Ajmal Muhammad Awais, Hassan Mubbashar, Shahzad Muhammad, Naveed Muhammad Ilyas, Channa Aijaz Ali, Ahmad Nasim
Department of Theriogenology, Faculty of Veterinary Science, University of Veterinary and Animal Sciences, Lahore, Pakistan.
Department of Clinical Sciences, College of Veterinary and Animal Sciences (Sub-Campus, University of Veterinary and Animal Sciences, Lahore), Jhang, Pakistan.
Vet Res Forum. 2024;15(5):251-255. doi: 10.30466/vrf.2024.2004618.3913. Epub 2024 May 15.
The Cholistani cow is considered one of the milch breeds of Zebu cattle. Despite being heat and tick-resistant, it has not yet gained much popularity among Pakistan dairy farmers due to its long calving interval. This study aimed to understand the basic reproductive physiology of Cholistani cows using sonography and reproductive biotechnologies such as estrus synchronization and timed artificial insemination to improve reproductive efficiency. In experiment 1, six Cholistani cows with mixed parity 3.20 ± 1.30 and weighing 400 kg were selected to monitor ovarian dynamics on alternate days by the same sonographer from the onset of heat through ovulation until the next ovulation. Experiment 2 measured the effect of estrus synchronization methods, controlled internal drug release-gonadotropin-releasing hormone (CIDR-GnRH, n = 31) and Ovsynch (OVS, n = 32) on various reproductive parameters. The mean estrous cycle length was 19.81 ± 0.56 days with two follicular waves. The mean inter-ovulatory interval was 20.80 ± 0.52 days, with a preovulatory follicular size of 13.83 ± 2.37 mm. Estrus response was higher ( > 0.05) in controlled internal drug release (CIDR)-GnRH (93.54%) than in OVS (84.37%) cows. Similarly, ovulation and conception rates were higher in CIDR-GnRH (91.66% . 68.42%) than in OVS cows (41.37% 33.33%), respectively. In conclusion, CIDR-GnRH results in a better estrus response, higher ovulation rate, and subsequently greater conception rate than OVS in dairy cows.
乔利斯坦牛被认为是瘤牛的乳用品种之一。尽管它耐热且抗蜱，但由于其产犊间隔长，在巴基斯坦奶农中尚未获得很高的知名度。本研究旨在利用超声检查以及发情同步化和定时人工授精等生殖生物技术来了解乔利斯坦牛的基本生殖生理学，以提高繁殖效率。在实验1中，选择了6头平均胎次为3.20±1.30且体重400千克的乔利斯坦牛，由同一位超声检查人员从发情开始到排卵直至下一次排卵，每隔一天监测其卵巢动态。实验2测量了发情同步化方法，即控释内植孕酮 - 促性腺激素释放激素（CIDR - GnRH，n = 31）和Ovsynch（OVS，n = 32）对各种生殖参数的影响。平均发情周期长度为19.81±0.56天，有两个卵泡波。平均排卵间隔为20.80±0.52天，排卵前卵泡大小为13.83±2.37毫米。控释内植孕酮（CIDR）-GnRH处理的母牛发情反应率（>0.05）高于OVS处理的母牛（分别为93.54%和84.37%）。同样，CIDR - GnRH处理的母牛排卵率（91.66%）和受胎率（68.42%）也分别高于OVS处理的母牛（41.37%和33.33%）。总之，与OVS相比，CIDR - GnRH在奶牛中能产生更好的发情反应、更高的排卵率，进而有更高的受胎率。
