Substitution of corn by mesquite pod meal in pellet diets for lambs: nitrogen compounds metabolism

Abstract

Quantification of total excretion of urine is essential to describe processes such as nitrogen balance, or even to estimate metabolizable energy and microbial protein synthesis by excretion of purine derivatives (PD). Total collection of urine for 24 hours over nine days, is laborious, very uncomfortable for the animals, and can interfere with other variables. For this reason, it is important to develop methodologies that allow the shortest possible time of urine collection, or even to make the total urine collection unnecessary. One opportunity is the use of spot urine collection with estimates based on creatinine excretion. In this context, the present study was conducted to compare the excretion of urinary metabolites using spot urine collection at intervals of 4 hours with those obtained from total urine collection lasting 24 hours in lambs.