1211 Beta-hydroxy-beta-methylbutyrate (HMB) supplementation to mouse dams in gestation does not affect birth weight variation or growth of offspring

Abstract

Abstract The objective of this study was to determine if supplementing diets with β-hydroxy-β-methylbutyrate (HMB) calcium salt for mouse dams throughout gestation would improve pup birth weight uniformity and growth performance of offspring. Dams were assigned to one of 4 treatments as follows: control (CON; n = 6), Low Level HMB (LL; 3.5 mg/g diet; n = 7), High Level HMB (HL; 35 mg/g diet; n = 8), and Low Level Pulse fed from gestational days 6 to 10 (PUL; 3.5 mg/g diet; n = 7). Supplementation began at mating and continued until birth. Dams gave birth and lactated for 28 days. Offspring were reared until 8 weeks of age. All mice had ad libitum access to a corn-soybean meal diet, with HMB supplementation provided only to dams during gestation. Supplementation of HMB had no effects on overall gestation and lactation performance of mouse dams. Dietary treatment during gestation did not affect total number of pups born per litter, birth weight of pups, or number weaned. Within litter variation, expressed as standard deviation and coefficient of variation, was not different among treatments for birth weight or weaning weight. Range of body weights within litter at birth, weaning, and 8 weeks of age were not affected by HMB supplementation. Overall, offspring growth performance was similar among treatments. However, body weight at 5 and 8 weeks of age was lower for offspring from the HL dams compared to offspring from LL dams (P < 0.05). Body composition of offspring at 5 and 8 weeks of age was similar regardless of HMB supplementation in dam diets during gestation. In conclusion, dietary HMB supplementation of mouse dams during gestation had no effect on birth weight of offspring, variation in birth weight, or growth performance of offspring.