[Effect of parenteral supplementation with beta-carotene in the form of an injection solution(Carofertin) on the fertility performance of dairy cows].

It was the aim of this study to investigate the effect of a supplementation with beta-carotene administered systemically (Carofertin) on the reproductive performance in dairy cows. One hundred cows received three injections of 20 ml Carofertin 3 to 4 weeks ante partum, 1 to 2 weeks post partum and 6 to 8 weeks post partum. Control cows (n = 101) were treated simultaneously with 20 ml 0.9% NaCl-solution. Serum concentrations of beta-carotene were determined before the first and the second beta-carotene injection, and at the time of first insemination. For all animals, serum concentrations of beta-carotene, results of puerperal controls, culling rate, culling reason, fertility parameters, progesterone production during the luteal phase, and cost per pregnancy were evaluated. Clinical examination during the puerperal phase revealed that cyclicity had started statistically significantly more often in control cows than in the cows receiving Carofertin. With regard to the other parameters, no significant group differences were found. Cost per pregnancy were higher in the Carofertin group (241.78 [symbol: see text]) than in the control group (171.40 [symbol: see text]). These results suggest that the use of Carofertin in dairy cows under the given experimental conditions for therapy or prophylaxis of fertility disorders might not be recommendable.