Quantitative feed restriction or meal-feeding of broiler chicks alter functional development of enzymes for protein digestion

Abstract

1. Two experiments were performed on broiler chicks to determine the effect of either quantitative feed restriction (QFR) from 5 to 11 d of age or meal-feeding (MF) from d 5 to 17 on development of activity of enzymes associated with protein digestion.

2. Proteolytic activity of the proventriculus was reduced by QFR but unaffected by MF.

3. General proteolytic and carboxypeptidase A activities of the pancreas were reduced by QFR and MF.

4. Amino- and dipeptidase activities of the small intestine were increased by QFR. Dipeptidase activity was unaffected by MF.

5. Nitrogen retention of QFR chicks was lower immediately following feed restriction but not in the 2 weeks following return to ad libitum access to feed.

6. Feeding regimen alters functional development of the enzymes of protein digestion and may therefore influence growth rate of broilers.

Acknowledgements

We thank Rob Evans and Steve Burke for their willing help with care and handling of chickens. J.P.S. held a scholarship from the Australian Agency for International Aid (AusAid).

Notes

^†Present address: 8 Elverna Close, Greensborough, Victoria 3088, Australia.

^‡Present address: RMB 2788 McDonald's Track, Seaview via Warragul, Victoria 3820, Australia.

¹Mean ± SE, n = 6 except on d 19 when n = 5 per treatment.

²From d 5 to 11 Group FI 40 chicks were given 40% of the intake of ad libitum fed chicks.

³SBW = starved body weight, chicks were starved for 16 to 18 h before being weighed and killed.

⁴Total activity of jejunum and ileum.

^* P<0.05

^** P<0.01

^*** P<0.001.

Additional information

Notes on contributors

I. Tarvid†

†Present address: 8 Elverna Close, Greensborough, Victoria 3088, Australia.

C.B. Gow‡

‡Present address: RMB 2788 McDonald's Track, Seaview via Warragul, Victoria 3820, Australia.