Interaction of number of boar sperm and insemination timing on fertility following induced ovulation

Artificial Insemination (AI);OvuGel®;Ovulation;Sow;Sperm

Esparza-Harris, Kendra Christine ; Loerch, Steve, ; ,Bahr, Janice, ; ,Wheeler, Matthew, ; ,Miller, David, ; ,Rodriguez-Zas, Sandra ; Knox ; Robert V.

关键词: Artificial Insemination (AI);    OvuGel®;    Ovulation;    Sow;    Sperm;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/98423/ESPARZA-HARRIS-THESIS-2017.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Variability in estrus and ovulation requires multiple inseminations during estrus to ensure one AI occurs close to ovulation. Induction of ovulation with a GnRH agonist after weaning improves synchrony of ovulation and allows for fixed time AI. However, the interaction between number of sperm in the AI dose and the timing of insemination has not been extensively evaluated. The objective of this study was to determine the effects of sperm numbers used in a single post cervical artificial insemination (PCAI) and the timing of insemination following induced ovulation in weaned sows. The experiment was performed in replicates at a 1000 sow, commercial research farm during summer and fall of 2014. Multiparous sows (n = 641) were allotted by parity (average = 2.8) and lactation length (average = 19.5 d) to receive a single PCAI using 1.5 or 2.5 billion viable sperm at either 22, 26, or 30 h following OvuGel® administration at 96 h post-weaning. Sows received fence-line boar contact once daily 3 to 6 d following weaning. Sub-populations of sows (n = 499) were assessed for follicle size and ovulation utilizing ultrasound at 8 h intervals.Of all sows, 88% expressed estrus within 6 d of weaning. At time of OvuGel® administration, 90% of sows had large (≥ 6.5 mm) follicles; with 89% of those ovulating by 48 h and 92% ovulating by 56 h following OvuGel®. There was no interaction (P > 0.10) between number of sperm and timing of insemination for fertility responses. There was a tendency for number of sperm (P = 0.06) to affect pregnancy rate with 2.5 billion (87%) inducing a greater pregnancy rate than 1.5 billion sperm (80%). Pregnancy was affected by AI timing (P < 0.05) and was greater (P = 0.002) following insemination at 22 h (85.1%) than 30 h (75%) whereas AI at 26 h (86%) did not differ. Farrowing rate was affected by the number of sperm with 2.5 billion (85%) increasing farrowing (P < 0.05) compared to use of 1.5 billion (75%) and tended (P = 0.10) to be affected by AI timing. Pregnancy rate and farrowing rate were not affected by replicate, lactation length, follicle size, or ovarian cysts, but were affected by parity, estrus expression and ovulation (P < 0.05). Total born was affected by the number of sperm (P < 0.05) with 2.5 billion (P = 0.03) increasing litter size compared to 1.5 billion, and was also influenced by whether ovulation had occurred by 56 h after OvuGel®, but was not affected by AI timing. The results of this study indicate that induction of ovulation in weaned sows resulted in 87% of sows ovulating within a 24 h period and that fertility with a single fixed time AI was improved using 2.5 compared to 1.5 billion sperm and insemination at 22 h to 26 h after OvuGel® compared to 30 h.