Milk-substitute diet composition and abomasal secretion in the calf

Area of Science:

• Animal Nutrition
• Digestive Physiology

Background:

• Milk-substitute diets are crucial for young calf nutrition.
• Understanding protein source effects on abomasal function is key for calf health and performance.

Purpose of the Study:

• To investigate how different protein sources in milk-substitute diets affect abomasal acidity and proteolytic activity in Friesian calves.
• To examine the influence of dry matter intake and concentration on abomasal acidity.

Main Methods:

• Friesian calves (20-58 days old) were fed diets with skim-milk powder (mildly or severely preheated), fish-protein concentrate, or soya-bean flour.
• Abomasal pouches were used to collect gastric juice, and digesta samples were analyzed for pH, titratable acidity, and protease activity.
• Experiment 2 varied dry matter intake and concentration in MHM diets.

Main Results:

• Mildly heat-treated skim-milk powder (MHM) resulted in lower digesta pH and higher titratable acidity compared to other protein sources.
• Acid secretion order was: fish-protein concentrate > MHM > severely preheated skim-milk powder (SHM) >= soya-bean flour (SF).
• Protease secretion order was: MHM > SHM = fish-protein concentrate > SF. Higher dry matter intake increased acid secretion.

Conclusions:

• Protein sources differentially stimulate abomasal acid and protease secretion in calves.
• These variations in abomasal function may influence overall calf performance.
• Dry matter concentration and intake play a role in regulating abomasal acidity.