Lecture 9: Ruminant Nutrition Flashcards
What taxonomy are ruminants
Ungulata
What order are ruminants
Artiodactyla
What suborder are cows, bison, goats, sheep
Bovidae
What suborder are camels, llamas, alpacas
Camelidae
What is the definition of a ruminant
Even toed hooved mammals that chew cud and have a complex 4 chamber stomach
What is the order through the 4 chamber stomach
- Reticulum
- Rumen
- Omasum
- Abomasum
What part of the 4 chambered stomach is glandular and synonymous to monogastric stomach
Abomasum
What side of the GI does majority of the rumen occupy
Left
What type of food do concentrate selectors eat
Soluble fibers, berries, fruit
What type of food do intermediate selectors eat
More fiber components, adaptable to both concentrates and low quality feeds
What feeding type is most advanced to foregut utilization
Grass/roughage feeders
What are pseudoruminants
Cud-chewing animals with 3 compartment stomachs and feet that resemble pads more than hooves
What are the first 2 stomachs (C1-2) in a pseudoruminant similar to in ruminant
Reticulum and rumen
What is the third compartment in a pseudoruminant similar to in a ruminant
Abomasum
What compartment in pseudoruminants secretes mucus and buffers
First compartment
What tastes do calves prefer
Sweet (sucrose, fructose, glucose)
What tastes do calves reject
Acidic
What taste do adult cattle prefer
Sweet and salty
What taste do adult cattle reject
Bitter (alkaloids)
Why are ruminant diets so diverse
Change depending on stage of production (ex: lactating, dry, calving, etc)
What do wintered cow-calves normally feed on
Grass
What do dairy cows usually feed on
Mix of hay, grain, vitamins and minerals
*70% grain
What do feedlot steer normally eat
Very high protein diet ~90% grain
Do wintered cows: cow-calf require more crude protein or fiber in their diet
Fiber
Feed intake determines the level of ___
Production
Feed intake affects the rate of __ and digestion in the rumen
Passage
How does cold weather affect feed intake
Increases it, require more energy
How does lactation affect feed intake
Increase it, need lots of energy for milk production
How does pregnancy affect feed intake
Decreases it, especially in last trimester
Feed higher concentrated feed
How does heat affect feed intake
Decreases
How does increased fat intake affect feed intake
Decreases
Provide some management factors that are related to feed intake
- Accessibility to feed
- Method of presentation
- Stress
- Housing conditions
- Handling/care
- Social interactions
Why are anabolic processes critical for a healthy rumen
Convert non-protein nitrogen sources to protein
What are some byproducts of fermentation
VFA, CO2, methane, ammonia, B vitamins, Non toxic compounds
What are some advantages of pregastric fermentation (3)
- Provide energy from fibrous material
- Microbes synthesized provide amino acids
- B complex vitamins
What are some disadvantages of pregastric fermentation (3)
- Digest readily available substrates such as starch, sugar, and proteins
- Reduce quality of high-quality proteins
- Produce a number of toxins
T or F: fermentation is efficient
False
What are some toxins produced by pregastric fermentation
- Nitrates—> nitrites
- Urea—> ammonia
- Non structural carbs—> lactic acid
- Tryptophan—>3-methyl indole
- Isoflabonoid estrogens—> estrogen
How is controlled amounts of urea helpful vs too much can become toxic
- Controlled amounts of urea can be given to cattle to produce proteins
- Too much urea can make too much ammonia and be toxic
How is chewing cud important to maintain ruminal pH
Rumen is producing a lot of VFA causing the rumen to become acidic, chewing cud allows the saliva to produce sodium bicarbonate and phosphates that will buffer ruminal fluid to prevent acidosis
What enzyme breaks down starch
Alpha-amylase
What is the most concentrated VFA in high grain diets
Propionate
What is the most concentrated VFA in high forage diets
Acetate
What are the two potential outcomes of dietary proteins
- Soluble proteins that will be broken down to amino acids—> ammonia and get absorbed in rumen only allowing some proteins to get absorbed in abomasum
- Insoluble proteins bypass rumen and get absorbed in abomasum
What is the fate of free amino acids in the rumen
Get transported into bacterial cells and are utilized for synthesis of microbial proteins and metabolized into energy
What are bypass proteins
Proteins not extensively degraded by rumen
What are natural bypass proteins
Corn proteins, blood proteins, feather meal
What are some ways to modify proteins to make them more bypass like
- Heat
- Chemicals
When fat intake increases digestibility ___
Decreases
Digestibility ___ with increased saturated fats
Decreases
What is the fat content like in forage diets
Low ~1-4%
What are fat contents like in grain diets
Variable but ~4-20%
What happens to fatty acids in the rumen
Take polyunsaturated fatty acids and hydrogenate them to hydrogenated fatty acids
___ acid depresses hydrogenation of FA
Linoleic
Describe the normal pathway of conjugated linoleic acid in a high roughage diet
- Linoleic acid (Cis)
- Stearic acid
Describe the conjugated linoleic acid pathway in high concentrate diets (low ruminal pH)
- linoleic acid (cis)
- CLA isomer (trans)
What is the negative impact of the CLA isomer (trans) as a result of a high grain diet
This isomer is inhibitory to milk fat synthesis
What are the effects of adding fat to ruminant diets (4)
- Reduced feed intake
- Reduced fiber digestion
- Reduced milk fat
- Increased propionate/acetate
Why would you want to add fat to a ruminant diet
- Increase energy density in diet
- Increase milk production or gain
What is the most important thing to make sure a calf gets after birth
Colostrum
How much colostrum does a calf need
10% body weight within 24hrs, at least half within first 3 hrs
When is grain, calf starter added into diet
1st or 2nd week
Why do you want to make sure you don’t overfeed powdered milk to calf
Abomastitis
What type of diet does a far off dry dairy cow (60-30 days) get
High fiber, moderate energy diet
Corn silage, alfalfa, soybean meal, grass hay
What does a close up dry dairy cow (0-30 days) get fed
TMR, moderate energy feed
Older cows are commonly given what 2 weeks prior to next lactation cycle
Minerals with ammonium, calcium chloride, and low magnesium to prevent hypocalcemia
What do lactating dairy cows get fed
TMR
TMR feeding provides better performance in __ and __ production because of ___ consistency
Milk, meat, and rumen environment consistency
What type of proteins should lactating dairy cows be fed, soluble or insoluble?
