Progress 09/01/08 to 08/31/11
Outputs
OUTPUTS: Controls were untreated and inseminated (AI) as normally practiced. OvuGel (OG) containing 200 mcg triptorelin acetate was administered intravaginally. Sows were weaned (Day 0) at 17-22 days of lactation. Gilts displayed at least one estrus and were individually fed 15 mg MATRIX/gilt/day for 14 days. Last feeding of MATRIX also = Day 0. Objective A: Sixty-three sows each were assigned to: Controls (C) or OG at 96 hrs; at 100 hrs or at 104 hrs after weaning and were AI without regard to estrus the next morning. C sows were observed for estrus from Day 4-7 and AI each day in estrus. Based on results of previous studies and Objective C and the desire for treatments and AI to conform to the normal work day, Objective B was combined with Objective F. In Objective C, 60 MATRIX-fed gilts each were assigned to: 1) C: PG 600 vehicle (V) + OG V; 2) PG 600 V + OG; 3) PG 600 + OG; or 4) PG 600 + OG V. Gilts received PG 600 V or PG 600 on Day 1 and OG V or OG at 104 hrs on Day 4. OG-treated gilts were AI once 22 hr later on Day 5. OG V-treated gilts were AI each day of estrus. Estrus detection was performed on Day 3-8 or until gilts no longer expressed estrus and again 18-24 days after AI to determine if the gilts had recycled. Thirty gilts/treatment were examined for ovarian follicle size and time of ovulation every 8 hrs for 56 hrs starting at 96 hrs on Day 4 by transrectal real-time ultrasound. In Objective D, 74 sows each were assigned to: 1) C: PG and OG Vs and AI each day of estrus; 2) OG 98-99 hrs after weaning and AI once 22 to 24 hrs later; 3) PG 600 on Day 0, OG 97-99 hrs after weaning and AI once 22 to 24 hrs later; and 4) PG 600 on Day 0 and AI each day of estrus. Time of AI was without regard to estrus. Ovarian follicle size and time of ovulation were examined by Transrectal ultrasound was performed on 19-21 sows/treatment starting 8 hrs after OG/OG V treatment and continuing every 8 hrs for 56 hrs. Objective E was a GLP target animal safety study and data were submitted to FDA for review. Eight sows each were assigned to: 2 ml of OG, 14 ml of OG or 2 ml of OG V 96 hrs after weaning. Changes in behavior and numerous parameters of physiological state were monitored. Blood serum was analyzed for hematological, chemical and hormonal parameters. Tissue samples representing all body systems were collected for histopathology at necropsy. Objective F was conducted with MATRIX-fed gilts at three sites. I. Morristown Sow Farm, Indiana and M2P2 Sow Farm, North Carolina: Ninety-six to 104 gilts each were allocated to the following at the two sites; 1) C: no OG and AI on each day of estrus; 2) OG and AI once at 3 to 7 hrs after OG treatment, if in estrus, otherwise AI once on Day 6 regardless of estrus status; 3) OG and AI once at 3 to 7 hrs after OG treatment and again on Day 6. II. DE Orr Sow Farm, Indiana: Sixty-eight gilts each were allocated to: 1) C: no OG and AI each day in estrus; 2) OG and AI at 4 to 6 hrs post OG regardless of estrus status; 3) OG and AI once on Day 6, 22-24 hrs post-OG without regard to estrus. PARTICIPANTS: Dr. Stephen Webel is the Principle Investigator of this proposed research project. Dr. Webel is Director of Reproduction Research and Development at JBS United, Inc., which is one of the founding partners of the joint venture company, Pennatek LLC. He has over 40 of years of experience in research, teaching, consulting and administration in swine reproductive physiology. Dr. Webel is also an Officer at Pennatek LLC and serves as the company's Vice President of Research. Dr. Robert Kraeling, L&R Research Associates, Inc., is a co-principle investigator/collaborator on this research project. He has over 35 years of experience in research, teaching and administration in swine reproductive physiology. Dr. Kraeling retired from a 34 year career with ARS, USDA in 2004. Dr. Robert Knox, Associate Professor of Animal Science, University of Illinois, is an investigator/collaborator on this research project. He has over 15 years of experience in research, teaching and extension in swine reproduction, including specific expertise in transrectal ultrasound techniques used to monitor ovulation in swine. Mark Swanson, Vice President of Development at Pennatek, is an investigator/collaborator on this research project. He has over 21 years of experience in research and administration in the pharmaceutical and biotechnology industries. Michael Johnston, JBS United Scientist, is an investigator/collaborator on this research project. He has over 25 years of experience in conducting on-farm research studies. Chris Anderson, an employee of Pennatek, has overseen the management of data in several swine studies over the past six years. This project provided training opportunities to graduate students; primarily, Jessica Taibl and Shawn Breen, and undergraduate students; primarily, Anne Visconti and Cody Skees, under the direction of Dr. Knox. These graduate students as well as undergraduate students assisted in the experimental design, data analysis, and report preparation. They also assisted with execution of ultrasonography. TARGET