Insulin-Like Growth Factor Levels During Pregnancy in the Cow are Affected by Protein Supplementation in the Maternal Diet

To determine if dietary protein supplementation in early pregnancy alters total circulating insulinlike growth factor (IGF) levels, genetically similar heifers were fed diets containing different levels of protein in the first and second trimesters of gestation. The groups were: low/low (L/L), fed a diet containing 7% crude protein (CP) per kg/DM (low protein) in the first and second trimesters; high/high (H/H), fed a diet containing 14% CP per kg/DM (high protein) in the first and second trimesters; low/high (L/H), fed low protein in the first trimester and high in the second trimester and vice versa for the high/low (H/L) group. At day 62 of gestation, there was a significant difference (

Induced hypocalcaemia in cows and sheep. II. Changes in plasma potassium levels

Mean plasma potassium levels were significantly lowered by 0.39 mmol/l (P 0.01) and 0.48 mmol/l (P < 0.05) respectively for a decrease of 1 mmol/l in EDTA titratable plasma calcium level in two groups of cows in which hypocalcaemia was induced to the 'recumbent comatose' stage by the infusion of NaEDTA over approximately three hours. In these cows plasma potassium levels did not return to normal in parallel with plasma calcium and did not start to rise until at least two hours after the nadir of hypocalcaemia. Plasma potassium levels remained relatively constant in a control experiment in which saline infusions over a similar period of time were carried out in the larger group of cows. Analysis of variance of the results in this group of cows showed a significant (P < 0.01) cow x infusion interaction. No difference in response of plasma potassium levels was observed in two groups of six wethers, one of which was infused with 0.9% saline and acted as a control group while the other was infused with NaEDTA and hypocalcaemia induced. The possible roles of parathormone and stress in producing the observed changes in plasma potassium levels are discussed

Induced hypocalcaemia in ruminants: Changes in some parameters of circulatory function

Hypocalcaemia was induced in cows and sheep by Na2EDTA infusion and the plasma calcium concentrations then related to cardiac output, stroke volume, mean right atrial pressure, mean right ventricular pressure, mean pulmonary arterial pressure, right ventricular work against pulmonary arterial pressure and pulmonary vascular resistance. It was found that for a fall in plasma calcium concentration of 1 mmol/l in cows cardiac output was reduced by 38 ml/kg bwt/min, stroke volume by 0·64 ml/kg bwt/beat, mean right atrial pressure increased by 7·6 mmHg, mean right ventricular pressure increased by 5·9 mmHg, mean pulmonary arterial pressure increased by 6·8 mmHg, right ventricular work against pulmonary arterial pressure decreased by 28·1 J/min and pulmonary vascular resistance increased by 41 dyn·cm5/s. In sheep cardiac output was reduced by 37·3 ml/kg bwt and stroke volume by 0·48 ml/kg bwt/beat for a fall in plasma calcium concentration of 1 mmol/1. The significance of these findings in hypocalcaemic disorders is discussed

Changes in Concentrations of Certain Plasma and Erythrocyte Minerals Associated with Hypomagnesaemia in Young Calves

Hypomagnesaemia was induced in young calves 1–2 weeks old by feeding them with a diet composed of skimmed milk and barley straw to which urea, potassium chloride and soya‐bean oil were added. Blood samples were collected from each calf once a week from the jugular vein until there was a significantly lower (P < 0.01) plasma magnesium (PMg) concentration in the experimental compared to the control calves receiving MgO instead of KCl. In addition to PMg, the blood samples were analysed for plasma sodium, potassium, calcium, inorganic phosphate and erythrocyte concentrations of magnesium, sodium and potassium and red blood cell counts. The erythrocyte magnesium (EMg) concentration decreased significantly (P < 0.01) in both groups. The decrease was, however, greater (P < 0.05) in the magnesium deficient group than in the control group. Erythrocyte sodium (ENa) concentration increased and erythrocyte potassium (EK) concentration decreased in both groups, and the changes did not differ significantly between the two groups. Plasma concentrations of sodium (PNa) and potassium (PK) and red blood cell counts did not change significantly in either group. Significant (P < 0.05) decreases in plasma calcium and inorganic phosphate concentrations occurred in the magnesium deficient group only. Veränderungen von Mineralstoff‐Konzentrationen im Plasma und in den Erythrozyten bei der Hypomagnesämie junger Kälber Bei 1–2 Wochen alten Kälbern wurde durch Verfütterung von Magermilch und Gerstenstroh mit Harnstoff‐Kaliumchlorid‐ und Sojaöl‐Zusatz eine Hypomagnesämie induziert. Dabei wurde einmal wöchentlich bei jedem Kalb eine Blutprobe aus der Vena jugularis entnommen, bis sich ein im Vergleich zu Kontrollkälbern, die anstatt KCl MgO erhielten, ein signifikant niedrigerer (p < 0,01) Plasma‐Magnesium‐(PMg)‐Spiegel ergab. Neben dem PMg wurden der Plasma‐Natrium‐, ‐Kalium‐, ‐Calcium‐ und ‐Phosphat‐Spiegel sowie die Konzentrationen von Magnesium, Natrium und Kalium in den Erythrozyten bestimmt. Die Zahl der Erythrozyten wurde ebenfalls ermittelt. Die Magnesium‐Konzentration in den Erythrozyten (EMg) nahm bei beiden Gruppen signifikant (p < 0,01) ab. Diese Abnahme war jedoch bei der Magnesium‐Mangelgruppe größer. Die Natrium‐Konzentration in den Erythrozyten (ENa) erhöhte sich, und die Kalium‐Konzentration in den Erythrozyten (EK) erniedrigte sich in beiden Gruppen. Dabei ergaben sich keine signifikanten Gruppenunterschiede. Die Plasma‐Natrium‐(PNa)‐ und Plasma‐Kalium‐(PK)‐Konzentrationen sowie die Zahl der Erythrozyten veränderten sich in keiner der Gruppen signifikant. Eine signifikante (p < 0,05) Abnahme der Plasma‐Calcium‐ und ‐Phosphat‐Konzentration ergab sich bei der Magnesium‐Mangelgruppe

