Relationships between urine pH and electrolyte status in cows fed forages

Area of Science:

• Animal Science
• Veterinary Medicine
• Nutritional Physiology

Background:

• Urine pH and electrolyte balance are crucial indicators of bovine health and metabolism.
• Forage-based diets are common in dairy and beef cattle production, influencing physiological parameters.

Purpose of the Study:

• To investigate the relationship between urine pH and electrolyte status (Na, Cl, K) in Holstein dairy cows and Japanese Black beef cows.
• To determine the impact of forage-based diets on urinary parameters in cattle.

Main Methods:

• Collected urine samples and balance measurements from 20 Holstein dairy cows and 24 Japanese Black beef cows.
• Analyzed urine pH and electrolyte concentrations (Na, Cl, K) in relation to dietary intake.

Main Results:

• Dairy cows fed 70-100% forages had a mean urine pH of 8.10. Beef cows fed Italian ryegrass silage and wheat bran had a mean urine pH of 7.73.
• Positive correlations were observed between urine pH and urinary K content (P=0.0012) or K intake (P=0.019) in dairy cows.
• A weak negative correlation was found between urine pH and urinary Na content in dairy cows (P=0.039), with no significant correlations in beef cows.

Conclusions:

• Increased potassium intake may directly elevate urine pH in dairy cows on high-forage diets.
• Electrolyte status, particularly potassium, plays a role in regulating urine pH in forage-fed dairy cattle, but not significantly in beef cattle under these conditions.