Testing white line strength in the dairy cow

Area of Science:

• Veterinary Medicine
• Animal Biomechanics
• Dairy Science

Background:

• The white line in bovine hooves is crucial for structural integrity.
• Lameness in dairy cattle is a significant welfare and economic concern.
• White line disease is a common cause of lameness, often associated with structural weakness.

Purpose of the Study:

• To investigate the tensile strength of the white line horn in dairy cows.
• To determine factors influencing white line tensile strength, including location and visible damage.
• To evaluate the effect of biotin supplementation on white line tensile strength.

Main Methods:

• Tensile strength testing of 576 white line horn samples from 14 dairy cows over 6 months.
• Samples collected from medial and lateral claws, zones 2 and 3, of hind feet.
• Analysis using a multilevel model, accounting for repeated measures and visible damage; biotin supplementation was assessed.

Main Results:

• Tensile strength varied significantly over time.
• Medial claws were stronger than lateral claws; zone 2 was stronger than zone 3.
• Visibly damaged white line exhibited significantly lower tensile strength; biotin supplementation had no effect.

Conclusions:

• Damage to the white line compromises its tensile strength.
• In healthy horn, the white line is biomechanically weaker in lateral hind claws and distal regions (zone 3).
• The distal lateral hind claw (zone 3) is the weakest point, correlating with common sites of white line disease lameness.