Muhammad Bilal (2008-VA-152)

Comparative Effect Of Cidr Based Estrus Synchronization Protocol With Or Without Gnrh In Non-Descript Cows During Low Breeding Season - 2015. - 32p.;

The livestock sector occupies a peculiar position in the national plan of economic development in Pakistan. It subscribed approximately 55.9 percent to the agricultural value added and 11.8 percent to national GDP with a growth rate of 2.7 % in 2013-14 (Anonymous 2014). Dairying has become an important subsidiary source of income for thousands of rural families with an important role in generating earning opportunity. In Pakistan dairy sector is developing and commercializing at a rapid pace to meet increasing requirement of milk and other dairy products (Dongre et al. 2011).
Pakistan owns renowned breeds of dairy buffaloes (Nili-Ravi and Kundi) and cattle (Sahiwal, Red Sindhi, Thari and many others). Cattle in Pakistan belong to genus Bos indicus. According to the latest livestock census (Anonymous 2006), out of 29.6 million cattle, 46% (13.6 million) have been described as non-descript. Non-descript cattle do not fall in any defined breeds of cattle. Milk production of non-descript cows is < 1000 lit per lactation in mountains area of NWEP pakistan (Khan and Usmani 2005). As non-descript breeds make up the largest group of cattle in Pakistan, there is a dire need to work on genetic improvement of these animals. Artificial insemination, the best tool for genetic up-gradation in dairy cattle is applied only in 11.1% cows in Pakistan (Anonymous 2006). The main hindrances are small sized scattered herds and lack of experienced technical manpower in the field. Estrus synchronization of a large number of animals and timed insemination can be used to overcome these hindrances .The technique may also help in
reducing a prolonged calving interval and postpartum anestrus and seasonality of breeding in these animals (Zafar et al. 2008).
Estrus synchronization widely practiced in temperate dairy cattle in developed countries (Hansen and Arechiga 1999). Before launching a large scale estrus synchronization program in non-descript cattle, there is a need to assess the efficacy of various synchronization protocols in terms of estrus incidence, intensity and conception rate. Additionaly, distinct differences have also been reported between Bos taurus and Bos indicus in terms of estrus duration and intensity of expression of estrus sign (Mattoni and Ouedraogo 2000). The low estrus intensity and less duration of estrus signs of Bos Indicus are due to smaller diameter of follicle as compared to that of Bos Taurus (Bo et al. 2003).
Developing successful methods for synchronizing estrus and ovulation in cattle has been a major research interest. Ultimately, the goal has been to achieve precise synchronization of ovulation so that cattle can be inseminated without regard to estrus detection. One method to increase conception rates is to use hormonal treatments in zebu breeds for synchronizing ovulation and for timed artificial insemination (TAI). Hormonal programs for synchronizing ovulation to control the follicular and luteal phases and estrus behavior have been used in Bos taurus cows and heifers(Castellanos et al. 1997), and Bos Indicus cows (Pinheiro et al. 1998).
The intensity and duration of estrus behaviors during the estrous cycle is highly variable among individuals. More commonly animals are diagnosed to be in estrus based on the mounting or standing to be mounted, appearance of mucus discharge, and other physical activities (Van Eerdenburg et al. 2002). Scoring system were established on the basis of observed estrus signs and most of them have taken mounting and standing to be
mounted behavior as the most reliable signs to predict ovulation time in Bos taurus cows (Roelofs et al. 2005). However, it is now well acknowledged that the expression of estrus behavior change with breed of cows (Naidu and Babu Rao 2006).
Fertility is an important parameter to assess the efficacy of estrus synchronization. Bos indicus cows after treatment with CIDR conception rate in adult cows 40% and in heifers 20% (Singh et al. 2006). CIDR may have ability to overcome the problems in field condition and increasing the reproductive efficiency by minimize the hindrance anestrus postpartum cows. In Pakistan research work have been done to evaluate the efficacy of CIDR for conception rate in indigenous cattle. Until now no study conducted on non- descript cattle. Therefore, it is hypothesized that CIDR+GnRH can provide better in vivo fertility compared to CIDR.

Department of Theriogenology


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