Research Summary - 2
Impact of administering an oral Solanum glaucophyllum/calcium bolus after calving on metabolic parameters following calving in multiparous dairy cows
| Date/Time: |
8/28/2026
14:45
|
| Author: |
Luciano Caixeta |
| Clinic: |
University of Minnesota |
| City, State, ZIP: |
Saint Paul, MN 55108-2020 |
E. Shepley, MS, PhD
1
;
L.S. Caixeta, DVM, PhD
1
;
S.M. Godden, DVM, DVSc
1
;
S. Davis, DVM
1
;
M. Ruch, BS
1
;
R. Leite, DVM (pending)
1
;
T.M. Chagas, DVM
1
;
R. Silveira, DVM, MS
1
;
1Department of Veterinary Population Medicine, University of Minnesota, Saint Paul, MN 55108
Introduction:
Postpartum
calcium (Ca) supplementation is a strategy used to mitigate the mineral drain
associated with the onset of lactation. While many oral calcium boluses
effectively manage transient hypocalcemia in the first 48 h postpartum, they
often fail to address dyscalcemia on day 4. To address this, a bolus was
developed incorporating calcium salts for mineral support alongside Solanum
glaucophyllum (SG) leaf to stimulate intestinal calcium absorption
via the release of 1,25-dihydroxyvitamin D. The inclusion of SG is expected to
increase Ca concentrations for up to 96 h. The objective was to compare serum
Ca, phosphorus (P), and magnesium (Mg) concentrations over the first 96 h in
multiparous cows receiving either a SG/calcium bolus, a commercial calcium
bolus, or no treatment after calving.
Materials and methods:
A
randomized controlled clinical trial was conducted on 8 commercial Holstein
dairy herds (range: 800 to 6,700) in the Upper Midwest. Multiparous cows were
block-randomized using each herd’s farm management software (DairyComp 305, VAS
Inc.) by lactation group and week due to one of three treatments: GB
(Goff-Bol, Silberhorn Animal Health) with two SG/calcium boluses provided as
soon as possible after calving, BK (Bovikalc, Boehringer Ingelheim) with
a first bolus provided as soon as possible after calving and a second provided
12-24 h later, or no treatment (NT) with no bolus given after calving.
Of the 1,870 cows enrolled in the study, a convenience sample of 325 cows (100
GB, 108 BK, and 117 NT) had blood samples collected at either 1, 2, 3, or 4 DIM
depending on the farm visit schedule. Blood samples were collected from the
coccygeal vessel via evacuated tubes without anticoagulant and transported on
ice for analyses. Total blood Ca, P, and Mg were measured in triplicate using
colorimetric assays using a small-scale chemistry analyzer (Chemwell-T, Awareness
Technology Inc). Lab personnel running the analyzer were blinded to treatment.
Data
were analyzed using multivariable linear mixed models. Fixed effects included
treatment, DIM at sampling, parity, milk yield at dry-off or last test day, DIM
at dry-off, and the treatment-by-DIM interaction. Herd was included as a random
effect.
Results:
Overall, serum Ca concentrations (mean ± Std. Err.) following calving were highest in GB cows (8.3 ± 0.37 mg/dL), followed by NT (7.8 ± 0.34 mg/dL) and BK (7.5 ± 0.34 mg/dL). A treatment-by-DIM interaction was observed with no evidence of a difference between treatments detected at 1, 2, or 3 DIM. However, at 4 DIM Ca concentrations of GB cows were higher at 9.0 mg/dL ± 0.39 than both BK cows at 8.0 ± 0.44 mg/dL (P = 0.03) and NT cows at 7.9 ± 0.39 mg/dL (P = 0.01).
Overall, serum P concentrations following calving were 5.0 ± 0.20 mg/dL for GB, 3.9 ± 0.16 mg/dL in BK, and 4.1 ± 0.16 mg/dL for NT. After stratifying by DIM, GB cows had higher P compared to BK at 2 DIM (4.5 ± 0.25 vs 3.6 ± 0.27 mg/dL; P = 0.03), 3 DIM (5.3 ± 0.28 vs 3.9 ± 0.22 mg/dL; P = 0.0002), and 4 DIM (5.9 ± 0.23 vs 4.5 ± 0.27 mg/dL; P = 0.0003). Similarly, GB cows had higher P compared to NT at 3 DIM (P = 0.0005) and 4 DIM (P < 0.0001), with NT levels at 3.9 ± 0.26 mg/dL and 4.4 ± 0.22 mg/dL, respectively.
Overall, serum Mg concentrations were 1.9 ± 0.10 mg/dL, 1.9 ± 0.09 mg/dL and 1.9 ± 0.09 mg/dL for GB, BK, and NT groups, respectively. After stratifying by DIM, Mg concentrations were lower in GB cows at 3 DIM (1.6 ± 0.11 mg/dL) compared to BK (2.0 ± 0.10 mg/dL; P = 0.003).
Significance:
Administration of the Solanum glaucophyllum/calcium boluses after calving extended blood mineral support beyond the first 48 h postpartum. Administration of the GB bolus improved serum Ca and P concentrations during early lactation compared to a conventional calcium bolus or no bolus after calving, particularly at later time points (4 DIM for Ca; 2, 3, and 4 DIM for P). Lower Mg concentrations in GB-treated cows at 3 DIM may reflect improved Ca status, though the magnitudes of differences between treatments were small.
