______ in cattle rations.

1, limestone

What macro mineral is important to feeding DDGS

Sulfur

In green lush pastures spring cattle may develop grass tetany. Producers can provide high _____ mineral to unlock alternative absorption pathways to alleviate mineral interactions in the spring forages. 

Magnesium

Ruminants lose water in many different ways. Which one has the greatest total body water loss (>50%)?

Respiration

What factors influence water intake in ruminants?

temperature, availability, DMI, Lactation

If cattle do not seem to be eating, what is the first thing a producer should consider?

Checking the waterer

Water can be expressed as a function of body weight. On average, about how much water should cattle be consuming per day?

1 gal/100 lbs

Along the gastrointestinal tract, the epithelium consist of columnar epithelium. These epithelium have directionalitymeaning there is an apical and basolateral side.

columnar, directionality

What is this primary role of vitamins and trace minerals in the ruminant feeding industry

Aid as a vehicle whereby service fees are charged to producers

What is commonly used to protect against iodine deficiency?

Ionized salt

Where are trace minerals typically stored?

tissue

What source of trace minerals is typically the cheapest?

Inorganic

Animals do not require any nutrient as a percent. What is a reasonable estimate to establish a nutrient requirement?

DMI

All warm-blooded mammals eat to a common energy endpoint when not limited by physical fill. T/F

True

When the caloric density of the diet increases then total feed intake _____ and the energy intake _____

decreases, stays the same

What mechanism currently explains how cattle achieve satiety in short periods of time?

hepatic oxidation theory

Chemostatic regulation of intake relates to the hormones and nervous signaling that tell the brain to stop eating. What affects this? Select all that apply.

Rate of digestion, soluble nutrients, caloric density of the diet

Ruminants and nonruminants differ in the sense of metabolic fuels because nonruminants utilize ____________ while ruminants utilize propionate.

glucose F

Feed intake increases propionate that then signals satiety through what reaction

oxidation

The hormone leptin from________ decreases appetite and decreases body weight. Ghrelin is another hormone from the    _______  that increases appetite and increases body weight. 

adipose, stomach

Why might an animal feel hungry if they have increased body fat when leptin is supposed to decrease appetite?

Insulin has a negative feedback on leptin

The hepatic oxidation theory's function on short-term feed intake is thought to function similarly in ruminants and non-ruminants. Why then does the difference in digestion of food in ruminants result in an increased importance when feeding highly fermentable diets? Select all that apply. 

High risk of acidosis, rapid fermentation means more acid production

Are predictions of dry matter intake increased, decreased, or not affected by anabolic steroids?

Increased by 6%

Propionate from rumen fermentation of CHO is used in which metabolic process to help in the formation of energy for the animal to use?

TCA cycle

Dairy x Beef crosses entering the beef system is a great example of how DMI is affected by breed type because...

Crosses eat 4% more than beef animals

What drives predictions of dry matter intake when one assumes no environmental or outside influences?

Caloric content of the diet

The presence of mud   ________ intake and  _________  caloric expenditure.  

decreases, increases

Which ionophore contributes to reductions in daily feed intake?

Monensin

What are the end products of digestion of carbohydrates in the rumen? 

VFA, MCP, CO2, CH4, H

In the digestion theory, which of these variables are (reaction rate, digesta retention time, concentration of reactants, reactor volume) positively related to digestion and which are negatively related to digestion?

reaction rate: positive

concentration of reactants: negative

reactor volume: negative

digesta retention time: positive

What is the y-axis is this graph illustrating retention time?

rate of appearance

What does the letter "C" represent is this graph illustrating retention time?

K1, primary site of pooling

When estimating shrunk body weight, we use body weight x 0.96. Why do we leave 4% out of the estimation? Select all that apply. 

Approximation of digesta in the GIT, cattle lose mass from stress of a trailer

T/F: Breed, sex, and physiological state affect maintenance requirements. 

True

What is the most accurate way to measure maintenance requirements of an animal?

Restrict feed and measure heat loss

What are the end products of digestion of lipids, protein, and nonstructural carbohydrates in the small intestine? Select all that apply.

amino acids, fatty acids, monosaccharides

T/F: Surface area does not define heat lost from the body.

false

Digesta retention time is approximated from reactor volume and digesta flow rate, meaning feed value can differ between a larger cow and a smaller cow. Why is this?

Rumen volume is a function of body size