Background
A calf's transformation from a pseudo-monogastric to a fully developed ruminant is a significant challenge.1 Volatile fatty acids, and butyrate in particular, drive ruminal development in terms of size, length and density of ruminal papillae.2 Previous controlled studies had shown increased starter intake and improved average daily gain (ADG) following Megasphaera elsdenii NCIMB 41125 administration to calves.3,4
The aim of this study was to address the health, growth performance and survival benefits of an M. elsdenii capsule in a large-scale study under commercial conditions.
Materials and methods
- 748 Holstein female calves, birth weight 30–60 kg (38.8 ± 4.3 kg).
- One commercial herd in Uruguay.
- Randomised treatment: control (CON, n = 397) and treated (LACT, n = 351).
- LACT received a single oral capsule with 5.0 × 109 CFU of M. elsdenii NCIMB 41125 (LactiproFLX®, Axiota Animal Health) between days 36 and 42. CON remained untreated.
- Weaning at day 62 ± 2; end of the post-weaning period at day 109 ± 4.
Nutritional plan. Transition milk for the first 5 days, then milk replacer until day 63, stepped up to 8 L/d on day 15; from day 43 the milk allowance was gradually reduced until complete weaning on day 63. Pelleted starter (21.7% CP, 7.0% fat, 26.1% starch) was offered ad libitum from day 15. Post-weaning: TMR (22.4% CP, 26.0% starch).
Statistical analysis. The association of treatment group with ADG was calculated using linear regression models, while the association with survival (risk of death or being sold for beef) was assessed with a Cox proportional hazard model. Differences in disease prevalence between treatment groups were assessed using a chi-square test.
The strain
Megasphaera elsdenii NCIMB 41125 was isolated from a high-producing dairy cow in South Africa. As reported on the poster, its distinguishing traits are:
- High specific growth rate (0.94 / h).
- Growth range of approximately pH 4.5 to 6.5.
- D- and L-lactate as preferred substrates.
- Utilises glucose and other carbohydrates.
- Tolerates ionophores.
The poster attributes these traits to reference 5 below (Meissner et al., 2010).
Results
| Variable | Control | LACT | SEM | p-value |
|---|---|---|---|---|
| Birth weight | 38.8 | 39.0 | 0.22 | 0.46† — did not reach statistical significance |
| Weaning weight | 77.2 | 79.0 | 0.50 | 0.01 |
| Final weight | 120.6 | 123.7 | 0.96 | 0.02 |
Did not reach statistical significance.
| Period | Control | LACT | p-value |
|---|---|---|---|
| Birth to weaning | 0.614 | 0.642 | 0.01 |
| Weaning to end of post-weaning | 0.906 | 0.937 | 0.18† — did not reach statistical significance |
| Birth to end of post-weaning | 0.746 | 0.773 | 0.02 |
Did not reach statistical significance.
| Condition | Control | LACT | p-value |
|---|---|---|---|
| Diarrhoea | 4.3% | 5.1% | > 0.2† — did not reach statistical significance |
| Pneumonia | 18.4% | 14.8% | > 0.2† — did not reach statistical significance |
Did not reach statistical significance.
Survival from enrolment (days 36–42) to day 120 of life. Control calves had a 3.26 times higher hazard of dying or being sold for beef than LACT calves (hazard ratio 3.26; 95% CI 1.61–6.60; p < 0.001), from the Cox proportional hazard model. Read off the poster's Kaplan–Meier curves, that corresponds to survival of approximately 97% in the treated group versus 91% in controls at day 120 — a difference of roughly 6 percentage points. The poster does not tabulate the counts, so those two figures are approximate; the hazard ratio is the value it reports.
Gains in body weight were significant at weaning and at the end of the post-weaning period, and the ADG advantage held over the full birth-to-end period. The ADG difference measured only over the weaning-to-end window did not reach significance (p = 0.18), and neither did the differences in diarrhoea or pneumonia (p > 0.2), where diarrhoea was numerically higher in the treated group.
Conclusions
A single oral capsule of M. elsdenii NCIMB 41125 was associated with higher growth performance pre-weaning, higher body weight at the end of the post-weaning period, and greater survival. Measured over the weaning-to-end window on its own, the daily gain advantage did not reach significance (p = 0.18).
References cited on the poster
- Khan M. et al., 2016. «Invited review: Transitioning from milk to solid feed in dairy heifers». J. Dairy Sci. 99:885–902.
- Diao Q. et al., 2019. «Review of Strategies to Promote Rumen Development in Calves». Animals 2019, 9, 490.
- Muya M. C. et al., 2017. «Performance of Holstein calves having free access to milk and dosed with Megasphaera elsdenii». Sci. Agric. v.74, n.3, p.189–194.
- Mazon G. et al., 2025. «Preweaning Megasphaera elsdenii supplementation in dairy-beef calves: impact on performance, behavior, and rumen development». Journal of Dairy Science 108(1):448–463.
- Meissner H. H. et al., 2010. «Ruminal acidosis: a review with detailed reference to the controlling agent Megasphaera elsdenii NCIMB 41125». South African Journal of Animal Science 40(2).
How to cite this poster
Guadagnini M, Moreira Dinardi MM, de Freitas Vidal LM, Martín Martínez M, Mazón G. Effects of a Megasphaera elsdenii NCIMB 41125 oral capsule on growth performance, health and survival in Holstein calves. Poster presented at: ADSA 2026 Annual Meeting; 21–24 June 2026; Milwaukee, WI, USA.
Abbreviations
- ADG
- Average daily gain, in kilograms per day.
- CFU
- Colony-forming units — the count of viable micro-organisms in the dose.
- CON
- Control group: calves that received no capsule.
- LACT
- Treated group: calves that received the single LactiproFLX® capsule.
- CP
- Crude protein, as a percentage of the ration.
- TMR
- Total mixed ration, fed after weaning.
- SEM
- Standard error of the mean — the precision of each average.
- HR
- Hazard ratio, with its 95% confidence interval, from the survival model.
This page is a transcription of the poster above, prepared so that the full results — including those that did not reach statistical significance — are readable, searchable and accessible without opening the PDF.
Limitations. Controls were left untreated: there was no placebo or sham-handled group, so handling at dosing is not controlled for. The poster does not state whether personnel assessing health outcomes were blinded. All 748 calves came from a single commercial herd in Uruguay, which limits generalisation to other herds and management systems. No ethics or animal-care approval is stated on the poster.
Where this page differs from the poster. The poster states «CON calves had 3.26 greater odds of dying or being sold for beef vs LACT (HR 1.61–6.60)». A Cox proportional hazard model yields a hazard ratio, not odds, and 3.26 is the point estimate whose interval is 1.61–6.60 — not a separate quantity. This page reports it as a hazard ratio. The poster also concludes «higher growth performance post-weaning»; the final body weight supports that (p = 0.02) but the daily gain measured over the weaning-to-end window alone does not (p = 0.18), so this page states both. The poster's strain panel additionally carries two product claims — «patented strain» and «proprietary freeze-drying technology» — which are not reproduced here because they are commercial statements, not study findings.
Study funded by Axiota Animal Health, manufacturer of LactiproFLX®. Two of the authors are employees of the company.
LactiproFLX® is a direct-fed microbial, not a prescription medicine. Availability, registration and the claims that may be made differ between markets: follow the label approved in yours.