Use of stored equine colostrum for the treatment of foals perceived to be at risk for failure of transfer of passive immunity.

The research article investigates the effectiveness of stored horse colostrum in the treatment of foals believed to be at risk of failing to gain passive immunity after birth. The study utilized a cohort of Thoroughbred foals and mares, and the results suggest that treatment with stored colostrum appears beneficial, although some foals still faced the risk of insufficient passive immunity despite the colostrum treatment.

Objective and Design of the Study

• The objective of the study was to evaluate the efficacy of using stored horse colostrum for treating foals considered at risk for failure of transfer of passive immunity (FTPI).
• A cohort study design was used for the research. The study involved 232 Thoroughbred foals and 191 Thoroughbred mares, where 41 of the mares gave birth to one foal on two different occasions.

Procedures

• Post childbirth, presuckle colostrum samples were collected from the mares. If the colostral refractive index (cRI) was 23% or above, the samples were frozen (-20 degrees C) and stored for at least a week but less than two years.
• Foals, whose mothers produced colostrum with a cRI value of less than 20%, were treated with 300 mL or more of the stored colostrum. This was done within 6 hours following childbirth, administered via a nasogastric tube, and repeated one to four times.
• Twenty-four hours after treatment or suckling, serum samples were obtained from both the treated and non-treated foals for the determination of serum IgG (sIgG) concentration.

Results

• Eight foals and their related dams were excluded from the data analysis. For the remaining 30 treated and 194 non-treated foals, the average sIgG concentration was found to be 1,597 ± 574 mg/dL.
• Thirteen foals (5.8% of the cohort) had sIgG concentrations less than 800 mg/dL. One foal (0.4% of the cohort) had an sIgG concentration less than 400 mg/dL.
• Nine of these foals had suckled from mares producing colostrum with a cRI value of 20% or more, and two foals had been treated with stored colostrum.

Conclusion

• According to the study, treatment with stored colostrum seemed to be effective in preventing FTPI in at-risk foals. However, the research noted that some foals were still at risk for FTPI even after suckling from or being treated with colostrum with adequate cRI values.