**4. Induction of estrus**

The problem of anestrus causes a huge economical loss to the farmers or producers. So, it needs to be solved immediately. Kumar et al. [1] have beautifully classified different ways of estrus induction. 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. All these treatment procedures are described below.

### **4.1 Non-hormonal treatment**

#### *4.1.1 Plant-derived heat inducers*

Different plant extracts are being used for the treatment of anestrus traditionally. Several estrus-inducing herbal medicines are available in Indian market. The efficacy of estrus-inducing preparations like Prajana, Janova, Estrona, and Sajani

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encouraged.

*4.1.3 Uterine and ovarian massage*

of female reproductive system.

*Induction and Synchronization of Estrus DOI: http://dx.doi.org/10.5772/intechopen.90769*

pigeon waste.

*4.1.2 Mineral supplementation*

is well established [3]. Other examples include Aloes, Heat-Up, Fertivet, Heat-raj, etc. These can be applied in delayed puberty, postpartum anestrus, and other problems. Though they can induce estrus in crossbred cows, the conception rate is remained unchanged. *Aegle marmelos* and *Murraya koenigii* are two medicinal plants used for the treatment of reproductive problems in livestock as well as laboratory animals [4–6]. Feeding the leaves of these plants individually or combined can help in starting the cascade of reproductive cycle. It is believed that they act like the gonadotropins. The other possible mechanism behind its efficacy is the antioxidant effect of the plant-derived substances enhancing the luteal function. The demand and usefulness of the plant-derived medicines are increasing day by day. As these are easily available, are economical, and have fewer side effects, these preparations can be successfully utilized especially in village level. Many times, the poor farmers cannot afford the cost of the hormonal estrus inducers which are not always available also. In this situation, herbal mixtures have emerged as a better option. A large comparative study is required to use these drugs as alternative to hormones. It is also recommended that these should be used along with vitamin and mineral supplementation. Kumar and Singh [7] have also reported about the use of the pigeon waste in estrus induction. They fed 100 gm dried pigeon waste for 3 days to anestrus cows and heifers and successfully induced estrus in 40% cows and 44% heifers. This may be due to the high iron, zinc, and other mineral content in the

Minerals have an important role in the reproduction of domestic animals, and their deficiency can cause several reproductive disorders. Deficiency of calcium is very common in postpartum cattle. Any alteration in Ca:P ration can affect the pituitary secretion and subsequently ovarian function [8]. This can cause delayed puberty, irregular estrus, etc. The optimum ratio of Ca:P should be within 1.5:1–2.5:1. Excess calcium is also harmful as it can disturb the absorption of other minerals. Phosphorus is a very important mineral for the normal reproduction. In the case of phosphorus deficiency, several disorders can be observed like delayed maturity, low conception rate, inactive ovary, etc. [8]. There are reports of other reproductive problems in areas with phosphorus deficiency. It includes silent estrus, delayed puberty, irregular estrus, and long inter-calving period [9]. Sodium and potassium are also necessary for maintaining normal reproductive physiology and energy metabolism, though excess consumption of potassium can cause a problem. Other trace minerals like zinc, selenium, cobalt, iodine, chromium, etc. also have a prominent role in the reproduction of domestic animals. Animals can come into anestrus if proper nutrition is not provided. So, feeding management should be the first approach to prevent the problem of anestrus. Minerals should be supplemented in optimum quantity. The use of area-specific mineral mixture should be

It is the most economical method for the treatment of anestrus. In this method, gentle massage of the uterus and ovary is done perrectally. There are reports which state about its utilization in estrus induction. There is no clear mechanism of action of this method. Possibly, it can be attributed to increased blood circulation on the surface of the ovary and stimulation of ovarian intrinsic factors [10, 11]. Application of this method needs experts who have a good idea about the anatomy
