Effects of immunomodulatory substances added to milk replacer on white blood cell populations during weaning

PAEZ LAMA, S.; MORALES-DE LA NUEZ, A.; MENDOZA-GRIMON, V.; HERNANDEZ- CASTELLANO, L. E.; SANCHEZ-MACIAS, D.; CASTRO, N.; ARGUELLO, A.

New Orleans, Louisiana.

Encuentro; Annual Meeting of American Dairy Science Association; 2011

American Dairy Science Association and American Society of Animal Science

To investigate the effect of immunomodulatory substances added to milk replacers on white blood cell populations during the first week of weaning, 21 goat kids (Majorera dairy breed) were randomly allotted into 3 groups. The first group was a control (CON), the second group received a daily dose of 200 mg/kg BW of Echinacea purpurea (ECH) and the third group received a daily dose of 20 mg/kg BW of Polypodium leucotomos (POL). Goat kids were artificially raised with a milk replacer ad libitum until they reach 10 kg of life BW. After that, animals were enrolled in the weaning protocol. Starter and fresh water were available throughout the weaning period. The first weaning week goat kids received 1 L/d of milk replacer twice daily (morning and afternoon). A blood sample was obtained before starting the weaning protocol and at the end of the first week in heparin containers. Immediately after collection, 50 μL of unclotted blood were added with 5 μL of CD4 (FITC) and 5 μL of CD8 (RPE) monoclonal antibodies (Serotec, Dusseldorf, Germany) and the reaction ran for 15 min at room temperature. After that, 50 μL of Optilyse (Beckman Coulter, Brea, CA) were added and the reaction ran for 15 min at room temperature to lyses red blood cells. Subsequently, 150 μL of saline serum were added to clarify the solution. Fifteen minutes later, the samples were redden using an FC500 flow cytometry device (Beckman Coulter, Brea, CA). An ANOVA (with repeated measures) procedure from SAS was used. Two white blood cell populations were observed clearly, lymphocytes plus macrophages (L+M) and polymorphonuclear (PMN) at both tested times. Control L+M, PMN and CD8 lymphocytes per mL were lower (P ≤ 0.05) than in preweaning samples but no differences were observed with ECH and POL. Control and ECH CD4 lymphocytes per mL were lower (P ≤ 0.05) than preweaning samples and POL kids. The addition of immunomodulatory substances would improve the immune status during the weaning in goat kids.