Morphological Development of the Gastrointestinal Tract of Helmeted Guinea Fowl (Numida meleagris) at Pre-Hatch and Post-Hatch.

Abstract

This study was conducted to investigate the morphological development of the Helmeted Guinea fowl (Numida meleagris) gastrointestinal tract pre- and post-hatch. Eighty seven (87) eggs were purchased from the Poultry unit of National Veterinary Research Institute (NVRI), out of which eighty one (81) were used for pre-hatch and six (6) were allowed to hatch for post hatch studies. The development was recorded daily at pre-hatch while it was observed at day 1 and 8 at posthatch. The result revealed that at day 8 of incubation a digestive tube appeared with a roundish structure in the middle of the tube. By day 10 of incubation, a dilatation had appeared cranial to the roundish structure identified as the proventriculus. At the same time a small outgrowth appeared at the caudal end of the tube also identified as one of the caeca. By day 11 of incubation, the crop had appeared separating the oesophagus into cervical and thoracic parts, respectively. By days 12 and 13 of incubation the second caecum and the duodenal loop became apparent. With the appearance of the duodenal loop, the gross anatomical development of the guinea fowl GIT was completed. The residual yolk decreased with age until it became vestigial by day 8 post-hatch. This study revealed that days 8-13 of incubation are the most critical period for the gross formation of the GIT in the guinea fowl.