Fertility

Fertility is the natural capability to produce offspring through regular sexual activity following the onset of puberty. Fertility is one of the main factors affecting the reproductive efficiency directly involved with the profit-loss equation of any farm, and herd fertility is the sole indicator of good or bad reproductive management practice. Fertility is directly associated not only with the female health condition but also equally important for contribution of male. The fertility rate denotes the reproductive efficiency of a female and is defined as the mean number of offspring born during her lifetime. Several factors are involved with normal fertility, such as the production of viable eggs by the female and sufficient healthy sperms by the male, successful transport of sperms through the female reproductive tract to the site of fertilization (fallopian tube), the fusion of sperm and ovum and implantation of the fertilized egg in the uterus. Problem(s) associated with any of those factors mentioned above can cause infertility, a phenomenon that refers to any difficulty or inability to establish clinical pregnancy. Factors contributing to reduced fertility or infertility in farm animals are nutrition, age, genotype, hormonal imbalance, management, body condition score, diseases, anatomical abnormalities in the reproductive tract, etc. Fertility usually declines with the progression of age in both sexes. In addition, high-yielding animals tend to decline in fertility as there is a negative genetic correlation between better production and reproduction. Good fertility can be achieved through insemination after 12-18 hours of the onset of estrous in cattle and buffaloes, 24-36 hours in sheep and goats, and 48-72 hours in the horse. The proper time of insemination and efficiency of the inseminator are important factors for successful conception. [Mohammad Shamsul Alam Bhuiyan]