AUDIENCES: There are approximately 67,000 pig producers in the U.S. Of these, 25 producers maintain more than 25,000 sows/gilts and represent approximately 40% of production. These largest producers will be our primary target. Our secondary target will be the 130 producers with 2,500-25,000 sows/gilts who account for approximately 20% of production. We will also market to the 2,400 producers with 250-2,500 sows/gilts who account for 28% of production. The key players involved in the purchase decision, in order of likely influence, will include swine veterinarians, pig production operators, and purchasing personnel. Swine veterinarians may be employed by the producer or serve as independent consultants. We will also target pork producers in the U.S., Canada and the EU. When the results from this project are published, other scientists in academia and the animal pharmaceutical industry will use this information as a basis for further research and university extension personnel will use this information to make swine producers aware of this new technology. PROJECT MODIFICATIONS: Based on results of previous studies, results from Objective C and the desire for practical animal treatments and inseminations to conform to the normal working day, Objective B was combined with Objective F, which was conducted at multiple productions sites. Optimal synchrony of ovulation occurred when OvuGel, containing 200 ug triptorelin acetate, was administered at 120 hours following the last MATRIX feeding compared with either 96 or 144 hours. PG 600 failed to improve precision of ovulation synchronization. Delaying the time of insemination until 24 hours following OvuGel appears to be too late to assure that sperm are present in the oviduct for gilts that ovulate as early as 130 hours. Previous data suggested that insemination must be performed at 120 hours, but it is not clear whether a second insemination 24 hours later will improve fertility. Therefore, the effectiveness trials above were conducted at three sites to obtain acceptable fertility data prior to implementing the protocols at all five proposed sites.
Impacts
Objective A: Results demonstrated that a single AI without regard to estrus the day after OG administration in weaned sows produces farrowing rates, litter size and piglet index comparable to controls AI multiple times during estrus. This is consistent with results from our previous trials. Administration of OG 96 hrs post wean produces higher litter size and piglet index than administration of OG at 100 or 104 hrs post wean, confirming identification of 96 hrs post wean as the optimal time for OG treatment in postpartum sows. Based on these results, we conclude that the optimal time for OG treatment is at 96 hrs after weaning. Objective C: Results demonstrated that OG containing 200 ug triptorelin given at 120 hrs after last feeding of MATRIX in gilts effectively synchronized ovulation after estrous cycle synchronization with MATRIX and that PG 600 failed to improve precision of ovulation synchronization. Objective D: Data are consistent with previous trials showing no difference in farrowing rate and litter size between OG and C sows. PG 600 reduced time to estrus after weaning, but failed to impact farrowing rate or litter size. Objective E: An approximate 4.5% decrease in weight was associated with the regression of mammary tissue following weaning. No dose-related abnormalities were detected for serum chemistry, hematology, urinalysis, or serum endocrine function results. The CVM, FDA concluded that intravaginal administration of triptorelin gel to postpartum sows within 96 hours of weaning may cause minor vaginal inflammation that is non-dose related, but that OG is safe when administered to postpartum sows at the labeled dose of 200 mcg. Objective F: Results from these trials confirmed results from Objective C, demonstrating that OG containing 200 ug triptorelin given at 120 hrs after last feeding of MATRIX in gilts effectively synchronized ovulation. In addition, delaying AI until 24 hrs following OG is too late to assure that sperm are present in the oviduct for gilts that ovulate as early as 130 hrs. Previous data suggested that insemination must be performed at 120 hours, but it was not clear if a second AI 24 hrs later would improve fertility. At both sites, the percentage of gilts pregnant at Day 30 was greatest for gilts in estrus on Day 5 and AI on Day 5 and 6, followed by gilts not in estrus on Day 5 and AI on Day 5 and 6, and gilts not in estrus on Day 5 and AI on Day 6. Also at both sites, the percentage of gilts pregnant at Day 30 was greater for all gilts AI on Day 5 and 6 than for gilts AI only on Day 6. Thus, treatment 2, with AI on Day 5 for gilts in heat, followed by fixed-time AI on Day 6, is probably the best option. Pennatek will conduct further research from internal funding to pursue an FDA approved claim. This research will focus on the following modifications: 1) checking heat on Day 5, not treating gilts in heat, but breeding them as normally practiced for C gilts or 2) gilts not in heat on Day 5 would be treated with OG on Day 5 and AI on Day 6.
