UDDER SIZE IN RELATION TO MILK SECRETION

Area of Science:

• Dairy Science
• Animal Physiology
• Veterinary Medicine

Background:

• Understanding milk production dynamics is crucial for dairy farming efficiency.
• Previous assumptions about milk secretion during milking required empirical validation.

Purpose of the Study:

• To determine the proportion of milk present in the dairy cow udder at the time of milking.
• To investigate the relationship between udder size and milk yield.
• To estimate the amount of secreting tissue required for milk production.

Main Methods:

• Analysis of milk presence in the udder prior to and during milking.
• Correlation studies between udder dimensions and milk yield.
• Estimation of secreting tissue mass relative to milk production.

Main Results:

• The majority of milk is present in the udder before milking commences.
• Milk secreted during milking does not exceed 20% of the total yield.
• Udder size is a strong indicator of a cow's milk secretion capacity.
• Approximately 1/5 pound of secreting tissue is needed to produce 1 pound of milk in 15 hours.
• Dry udder weight ranges from 6 to 8 pounds.

Conclusions:

• Dairy cow milk is primarily pre-formed in the udder, not secreted during milking.
• Udder size is a reliable predictor of milk yield potential.
• Specific tissue-to-milk ratios provide insights into mammary gland efficiency.