6 Effect of Exogenous Melatonin on the Cellular and Humoral Response of Holstein Heifer Calves During Vaccination

Autor: Martin, Allie, Machado, Vinicius, Crossland, Whitney L
Rok vydání: 2022
Předmět:
Zdroj: J Anim Sci
ISSN: 1525-3163
0021-8812
DOI: 10.1093/jas/skac028.027
Popis: Despite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in beef and dairy industries. Melatonin has been used as a vaccine adjuvant in many species, yet there are few studies in cattle. It was hypothesized implantation of slow-release (90-day) exogenous melatonin during vaccination could bolster cellular and humoral immune function. The objective was to evaluate the effect of exogenous melatonin on polymorphonuclear leukocyte (PMN) function and adaptive immune response in dairy calves vaccinated against a model antigen (ovalbumin). Total serum protein (TSP) was measured in Holstein heifer calves (n=60; < 3 d old) which were randomly assigned to one of four treatments: either no treatment (CON), a two-series vaccination of 0.5 mg ovalbumin on d 0 and 21 (VAC), an implantation of 24 mg melatonin on d 0 (MEL), or both melatonin and vaccine treatments (MVAC). Jugular blood was collected on days 0, 21, 42, 63, and 84 to measure PMN function and anti-ovalbumin immunoglobulin-G (IgG). Experimental design was a RCBD with repeated measures (day), a two-by-two factorial arrangement of treatments, and block was enrollment cohort. TSP was not correlated with any measurements on day 0 (r2 ≤ 0.16,P ≤ 0.23). There was a treatment by day interaction for median florescent intensity of phagocytosis where MVAC was greater than other treatments on day 42 (P =0.01). Across treatments, neutrophil oxidative burst intensity decreased after day 0 (P < 0.01) and phagocytosis intensity increased toward day 42 and decreased toward day 84 (P < 0.01). As expected, there was a treatment by day interaction (P < 0.01) were vaccinated calves developed greater anti-ovalbumin IgG over time than non-vaccinated calves, and MVAC tended (P = 0.08) to be greater than VAC on d 63. Exogenous melatonin may influence PMN function and potentially IgG response during vaccination.
Databáze: OpenAIRE
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