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Use of avian antibodies against lipopolysaccharides to improve gastrointestinal function in early lactation dairy cows
Subacute ruminal acidosis (SARA) has been associated with decreased milk production in early lactation dairy cows. During SARA, increased lipopolysaccharides (LPS) are released in the rumen from the breakdown of gram negative bacteria, increasing LPS concentrations and potential translocation to blood. Presence of LPS in the blood stream leads to activation of the acute phase response in peripheral blood, which in turn leads to a reduced DMI and milk production. An avian-derived anti LPS polyclonal antibody preparation (PAP-LPS) was developed (Camas Inc., LeCenter, MN) to use as a feed additive in dairy cattle. Our objective was to evaluate the effectiveness of PAP-LPS in decreasing the intensity of the inflammatory response and increasing milk yield on early lactation dairy cows. Primiparous (Pr; n = 174) and multiparous (Mu, n = 226) Holstein cows from one herd were randomly allocated to one of three treatments: 1) PAP-LPS (n = 55 Pr and n = 70 Mu), 2) Placebo (n = 66 Pr and 77 Mu), and 3) Control (n = 53 Pr and 79 Mu). Cows on PAP-LPS received a dose of 3 g/d of PAP-LPS via oral drench in a water suspension, while Placebo received the same dose of a PAP-LPS inactivated by an acid-shock treatment. Control cows did not receive any treatment. The PAP-LPS and Placebo treatments were administered from d 0 (calving) until 14 DIM. Milk production was recorded from d 0 to d 98 and weekly averages were used in a repeated measures analysis using the MIXED Procedure of SAS and a first-order autoregressive covariate structure. The model included the fixed effects of treatment, parity and treatment x parity interactions. Feeding PAP-LPS increased (P = 0.04) total milk production on the first 98 DIM when compared with Control (3881 and 3769 kg, respectively), while only tended to increase it (P = 0.07) when compared to placebo (3785 kg). A week x treatment interaction was observed (P = 0.088) for weekly average milk production. Weekly average milk production was greater (P < 0.05) for PAP-LPS vs. Control on weeks 3, 4, and 10. On week 6, cows fed PAP-LPS had greater (P < 0.05) milk production (44.9 kg/d) when compared with both Control (43.1 kg/d) and Placebo (43.1 kg/d). In conclusion, feeding PAP-LPS increased milk production in early lactation dairy cows, likely due to a reduced inflammatory response during diet transition.
Keywords: Dairy cows, LPS, Avian antibodies