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Maternal body condition during late-pregnancy and its influence on calf development and whole-blood mRNA abundance after ex vivo lipopolysaccharide challenge.

M. G. Lopes

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06-22-2020

Abstract:

77
Maternal body condition during late-pregnancy and its influence on calf development and whole-blood mRNA abundance after ex vivo lipopolysaccharide challenge.
M. G. Lopes*1,2, A. S. Alharthi2,3, Y. Liang2, H. Dai4, V. Lopreiato5, M. N. Corr�a1, J. J. Loor2. 1NUPEEC (N�cleo de Pesquisa, Ensino e Extens�o em Pecu�ria), Departamento de Cl�nicas Veterin�ria, Programa de P�s-Gradua��o em Biotecnologia, Universidade Federal de Pelotas Pelotas, RS, Brazil, 2Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois Urbana, IL, 3Department of Animal Production, College of Food and Agriculture Sciences, King Saud University Riyadh, Saudi Arabia, 4College of Veterinary Medicine, Nanjing Agricultural University Nanjing, China, 5Department of Animal Sciences, Food and Nutrition, Faculty of Agriculture, Food and Environmental Science, Universit� Cattolica del Sacro Cuore Piacenza, Italy.

Body reserves of dairy cows in late-pregnancy are directly related to energy status and play a key role in the partition of nutrients to the rapidly-growing fetus. We investigated effects of maternal body condition score (BCS) during late-pregnancy on calf development and whole blood mRNA abundance after ex vivo lipopolysaccharide (LPS) challenge. Forty-nine multiparous Holstein cows from a larger cohort were retrospectively divided by prepartal BCS into normal BCS ≤3.25 (n = 30; NormBCS) and high BCS ≥3.75 (n = 19; HighBCS) groups. Calf development was assessed through BW, wither and hip height, hip width and body length from birth to 9 wk of age. Blood samples were collected at birth (before receiving colostrum, d 0), and at 21 and 42 (at weaning) days of age for whole blood challenge with 3 �g/mL of LPS before RNA isolation. The statistical model used in SAS 9.4 included BCS, Age and their interactions as fixed effects. A One-Way ANOVA was used to determine differences in body measurements at birth with BCS as fixed effect. Birth BW was lower (P = 0.03) in calves born to HighBCS cows and remained lower (P = 0.04) at 9 wk of age. At birth, whole blood from calves born to HighBCS vs. NormBCS cows had greater (P ≤ 0.03) mRNA abundance of IL1B and GSR coupled with lower GPX1 after LPS challenge. The longitudinal analyses of d 0, 21, and 42 data revealed a BCS x Age effect for GPX1 (P = 0.02) due to lower abundance at birth in blood from calves born to HighBCS vs. NormBCS cows. With the exception of IRAK1, MPO, GSS, and CBS, all genes experienced a decrease (P < 0.01) in abundance over time. Overall, results suggest that BCS in late-prepartum not only influences calf development in utero, but also the abundance of key genes related to cytokine production and antioxidant function in whole blood.

Keywords: BCS, fetal programming, neonatal immunity.

Biography: PhD student in the Biotechnology Graduate Program at the Federal University of Pelotas, Brazil and�Visiting Scholar in the Mammalian NutriPhysioGenomics Laboratory at the University of Illinois, USA