Prepartum anti-inflammatory treatment in Holstein dairy cattle: Effects on type 1/type 2 immunity in neonatal calves

The objectives of this study were to: (1) assess the effects of acetylsalicylic acid (ASA) administration 14 days before the expected calving date to Holstein dairy cows on the type 1/ type 2 immunity in the neonatal period of their Holstein dairy calves, and (2) investigate correlations between type1 /type2 immunity with serum total protein (TP) and immunoglobulin G (IgG) concentration in dairy calves during the neonatal period. Prepartum cows (n = 205) from a commercial dairy farm located in central Pennsylvania were enrolled in the study. At 14 ± 3 d before calving, cows were blocked by parity (Nulliparous [NULL], n = 58; parous [PAR], n = 147) and randomly allocated into one of two treatment groups: (1) ASA (n = 102): Cows received one oral administration with 4 boluses of acetylsalicylic acid (480 grain/bolus; equivalent to 125 g/cow); or (2) PLC (n = 103): Cows received one oral administration with 4 gelatine boluses filled with water. Only live singleton heifer calves were enrolled in the study (ASA-CLF, n = 47 and PLC-CLF, n = 46). Blood samples were collected within 3 days after birth and then weekly until week 4. The data were analyzed using UNIVARIATE and MIXED procedures of SAS as a randomized complete block design, and pearson correlation coefficients were computed using the PROC CORR procedure. Within three days after birth, calves born to ASA-treated cows had higher type 1/ type 2 immunity values compared with calves from placebo-treated cows (ASA-CLF: 0.079 ± 0.003; PLC-CLF: 0.059 ± 0.003; p = 0.0003). Regardless of treatment, the type 1/ type 2 immunity values on study calves significantly declined over time, peaking at 24-72 h of life and reaching its lowest value at 21-23 days of life (24-72 h= 0.06 ± 0.002; 7-9 d= 0.04 ± 0.002, 14-16 d= 0.02 ± 0.002, 21-23 d= 0.01 ± 0.002, p < .0001). The type 1/ type 2 immunity ratios were correlated to both TP and IgG serum concentrations. These findings suggest that ASA treatment might alter neonatal calf immunity, as evidenced by a higher type 1/ type 2 immunity values and that a type-1 biased immunity may be associated with a better passive immune transfer as shown by the correlation between type 1/type 2 immunity values with TP and IgG. Further research is needed to understand the possible mechanisms involved with the type-1 biased immunity observed in study calves and its associations with prepartum dam's ASA treatment.