Directory UMM :Data Elmu:jurnal:A:Animal Feed Science and Technology:Vol85.Issue3-4.Jun2000:
Animal Feed Science and Technology
85 (2000) 223±238
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
I.V. Nsahlai*, P.O. Osuji, N.N. Umunna
International Livestock Research Institute (ILRI), P.O. Box 5689, Addis Ababa, Ethiopia
Received 10 November 1998; received in revised form 26 April 1999; accepted 9 March 2000
Abstract
This study examined the in¯uence 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 ampli®ed 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 signi®cant at least at P0.05 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 in¯uence on the concentration of PD or creatinine
(CR) nor on the PD:CR ratio in urine. Diets in¯uenced (P
85 (2000) 223±238
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
I.V. Nsahlai*, P.O. Osuji, N.N. Umunna
International Livestock Research Institute (ILRI), P.O. Box 5689, Addis Ababa, Ethiopia
Received 10 November 1998; received in revised form 26 April 1999; accepted 9 March 2000
Abstract
This study examined the in¯uence 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 ampli®ed 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 signi®cant at least at P0.05 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 in¯uence on the concentration of PD or creatinine
(CR) nor on the PD:CR ratio in urine. Diets in¯uenced (P