Impacto a medio y corto plazo del estrés térmico sufrido durante los primeros 90 días de vida en terneras de recría Holstein
Elisa Cáceres MartÃn1, Maria Eugenia Revilla Ruiz2, Gabriela Garay Peña2, Patricia Carulla2, Alejandro Pérez-Navarro2, José Luis Pesántez Pacheco2, Luis Ayala Guanga2, Juan Vicente González Martín2, Francisco Sebastián2, Susana Astiz2
(1)-Department of Veterinary Medicine, School of Biomedical and Health Sciences, Universidad Europea de Madrid, C/ Tajo s/n, 28670 Villaviciosa de Odón, Madrid, Spain (2)-
Introduction: Heat stress (HS) exerts a negative effect on dry matter intake. The aim of this study was to evaluate how nutrition-related metabolic markers evolved after heat stress exposure in Holstein heifers
Material and methods: A total of 321 healthy calves (50% randomly selected from the calves included in a global project at a commercial rearing-farm in Valencia) were sampled and followed from arrival until leaving the farm, or dead/slaughtering. Climate data from the weather station nearest to the farm (Chiva, Valencia; https://www.meteochiva.com/) was collected and daily Temperature-humidity-index (THI) for the first 90 days after the arrival of each calf calculated. Heat stress days (HSd) were days with THI≥72 suffered for ≥14h/day. Four groups were created: “NO-HS” (no HSd, n=130), “Mild-HS” (<3HSd with THI:72-79, n=133), “Moderate-HS” (>3HSd with THI:72-79, n=46), and “Severe-HS” (≥1HSd with THI>80, n=12). Blood samples were collected at “Arrival” 7d after arrival (23.58±8.04d-old); “Preweaning” (at beginning of the reduction in milk intake; 55.28±10.99d-old); “Postweaning” (69.32±9.84d-old) and when moved to collective pens (“pens”; 137.5±17.95d-old). Plasmatic glucose, fructosamine, lactate, β-hydroxybutyrate; non-esterified-fatty-acids, triglycerides, total-cholesterol, high- and low-density-lipoproteins and urea were assessed with bioanalyzer (Konelab-20;Thermo-Fisher-Scientific, USA).
Results: Some results are summarized in the table.
Table. Metabolites in Holstein heifers according to the intensity of heat stress suffered during the first 90d of life.
Most changes in metabolites triggered by heath-stress suffered since arrival at the farm, were observed at postweaning and when moved to collective pens. Metabolites most frequently affected were glucose, triglycerides and HDL. Although changes induced depended on the metabolite, heat stress was associated to reduced levels, excepting urea, which resulted higher in heat-stressed calves.
Conclusions: there was an effect of heat-stress on the metabolism of the rearing Holstein calves. The lipidic profile underwent the greatest changes, with triglycerides and HDL being mostly affected, and the moderated and severed heat stressed calves showing the lowest levels compared to non-heat stressed calves. Therefore, heat-stress suffered during the first 90 days of life was linked to short-and medium-term changes in markers related to the energetic metabolism in rearing Hosltein heifers.
Funding: CDTI-IDI-20200936; P. Carulla’s grant Universitat Politècnica Valencia-PAID-01-20
