A Meta-Analysis of the Impact of Monensin in Lactating Dairy Cattle. Part 1. Metabolic Effects

Forest plot of the effect of monensin on circulating BHBA in lactating dairy cows. Standardized mean diff. = standardized mean difference (standardized using the z-statistic). Thus, points to the left of the line represent a reduction in the trait, whereas points to the right of the line indicate an increase in the variable. Each square represents the mean effect size for that study. The upper and lower limit of the line connected to the square represents the upper and lower 95% confidence interval (CI) for the effect size. The size of the square reflects the relative weighting of the study to the overall effect size estimate with larger squares representing greater weight. The dotted vertical line represents the overall effect size estimate. The diamond at the bottom represents the 95% CI for the overall estimate. The solid vertical line represents a mean difference of zero or no effect. Study refers to the first author and year of the publication.

Funnel plot of monensin effect on BHBA for assessing publication bias. SMD = standardized mean difference; SE of SMD = SE of the standardized mean difference. The relative size of the circles represents the relative weighting of the study with the larger circles representing greater weight. The horizontal line represents the overall effect size estimate. The 2 diagonal lines indicate an estimate of the 95% confidence interval of the effect size estimate. Interpretation: Publication bias may be present if there are an unequal number of studies (particularly smaller weight studies) on one side of the horizontal line.

Forest plot of the effect of monensin on circulating NEFA in lactating dairy cows. Standardized mean diff. = standardized mean difference (standardized using the z-statistic). Thus, points to the left of the line represent a reduction in the trait, whereas points to the right of the line indicate an increase in the variable. Each square represents the mean effect size for that study. The upper and lower limit of the line connected to the square represents the upper and lower 95% confidence interval (CI) for the effect size. The size of the square reflects the relative weighting of the study to the overall effect size estimate with larger squares representing greater weight. The dotted vertical line represents the overall effect size estimate. The diamond at the bottom represents the 95% CI for the overall estimate. The solid vertical line represents a mean difference of zero or no effect. Study refers to the first author and year of the publication.

Forest plot of the effect of monensin on circulating glucose concentrations in lactating dairy cows. Standardized mean diff. = standardized mean difference (standardized using the z-statistic). Thus, points to the left of the line represent a reduction in the trait, whereas points to the right of the line indicate an increase in the variable. Each square represents the mean effect size for that study. The upper and lower limit of the line connected to the square represents the upper and lower 95% confidence interval (CI) for the effect size. The size of the square reflects the relative weighting of the study to the overall effect size estimate with larger squares representing greater weight. The dotted vertical line represents the overall effect size estimate. The diamond at the bottom represents the 95% CI for the overall estimate. The solid vertical line represents a mean difference of zero or no effect. Study refers to the first author and year of the publication.

Forest plot of the effect of monensin on serum or blood urea concentrations in lactating dairy cows. Standardized mean diff. = standardized mean difference (standardized using the z-statistic). Thus, points to the left of the line represent a reduction in the trait, whereas points to the right of the line indicate an increase in the variable. Each square represents the mean effect size for that study. The upper and lower limit of the line connected to the square represents the upper and lower 95% confidence interval (CI) for the effect size. The size of the square reflects the relative weighting of the study to the overall effect size estimate with larger squares representing greater weight. The dotted vertical line represents the overall effect size estimate. The diamond at the bottom represents the 95% CI for the overall estimate. The solid vertical line represents a mean difference of zero or no effect. Study refers to the first author and year of the publication.

Influence analysis for the effect on monensin on circulating BHBA concentrations. Plot depicts the impact of removing each individual study on the point estimate of the effect size for monensin on circulating BHBA concentrations and on the lower and upper 95% confidence interval (CI) for the effect size. Numbers at the bottom of the graph refer to the standardized mean difference. Individual studies are listed by first author and year of publication.