Beta-carotene could improve mare fertility:
- as a precursor of vitamin A in the follicles, it participates in the synthesis of oestrogens and is thus favourable to good follicular growth,
- as local antioxidant, it protects cells in the reproductive system from attack by free radicals,
- following ovulation, it assures the correct functioning of the corpus luteum within which it takes part in the synthesis of progesterone. It contributes in this way to maintaining gestation.
Amongst the effects observed when supplementing with beta-carotene we can note more visible heats, a reduction in the number of ovarian cysts, an improved fertility level, a reduction in embryo mortality as well as a drop in the number of retained placentas.
In the stallion, beta-carotene participates (as a precursor of vitamin A) in the synthesis of testosterone. It assures correct production and maturity of spermatozoa. Thanks to its' antioxidant action, it helps protect spermatozoa from attack by free radicals.
Vitamin A affects protein synthesis with consequences on epithelium integrity in the reproductive system, the production of sexual hormones and immunity.
Vitamin E and organic selenium reinforce the antioxidant action of beta-carotene. Furthermore, supplementing with them allows an increase in colostrum antibody concentrations (IgG and IgM) as well as the quantity of colostrum produced, thus leading to a better transfer of immunity from the mare to the foal.
Zinc can play a part in reproduction as an essential activator of sexual hormone production enzymes, and also in its' function of transporting vitamin A.
Supplementing with copper would seem to improve the liberation of sexual hormones (FSH and LH) at a cerebral level (pituitary).
Manganese and vitamin B3 intervene in the production of sexual hormones.
Iodine is essential for synthesising thyroid hormones that stimulate FSH and LH production by the pituitary gland.