56 Vitamin and Mineral Supplementation Throughout Gestation Affects Liver Trace Mineral Status of Dam and Neonatal Calves but not Calf Morphometric Characteristics

Abstract

Abstract Objectives were to evaluate the effects of feeding a vitamin and mineral supplementation (VMSUP) to heifers throughout gestation on trace mineral status of the dam and calf, calving parameters, and calf characteristics. We hypothesized that VMSUP throughout gestation would enhance mineral status in the dam and offspring at birth and positively impact calf morphometric characteristics. Thirty-one Angus-based heifers (body weight [BW]=273.7 ± 1.10 kg) were estrous synchronized, bred with female sexed semen, then were randomly assigned to either a basal diet targeting gain of 0.45 kg/d (CON; n=14) or the basal diet plus a vitamin and mineral supplement (VTM; n=17; 113 g•heifer-1•d-1). Liver biopsies were obtained from dams at breeding, d 84 and 180 of gestation, and at calving from dams and calves. Trace mineral concentrations were determined via inductively coupled plasma mass spectrometry. Calving ease, calf vigor and body weight were recorded at birth, and body measurements were recorded at 24 h after birth. Data were analyzed using the GLM Procedure of SAS using repeated measures analysis when appropriate. In maternal liver, concentrations of selenium and copper were affected by a treatment × day interaction (P < 0.0001), being greater (P < 0.001) for VTM than CON at all post-breeding timepoints and decreasing (P ≤ 0.05) from d 84 to calving; while zinc, molybdenum, manganese, and cobalt were not (P ≥ 0.20) affected by treatment. In calves, concentrations of liver selenium, copper, zinc, and cobalt were greater for VTM than CON (P < 0.05). Gestation length, calving distribution, ease and vigor scores, calf BW and body measurements were not affected by treatment (P = 0.278). Therefore, VTM supplementation throughout gestation affected liver trace mineral reserves of dam and calf; but did not affect calf size or any of the calving parameters evaluated. These results suggest that as gestation progresses, maternal liver mineral stores decrease to provide for the gestating calf.