Presence or severity of hypophosphatemia is not associated with survival outcome in postpartum downer dairy cows.

OBJECTIVE: To evaluate the association between serum phosphorus concentration and the outcome of postpartum downer cows. ANIMALS: Postpartum downer dairy cows presented over a 22-year period. PROCEDURES: In this cross-sectional study (1994 to 2016), medical records of all postpartum downer cows presented to a referral large animal hospital were reviewed. The association between serum inorganic phosphorus concentration and survival was assessed using a multivariable logistic regression. RESULTS: 907 postpartum downer dairy cows were included and classified as hypophosphatemic (mild: > 2.25 to < 3.25 mg/dL, moderate: > 1.50 to ≤ 2.25 mg/dL, and severe: ≤ 1.50 mg/dL), normophosphatemic (≥ 3.25 and ≤ 8.76 mg/dL) or hyperphosphatemic (> 8.76 mg/dL). Hypophosphatemia was observed in 19.4% of the cows (n = 176). Of those, 54.5% (n = 96) were also hypocalcemic. Overall, 58.4% cows (n = 530) survived after hospitalization. Hypophosphatemia was not significantly associated with the outcome of postpartum downer cows (mild: OR = 1.0, 95% CI: 0.6 to 1.8; moderate: OR = 0.5, 95% CI: 0.2 to 1.1; severe: OR = 1.0, 95% CI: 0.4 to 2.4). CLINICAL RELEVANCE: Low serum phosphorus concentration was frequently observed with hypocalcemia and was not associated with the outcome of postpartum downer cows.

Efficacy of sainfoin (Onobrychis viciifolia) pellets against multi resistant Haemonchus contortus and interaction with oral ivermectin: Implications for on-farm control.

The worldwide spread of resistance to anthelmintic (AH) drugs in gastrointestinal nematodes (GINs) imposes to explore alternative solutions. Amongst those, the possible use of tannin-containing nutraceuticals appears as a relevant option to replace (or decrease the frequency of) chemical-based treatments. Our objectives were to test the AH efficacy of sainfoin pellets against a multiresistant strain of Haemonchus contortus in experimentally infected lambs and to examine possible interaction between ivermectin (IVM) and condensed tannins (CT)-rich ressource. In vivo study was performed with twenty-four lambs were inoculated (Day 0) with multiresistant H. contortus infective larvae. On D21 Post-Infection, the lambs were assigned to two dietary treatments (sainfoin vs lucerne control pellets). On D39, half of the animals per group received 0.25ml/kg of an oral ivermectin treatment. On D47, animals were slaughtered to count worms. The consumption of sainfoin was associated with higher packed cell volume (PCV) values (P<0.05) and reduced faecal egg counts (FECs) (P<0.05). For the experimental feeding period, FECs were overall reduced by 50% in the sainfoin group. The diet did not have significant effect on the worm number but sainfoin significantly reduced female fertility. Decrease in plasma IVM concentrations was observed in the sainfoin-fed animals and was associated with a decrease of IVM efficiency when compared with the control group. Incubating tannin in vitro with ivermectin and rumen fluid showed a blocking of ivermectin by the tannins. This suggests that tannins lower the IVM intestinal absorption compromising thereby drug plasma bioavailability and efficacy. Tannin-containing nutraceuticals alter the biology of multiresistant nematodes, thus representing an option for their sustainable control. In vivo and in vitro interactions between nutraceuticals and chemicals impose caution when both tannin-rich diet and drug-based treatments are combined. Further studies are required to clarify the mechanisms that support such interactions.

Prions in milk from ewes incubating natural scrapie.

Since prion infectivity had never been reported in milk, dairy products originating from transmissible spongiform encephalopathy (TSE)-affected ruminant flocks currently enter unrestricted into the animal and human food chain. However, a recently published study brought the first evidence of the presence of prions in mammary secretions from scrapie-affected ewes. Here we report the detection of consistent levels of infectivity in colostrum and milk from sheep incubating natural scrapie, several months prior to clinical onset. Additionally, abnormal PrP was detected, by immunohistochemistry and PET blot, in lacteal ducts and mammary acini. This PrP(Sc) accumulation was detected only in ewes harbouring mammary ectopic lymphoid follicles that developed consequent to Maedi lentivirus infection. However, bioassay revealed that prion infectivity was present in milk and colostrum, not only from ewes with such lympho-proliferative chronic mastitis, but also from those displaying lesion-free mammary glands. In milk and colostrum, infectivity could be recovered in the cellular, cream, and casein-whey fractions. In our samples, using a Tg 338 mouse model, the highest per ml infectious titre measured was found to be equivalent to that contained in 6 microg of a posterior brain stem from a terminally scrapie-affected ewe. These findings indicate that both colostrum and milk from small ruminants incubating TSE could contribute to the animal TSE transmission process, either directly or through the presence of milk-derived material in animal feedstuffs. It also raises some concern with regard to the risk to humans of TSE exposure associated with milk products from ovine and other TSE-susceptible dairy species.