Effects of intrauterine infusion of Escherichia coli endotoxin in normal cows and in cows with endometritis induced by experimental infection with Streptococcus agalactiae

Two experiments were carried out to describe the effects of intrauterine infusion of Escherichia coli endotoxin on some aspects of nonspecific uterine defense mechanisms in healthy cyclic cows (Experiment 1) and in cows with induced endometritis by experimental infection with Streptococcus agalactiae (Experiment 2). In Experiments 1 and 2, the mean loge total white cell counts (>95% neutrophils) in the uterine flushing fluid of the endotoxin-treated group were significantly increased (

A comparison between the main clinical signs of milk fever in cows with those of hypocalcaemia induced by Na2EDTA solution

In one study, 6 cows with high erythrocyte potassium concentrations (HK cows) and 7 with low erythrocyte potassium concentrations (LK cows) were infused with 4.7% Na2EDTA solution intravenously for 4 h. The immediately observable clinical signs and the sequelae over a period of weeks were recorded and compared. There were no differences in the clinical responses of HK or LK cows to the infusion of Na2EDTA. In a second study, these clinical signs plus those produced experimentally by three other research groups were compared with both the clinical signs of milk fever recorded in three text books and those observed by one of the authors over a period of 25 years in dairy cattle practice. All of the clinical signs of milk fever occurred in the experimental model, but there were extra signs (excessive salivation, excessive lip and tongue actions, and tail lifting) which were not present or recorded in naturally occurring cases of hypocalcaemia. Hypocalcaemia induced in cows by the intravenous infusion of 4.7% Na2EDTA solution is a reasonably good model for the reproduction of the clinical signs of milk fever, but because of the extraneous signs, and the unusual nature of the subsequent deaths of 3 of 13 cows infused for 4 h, and the death of 1 of 2 cows infused for 4 h daily for 3 days, the model may not be a valid one for periods longer than 4 h in cows

Evaluation of the effect of ketoprofen on experimentally induced ephemeral fever in dairy heifers

To evaluate ketoprofen for the therapy of ephemeral fever.A blind controlled clinical trial.Sixteen cattle (one immature Holstein bull, eight Holstein and seven Jersey heifers).Ephemeral fever was induced by the intravenous injection of blood leucocyte layer from a clinical case. Ketoprofen solution or a coded placebo was injected intramuscularly at the rate of 3 mg/kg daily for three days.Ketoprofen reversed locomotor dysfunctions significantly compared with controls, but did not have any effect on rectal temperatures, leucocyte counts, plasma fibrinogen concentrations, ionised Ca-concentrations or the presence of dyspnoea.Ketoprofen is a safe and effective drug for the treatment of locomotor symptoms of milk fever, but has no effect on the duration of clinical respiratory abnormalities

Effects of hypocalcaemia on blood flow to the ovaries of the sheep

The objectives of the study were to use sheep as a model to determine whether a reduction in plasma calcium concentration similar to that observed during periods of postpartum subclinical hypocalcaemia in lactating dairy cattle might affect the blood flow to the ovaries. Different levels of hypocalcaemia were induced in each of six, non-pregnant sheep by the slow intravenous infusion of Na2-EDTA. Measurements of blood flow to the ovaries were made before and after the induction of hypocalcaemia, using 113Sn and 46Sc radiolabeled microspheres. As plasma ionized calcium was reduced, there was a significant decline in ovarian blood flow. Ovarian blood flow (percentage of resting) = 0.54Ca++ (percentage of resting) + 58.4. This model was significant at P < 0.01, with R2 = 0.92. Accordingly, a reduction in plasma ionized calcium of 50% would yield a reduction in ovarian blood flow of 16%