Effects of number of frozen-thawed ram sperm and number of inseminations on fertility in synchronized ewes under field condition

Abstract

The effects of the number of frozen-thawed ram sperm per single and double intra-cervical artificial insemination (AI) on fertility in ewes were studied. A total of 89 non-pregnant ewes were synchronized for oestrus with two doses of 100 µg PGF 2α (Cloprostenol) 9 days apart. The ewes were randomly assigned to one of four groups; D200 (n = 23; double AI with 200 × 10 6 sperm), S200 (n = 24; single AI with 200 × 10 6 sperm), D100 (n = 24; double AI with 100 × 10 6 sperm) and S100 (n = 18; single AI with 100 × 10 6 sperm). Ewes were inseminated within 12 to 18 h for single AI and, within 10 to 12 h and 16 to 18 h for double AI after the onset of oestrus. The onset of oestrus ranged from 28 to 76 h (54.33 ± 1.28 h). The high percentage (29.2%) of ewes showed oestrus between 51 to 60 h. The non-return rates were highest in group D200 (56.5%) and differed significantly (p < 0.05) from group S100 (11.1%). No ewes were pregnant in group S100, and the pregnancy rates among the remaining groups did not differ. The mean gestation period was 152.8 ± 0.5 days and no difference was observed among the groups. The lambing and multiple birth rates were 100% in group D200. The single and twin lambing was highest in group D100 (33.3%) and group D200 (83.3%), respectively. Only one triplet lambing and the highest lambing size (2.2 ± 0.2) was recorded in group D200. In conclusion, double AI with 200 × 10 6 sperm showed comparatively most practical for achieving high pregnancy rates and lambing performances in Bangladeshi ewes under field conditions.

Effects of cervical ripening treatments on pregnancy rates following transcervial artificial insemination in ewes

“…The mean volume, mass motility, concentration and motility were 0.75 ± 0.14 ml, 3.4 ± 0.65, 3.5 ± 0.47, 3398.6 ± 562.47 × 106/ml and 80.10 ± 5.70%, respectively. Estrus synchronization: All ewes were synchronized for estrus using two doses of prostaglandin F2α (Ovuprost®, Cloprostenol, Bayer New Zealand Ltd., Auckland, New Zealand) 0.5 ml deep im per ewe at an interval of 9 days (Jha et al, 2020). Animals were closely observed for estrus behavior using a teaser ram.…”

“…Achieving acceptable pregnancy rates is very important for uptake to AI technology by sheep farmers. To establish an AI program in Bangladeshi ewes, studies on estrus synchronization, AI techniques using chilled and frozen Introduction semen have been accomplished (Roy et al, 2014;Jha et al, 2020). However, the pregnancy rates reported 60 -70% with fresh semen and 11 -26% with frozenthawed semen following transcervical insemination (TC-AI; Azizunnesa, 2016;Rekha et al, 2016Rekha et al, , 2018Jha et al, 2020), which is not acceptable for field AI purpose.…”

“…To establish an AI program in Bangladeshi ewes, studies on estrus synchronization, AI techniques using chilled and frozen Introduction semen have been accomplished (Roy et al, 2014;Jha et al, 2020). However, the pregnancy rates reported 60 -70% with fresh semen and 11 -26% with frozenthawed semen following transcervical insemination (TC-AI; Azizunnesa, 2016;Rekha et al, 2016Rekha et al, , 2018Jha et al, 2020), which is not acceptable for field AI purpose. This lower pregnancy rates in ewes are due to complex cervical anatomy (long, convoluted funnelshaped cervix) that prevents the passage of AI pipette into the body of uterus, as a result, there is the reduction in a high proportion of the spermatozoa when they arrive the place of fertilization (Wulster-Radcliffe et al, 2004;Kershaw et al, 2005;Leethongdee, 2010).…”

Semen evaluation: methodological advancements in sperm quality-specific fertility assessment

“…The integrity of the plasma membrane is essential for proper sperm function and fertility, pertaining to its function to maintain homeostasis [ 101 , 102 ], protection against foreign agents, and interactions with other cells, including oocytes, and the epithelial lining of the female reproductive tract [ 103 , 104 ]. Sperm fertility is dependent on the integrity of the plasma membrane, as it plays an important role in different physiological events such as capacitation, acrosomal reaction, and zona binding [ 105 ].…”

Developing a Cost Structure of Frozen Semen Production and Performance of Artificial Insemination for Sheep Breeding Program

“…Moreover, the farmers favor to practice low input technology in their extensive farming system (Bora and Das, 2013). In Bangladesh, preliminary work on artificial insemination in sheep breeding program has been performed by many researchers (Rekha et al 2016;Naher et al 2016;Jha et al 2020). Till to date, there is found no information about the cost structure of frozen ram semen as well as Developing a Cost Structure of Frozen Semen Production and Performance of Artificial Insemination for Sheep Breeding Program performance artificial insemination.…”