367 Early Fetal to Neonatal Vitamin a Supplementation Improves Growth Performance and Development of Muscle and Pre-Adipocyte in Korean Native Calves

Abstract

Abstract This study aimed to investigate the effects of vitamin A supplementation during the early fetal to neonatal stages on growth performance, blood metabolites, and the development of muscle and pre-adipocytes in Korean native calves. Twenty female newborn calves [day 0 of age; initial BW: 31.2 kg (SD 3.07)] were stratified based on whether they received vitamin A supplementation during the early fetal to neonatal stages, and then randomly allocated to four groups using a 2 × 2 factorial arrangement. Vitamin A supplementation was conducted as follows: fetal stage (control: 7,800 IU/kg of as-fed, treatment: 22,800 IU/kg of as-fed); neonatal stage (control: 17,000 IU/day, treatment: 53,000 IU/day). Growth performance, blood variables, mRNA expression in muscle tissue, and muscle fiber diameter were evaluated during the experimental period and analyzed using the MIXED procedure with Tukey's test by SAS 9.4 software. As a result, fetal-vitamin A treatment group exhibited higher (P < 0.05) serum vitamin A concentrations and blood glucose concentrations on the day 3 of age. Similarly, vitamin A supplementation in the neonatal stage significantly increased (P < 0.05) serum vitamin A concentrations at day 30 and 60 of age, as well as albumin and glucose concentrations at day 60 of age. Moreover, both birth and weaning BW were significantly greater (P < 0.05) in calves receiving vitamin A supplementation during the fetal stage. However, feed intake and muscle fiber diameter showed no differences (P > 0.05) between the groups. In addition, supplementation of vitamin A during the fetal stage resulted in upregulation (P < 0.05) of ZNF423 mRNA expression in the longissimus dorsi muscle, whereas neonatal supplementation upregulated (P < 0.05) the mRNA expression of PAX7 and MYF5. Our findings suggested that vitamin A supplementation during the early fetal to neonatal stages can enhance the growth performance of offspring calves and potentially promote an increase in pre-adipocyte and satellite cell storage in muscle tissue. This information can be applied in integrated fetal-neonatal nutrient feeding strategies in beef cattle.