THE EFFECT OF MELOXICAM ON THE ABILITY OF NEONATAL DAIRY CALVES TO ABSORB IGG PROVIDED BY COLOSTRUM REPLACER

The objective of this study was to determine the effect of meloxicam, administered either in pill form immediately prior to colostrum replacer (CR), or powder form, mixed in solution with CR, on the immunoglobulin G (IgG) uptake, growth, and health of pre-weaned calves. A pilot study considering the potential benefits of meloxicam in pre-weaned heifers indicated administration of the drug following difficult parturition improved body weight (BW) and overall health, but was not associated with passive transfer of immunity (Murray et al., 2015). However, calves from this study were sampled from 10 commercial farms, and therefore, treatment administration was inconsistent, indicated by highly variable passive transfer rates from farm to farm. A total of 30 Holstein dairy calves (16 bulls and 14 heifers) with an average BW of 44.3 kg were housed in a naturally ventilated enclosed calf room and blocked by expected birth date. Calves were removed from the dam within 30 min, prior to suckling, weighed, and randomly assigned to 1 of 3 treatments in a randomized complete block design. Treatments were as follows: (1) CR at 0 hours with no meloxicam (control, CON), (2) 1 mg/kg meloxicam in pill form, before administration of CR (P), or (3) 1 mg/kg meloxicam during administration of CR, crushed and mixed into solution (S). All calves were fed 675 g dry matter (DM) CR for a total fluid volume of just over 3 L, providing a dose of 180 g IgG. Beginning at 24 h of life, calves were offered 432 g DM of milk replacer (MR) (24% CP, 17% fat) daily, split into 2 feedings. Free choice textured starter and water were offered from 24 hours until completion of the study at 42 d. Blood samples were collected at 0 h to analyze initial serum IgG and circulating ketone concentrations, and at 6, 12, 18, and 24 h of life to analyze IgG uptake. Blood samples were collected weekly thereafter for analysis of glucose, plasma urea nitrogen (PUN), and blood ketone concentration. Measurements such as time of consumption for MR, BW, length, hip and withers height, and heart girth were also recorded weekly. There was no effect of meloxicam on skeletal measurements or average daily gain (ADG); however, calves having received meloxicam in pill form before CR administration tended to gain length at a faster rate (cm/d) than those having received colostrum crushed into powder and mixed into solution. There was no significant effect of meloxicam on MR intake, time of consumption for MR, total DMI, or feed efficiency; however, calves having received meloxicam tended to consume a greater amount of starter than those having received the CON treatment. This coincided ketone levels which tended to be greater in blood samples from calves having received meloxicam, compared to those which did not, indicative of greater rumen development. There was no effect of meloxicam on PUN. Calves having received meloxicam in pill form had lesser blood glucose concentrations than those having received meloxicam in powder form, mixed into solution. While all calves met passive transfer, and meloxicam did not affect apparent efficiency of absorption (AEA) of IgG, serum total protein (STP), or IgG uptake at 6, 18, and 24 h after birth, calves having received the drug did show decreased IgG uptake at 12 hours. Results of this study suggest that administration of meloxicam at 0 h offers positive effects on starter intake, and therefore rumen development of pre-weaned dairy calves. The dosing of meloxicam in pill form prior to CR, as compared to powder form in solution, also offers positive results for rumen development, indicated by lower blood glucose levels