Publications
- No publications reported this period
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Progress 09/01/09 to 08/31/10
Outputs
OUTPUTS: The recent introduction of MATRIX for gilt estrus synchronization reduces the size of the pool required to provide replacement gilts. However, MATRIX synchronizes estrus of gilts within 4-9 days following last feeding in randomly cycling females. Therefore, an additional treatment to more precisely control ovulation is needed so that all gilts in a group may be inseminated on the same day without regard to estrus. We previously demonstrated that intravaginal administration of Pennatek's OvuGel (OG) at 120 hours after last feeding of MATRIX effectively synchronized ovulation in gilts. This project is investigating this new approach to precisely control ovulation after weaning in the sow and after estrous cycle synchronization with MATRIX in the mature gilt, which has already reached puberty and begun to cycle. Outputs for Objectives A and E were provided in our previous annual report. As indicated in that report, those objectives were completed. All data collection was completed and subjected to statistical analysis for Objective C and D. In Objective C, 60 gilts each were assigned to: 1) C (Control): P.G. 600 vehicle + OvuGel vehicle, 2) OG: P.G. 600 vehicle + OvuGel, 3) PG+OG: P.G. 600 + OvuGel, or 4) PG: P.G. 600 + OvuGel vehicle. All gilts were fed MATRIX for 14 days. The last feeding of MATRIX was at 7:00 am +/- 2 hours (Day 0). Gilts received PG vehicle or PG at 7:00 am +/- 1 hour on Day 1 and OG vehicle or OG at 104 hours +/- 1 hour after last feeding of MATRIX (3:00 pm +/- 1 hour on Day 4). Gilts treated with OG were inseminated once 22 +/- 1 hour later (1:00 PM +/- 1 hour on Day 5). Gilts treated with OG vehicle were inseminated the first day they were observed in estrus and at 24 hour intervals for the duration of estrus. Estrus detection was performed on all gilts on Day 3 through Day 8 or until gilts no longer expressed estrus and again between Days 18-24 following insemination to determine if the gilts had recycled. Thirty gilts per treatment group were examined for ovarian follicle size and time of ovulation using transrectal real-time ultrasound at 8-hour intervals for 56 hours starting at 96 hours (Day 4) after last feeding of MATRIX. In Objective D, 74 sows (PIC C29) each were allotted to one of four treatments; 1) C (Control): sows treated with vehicles and inseminated at onset of estrus and daily for the duration of estrus; 2) OG: sows treated with OvuGel 98-99 hours after weaning and inseminated once 22 to 24 hours later; 3) PG+OG: sows treated with P.G. 600 on Day 0 at weaning and with OvuGel 97-99 hours after weaning and inseminated once 22 to 24 hours later; and 4) PG: sows treated with P.G. 600 on Day 0 at weaning and inseminated at onset of estrus and daily for the duration of estrus. Estrous behavior was recorded for sows receiving OvuGel, but time of insemination was without regard to estrus. Transrectal ultrasound examination to determine ovarian follicle size and time of ovulation was performed on 81 sows (19-21 per treatment). Examinations started at 8 hours after the time of OvuGel/OvuGel vehicle gel treatment and continued at 8-hour intervals until 56 hours after OvuGel/OvuGel vehicle gel treatment. PARTICIPANTS: Dr. Stephen Webel is the Principle Investigator of this proposed research project. Dr. Webel is Director of Reproduction Research and Development at JBS United, Inc., which is one of the founding partners of the joint venture company, Pennatek LLC. He has over 40 of years of experience in research, teaching, consulting and administration in swine reproductive physiology. Dr. Webel is also an Officer at Pennatek LLC and serves as the company's Vice President of Research. Dr. Robert Kraeling, L&R Research Associates, Inc., is a co-principle investigator/collaborator on this research project. He has over 35 years of experience in research, teaching and administration in swine reproductive physiology. Dr. Kraeling retired from a 34 year career with ARS, USDA in 2004. Dr. Robert Knox, Associate Professor of Animal Science, University of Illinois, is a co-principle investigator/collaborator on this research project. He has over 15 years of