Insoluble—> bypass proteins
What do cow calf beef cattle get fed
Mostly pasture with some supplements of vitamins, grains and minerals in dry or winter seasons
What is the 7-9-11 rule in feeding beef cattle
Protein requirements are 7, 9, and 11% for mid-gestation, late pregnancy, and lactation respectively
What is the 14-12-10 rule in feeding beef cattle
Protein requirements for feeder calves are 14% in 550-800lbs, 12% in 800-1000lbs and 10% in 1000lbs
What is the 55-60-65 rule in feeding beef cattle
Energy requirements for beef cattle in midgestation are 55%, 60% in late gestation and 65% in early postpartum
What do feedlot cattle get fed
TMR
80-90% concentrate
10% fiber
What % BW should feedlot cattle be eating/day
1.5-3.5%
How many lbs should feedlot cattle gain/day
2.5-3.5lbs
What are some non-protein nitrogen sources that can be added to feedlot cattle diet
- Broiler litter
- Biurate or urea
- Trace minerals
What is the purpose of partitioning agents
Partition energy to muscle and fat
How do implants work as partitioning agents
Increase insulin growth like factor 1 (IGF1) and average daily gain (ADG)
How do ionophores work as partitioning agents
Anti microbials that increase feed efficiency
In addition to increasing feed efficiency, ionophores also prevent __ and ___
Bloat and ruminal acidosis
How does pulmonary edema occur as a result of rumen metabolic disorders
Switching from dry forage to lush green pastures
Lush green pastures are high in tryptophan which converts to 3-methyl indole and that produces a toxic metabolite that damages lung tissue
How do we prevent pulmonary edema from occurring as a result of rumen metabolic disorders
Gradual adaption to pastures high in tryptophan and can give ionophores
What is bloat in ruminants
Gas trapped in rumen, causes abdominal distention and asphyxiation
What is free gas bloat
Gas trapped in rumen contents and forms foam
Results in obstruction in esophagus
What can cause free gas bloat
Animals switched from forage to high grain diets
Fermentable carbs produce lots of gas and decrease pH can increase ruminal contractions
What side of the animal would be distended in bloat
Left—rumen is on the left side
How can you determine if an animal has free gas bloat vs frothy bloat
Pass a stomach tube, in free gas bloat there will be an obstruction in the esophagus but not in frothy bloat
What is frothy bloat
Rumen filled with froth or foam
What can cause frothy bloat
Legumes or grain
How can we treat bloat
- Rumenotomy or trocarization
- Stomach tube- can pass oils through to break up foam
What can be done for chronic bloaters
Sx implant of temporary fistula
What causes ruminal lactic acidosis
Excessive highly fermentable carbohydrates (grain)
What is the number one nutritional feedlot problem
Ruminal lactic acidosis
What do the fermentable carbohydrates in ruminal acidosis produce lots of
VFA and lactic acid which can be toxic
How is hydration affected in ruminal lactic acidosis
Lactic acid creates an osmotic pull of water into rumen, dehydrating animal
How does ketosis happen in ruminants
Usually a result of a negative energy balance caused by high rate of milk production resulting in conversion of FA to ketones
What is polioencephalomalcia
Result of acid build up in the rumen that kills good microbes that produce vitamin B complexes during fermentation. Vit B1 is needed for glucose metabolism in the brain so without that we can get lesions, swelling, necrosis, and edema in the brain
What are some clinical signs of polioencephalomalacia
Dullness, muscular spasms, circling, blindness, convulsions, death
Polioencephalomalacia is caused by a severe deficiency in ___
Thiamin
When does hypocalcemia usually occur in cattle
Post calving, calcium is drained into colostrum and milk
PTH is inactivated by alkaline pH and therefore fails to mobilize calcium from bone
Example diet calculation: Pearson square
Balance 100kg diet so that it contains 16% CP using grain sorghum (9.5% CP) and soybean meal (49% CP)
Soybean meal: 16-9.5= 6.5
Sorghum 16-49%= 33
Total= 33+6.5= 39.5
How much dry matter should a 1600lb cow consume with a desired intake of 3.5% BW
1600(0.035)=56lbs
If you feed a cow 10lbs of 70% dry matter high moisture shelled corn, how many lbs dry matter is she consuming in corn
7lbs
If you feed a cow 10lbs of 18% CP. knowing 90% dry matter, how many lbs of protein is she consuming. Then determine amount of protein on a dry matter basis
- 90% of 10lbs= 9lbs DM
- 9lbs (0.18)= 1.62lbs protein
