Abstract
To determine effects of late gestational nutrient restriction (NR) on neonatal blood chemistry and hematology, primiparous fall-calving crossbred beef heifers [BW: 451 ± 28 (SD) kg; BCS: 5.4 ± 0.7] were individually fed either 100% (control; CON; n = 12) or 70% (n = 13) of NASEM net energy and metabolizable protein requirements for maintenance, pregnancy, and growth from d 160 of gestation to parturition. Calf jugular blood was obtained at 0 (pre-suckling), 6, 12, 24, and 48 h postnatally to determine serum chemistry and complete blood cell count. Data were analyzed with fixed effects of treatment, hour, and their interaction, using repeated measures. Calving date was a fixed effect; calf sex was included when P < 0.25. The treatment x hour interaction (P < 0.10) affected total protein, globulin, gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), creatinine, creatine kinase, red blood cells (RBC), hemoglobin, hematocrit, sodium, anion gap, and potassium. Total protein and globulin at 6 to 48 h were greater (P ≤ 0.02) in NR calves. Calves from NR heifers had greater (P < 0.08) GGT at 6, 12, and 48 h and greater (P ≤ 0.07) AST at 0 to 24 h. Creatinine at 24 h and creatine kinase at 6 to 24 h were greater (P < 0.04) in NR calves. Hematocrit from 6 to 24 h and RBC and hemoglobin at 6 and 12 h were greater (P ≤ 0.09) in CON calves. Sodium from 0 to 48 h and anion gap at 6 h were greater (P < 0.09) in CON calves. Calves from NR heifers had greater (P = 0.03) 0 h potassium. Treatment affected chloride, which was greater (P = 0.08) in CON calves. These data indicate calves born to nutrient restricted heifers may experience more trauma at calving but have improved passive transfer.
Complete Blood Cell Count and Retinal Vessel Diameters
