Effect of form and of quality of feed on the concentrations of purine derivatives in urinary spot samples, daily microbial N supply and predictability of intake

• Published in: Animal feed science and technology 2000, Vol.85 (3), p.223-238
• Main Authors: Nsahlai, I.V, Osuji, P.O, Umunna, N.N
• Format: Article
• Language: English
• Subjects: Animal productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Intake; Metabolisms and neurohumoral controls; Nitrogen metabolism. Proteins. Glycoproteins. Nucleic acids. Collagen; Prediction; Purine derivatives; Terrestrial animal productions; Urinary spot sample; Urine output; Vertebrates; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0377-8401; 1873-2216
• DOI: 10.1016/S0377-8401(00)00138-3

This study examined the influence of dietary variation on the usefulness of urinary spot purine derivatives (PD) collected at three periods (8:00–9:30, 14:00–15:30 and 20:00–21:30 hours) as predictors of intake by cattle. Diets comprised teff ( Eragrotis tef) straw, fresh and dried napier grass and fresh napier grass supplemented with 1.5 (as fed) of dry alfalfa hay. Variation in dry matter intake (DMI) was further amplified by using calves ranging between 65 and 207 kg live weight ( W). DMI and digestible organic matter (OM) ranged from 1.36 to 7.34 and from 0.67 to 3.88 (kg per day), respectively. The only differences (in intake, digestibility, microbial PD and N supply) among the diets which were significant at least at P=0.05 were due to supplementation with alfalfa. The excretion of allantoin and total PD were within the ranges 3.33–47.37 and 3.60–47.37 (mmol per day), respectively. The sampling period had no influence on the concentration of PD or creatinine (CR) nor on the PD:CR ratio in urine. Diets influenced ( P