[Dynamic tracheal collapse in a wagyu calf with multiple rib fractures after dystocia]. / Ein dynamischer Trachealkollaps bei einem Wagyukalb mit multiplen Rippenfrakturen nach einer Schwergeburt.

A dynamic tracheal collapse caused by multiple rib fractures in a neonatal wagyu calf was diagnosed by radiography, endoscopy and computed tomography. Conservative treatment, consisting of the medical treatment of respiratory inflammation and the reduction of environmental and social stress was initiated. The respiratory signs improved significantly, and the calf was discharged. The condition deteriorated after several weeks without treatment, most likely due to of excessive callus formation of the fractured ribs causing increased reduction in tracheal diameter.

Evaluation of the relationship between ionized and total calcium concentrations in blood during the first week of lactation in dairy cows.

BACKGROUND: Diagnosis of subclinical hypocalcemia in cattle is based on concentration of total Ca ([TCa]) in serum or plasma below the reference range, with [TCa] serving as proxy for the concentration of ionized Ca ([iCa]). HYPOTHESIS/OBJECTIVES: To investigate the relation between [iCa] and [TCa] in periparturient cows over time, and its association with various metabolites. ANIMALS: Thirty periparturient dairy cows. METHODS: Prospective observational study. Blood from periparturient cows was obtained between 4 days before and 7 days after calving. Samples underwent blood gas analysis and blood biochemical analysis. The ratio of [iCa] : [TCa] was computed. Repeated measures linear regression analyses, spearman correlation-, Deming regression- and receiver operating characteristic (ROC) analyses were conducted. RESULTS: Correlations between [iCa] and [TCa] ranged from r = 0.55 to r = 0.84. The diagnostic value of [TCa] to identify cows with [iCa] below the arbitrary cut-off of 1.1 mmol/L was weak in particular during the first 24 hours of lactation, but continuously improved toward the end of the study with areas under the ROC curve increasing from 0.64 at d 0 to 0.93 at d +4 after calving. Strongest association with [iCa] : [TCa] were found for albumin (r2 = 0.58, P < .0001), pCO2 (r2 = 0.45, P = .0003), the standard [HCO3 ] (r2 = 0.22, P = .01), lactate (r2 = 0.16, P = .04) and [NEFA] (r2 = 0.15, P = .05). CONCLUSION AND CLINICAL IMPORTANCE: The [TCa] is of limited value to identify cows with subnormal [iCa] in the first hours and days of lactation, a finding apparently attributable to the increased variation of a number of metabolic variables that affect the ratio of [iCa] : [TCa].

Effects of oral or parenteral iron supplementation on haematological parameters, blood iron status and growth in newborn calves fed milk replacer.

BACKGROUND: This study aimed to assess the influence of early life iron supplementation on the haematological parameters of calves fed milk replacer on a high plane of nutrition. METHODS: Thirty calves were allocated to receive either a sham treatment (CON), injection of 1000 mg Fe3+ (INJ) or oral administration of 1050 mg Fe3+ (ORAL), all administered less than 1 hour after birth. Blood was obtained before treatment, on days 1, 3, 5 and 7 of life and once weekly until week 9. Samples were analysed for haemoglobin (Hb), packed cell volume (PCV) and estimated transferrin saturation (%TSAT). RESULTS: The Hb and PCV of calves in the INJ and ORAL groups were above the values of those in the CON group throughout the study. Hb and PCV of the CON group remained within the reference range for calves. The %TSAT exceeded reported ranges in the ORAL group in the first week. Values for the CON group were below the INJ and ORAL groups throughout the entire study. Average daily gain did not differ between treatments. LIMITATIONS: The sample size was insufficient to assess the influence of iron supplementation on disease development. Furthermore, the study was set in a controlled environment and not performed under field conditions. CONCLUSIONS: Oral and subcutaneous iron administration had similar effects on haematological development but resulted in numerically different transferrin saturation. Control animals showed lower Hb and PCV but did not develop overt anaemia.

Effect of Dietary Phosphate Deprivation on Red Blood Cell Parameters of Periparturient Dairy Cows.

Postparturient hemoglobinuria is a sporadic disease characterized by intravascular hemolysis and hemoglobinuria in early lactating dairy cows. The condition has empirically been associated with phosphorus (P) deficiency or hypophosphatemia; however, the exact etiology remains obscure. This paper summarizes two controlled studies investigating the effect of P deprivation during the transition period. In Study I, 36 late pregnant dairy cows were randomly assigned to either a diet with low, or adequate, P content from four weeks before calving to four weeks after calving. In Study II, 30 late pregnant dairy cows were again assigned to either a diet with low, or adequate, P for the last four weeks before calving only. Pronounced hypophosphatemia developed during periods of restricted P supply. In early lactation, a subtle decline of the red blood cell count occurred independently of the dietary P supply. In Study I, anemia developed in 11 cows on deficient P supply, which was associated with hemoglobinuria in five cases. Neither erythrocyte total P content nor osmotic resistance of erythrocytes were altered by dietary P deprivation. Restricted dietary P supply, particularly in early lactation, may lead to postparturient hemoglobinuria, but more frequently causes clinically inapparent hemolysis and anemia in cows.

