Improving On-Site Diagnostics and Sustainability Tactics for Pregnancy Toxemia and Failure of Passive Transfer of Immunity in Meat Sheep in Pennsylvania Farms
Open Access
- Author:
- Sjoberg, Amy
- Area of Honors:
- Veterinary and Biomedical Sciences
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Robert John Vansaun, Thesis Supervisor
Robert John Vansaun, Thesis Honors Advisor
Justin D Brown, Faculty Reader - Keywords:
- Pregnancy Toxemia
Hyperketonemia
Failure of Passive Transfer of Immunity
Meat Sheep
Hand-Held Meters
Colostrum Quality - Abstract:
- Pregnancy toxemia is a nutritional disease that is incredibly detrimental to the meat sheep production industry. Through prevention techniques and early diagnosis, prevalence of this disease could be mitigated. Failure of passive transfer of immunity is also harmful to this industry, responsible for the illness and mortality of many lambs. This study was completed to analyze the use of two hand-held meters for use on farms for early diagnosis of PT and FPTI. There were also objectives to identify a metabolite that may be more indicative of PT status, as well as the sustainability impacts that PT has on a farm. Whole blood samples were taken from ewes during late gestation and from lambs within the first week of life. Ewe blood samples underwent full metabolic profiling and hand-held meters were evaluated using these samples. Lamb serum was harvested off of the blood samples and was evaluated using a hand-held refractometer to investigate total protein. Lastly, colostrum samples were taken after lambing and were evaluated for IgG content. The CentriVet meter illustrated high predictivity for BHB concentrations in whole blood and glucose concentrations in whole blood R^2=0.871 and R^2=0.858 respectively with ,p<0.001. The hand-held refractometer was utilized to evaluate the Brix of the colostrum samples and the total protein of the lamb serum samples. Due to the viscosity and opacity of some of the colostrum samples there were several dilutions that occurred. The predictive ability of the meter with these diluted samples was high (R^2=0.680, p<0.001) though without dilution the meter was less useful in accurately predicting the quality of the colostrum. The refractometer was illustrated to be less predictive of lamb serum IgG concentration (R^2=0.220,p<0.001) though this appeared to be caused by an error in the ELISA reproducibility and not indicative of the meter’s ability to properly measure the total protein. Overall, the lamb performance parameters and IgG measures all had a main effect of breed illustrating Dorsets with higher IgG in colostrum, but the Hampshire crosses with higher birth weight and lamb serum IgG. Lastly, there was no significant association between the BHB and glucose concentration of the ewe and the RID of the colostrum, though there was a small correlation with a negative trend between the glucose from the ewe whole blood and RID of the colostrum. This would indicate that maintaining ewe health can decrease the prevalence of failure of passive transfer of immunity in lambs improving sustainability in sheep farms.