90-day dietary toxicity study with esterified propoxylated glycerol (EPG) in micropigs.

The subchronic (90-day) toxicity of esterified propoxylated glycerol (EPG) was assessed in micropigs. Animals (5/sex/group) received feed containing 5%, 10%, and 17% EPG, mixed accordingly throughout the study to deliver 1.5, 3, and 5 g/kg bw/day of EPG, respectively. Corn oil served as the vehicle control (0 g/kg bw/day). Subsets of animals were evaluated at Week 6; the remainder between Weeks 12 and 14. With the exception of liver and serum vitamin levels, statistically significant difference between control and EPG groups were seen sporadically, and with no apparent connection to treatment and/or no consistency across time intervals. EPG intakes of 3 and 5 g/kg bw/day, but not at 1.5 g/kg bw/day were associated with significantly lower serum 25-OH vitamin D levels. Serum total vitamin D levels were significantly lower across all EPG groups. There were also trends toward lower levels of liver vitamins A and E among EPG-treated animals, but the effects were less consistent. The effects on vitamin levels observed in EPG-treated animals were not accompanied by any signs of vitamin deficiency (e.g., effects on growth, clinical signs, or clinical pathology), and might have been related to the larger mass of EPG acting as a lipid "sink" during transit in the gastrointestinal tract.

A study to develop methodology for feeding 24-hour-old neonatal swine for 3 weeks.

Pediatric evaluations are useful only when the animal model and human neonate have similar timing in system development. The objective of this study was to compare the growth of 24-hour-old swine provided 3 different feeding regimens of a simulated sow milk formula for 3 weeks. Three groups of three swine per sex were used. Group 1 was fed every 4 hours for weeks 1 through 3. Group 2 was fed every 3 hours during week 1 and every 4 hours during weeks 2 and 3. Group 3 (as close to ad libitum as possible) was fed every 2 hours for the first 2 days; every 2.5 hours for the next 2 days; every 3 hours for the next 3 days; and every 4 hours during weeks 2 and 3. No mortality occurred. Body weights were within normal limits. Organ weights, physical and ophthalmologic examinations, hematology and serum chemistry parameters, gross necropsy observations, and microscopic evaluation of the brain, liver, and kidneys were not affected by the three feeding regimens. Day 21 body weight gain of group 3 was greater than that for groups 1 or 2. Mean formula consumption (ounces/day) over 21 days was significantly increased (p < .01) for group 3 (males and combined sexes) compared to the two other groups, supporting the greater weight gain of group 3 versus groups 1 and 2 over the 21-day feeding period. Body weights of the piglets fed simulated sow milk and historical control 21-day-old suckling pigs were within the same range. Only the labor-intensive feeding of simulated sow milk in a regimen close to ad libitum produced maximal weight gain in 24-hour-old piglets during the initial 3 weeks postpartum.