What is the main thing that occurs in the pre-ruminant phase?
Reticular or Esophageal groove closure
What causes for the esophageal groove to close?
Suckling promotes salivation
As milk passes pharynx, stimulates chemoreceptors with afferent patheways in glossopharyngeal nerve. Receptors react to Na in calves and Cu in lambs
Efferent vagal output leads to groove closure
What does saliva contain to help with milk digestion
Esterase, begins digestion of milk lipids
When does abomasal secretion occur?
What do abomasal secretion contain?
Rennin and HCl
What do Rennin and HCl promote?
Hard curd formation by ppt Ca and caseinate
What does the hard curd formation allow to enter duodenum?
Remaining fractions, whey proteins (albumins and globulins) enter duodenum rapidly
What occurs to hard curd?
SLow digestion - 12-18hrs
Butterfat hydrolyzed by lipase from mammary and esterase from saliva
Ppt caseinate undergoes proteolysis by rennin
What is ruminal drinking
Milk goes to rumen
Lactose fermented to lactic acid
Poor milk clot formation
What occurs to salivary gland during transitional phase?
increase in size and amount secreted
What does proper rumen development during transitional phase require?
What does metabolism become based on during transitional phase?
VFA production, not glucose
What is used instead of rennin in weaning/post weaning phase?
4 benefits of inophores
1. Increase feed efficiency
2. Helps prevent acute lactic acidosis
3. Helps prevent frothy/grain bloat
4. Helps prevent ketosis in lactating dairy cows
4 rumen manipulations
1. Ionophores - monensin
4. Protected enzymes
Addition of selected active microbes whose fermentation pathways are desirable in particular diet
Living organisms administered in dry feed
Need to be fed constantly - not permanently established
2 examples of probiotics
Yeast - absorb starch molecules, increase feed efficiency
Transfaunation - useful in younger animals
Read Carbohydrate engorgement