Acute phase response in lactating dairy cows during hyperinsulinemic hypoglycaemic and hyperinsulinemic euglycaemic clamps and after intramammary LPS challenge.

The link between energy availability, turnover of energy substrates and the onset of inflammation in dairy cows is complex and poorly investigated. To clarify this, plasma inflammatory variables were measured in mid-lactating dairy cows allocated to three groups: hyperinsulinemic hypoglycaemic clamp, induced by insulin infusion (HypoG, n = 5); hyperinsulinemic euglycaemic clamp, induced by insulin and glucose infusion (EuG; n = 6); control, receiving a saline solution infusion (NaCl; n = 6). At 48 h after the start of i.v. infusions, two udder quarters per cow were challenged with 200 µg of E. coli lipopolysaccharide (LPS). Individual blood samples were taken before clamps, before LPS challenge (i.e. 48 h after clamps) and 6.5 h after. At 48 h, positive acute phase proteins (posAPP) did not differ among groups, whereas albumin and cholesterol (index of lipoproteins), negative APP (negAPP), were lower (p < 0.05) in EuG compared to NaCl and HypoG. The concentration of IL-6 was greater in EuG (p < 0.05) but only vs. HypoG. At 6.5 h following LPS challenge, IL-6 increased in the NaCl and EuG clamps (p < 0.05), while TNF-α increased (p < 0.05) in the EuG only. Among the posAPP, haptoglobin markedly increased in EuG (p < 0.05), but not in NaCl (p = 0.76) and in HypoG; ceruloplasmin tended to decline during LPS challenge, the reduction was significant when all animals were considered (p < 0.05). Conversely, all the negAPP showed a marked reduction 6.5 h after LPS challenge in the three groups. In conclusion, EuG caused an inflammatory status after 48-h infusion (i.e. decrease of negAPP) and induced a quicker acute phase response (e.g. marked rise of TNF-α, IL-6) after the intramammary LPS challenge. These data suggest that the simultaneous high availability of glucose and insulin at the tissue-level makes dairy cows more susceptible to inflammatory events. In contrast, HypoG seems to attenuate the inflammatory response.

Relation of inflammation and liver function with the plasma cortisol response to adrenocorticotropin in early lactating dairy cows.

In this study we examined the relationship between cortisol and inflammatory status in early lactating dairy cows after a stimulation test of the adrenal cortex. Twenty-four cows were grouped into quartiles (6 cows per each quartile) in accordance with the liver activity index (based on plasma concentration of negative acute phase proteins in early lactation); the quartiles were lower (LO; cows with the lowest liver functionality), intermediate lower, intermediate upper, and upper (UP; cows with the highest liver functionality). Each cow was injected i.v. with 20 µg of a synthetic analog of ACTH at 35 d in milk (DIM). Blood samples were taken to assess inflammatory status, and at 0, 30, and 60 min after ACTH challenge to measure total cortisol. The free cortisol fraction was analyzed in the LO and UP quartiles and the bound cortisol fraction was estimated as the difference between total and free cortisol. The LO, in comparison with the other quartiles, suffered a more severe inflammatory status, with the highest values of haptoglobin, reactive oxygen metabolites, and total nitric oxide metabolites and the lowest concentration of direct or indirect markers of negative acute phase proteins. The cows in the LO quartile had the highest values of plasma nonesterified fatty acids and ß-hydroxybutyrate at 7 DIM, suggesting a more severe body lipid mobilization. The LO quartile cows showed the highest frequency of health problems and the lowest milk yield in the first 35 DIM. Thirty minutes after the ACTH treatment, the concentration of total cortisol was lower in LO in comparison to other groups. Similarly, the bound cortisol fraction was lower in LO versus UP. The adrenal response appeared inversely related with health status after calving (e.g., lower in LO cows, experiencing the most severe inflammatory status). The lower increase in cortisol after the ACTH challenge in cows with greater inflammation (LO quartile) seems a consequence of the lower availability of cortisol-binding globulin synthetized by the liver, but other mechanisms can be involved (e.g., rate of cortisol production, secretion, and metabolic clearance). Our data provide evidence that inflammation and metabolic changes reduce the concentration of circulating plasma cortisol during an acute stress. Hence, the acute phase response in dairy cows should be taken into account to interpret the results obtained from stimulation tests of the adrenal cortex.

Mortalidad perinatal en la provincia de Chubut / Perinatalmortality in the province of Chubut

Se analizarona través de un método clasificatorio sencillo las muertes perinatales (n:115) ocurridas en los hospitales de Comodoro Rivadavia, Trelew, Puerto Madryn y Esquelen 1994. El método empleado puede agrupar rápidamente las causas evitables con el objetivo de desarrollar futuras acciones preventivas o curativas del sistema de salud. En la mortalidad fetal predominaron los fetos macerados con peso menora 2500 grs. En la mortalidad neonatal las causas más comunes fueron: bajo peso y prematurez (66 por ciento) y muy bajo peso (45 por ciento). Casi la mitad de la mortalidad neonatal ocurrió en el primer día de vida. Se comprobó una muy elevada frecuencia (43 por ciento) de falta de control del embarazo en la- mortalidad fetal y neonatal. Los resultados obtenidos con el método clasificatorio propuesto permiten inferir la necesidad de mejorar los niveles de atención primaria dela embarazada y los estándares de atención del neonato de bajo peso para disminuir la mortalidad perinatal

Mortalidad perinatal en la provincia de Chubut / Perinatalmortality in the province of Chubut

Se analizarona través de un método clasificatorio sencillo las muertes perinatales (n:115) ocurridas en los hospitales de Comodoro Rivadavia, Trelew, Puerto Madryn y Esquelen 1994. El método empleado puede agrupar rápidamente las causas evitables con el objetivo de desarrollar futuras acciones preventivas o curativas del sistema de salud. En la mortalidad fetal predominaron los fetos macerados con peso menora 2500 grs. En la mortalidad neonatal las causas más comunes fueron: bajo peso y prematurez (66 por ciento) y muy bajo peso (45 por ciento). Casi la mitad de la mortalidad neonatal ocurrió en el primer día de vida. Se comprobó una muy elevada frecuencia (43 por ciento) de falta de control del embarazo en la| mortalidad fetal y neonatal. Los resultados obtenidos con el método clasificatorio propuesto permiten inferir la necesidad de mejorar los niveles de atención primaria dela embarazada y los estándares de atención del neonato de bajo peso para disminuir la mortalidad perinatal (AU)