75 Assessment of allometric changes of visceral organs in pigs from birth to 10 kg bodyweight at 14 days post-weaning

Abstract

Abstract Visceral organs (VO) play a crucial role in nutrient metabolism needed for growth and development. Although many studies have documented selected VO growth during early development or around the time of weaning, few studies have documented complete VO growth from birth through the post-weaning (PW) period. The objective of this study was to assess allometric changes of VO growth from birth through d 14 PW. Crossbred pigs were randomly assigned to slaughter (n = 6, 3 male and 3 female) for tissue collection at birth (pre-suckle), 1 and 7 days after birth, at weaning (20.0 ± 1.3 d), and days 1, 2, 5, 7, and 14 PW. Pigs were fed a common PW diet formulated to meet or exceed NRC (2012) estimates. Body weight (BW) and VO were collected and measured (Table 1). Data were analyzed by ANOVA using GLM procedure of SAS with linear and quadratic effects of age determined by contrast statements. BW, absolute small intestine length (SIL), and absolute large intestine length (LIL) increased (linear, P < 0.001) with age. Absolute stomach, liver, pancreas, and total VO weight (including the previously mentioned organs in addition to heart, lungs, kidneys, and spleen) increased (linear and quadratic, P < 0.0001) with pig age and BW. Relative weight (relative to BW) for stomach (0.52 - 0.82%, respectively), liver (2.99 - 3.17%, respectively), pancreas (0.14 - 0.22 %, respectively), and total VO weight (9.95 - 17.64%, respectively) also increased (linear and quadratic, P < 0.0008) over time (d 0 - 14 PW). The SIL relative to total intestinal length (83.79 - 82.14%, respectively) and relative LIL (16.21 - 17.86, respectively) did not change (P > 0.05) from birth to d 14 PW. In conclusion, the weight of the assessed VO increased hyperallometrically from birth to d 14 PW.