Authors : Mehdi Kazemi-Bonchenari, Kamran Rezayazdi, Hossein Ali Ghasemi, Amir Hossein Farahani, Mehdi Dehghan-Banadaky and Ata Mahdavi
Abstract: This study was conducted to evaluate the effect of Supplemented Rumen Degradable Protein (SRDP) on excretion of Total Purine Derivatives (TPD; urinary allantoin, urinary uric acid, milk allantoin and milk uric acid) and contribution of purine derivatives excreted through urine or milk in TPD. Multiparous lactating Holstein cows (n = 15) with an average Body Weight (BW) of 643 kg, days in milk; 21 days and milk yield 30 kg days•1 fed a basal diet with different levels of SRDP (treatments 1-3 were 0, 50 and 100 g days•1 SRDP, respectively). The TPD excretion was 464.81, 468.70 and 480.83 mmol days•1 for treatments 1-3, respectively (p = 0.009). Urinary allantoin (p = 0.01) and uric acid (p = 0.04) and milk allantoin (p = 0.02) were affected but milk uric acid was not affected by SRDP. Although, the amounts of excreted purines affected with SRDP, the contribution of Urinary Purine Derivatives (UPD) and Milk Purine Derivatives (MPD) to TPD were approximately constant. Urinary allantoin, urinary uric acid, milk allantoin and milk uric acid accounted approximately 91.63, 4.54, 3.07 and 0.73% of excreted TPD, respectively. In conclusion, regardless the effect of SRDP, the results indicate that urinary allantoin accounted the greatest and milk uric acid accounted the least contribution in TPD excretion in lactating Holstein cows.
Mehdi Kazemi-Bonchenari, Kamran Rezayazdi, Hossein Ali Ghasemi, Amir Hossein Farahani, Mehdi Dehghan-Banadaky and Ata Mahdavi, 2011. Effect of Rumen Degradable Protein Supplementation on Purine Derivatives Excreted Through Urine and Milk in Lactating Holstein Cows. Journal of Animal and Veterinary Advances, 10: 2389-2393.