Search

In 3-year-experiments green forage from Dactylis glomerata and Festuca species, produced by differentiated cutting frequencies, was ensiled under laboratory conditions. The forage was almost without nitrate. Because of the higher content of water-soluble carbohydrates the fermentability coefficients of Festuca species were above of Dactylis glomerata. The fermentability coefficients of both plant species were inferior in the second and third cut, even if the first cut was delayed until July. Despite of similar fermentability coefficients of the two plant species silages contained different amounts of lactic and butyric acid. The portion of lactic acid amounted to 52 to 57% and 60 to 73% of total acids, the proportion of butyric acid 30 to 35% and 18 to 25% for Dactylis glomerata and Festuca species, respectively. According to the high fermentability coefficients silages free of butyric acid would be expected, however, by both species butyric acid always was formed, in some cases at high concentrations. In the contrary the amounts of ammonia, acetic acid and alcohol as well as the pH-value were almost extremely low. It can be concluded that the quality of silages produced of green forages with low nitrate cannot be assessed adequately by the current evaluation key.

During a three-week intraruminal butyric acid resp. Na-butyrate load (1 g/kg body weight) we investigated the hormones insulin, cortisol, triiodothyronine (T3) and thyroxin (T4). Distinct effects on insulin concentration were found during the diurnal course which was after butyric acid application in the morning for nine hours depressed followed by a surplus incretion. In the morning the anteprandial concentrations of insulin, cortisol, T3 and T4 were not changed in the whole time. One cow was ill on ketosis and showed strong changes of hormones.

Three-week intraruminal butyric acid resp. Na-butyrate load in young fattening bulls, fattening bulls and cows induces different changes of mineral metabolism dependent on acid-base-stress. In young fattening bulls we observed typical sings of acidosis hyperphosphatemia and hypercalcaemia resp. hyperphosphaturia and hypercalciuria. In fattening bulls and cows we did not see such changes. Strong acidotic metabolism suppresses the activity of alkaline phosphatases significantly. During a three-week butyric acid load changes in bone mineralisation did not develop.

Acid-base balanced in cows were but slightly affected by butyric acid exposure experiment over three weeks. Applications of sodium butyrate over the same period of time, on the other hand, was associated with buildup of alkalosis in the second half of the experimental period, with alternation of loading, compensation, and reloading being recordable. Nitrogen metabolism in cows was but slightly affected under the given experimental conditions. However, clearly noticeable impairment of nitrogen metabolism was exhibited by one cow that had fallen ill, in the course of experimentation.

Two cows each received intraruminal applications of 1.0 g/kg B.W. of butyric acid or sodium butyrate, for three weeks running, before daily applications were increased up to 2.0 kg/B.W., within one week. Resulting alterations primarily included increase in acidosis or alkalosis, whereas the typical symptoms of ketosis were lacking. Signs of impaired liver function were to some extent recordable in response to sodium butyrate.

Heparin, sodium butyrate, and the absence of platelet derived factors in the nutrient medium are able to inhibit the decrease of the content of myosin in cultivated arterial smooth muscle cells. Factor VIII and thrombin have no significant influence on this process.