Selection for milk production from a lactation biology viewpoint

Area of Science:

• Animal Science
• Genetics
• Dairy Production

Background:

• Dairy cow milk production has dramatically increased over the past 30 years.
• Improvements stem from genetic selection, artificial insemination, nutrition, and mastitis control.
• New management tools also contribute to enhanced dairy operations.

Purpose of the Study:

• To review the impact of selection for milk production on the bovine mammary gland.
• To investigate the relative importance of structural versus functional changes in the udder.
• To explore methods for selecting genetically superior dairy animals.

Main Methods:

• Literature review of studies on dairy cow selection and mammary gland physiology.
• Analysis of research on genetic selection methods and management practices.
• Consideration of techniques for measuring hormones and mammary tissue function.

Main Results:

• Long-term selection for milk production has altered both udder structure and function.
• Improved udder functionality appears to be a more critical factor than structural changes.
• Hormonal and mammary tissue assays are being explored for genetic selection.

Conclusions:

• Selection for increased milk yield has significantly impacted the bovine mammary gland.
• Enhanced udder functionality is crucial for continued genetic improvement in dairy cows.
• Developing precise selection techniques is key for future dairy breeding programs.