APSC MIDTERM

describe major dairy breed with average fat content (list 4)

Jersey: 4.8% 

Holstein: 3.6%

Guernsey: 4.6%

Ayrshire: 4%

major breed of dairy goat

Sable

Alpine

Nubian

Saanen 

roles of rumen microorganisms/bacteria 

• cellulose digestion

• starch digestion

• protein digestion

• produce fatty acids 

explain rumen vs monogastric characteristics(3 comparisons)

1. rumen doesn’t have amylase enzyme, monogastric has the enzyme, like silva to digest glucose 

2. rumen has billion cells of bacteria supplying amino acids to complete micro protein synthesis. no micro protein in monogastric doesn’t supply bacteria 

3. rumen utilizes cellulose; monastic doesn't have cellulase enzyme therefore does not produce cellulose

Major rumen volatile fatty acid 

• Acetetic

• propunic 

• butyric 

Classify rumen bacteria

• cellulose digesting bacteria: digest the cellulose fibers of plant cell walls by secreting hydrolytic enzymes. 

  • Fibrobacter succinogenes

  • Ruminococcus flavefaciens

  • Ruminococcus albus 

• starch digesting bacteria: ferment all carbohydrates

  • Amylolytic Bacteria

• acid utilizing bacteria: provides a site where the rumen microorganisms can digest carbohydrates, proteins, and fiber.

  • Anaerovibrio lipolytica

  • Fusobacterium necrophorum

  • Megasphaera elsdenii

Pictures, know and identify:

• rumen 

• reticulum

• omasum

• abomasum 

compare cow and horses digestive system 

• horse: larger cecum, postgastric system, after cellulose 

• cow: pregastric system 

Small intestine function 

The small intestine functions in digestion and absorption of nutrients and as an important barrier and immune organ in the body.

saliva function

• buffering agent to protect rumen estrosis 

• supply minerals and nutrients 

• help swallow, mixing food 

describe saliva pH 

The normal pH of grass-fed ruminants is 6-7. A pH value of 5.5-6 is seen in cattle on high-grain diets or pasture-fed cattle with early lactic acidosis.

extra credit:

biological methane gas production system 

• carbon dioxide + hydrogen produce methane gas

• carbon dioxide + acetic acid produce methane gas 

• Carbon dioxide + methanol produce methane gas