The aim of this research was to study rabbit digestive system at two ages during weaning by evaluating alkaline phosphatase (ALP) intestinal distribution and morphological, biochemical and haematological variables. Two groups of six New Zealand White × California rabbits, of 21 and 35 d of age respectively, were used. Significant differences between the two ages on live body weight (P<0.001), small intestine length (P<0.01) and pancreas weight (P<0.01) were noticed, being higher in 35 d rabbits. No differences were observed in the a-amylase activity of the jejunum. Nevertheless, a-amylase activity of blood serum was almost twice in 35-d rabbits compared to younger rabbits (P<0.05). Blood glucose concentration was lower in 35 d rabbits (P<0.05). The values of haematological profile were significantly higher in older rabbits for haematocrit (P<0.001), red blood cell count (P<0.05), haemoglobin concentration (P<0.001) and mean corpuscular volume (P<0.01). No differences due to age were observed for mean corpuscular haemoglobin concentration and mean corpuscular haemoglobin. A strong ALP reaction was observed along the brush border of the villous epithelial cells of the small intestine at both ages, being this reaction more intense at 35 d. There was no ALP positive or a faint /discontinuous reaction along the brush border of the caecum at 21 d while a positive reaction was observed at 35 d. The proximal colon presented an ALP positive reaction at 21 d but stronger at 35 d of life while the colon distal was ALP negative at both ages.
Rabbit; intestine; a-amylase; alkaline phosphatase; haematological profile