Effect of the duration of feeding of a protein-free diet on endogenous ileal nitrogen and amino acid loss in the growing pig

✍ Scribed by Suzanne M Hodgkinson; Paul J Moughan; Gordon W Reynolds

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 89 KB
• Volume: 80
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/1097-0010(200007)80:9<1407::aid-jsfa656>3.0.co;2-s

✦ Synopsis

The aim of the study was to determine whether endogenous nitrogen and amino acid excretions at the terminal ileum change over time in the growing pig fed a protein-free diet for 8 days. Seven entire male pigs with an overall mean live weight of 81.6 kg (SEM 3.3 kg) and surgically implanted postvalve T caecum cannulas were fed a semi-synthetic casein-based diet for 8 days. Food was withheld from the pigs for 24 h, after which they were fed a protein-free diet for a further 8 days at a rate of 10% of metabolic body weight per day. Chromic oxide was included in the protein-free diet as an indigestible marker. Ileal digesta were collected continuously from 13:00 to 18:00 h on each day of the experimental period. Endogenous ileal nitrogen ¯ows were determined for each pig each day the protein-free diet was given, and endogenous ileal amino acid ¯ows for the ®rst and eighth days. There were no signi®cant (P b 0.05) effects of the duration of feeding of the protein-free diet on endogenous ileal total nitrogen or amino acid ¯ows, except for the amino acids glycine and cysteine, the ¯ows of which signi®cantly decreased over the 8 day period (P 0.01 and P 0.05 for glycine and cysteine respectively), from (mean AE SEM) 1639 AE 217 to 892 AE 212 mg g À1 dry matter intake (DMI) for glycine and from 173 AE 13 to 127 AE 19 mg g À1 DMI for cysteine. The relative contributions (moles of each amino acid as a proportion of total moles of amino acids) of threonine, glycine and cysteine decreased signi®cantly (P 0.05) and that of proline increased signi®cantly (P 0.05) during the 8 days that the protein-free diet was fed to the pigs.