Abstract #T156

# T156
Supplementation of dairy cows with a blend of direct-fed microbes: Thermoregulation and immunity.
L. N. Resende1, R. B. Silva2, A. P. Peconick1, R. A. N. Pereira3,2, M. N. Pereira*1,2, 1Universidade Federal de Lavras, Lavras, MG, Brazil, 2Better Nature Research Center, Ijaci, MG, Brazil, 3Empresa de Pesquisa Agropecuaria de Minas Gerais, Lavras, MG, Brazil.

Probiotics (PBT) may have systemic effects on dairy cows. This experiment evaluated the effect of a liquid supplement containing a blend of viable lactic acid bacteria, spore forming bacteria, and yeast (S. cerevisiae) cultured in consortium (Global Saúde, Brazil/SCD Probiotics, USA) on body temperature and immune response of dairy cows. Twenty-six Holstein cows (185 ± 141 DIM) were individually fed a standard TMR for 14 d and treatments control (CTL) or PBT (3.5 mL/kg of TMR DM) for 56 d, in a covariate adjusted randomized block design with repeated measures over time. Immunity in response to a virus/leptospirosis vaccine on d 36 (D0) was evaluated. Rectal temperatures were increased by PBT at 0900 h (38.3 vs 38.1°C. P < 0.01, SEM 0.05), 1530 h (38.8 vs 38.5°C. P = 0.01, SEM 0.03), and 2200 h (38.5 vs 38.2°C. P = 0.02, SEM 0.07). The frequency of cows with rectal temperature >39.2°C at 1530 h was 18.2% on PBT and 6.3% on CTL (P < 0.01). Skin temperature tended to be increased by PBT at 0900 h (34.1 vs 33.8°C. P = 0.10, SEM 0.13) and was increased at 2200 h (35.1 vs 34.7°C. P = 0.02, SEM 0.12). Sweating rates in wk 4 (90.4 vs 66.9 g/m2/h. P = 0.05, SEM 7.33) and 5 (103.9 vs 72.1 g/m2/h. P = 0.01, SEM 10.34) were increased by PBT. Time spent laying down was reduced by PBT (742 vs 813 min/d. P = 0.04, SEM 29.3). Respiratory rate did not differ (P ≥ 0.34). Interleukin 4 in serum tended to be reduced by PBT on d 0 (779 vs 859 pg/mL. P = 0.10, SEM 38.2) and did not differ on d 7 and 14 relative to vaccination (P ≥ 0.26). Interleukin 12 was reduced by PBT on d 7 (611 vs 709 pg/mL. P = 0.02, SEM 47.4), but did not differ on d 0 and d 14 (P ≥ 0.27). Interferon gamma and Interleukin 10 did not differ (P ≥ 0.20). At d 0, the concentration of monocytes as a proportion of leukocytes tended to be increased by PBT (3.8 vs 5.7%. P = 0.10, SEM 0.83). Milk SCC was increased by PBT (49,500 vs 67,000 cells/mL. P = 0.03, SEM 6,250). The increase in DMI and milk yield induced by PBT was associated with increased body temperature and sweating rate at similar respiration rate, alteration in immunity markers, and increased SCC of cows with low SCC (<100.000 cells/mL), suggesting increased immunity of the mammary gland.

Key Words: probiotic, direct-fed microbes, yeast