Some abstracts do not have video files because ASAS was denied recording rights.
1371
The effect of a monensin controlled release capsule at prepartum on betahydroxy butyrate, milk yield, fat, protein, postpartum diseases, rectal temperature, and body condition in Holstein cows
The objective was to evaluate the effect of a monensin controlled release capsule given prepartum on blood BHB, milk yield, fat and protein, incidence of postpartum diseases, rectal temperature, and BCS in confined Holstein cows. The study was conducted in a 400-cow dairy operation (ME 305 12,500 kg). Cows were housed in a free-stall system, fed a TMR and milked 3X. Eighty cows of parity ≥2 were randomly assigned either a treatment (n=40) or a control group (n=40) at 30 days before expected parturition. Treatment group received a capsule of monensin orally (Rumensin®, ELANCO, Chile, releasing 300 mg of monensin daily for 95 days). Control cows were randomly matched by parity and expected due date. The outcome variables were blood BHB at 7, 14, 21 and 28 days postpartum, rectal temperature up to 3 days postpartum, incidence of retained fetal membranes, metritis, endometritis, monthly test day milk yield, fat (%) and protein (%) and changes in BCS from prepartum (~ 30 days before calving) to calving and from parturition to 30 DIM. Continuous variables over time were analyzed by repeated measure ANOVA. Postpartum disorders were analyzed by logistic regression. BCS changes were analyzed by ANOVA. Monensin group had lower rectal temperature at day 1 postpartum (40.3 vs 38.9 ° C; P = 0.08) and higher protein % on test day 1 (3.51% vs 3.20%) than controls (P = 0.0007). There were no differences for milk yield, blood BHB, fat % over time and incidences of postpartum disorders (P > 0.05). The change in BCS from prepartum to parturition was 0.01 and 0.17 for controls and treated cows, respectively (P = 0.01). The change in BCS from parturition to 30 DIM was – 0.31 and – 0.13 for controls and treated cows, respectively (P= 0.008). It is concluded that monensin improved milk protein on test day 1, decreased rectal temperature on day 1 postpartum and modulated positively the changes in BCS both prepartum and postpartum.
Keywords: monensin, milk yield, diseases