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Gross morphology, morphometric characteristics, and sequential changes in digesta fiber fractions of gastrointestinal tract segments from high postpartum piglet mortality extensively reared swine
The gross morphology, morphometric characteristics, and sequential changes in digesta fiber fractions of gastrointestinal tract segments harvested from high postpartum piglet mortality (21.79%) of extensively reared swine were investigated. Swine had access to forage with moderately high NDF (50 to 60%) and ADF (30 to 43%) throughout this study and consumed a basal diet of corn and soybean with added minerals. Harvested stomach was dissected and emptied of its content (900g of digesta) via a 4cm incision in the cardiac/oesophageal region. Stomach volume was 4,540 ml and its empty weight (579.14 g) was below that reported for concentrate fed intensively reared swine (0.64% versus 1.20% of body-weight). In addition, a conspicuous 6.5 cm long fingerlike sacculation and segmentation of the fundus was visible both externally and along the inner walls of the dissected stomach. The length of the small intestine (18.69 m) was equivalent to average values reported for adult swine (18 m). The large intestine length (455 cm) was greater than 50% of the value reported for adult swine (750 cm). Stomach, caecum (proximal, medial and distal regions), and colon digesta were sampled and analyzed for DM, NDF and ADF content. Stomach digesta NDF and ADF (24.53 and 12.98%) reflected the values expected for extensively reared swine consuming soybean meal and corn concentrate. NDF and ADF values of caecum proximal (32.47 and 16.67%), medial (35.98 and 19.24%), and distal (31.78 and 16.69%) regions were higher than those of a composite colon digesta sample (25.47 and 13.06%). The DM values of caecum proximal (14.70%), medial (16.10%), and distal (19.44%) regions were lower than those of a composite colon digesta sample (23.19%). Hence, extensively reared swine display intestinal morphology and morphometric characteristics which indicate the need for caecal digestion and colon absorption of nutrients. However, even these modifications may be inadequate to meet nutrient requirements of gestating extensively reared swine, as evidenced by high early postpartum piglet mortality rates of this study’s herd.
Keywords: morphology; GIT; mortality