1. Assessment of Goat Colostrum Quality and Passive Transfer Status
AASRP Research Summaries
AABP Annual Conference 2019
St. Clair EV, Russell RW, Van Saun RJ*
Department of Veterinary and Biomedical Sciences
Pennsylvania State University

2. Introduction Importance of Ig transfer from colostrum
Fleenor and Stott, JDS 1980
Importance of Ig transfer from colostrum
Health status
Growth performance
Consumption of adequate amount of high quality colostrum most critical factor in kid survival
Methods to assess quality?
AASRP Research Summaries 2019

3. Introduction
Feeding of high-quality colostrum is the single most important event in a kid’s life to ensure viability and survivability
Colostrum quality is based on concentration of immunoglobulin-G (IgG)
Effectiveness of passive transfer is based on delivering sufficient quantity of colostrum in a timely manner relative to birth to achieve adequate blood IgG concentration that would be protective from disease
In dairy calves: 10 mg/ml of serum IgG concentration is desired
Heinrichs et al., USDA:APHIS:VC:NAHMS, 1992
AASRP Research Summaries 2019

4. Study Objectives
Evaluate relationships between colostrum quality, feeding practices and evaluation methods of colostrum absorption
Determine serum IgG concentrations in goat kids post-colostrum feeding
Relate total IgG consumed to serum IgG concentration – evaluate any factors influencing serum IgG concentration
Establish if any relationship between serum total protein and IgG concentration for evaluating colostrum intake
AASRP Research Summaries 2019

5. Materials and Methods
Colostrum and serum samples were collected from a commercial 900-doe goat dairy
All procedures approved by Penn State IACUC
Colostrum IgG determined by Brix and RIA methods
Colostrum feeding protocol: 6-8 oz twice within 24 hrs.
Blood samples were collected from kids between 1-4 days post birth and frozen for analysis
Herd records were collected:
Ewe data: age, LN, # kids (live, dead), dry period, previous lactation lengths, previous production, date of kidding
Mode of feeding (bottle, tube, bucket), volume, timing relative to birth
AASRP Research Summaries 2019

6. Materials and Methods
Kid serum samples (n=57) were analyzed for total IgG concentration
Total serum IgG concentration was determined with an ELISA assay (ZeptoMetrix, Buffalo, NY)
Kid serum samples analyzed for Total Protein (TP; g/dL) by a digital refractometer (MISCO, Solon, OH)
Hemolyzed samples resulted in extremely high TP and were removed from data analysis (n=30 for analysis)
Efficiency calculation assumed 10% of birth weight as blood volume to determine total IgG in blood
AASRP Research Summaries 2019

7. Statistical Analysis
SAS 9.4 Proc GLM, ANOVA to determine significant effects on serum IgG concentration or IgG absorption efficiency:
Model main effects were: IgG consumed; Timing to colostrum feeding and their interaction
Other effects tested included ewe age, LN, #kids, dry period length, kid age at bleeding
Correlation and regression modeling were used to determine predictive relationship between serum IgG and total protein concentration
AASRP Research Summaries 2019

8. Results
Paired (n=114 total) Brix and RID determinations were performed on 58 individual and 56 pooled doe colostrum samples.
These samples were all post-thaw while 58 Brix determinations were made on fresh colostrum samples
Mean ± standard deviation (median, range) RID concentrations for all samples was 71.0 ± 36.8 mg/mL (74.2 mg/mL, mg/mL).
Paired (n=114 total) Brix and RID determinations were performed on 58 individual and 56 pooled doe colostrum samples
Overall post-thaw Brix determinations were 20.7 ± 4.5 (20.3, ). Fresh sample mean Brix values were 21.2 ± 4.7 (21.7, )
AASRP Research Summaries 2019

9. Brix Determination
Brix measurements determined in fresh and thawed colostrum were highly correlated (P<0.0001) for all (r=0.97), individual (r=0.98) or pooled (r=0.76) samples.
Similarly, post-thaw Brix and RID measures were highly correlated (P<0.0001) in overall (r=0.85), individual (r=0.89) and pooled (r=0.77) samples.
Accounting for type of sample (individual vs pooled) influenced (P=0.045) the association between Brix in fresh and post-thaw samples (r2=0.94, P<0.0001)
RID (mg/mL) = 6.97(Brix) (r2=0.73, P<0.0001)
AASRP Research Summaries 2019

10. Results Mean ± SD Median Range Serum Total Protein, g/dL 6.0 ± 0.8 6.0
4.5 – 7.2
Serum IgG, mg/mL
15.8 ± 7.3
15.3
3.1 – 36.1
First feeding colostrum IgG, g
17.6 ± 6.3
18.0
6.0 – 39.0
Total colostrum IgG, g
35.0 ± 11.2
36.1
11.9 – 64.3
Time to first feeding, min
106 ± 136 60
IgG Absorption Efficiency, %
16.8 ±8.8
16.4
3.6 – 52.9
AASRP Research Summaries 2019

11. Factors influencing serum IgG concentration:
Results
Factors influencing serum IgG concentration:
Total IgG consumed showed the greatest influence (P=0.0020) with no effect of method of feeding or time to feeding.
Amount of IgG fed at 1st feeding (P=0.0069), volume at first feeding (P=0.10), time to second feeding (P=0.061) and age (P=0.047) accounted for more variation (r2=0.45, P=0.0093) in serum IgG concentration than total IgG consumed (r2=0.36, P=0.013).
Serum TP (P<0.0001), amount IgG at first feeding (P=0.083), kid age (P=0.017) and interaction of amount at first feeding and kid age (P=0.033) influenced IgG concentration (r2=0.82, P<0.0001)
AASRP Research Summaries 2019

12. Results Factors influencing serum TP:
Overall model (P<0.0001) accounting for time to first and second colostrum feedings, amount fed, age of kid and serum IgG concentration accounted for 84% of variation in TP, but only serum IgG was significant (P=0.0003)
Serum IgG concentration alone accounted for 73% of variation in serum TP (P<0.0001)
Incorporation of age at bleeding (P=0.08) only slightly improved the relationship between TP and serum IgG concentration (r2=0.76, P<0.0001).
Best model (r2=0.82, P<0.0001) included serum IgG (P<0.0001), first feeding amount (P=0.05), kid age (P=0.008) and interaction of first feeding amount and age (P=0.01)
AASRP Research Summaries 2019

13. Serum IgG Relationships
AASRP Research Summaries 2019

14. Results
Total IgG consumed was negatively associated (P=0.012) with IgG absorption efficiency
Time to second feeding (P=0.023) and IgG amount at second feeding (P=0.015) explained the greatest amount of variation (r2 = 0.23, P=0.0016) in calculated efficiency of colostrum absorption
AASRP Research Summaries 2019

15. Conclusions
Brix refractometer can accurately evaluate IgG content in goat colostrum similar to dairy cattle
These data suggest feeding a total of 35 g IgG in two feedings can achieve a serum IgG concentration of 15 mg/mL
A serum total protein value of 6.0 g/dL is associated with a serum IgG concentration of 15 mg/mL
Further research to assess the relationship between health status and IgG transfer to better define passive transfer guidelines.
AASRP Research Summaries 2019

16. Acknowledgements Cypress Grove Chevre goat dairy and farm crew
Dr. Andrea Mongini
Louise Byler for statistical support
American Dairy Goat Association for partial funding
Department of Veterinary & Biomedical Sciences for partial funding
AASRP Research Summaries 2019