Activity of plant wastes on acute phase and immune response in heifers

The effect on acute phase and immune response of a patented protected plant waste (PW), containing mainly terpenes (linalool, p-cimol, myrcene) has been evaluated in dairy heifers under ACTH challenge (AC). The experimental protocol involved 3 groups of 5 heifers that were fed the same basal diet. The CTR group received no PW integration, while experimental groups received 0.3kg/head/day (LOW) or 0.9kg/head/day (HIGH) of PW. After 21 days, all the heifers were treated with ACTH (0.5mg/head of Synachten – Novartis – twice a day) from day 22 to day 26. Blood was sampled before (days 19 and 22) and during (days 24 and 26) AC, and analysed for cortisol, employing an immunoenzymatic kit, and for glucose, ceruloplasmin (Cp), haptoglobin (Hp) and Zn by an automatic analyser (ILab 600, Instrumentation Laboratory) according to Bertoni et al. [1]. Real Time PCR (Sybr® Green chemistry) was performed on total RNA isolated from whole blood, to analyse the transcriptional pattern of TNF-α, IFN-γ, IL-2 and IL-6.

Biochemical data were analysed with a factorial model (GLM) with fixed effects for dose of PW (3 levels), ACTH treatment (2 levels) and their interaction (SPSS, [2]). Biomolecular data were calculated as relative expression (n-fold) compared to animals without PW integration. The n-fold variations before and during AC were analysed with T-test.

In the CTR group, cortisol, glucose, Hp, Cp increased whereas Zn decreased (P<0.01) after AC [3,4] as well as the proinflammatory cytokines. The increase of Hp after AC was lower (P<0.05) in PW groups compared to the CTR group. The administration of high dose of PW (HIGH group) reduced Cp and increased Zn concentrations both before and during AC (P<0.01). No relevant modifications of cytokines expression patterns were observed in relation to PW administration. These results show a positive effect of the administration of PW on the acute phase response, especially at the highest dose.

Aknowledgments: The research was supported by SAFEWASTES, EU Project number 513949, Bruno Stefanon

References: [1] Bertoni, G., Trevisi, E. (1998) Zoot. Nutr. Anim. 24: 17–29. [2] SPSS (1997) Advanced Statistics 7.5. SPSS Inc., Chicago, IL. [3] Arthington, J. D., Eicher, S. D. (2003) J. Anim. Sci. 81: 1120–1125 [4] Cebra, C. K., Heidel, J. R. (2003) J. Vet. Intern. Med. 17:902–7.