An automated experimental milker for rat

Area of Science:

• Animal Physiology
• Lactation Biology
• Experimental Method Development

Background:

• Understanding the development of sucking pressure in rat pups is crucial for neonatal research.
• Previous methods for milk collection in rats have limitations.
• Developing an automated system can improve efficiency and consistency in milk yield studies.

Purpose of the Study:

• To investigate the development of intra-oral negative sucking pressure in male and female rat pups.
• To design and evaluate an automated experimental milker for rats.
• To assess the milk yield of lactating rats using the developed automated milker.

Main Methods:

• Sucking pressure was measured using an artificial nipple in rat pups from postnatal days 4 to 18.
• Negative sucking pressure was calculated via regression analysis for days 14 and 18.
• An automated milker utilizing alternating pressures and a microcomputer was employed for milk collection.

Main Results:

• Mean maximum intra-oral negative sucking pressure on day 18 was -160.1 mmHg for males and -103.4 mmHg for females.
• The automated milker was set to a maximum negative pressure of -160 mmHg.
• The maximum mean milk yield achieved was 3.18 g on day 14, adequate for chemical analysis.

Conclusions:

• Significant sex-based differences exist in the development of rat pup sucking pressure.
• The automated experimental rat milker is a viable tool for milk collection, though optimization is needed.
• The milk yield obtained is sufficient for subsequent chemical analyses, supporting its utility in research.