Liver phosphorus content and liver function in states of phosphorus deficiency in transition dairy cows.

Phosphorus (P) deficiency in early lactating dairy cows is receiving increased attention because of incentives aiming at curtailing environmental pollution with P by reducing dietary P in ruminant diets. An in-vitro study using bovine hepatocytes incubated for 7 days with phosphate (Pi) concentrations of 0.9, 1.8 or 2.7 mmol/L, and an in-vivo study feeding late pregnant dairy cows diets with either adequate (0.28% and 0.44% in DM ante-partum and post-partum respectively) or low P content (0.15% and 0.20% in DM ante-partum and post-partum respectively) from 4 weeks before to 4 weeks after calving were conducted to explore effects of P deprivation on liver function. In vitro the relative abundance of mRNA of key enzymes of the carbohydrate metabolism in incubated hepatocytes and liver metabolites in culture medium were determined. In vivo health and productivity of experimental cows on low and adequate dietary P supply were monitored, and liver tissue and blood samples were obtained repeatedly. Liver tissue was assayed for its triacylglycerol-, mineral and water content as well as for the relative abundance of mRNA of enzymes of the carbohydrate-, fat- and protein metabolism. Reduced Pi-availability was not associated with altered enzyme transcription rates or metabolic activity in-vitro. The most prominent clinical finding associated with P deprivation in-vivo was feed intake depression developing after the first week of lactation. Accordingly cows on low P diets had lower milk yield and showed more pronounced increases in liver triacylglycerol after calving. Although the liver P content decreased in P deficient cows, neither negative effects on enzyme transcription rates nor on blood parameters indicative of impaired liver metabolic activity or liver injury were identified. These results indicate the P deprivation only indirectly affects the liver through exacerbation of the negative energy balance occurring as P deficient cows become anorectic.

Changes of the erythrocyte phenotype and blood biochemistry in dairy calves during the first ten weeks of age.

BACKGROUND: Bovine erythrocytes undergo important changes in their morphology and chemical composition during the first weeks of age, which must be understood to accurately interpret hematology results in calves. The objectives of this prospective cohort study were to describe physiological changes of calf erythrocytes and to investigate mechanisms potentially causing these changes. METHODS: Blood samples from 30 clinically healthy dairy calves were obtained from birth to the tenth week of age in weekly intervals. Hematological and plasma biochemical parameters as well as the mineral electrolyte content of erythrocytes were determined and followed over time. The changes of parameters characterizing the erythrocyte phenotype over time were compared to the changes of plasma and erythrocyte biochemical parameters and possible associations were investigated using correlation and stepwise regression analyses. RESULTS: Although the erythrocyte mean corpuscular volume (MCV) declined from 43.6 ± 3.7 fL to 35.6 ± 3.2 fL between the first and seventh week, the red blood cell count (RBC) increased from 7.2 ± 1.1 × 1012/L to 9.3 ± 1.0 × 1012/L until the fifth week of age. The blood hemoglobin (Hb) concentration increased from 0.96 ± 0.16 g/L to 1.16 ± 0.11 g/L in the first three weeks of age and remained at this level until the end of the study. Changes in MCV were accompanied by a decline of the erythrocyte potassium content (KERY) from 91.9 ± 13.5 to 24.6 ± 7.2 mmol/L and a concomitant increase of the erythrocyte sodium content from 45.0 ± 32.0 to 102.7 ± 26.5 mmol/L. MCV was found to be associated with KERY, the primary determinant of the intra-erythrocyte osmotic pressure from the sixth week of age and with blood hemoglobin, the primary determinant of the intra-erythrocyte oncotic pressure from the eighth week of age, when KERY, blood Hb and MCV already had reached or approached normal levels of adult cattle. The plasma iron concentration was not found to be associated to any of the studied hematological parameters. CONCLUSION: A volume reduction of 20% in bovine neonatal erythrocytes is a physiological change occurring during the first weeks of age and is neither associated with sideropenia nor with anemia in healthy calves. The mechanism driving the observed erythrocyte volume change could not be identified. Results of the correlation and regression analyses indicate that changes in intra-erythrocyte osmotic or oncotic pressure are improbable underlying causes. Results reported here show that KERY is an unreliable indicator for the K homeostasis of the intracellular space in neonatal calves and that a decrease in MCV in early life per-se is an unreliable indicator for the development of microcytic anemia.