The protein and energetic deficiency have influence on the semen production and libido due to a low plasmatic concentration of 17B oestradiol, a lack of lysine, methionine and tryptophan that produce cytologic and histologic changes in the testis levels with damage on spermatogenesis and sperm quality.
Regarding to the minerals we have to pay attention to the correct relationship between calcium (Ca) and phosphorus (P), (1,3-1,5) for a good bone development and a correct stance. The lack of phosphorus produces muscular weakness, joint stiffness and loss of fertility. Sodium is an essential ion. Usually with 0,3-0,5 % of sodium chlorine in the feed, the requirements of the boars are covered. The excess of chlorine affects the electrolytic balance, because it produces an acid medium. For avoid this, it is advisable to use sodium bicarbonate to reduce the acidity and bone calcification problems. Potassium (K) and magnesium (Mg) are generally found in abundance in all the raw material used.
Zinc has an important influence on the spermatogenesis, on the chromatin decondensation process, on the Leydig cell maturation process, on the luteinizing hormone response and steroid production. The recommended levels are between 100-125 ppm. Selenium keeps spermatozoon membrane integrity and produces positive effect on sperm motility. The recommendation is 0,2-0,25 ppm.