The abomasum is a versatile organ which can expand significantly to hold 6L of milk/milk replacer at one time.

The abomasum works to slowly trickle food into the intestine to prevent the intestine being overloaded. If too much food enters the intestine too quickly, the intestine becomes overwhelmed, food is not fully digested, and it will ferment in the intestine causing nutritional scour.

Intestine becomes overwhelmed, food is not fully digested, and it will ferment in the intestine causing nutritional scour.

Osmolality
Osmolality can be described as the concentration of the solution, or the number of particles in the solution.

Milk is made up of higher levels of butter fat for energy, where as CMRs have higher lactose levels which will increase the osmolality. Ingredients such as delactosed whey have high ash levels which will also raise the osmolality.

Abomasal Bloat
The causes of abomasal bloat seem to be multifactorial, although the condition is not fully understood
Calves will stop eating, may show abdominal bloat, recumbency and often die within 48h
In more mild causes they may be depressed, unwilling to drink and have scour
There is thought to be a bacterial contribution
Preventative measures can include:
Ensure feed regimes are consistent
Provide water at all times
Feed smaller volumes of milk more regularly
Chose milk replacers with milk protein sources rather than plant protein
Do not feed milk replacers at excessively high concentrations - I.e. milk replacers high in plant protein should not be fed above 150g/l