Estrus cycle is a rhythmic change that occur in the reproductive system of females starting from one estrus phase to another. The normal duration of estrus cycle is 21 days in cow, sow, and mare, 17 days in ewe, and 20 days in doe. The species which exhibit a single estrus cycle are known as monstrous and species which come into estrus twice or more are termed polyestrous animals. Among them some species have estrus cycles in a particular season and defined as seasonal polyestrous. It includes goats, sheep, and horses. On the other hand, cattle undergo estrus throughout the year. The estrus inducers can grossly be divided into two parts, that is, non-hormonal and hormonal. Non-hormonal treatments include plant-derived heat inducers, mineral supplementation, uterine and ovarian massage, and use of Lugol’s iodine. The hormones that are used in estrus induction are estrogen, progesterone, GnRH, prostaglandin, insulin, and anti-prolactin-based treatment. Synchronization can shorten the breeding period to less than 5 days, instead of females being bred over a 21-day period, depending on the treatment regimen. The combination of GnRH with the prostaglandin F2α (PGF2α)- and progesterone-based synchronization program has shown a novel direction in the estrus synchronization of cattle with the follicular development manipulation.
Part of the book: Animal Reproduction in Veterinary Medicine
Poor soil fertility and soil degradation induced by persistent conventional farming with repeated tillage and removal or in situ burning of crop residue are major limitations to food security and environmental sustainability. However, degraded agricultural lands with depleted soil organic carbon (SOC) stocks are capable of soil carbon restoration through improved management practices like aggregation, humification and deep placement of C that can increase SOC seques-tration. According to FAO, conservation agriculture (CA) is arrived at as a solution to restore SOC with three pillars of minimum soil disturbance, permanent organic soil cover and diversified crop rotations. A significant increase in SOC levels under zero tillage (ZT) over conventional tillage (CT) was found; returning more crop residues to the soil is associated with an increase in SOC concentration that is further increased by crop diversification. Additionally, the incorporation of high-value trees with CA is treated as a working model for C storage. Thus, conservation agriculture is an operational approach to restore SOC that aggrades soil, reduces environmental footprints and makes agricultural systems more resilient to climate change.
Part of the book: Natural Resources Management and Biological Sciences
The exploitation of nature for decades due to several anthropogenic activities has changed the climatic conditions worldwide. The environment has been polluted with an increase of greenhouse gases. The major consequences are global warming, cyclone, an increase in sea level, etc. It has a clear negative impact on the natural environment including aquatic ones. As a result, production of fish in the aquaculture system and marine system is greatly affected. Marine ecosystems like coral reefs are also destroyed. Decreased fish production has also affected the livelihood and economic condition of the fish farmers. So, corrective measures should be taken to reduce the climate changes for minimizing its effects on fish production. Using more eco-friendly substances, planting more trees, and preserving our nature are some steps to be taken. Awareness should also be generated among the common people.
Part of the book: Inland Waters