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Object: Determination of vitamin A and Beta caroten status in
Holestein cow.
Design: Cross sectional study.
Animals: A total of 342 blood and 371 liver samples from Holestein cows n both sexes and 5 age groups as <2, 2-3, 3-4, 4-5, 5< years.
Procedure: Livels of vit . A as well as 3 caroten were determined in serum and liver by a spectrophotometer at wave length of 325 and 453nm as follows:
Levels of vitamin A serum and liver = (0.000017 figure of Beta carotene)-absorbtion levels at 325nm/ 0.00182
Levels of B carotene In serum and liver = Absorption levels at 453nm/000258
Hex an was used as a blank.
Statistical analysis: Results were analyzed by ANOVA
Results: In this survey the levels of vitamin A and Beta carotene
of serum and liver were 67.2 ± 3.1, 85.5 + 4.0 ) g/dl and 189.3 +3.0, 21.1 ±1 g/g respectively. Differences of liver vitamin A levels in
4 and 5 age groups and also between these two age groups and others were significant (P<0.OOl). In the meanwhile levels of liver vitamin A and those of liver and serum 13 carotene of females were
significantly higher than of males. Effects of season alone and both
of season and sex, season and age, age and sex combinations were different. Apart from vitamin A and B carotene the relationship
among all the other variants of this survey were significant.
Conclusion: On the basis of the results of this survey effects of
nutrition and to some extent female and vitamin A and [3carotene
were highly considerable but high levels of liver vitamin A in winter were not explainable. J. Fac. Vet. Med. Univ. Tehran. 58,