How Nutrient Deficiencies in Sheep Lead to Reproductive Disorders

Mutton is tender, delicious, and rich in nutrients, making it an excellent tonic for winter. Eating mutton in winter provides both nourishment and protection against the cold. As people's understanding of mutton grows and demand for it continues to increase, mutton sheep production and breeding are particularly important, especially since the reproductive capacity of mutton sheep directly affects the development of the sheep industry. Below, the author mainly discusses the impact of nutrient deficiencies on reproductive disorders in sheep.

Carbohydrates. They are the main component of animal feed. If the dietary energy level is high around the time of estrus in ewes, the ovulation rate can be increased, with no adverse effects on early embryonic survival. However, if ewes gain weight too quickly or consume too much energy, the conception interval will be prolonged. To improve reproductive performance, postpartum ewes should be supplied with higher energy to avoid excessive weight loss, but energy intake should be increased gradually, otherwise it will cause obesity.

Protein. Protein deficiency can cause delayed ovulation at puberty and prolonged anestrus in ewes. However, excessively high protein levels also have adverse effects on fertility. In addition, feeding high-protein feed increases ammonia levels in the rumen, which can have toxic effects on embryos and may also have other adverse effects on fertility.

Vitamins. The vitamins required by sheep come mainly from three sources: first, intake from the diet; second, synthesis of various vitamins by tissues; third, vitamins synthesized by rumen microorganisms. Vitamin deficiency can occur in the following situations: first, vitamins in feed are completely lost due to prolonged storage; second, long-term indoor housing or prolonged stress in sheep reduces vitamin synthesis by tissues. For example: Vitamin A is essential for the normal development of epithelial cells in animals. If deficient, it will affect fertility to some extent, mainly manifested as delayed puberty in rams and ewes, abortion or reduced litter size in ewes, blindness or ataxia in newborn lambs, retained placenta, high morbidity, keratinization and degeneration of the placenta, increased incidence of endometritis, reduced libido in rams, testicular atrophy, reduced sperm count in the seminiferous tubules, and decreased ovarian function in ewes; regarding beta-carotene, some have found that deficiency of beta-carotene with sufficient vitamin A can cause decreased liver ketone levels, delayed ovulation, reduced estrus intensity, ovarian cysts, increased morbidity, delayed uterine involution, prolonged time for postpartum ovarian function recovery, and increased early embryonic mortality; vitamin D deficiency easily causes delayed estrus; vitamin E and selenium are important antioxidants, but their mechanism of action in reproduction is still unclear. It has been reported that vitamin E deficiency can cause congenital malformations in lambs.

Mineral deficiency or imbalance. This condition can cause infertility in sheep. Calcium indirectly affects reproduction. Phosphorus participates in energy metabolism, bone development, and milk production, so it is closely related to reproduction. Selenium deficiency mainly causes reduced fertility. Iodine participates in the synthesis of thyroxine, so it affects sheep reproduction through thyroxine synthesis.