Comparative studies on bone structure in dairy cows with different feeding conditions

Area of Science:

• Veterinary Medicine
• Animal Science
• Bone Biology

Background:

• Bone is a dynamic tissue, and its structure in dairy cows is influenced by diet.
• Understanding dietary impacts on bone morphology is crucial for animal health.
• Previous research has not fully elucidated the effects of specific feed components like rapeseed cakes on cow bone structure.

Purpose of the Study:

• To investigate the histomorphometrical and immunohistochemical differences in bone morphology of dairy cows fed self-produced grain versus rapeseed cakes.
• To identify specific bone-related factors influenced by these dietary components.

Main Methods:

• Histomorphometrical analysis of bone structure.
• Immunohistochemical examination of bone cells and tissues.
• Comparison between two groups of healthy dairy cows with distinct diets (self-produced grain vs. rapeseed cakes).

Main Results:

• Rapeseed cake-fed cows had significantly fewer osteocytes per mm² compared to grain-fed cows.
• Absence of BMP2/4 positive cells and a significant increase in FGFR1 in supportive tissues of rapeseed cake-fed cows.
• Differential expression of MMP2, bFGF, apoptosis, defensin, osteopontin, and osteocalcin between the two dietary groups.

Conclusions:

• Rapeseed cake feeding in dairy cows leads to a decrease in osteocytes and an increase in FGFR1, suggesting compensatory growth stimulation in supportive tissues.
• The absence of MMP2 and increased osteopontin/osteocalcin in rapeseed-fed cows indicates potential disturbances in bone mineralization and metabolism.
• These findings highlight the need for further investigation into the long-term effects of rapeseed cakes on dairy cow bone health.