Developing a single fixed-time artificial insemination (FTAI) protocol would benefit small-scale and niche market pork producers by decreasing semen costs and labor associated with detection of estrus. The objective of this study was to test the efficacy of an artificial insemination (AI) breeding system using triptorelin acetate, a GnRH agonist (OvuGel®; JBS United Animal Health, LLC, Sheridan, IN) that induces ovulation. A total of 96 sows (parity, 3.5 ± 0.2; body condition score (BCS), 2.5 ± 0.07) were weaned (h 0) after a 24.8 ± 0.6 d lactation on five participating small swine farms and allocated to one of four treatment groups: 1) TRT1: (n = 24) OvuGel applied intravaginally at h 96 and AI at h 120; 2) TRT2: (n = 24) P.G. 600® (400 IU eCG and 200 IU hCG, Merck Animal Health, Inc., De Sota, KS) injected intramuscularly at weaning, OvuGel at h 96 and AI at h 120; 3) TRT3: (n = 24) P.G. 600 at weaning, and AI at 0 and 24 h after first detection of estrus; and 4) TRT4: (n = 24) AI at 0 and 24 h after first detection of estrus. Treatments 1 and 2 were FTAI protocols with sows being inseminated without regard to estrus onset. Treatments 3 and 4 were consistent with current industry AI practices. The proportion of females displaying estrus by d 7 post-weaning was greater (P < 0.05) for sows that received OvuGel (94.5 %) compared to sows that did not receive OvuGel (82.2 %). There were no effects (P > 0.05) of P.G. 600 or P.G. 600 x OvuGel on females displaying estrus by d 7 or d 10 post-weaning. Weaning to estrus interval was decreased (P < 0.05) for sows that received P.G. 600 (4.9 ± 0.4 d) compared to sows that did not receive P.G. 600 (5.4 ± 0.4 d). There were no effects (P > 0.05) of OvuGel or P.G. 600 x OvuGel on the weaning-to-estrus interval. There were no effects of P.G. 600, OvuGel or P.G. 600 x OvuGel (P > 0.1) on pregnancy rate (total sows pregnant/inseminated) (61.2 %), total litter size (11.3), number born dead (1.0) or number of mummies (0.2). There was an effect (P < 0.05) of P.G. 600 x OvuGel on total born live (10.2). Sows treated with OvuGel had a greater number of live piglets born per semen dose (5.4) compared to sows that did not receive OvuGel (3.2) (P < 0.05). These results suggest that FTAI protocols may be employed on small-scale pig farms without compromising reproductive performance. / Master of Science / Reproductive tools such as the development of a single fixed-time artificial insemination (FTAI) protocol would benefit small scale and niche market swine producers by decreasing semen costs and labor associated with the detection of behavioral estrus or “standing heat”. OvuGel® (JBS United Animal Health, LLC, Sheridan, IN) is a gonadotropin releasing hormone (GnRH) agonist in the form of triptorelin acetate that mimics endogenous secretion of GnRH from the hypothalamus. Because the drug stimulates pituitary luteinizing hormone (LH) secretion and ovulation in weaned sows it offers potential for use in FTAI. The objective of this study was to test the efficacy of a FTAI breeding system using OvuGel to induce ovulation on five participating small-scale and niche market swine farms. A total of 96 sows (parity, 3.5 ± 0.2; body condition score (BCS), 2.5 ± 0.07) were weaned (h 0) after a 24.8 ± 0.6 d lactation and allocated to one of four treatment groups. In TRT1, OvuGel was administered 96 h after weaning with sows receiving a single insemination 22 ± 2 h later. In TRT2, sows received an intramuscular injection of P.G. 600® (400 IU eCG and 200 IU hCG, Merck Animal Health, Inc., De Sota, KS) at weaning, were given OvuGel 96 h post-weaning and were inseminated 22 ± 2 h later. Sows in TRT1 and TRT2 groups were inseminated whether behavioral estrus was exhibited or not. Weaned sows allocated to TRT3 received P.G. 600 at weaning, and once-daily estrus detection using a mature boar and females were inseminated when estrus was first detected and then again 24 h later. Sows allocated to TRT4 were given once-daily estrus detection, and inseminated at onset of estrus and again 24 h later. Treatment groups TRT1 and TRT2 represented the single, FTAI protocol whilst TRT3 and TRT4 groups were representative of current AI practices in today’s swine industry. Sows that had received OvuGel had a greater proportion of females displaying estrus by d 7 post-weaning compared to sows that did not receive OvuGel. There were no effects of P.G. 600 alone or P.G. 600 and OvuGel in combination on the proportion of females displaying estrus by d 7 or d 10 post-weaning. Weanto-estrus intervals were decreased in sows receiving P.G. 600 but not for sows receiving OvuGel or P.G. 600 and OvuGel. Reproductive performance measures such as pregnancy rates, total litter size, number of pigs born dead, or number of mummies were not affected by P.G. 600, OvuGel or the combination of P.G. 600 and OvuGel; however, there was an effect of the P.G. 600 by OvuGel interaction on total pigs born alive. Furthermore, sows treated with OvuGel had a greater number of live pigs born per semen dose compared to sows that did not receive OvuGel. These findings suggest that FTAI protocols may be used as a reproductive tool on small-scale pig farms without compromising reproductive performance.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/77395 |
| Date | 11 April 2017 |
| Creators | Fabi, Amanda Jean |
| Contributors | Animal and Poultry Sciences, Estienne, Mark J., Clark-Deener, Sherrie, Wood, Cynthia M. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/vnd.openxmlformats-officedocument.wordprocessingml.document |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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