Effects of long-term postbiotic supplementation on dairy heifer calves: Performance and metabolic indicators

Seventy heifer calves were used to evaluate the effects of a postbiotic supplement on growth performance and blood metabolites from birth 219J. Dairy Sci. Vol. 102, Suppl. 1 to wk 18 at a commercial dairy farm in South Dakota. After birth calves were assigned to: 1) Control with no supplement (CON; n = 35) and 2) supplemented with 3 g/d Probisan in milk from birth to weaning, and 1.5 g/kg concentrate mixture after weaning (PRO; n = 35). All calves were fed 2.6 L per meal until wk 8 (weaning transition). A commercial starter was fed ad libitum from d 14 and hay and concentrate mixture after weaning. Body weight, hip width and intake were individually recorded (weekly, biweekly and daily; respectively). Blood was drawn biweekly from birth to measure plasma concentrations of glucose, BHB, and triglycerides. Data were analyzed as a completely randomized design with repeated measures using mixed models (SAS 9.4). No differences were detected (P \u3e 0.10) between groups for average body weight (71.8 ± 0.9 kg), growth rate (785 ± 11 g/d), or hip width (20.1 ± 0.1 cm). Groups consumed similar (P \u3e 0.10) amount of starter from wk 3 to 5 (226 ± 67 g/d), but from wk 6 to 10, PRO calves consumed less (P = 0.043) amounts (CON = 926 ± 51 and PRO = 804 ± 50 g/d). Glucose (103.5 ± 1.21 mg/dL), BHB (0.648 ± 0.035 mmol/L), and triglycerides (13.20 ± 0.71 mg/dL) did not vary (P \u3e 0.10) between groups and no interaction between treatment and week. However, metabolites changed (P \u3c 0.001) throughout time where glucose decreased from 110.4 to 93.7 mg/dL (wk 0 to 6 and 10 to 18, respectively), BHB increased from 0.448 to 1.015 mmol/L (wk 0 to 6 and 10 to 18, respectively), and triglycerides were highest at wk 0 (21.77 mg/dL) and lowest at wk 18 (7.46 mg/dL). These changes were in accordance with the milk consumption reduction and the development of rumen functions throughout time. In conclusion, despite the lower consumption of solid feeds intake from wk 6 to 10 by PRO calves, no differences were detected in growth performance. Blood metabolites were similar between groups and their pattern change over time indicated similar rumen development. Study supported by Pentabiol, Spain