Failure of Passive Immune Transfer in Calves: A Meta-Analysis on the Consequences and Assessment of the Economic Impact

Abstract

Low colostrum intake at birth results in the failure of passive transfer (FPT) due to the inadequate ingestion of colostral immunoglobulins (Ig). FPT is associated with an increased risk of mortality and decreased health and longevity. Despite the known management practices associated with low FPT, it remains an important issue in the field. Neither a quantitative analysis of FPT consequences nor an assessment of its total cost are available. To address this point, a meta-analysis on the adjusted associations between FPT and its outcomes was first performed. Then, the total costs of FPT in European systems were calculated using a stochastic method with adjusted values as the input parameters. The adjusted risks (and 95% confidence intervals) for mortality, bovine respiratory disease, diarrhoea and overall morbidity in the case of FPT were 2.12 (1.43-3.13), 1.75 (1.50-2.03), 1.51 (1.05-2.17) and 1.91 (1.63-2.24), respectively. The mean (and 95% prediction interval) total costs per calf with FPT were estimated to be €60 (€10-109) and €80 (€20-139) for dairy and beef, respectively. As a result of the double-step stochastic method, the proposed economic estimation constitutes the first estimate available for FPT. The results are presented in a way that facilitates their use in the field and, with limited effort, combines the cost of each contributor to increase the applicability of the economic assessment to the situations farm-advisors may face. The present economic estimates are also an important tool to evaluate the profitability of measures that aim to improve colostrum intake and FPT prevention.

Fig 1. Flowchart on selection of papers.

BRD: Bovine Respiratory Diseases; ADG: Average Daily Gain; 1: Some papers included several outcomes at a glance; 2: Some papers were excluded at the previous stage (literature review) based on its title.

Fig 2. Forest graph for mortality.

Adjustments were made for the moderator FPT_DIAG1. The column on the left refers to the values of FPT_DIAG1. The column on the right refers to the log-scale observed outcomes (OR or RR) and their relative 95% CIs. The grey squares represent the log-effect size adjusted for FPT_DIAG1.

Fig 3. Forest graph for bovine respiratory disease.

The column on the right refers to the observed outcomes (OR or RR) and their relative 95% CIs.

Fig 4. The total cost of the contributors in cases of FPT for beef and dairy in the baseline scenario.

BRD: bovine respiratory disease; ADG; average daily gain.