Effects of substituting starch with fat on the acid-base and mineral status of female horses.

Feeding a high-fat diet may have potential advantages by maintaining pH homeostasis during intense exercise; conversely, effects including elevated PCV and increased plasma concentration of total protein may indicate effects detrimental to performance by reducing perfusion of tissues and organs. Six horses were used to determine the effects of an replacement of starch (diet '0.00') with 0.33, 0.67, 1.00 and 1.33 g soybean oil/kg bwt/day (diets '033', '0.67', '1.00' and '1.33') on venous and renal acid-base status and fractional clearance (FC) of electrolytes in a postprandial state but prior to exercise. Venous blood and urine were sampled for 3 days at the end of the 28 day periods, in each case 3 h postprandially. Throughout the study, the horses put on weight by 35 kg (P<0.05). From diet '0.00' to '0.67', blood pH decreased (P<0.05) and carbon dioxide tension increased (P<0.05). Simultaneously, the base and net acid-base concentration in the urine rose (P<0.05) but diuresis decreased (P<0.05) and, therefore, the daily excretion of bases and net acid-bases was only unsystematically affected. From diet '0.00' to '1.33', the FC of magnesium and chloride fell (P<0.05). These results suggested that the exchange of starch with up to moderate amounts of fat affects the venous and renal acid-base status of resting horses. The decrease in urine volume is most striking. Further research is needed to investigate the importance of these effects for sporting performance.

[The content of ascorbic acid in plasma and in 14 tissues of lambs of different ages during normal feeding and feeding restricted from time to time during the suckling period]. / Der Gehalt an Ascorbinsäure im Plasma und in 14 Geweben von Lämmern unterschiedlichen Alters bei normaler und bei zeitweise restriktiver Fütterung während der Säugeperiode.

In normally fed lambs (group 1) the content of ascorbic acid (AA) in the plasma on day 8, 18, 28, 38, 48, 60 and 100 after birth was the same as in lambs, that were fed on days 8 to 17 (group 2), 8 to 26 (group 3) and 8 to 35 (group 4) on the maintenance level. The restrictive feeding induced for a certain time a decrease in the glucose content of the plasma. In the lambs of group 2 and 3 there was no differences in the content of AA in 14 tissues compared to group 1. In the lambs of group 4 the body weight on the 35th day was only 54 and the mass of the hypophysis 60, of the lung 55.9, of the liver 51, of the heart 47.2, of the spleen 44.7 and of the kidney 38% of that of group 1; there was a tendency to a lower content of AA in most tissues. With increasing age the content of AA in the cerebrum, in the cerebellum, in the brain stem and in the testicles decreased; the highest content in the hypophysis was determined on day 180. The regulation of the synthesis of AA in the liver under normal and pathological conditions is discussed.

[The effects of glucocorticosteroids on lipolysis stimulated by fasting and liver function in cows]. / Glukokortikosteroideinfluss auf die fastenstimulierte Lipolyse und die Leberfunktion bei Kühen.

During a five-day period prednisolone (200 mg/d) reduced the rise of FFA, beta-hydroxybutyrate and bilirubin concentrations in the blood plasma of three cows compared with three control animals. The liver fat content remained within the physiological range. The reduced lipolysis in the experimental group was the result of a reactive hyperinsulinaemia, a more effective energy metabolism and a diminished metabolic activity. Harmful effects on the liver function could not be observed. Plasma cortisol concentration was reduced for only a short time.

[The concentration of ascorbic acid, total protein, alpha-amino-N, glucose, 3-hydroxybutyrate and cholesterol and the activity of adenosine deaminase in the blood of sheep in five different periods of pregnancy and the content of ascorbic acid in 14 tissues]. / Die Konzentration an Ascorbinsäure, Gesamtprotein, alpha-Amino-N, Glucose, 3-Hydroxybutyrat und Cholesterol sowie die Aktivität der Adenosin-Desaminase im Plasma von Schafen in fünf verschiedenen Abschnitten der Trächtigkeit und der Gehalt an Ascorbinsäure in 14 Geweben.

Analyses of different compounds in the plasma of healthy sheep before birth were conducted from day 70 to 43 (group 1), 42 to 22 (group 2), 21 to 15 (group 3), 14 to 8 (group 4) and 7 to 1 (group 5). There were significant differences in the concentration of ascorbic acid, total protein, total alpha-Amino-N, glucose, 3-hydroxybutyrate and of adenosine deaminase in the plasma between several groups, their significance is discussed. There was no difference in the concentration of cholesterol in the plasma of the sheep of the 5 groups. The content of ascorbic acid in 14 different tissues of sheep of the age of 6 and 12 months was analysed. There were significant differences between the 2 groups in the levels of ascorbic acid of the cerebrum and cerebellum, the hypophysis, the lungs, the kidneys and the spleen.