Discipline: Biological Sciences
Subcategory: Cell and Molecular Biology
Room: Exhibit Hall
Nallely Mendez - Department of Agricultural Sciences, Fort Valley State University, Fort Valley, GA
Co-Author(s): Yuri Smith (partner) and Sha Tao, Department of Animal and Dairy Science, University of Georgia, Athens, GA
Abrupt milking cessation, or dry-off, of the dairy cow, is a stressful event due to housing and dietary changes, milk stasis, and dry cow vaccination. The early dry period is critical for optimal mammary growth and minimizing new intramammary infections, thereby maximal milk production and lowering mastitis incidence in the subsequent lactation. Dry cow vaccination is normally given on the day of dry-off, but the increased inflammation in the early dry period due to vaccination on the cow’s future performance has been overlooked. Two groups of Holstein dairy cows have enrolled: The Control group receives dry cow vaccination 2 d before dry-off according to farm SOP (n = 55) and the Early vaccination group receives dry cow vaccination at 11 d before dry-off (n = 38). Cows are milked three times a day before dry-off in open-sided free stall barns. An Evaporative cooling system is equipped in the free stall barn including fans over the free stalls and feed bunk and soakers over the feed bunk. Two days before dry-off and on the day of dry-off, cows are only milked once daily and housed on pasture with natural shade, and fed only hay. Blood samples were collected on d -11 (before vaccination), d -9, -7, and -2 (before vaccination) into vacutainers containing sodium heparin or without anti-clotting factors to collect plasma or serum. Peripheral blood mononuclear cells (PBMC) proliferative responses to mitogens (lipopolysaccharide [LPS] and Concanavalin A [ConA]) were evaluated. We exported the daily milk yield before dry-off from the farm DHI system. The milk yield data showed that Early vaccination reduced milk yield before dry-off. The stimulation index data for ConA showed vaccination schedule had no effect on PBMC proliferation in ConA. The stimulation index data for LPS showed Vaccination schedule had no effect on PBMC proliferation in LPS. We can conclude that the early vaccination reduced milk yield before dry-off but did not affect mononuclear cells’ proliferative responses to mitogens immediately after dry-off.References: Steele, N. M., T. H. Swartz, Et al., (2019) The effects of J5 bacterins on clinical, behavioral, and antibody response following an Escherichia coli intramammary challenge in dairy cows at peak lactation. J. Dairy Sci. 102:11233-11249.Carpenter, A. J., C. M. Ylioja, et al., (2016) Hot topic: Early postpartum treatment of commercial dairy cows with nonsteroidal anti-inflammatory drugs increases whole-lactation milk yield. J Dairy Sci. 99:672-679.Mezzetti M, Minuti A, et al., (2020) Inflammatory status and metabolic changes at dry-off in high-yield dairy cows. Italian Journal of Animal Science. 19:51-65.
Funder Acknowledgement(s): I thank Sha Tao, Jing Gao, Yuri Smith, and Caroline G. Savegnago for help in this field at the Department of Animal and Dairy Science. The Funding was provided by the UGA College of Agricultural and Environmental Sciences. This study was partially supported by the UGA College of Agriculture and Environmental Sciences through the UGA-FVSU Rising Scholars Internship program. The author would like to thank for financial support from NSF HBCU-UP (HRD-2011903).
Faculty Advisor: Sarwan Dhir, Dhirs0@fvsu.edu
Role: My involvement in the research included designing the experiments, collecting the data and preparing the date for the poster presentation.