English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Bouda J., P. Jagos, VI. Dvorak, V. HamSik: Vitamin A and Carotene Meta­ bolism in Cows and their Calves Fedfrom Buckets. Acta vet. Bmo, 49, 1979: 45-52~ The vitamin A and carotene metabolism has been studied in 40 cows and their calves up to the age of three months under conditions of intensive production during winter season. The vitamin A level in blood plasma of pre-partum cows was found to be lower than that of post-partum cows. The vitamin A concentration in the first colostrum was 10 times higher than the concentration found in cow blood plasma. The carotene level in colostrum was lower than that in blood plasma of cows. Before the first colostrum intake the average vitamin A concentration in blood plasma of calves was very low and did not exceed 10 pg/100 ml. After the colostrum ingestion the plasma vitamin A level raised, the hypovitaminosis A was, however, found in 75 % of followed calves and in high number of calves continued up to the age of 3 weeks. In the following period the occurrence of hypovitaminosis in calves was reduced which was brought about by the addition of vitamin in milk substitute. The significant rise in plasma vitamin A levels occurred during the first weeks of calf life after vitamin A had been supplemented into the first colostrum. The carotene levels in blood plasma of calves up to the age of 8 weeks were very low and their increase appeared after the hay ingestion. Under conditions of large-scale animal production the animals are concentrated in a small area and therefore the· hypovitaminoses are accompanied by a potential danger of a disease affecting first of all the alimentary and respiratory tracts. It follows from our results that the addition of vitamin A to calves in first days of their lives, especially in winter season, is of a great imporance.

Vitamin A and Carotene Metabolism in Cows and their Calves Fed from Buckets