On the variation of urinary creatinine in buffalo calves and the effect of dietary protein intake on urinary creatinine, creatinine-nitrogen ratio and creatinine coefficient

SUMMARY Variation in urinary creatinine in nine male and twelve female buffalo calves divided into three equal groups on diets containing three levels of dietary protein intake (low, medium and high) was estimated. The variation in urinary creatinine (% and total) was large from animal to animal and also from day to day ( P < 0·01) in the same animal. It was not affected ( P > 0·05) by the level of dietary protein. The creatinine-nitrogen ratio decreased ( P < 0·01) with increase in the protein level of the ration, but the creatinine coefficient (creatinine per kg body weight) did not differ significantly ( P > 0·05). The male and female animals responded similarly. It was concluded that urinary creatinine (% and total) and the creatinine coefficient cannot be used as an index either in nutrient balance studies or for evaluating ruminant nutrition in general. The creatinine-nitrogen ratio could also not provide a suitable yardstick to evaluate protein status of the animals because of the significant interaction of days × protein. The nitrogen balance is considered to be better for this purpose.