experience in research, teaching and extension in swine reproduction, including specific expertise in transrectal ultrasound techniques used to monitor ovulation in swine. Mark Swanson, Vice President of Development at Pennatek, is a co-principal investigator/collaborator on this research project. He has over 21 years of experience in research and administration in the pharmaceutical and biotechnology industries. Chris Anderson, an employee of Pennatek, has overseen the management of data in several swine studies over the past five years. This project provided training opportunities to graduate students; primarily, Jessica Taibl and Shawn Breen, and undergraduate students; primarily, Anne Visconti and Cody Skees, under the direction of Dr. Knox. These graduate students as well as undergraduate students assisted in the experimental design, data analysis, and report preparation. They also assisted with execution of ultrasonography. TARGET AUDIENCES: There are approximately 67,000 pig producers in the U.S. Of these, 25 producers maintain more than 25,000 sows/gilts and represent approximately 40% of production. These largest producers will be our primary target. Our secondary target will be the 130 producers with 2,500 - 25,000 sows/gilts who account for approximately 20% of production. We will also market to the 2,400 producers with 250 - 2,500 sows/gilts who account for 28% of production. The key players involved in the purchase decision, in order of likely influence, will include swine veterinarians, pig production operators, and purchasing personnel. Swine veterinarians may be employed by the producer or serve as independent consultants. We will also target pork producers in the U.S., Canada and the EU. When the results from this project are published, other scientists in academia and the animal pharmaceutical industry will use this information as a basis for further research and university extension personnel will use this information to make swine producers aware of this new technology. PROJECT MODIFICATIONS: The work plan for Objective B has been modified based on the results of previous studies and the desire for practical animal treatments and inseminations to conform to the normal working day. The optimal synchrony of ovulation was observed when OvuGel was administered at 120 hours following the last MATRIX feeding, as compared with either 96 or 144 hours. However, delaying the time of insemination until 24 hours following OvuGel appears to be too late to assure that sperm are present in the oviduct for gilts that ovulate as early as 130 hours. The previous data suggest that insemination must be performed at 120 hours, but it is not clear whether a second insemination 24 hours later will improve fertility. The proposed work plan provides for treatment with OvuGel and insemination within normal farm work schedules and secondly evaluates a single compared with two inseminations. The proposed treatments include feeding cycling gilts 15 mg. MATRIX for 14 days followed by: 1) Control gilts inseminated according to normal farm procedures at detected estrus; 2) OvuGel treatment at 104 hours after last MATRIX feeding with insemination at 120 hours; 3) OvuGel as in Trt. 2 with two inseminations at 120 and 144 hours; 4) OvuGel treatment at 118 hours after last MATRIX feeding with insemination at 120 and 144 hours. Results of this study will provide comparison between two practical times for OvuGel treatment and between one versus two inseminations at the earlier treatment time. Results of this study are expected to reveal the optimal practical time for OvuGel treatment and whether a second insemination at 144 hours will increase fertility. The results from this study will provide data required to develop the work plan for Objective F.
Impacts
OBJECTIVE C: The percentage of gilts, which expressed estrus was similar among treatments, but time from last feeding of MATRIX to estrus (hours/days) was greater (P< 0.0001) for C (134/5.5) and OG (127/5.2) gilts than for PG+OG (114/4.8) and PG (118/4.8) gilts. The percentage, which ovulated at 48 hours (P< 0.001) and 56 hours (P< 0.01) after treatment, was greater for OG (85 & 88) and PG+OG (85 & 86) gilts than for C (65 & 73) and PG (66 & 71) gilts. Doses of semen/gilt inseminated were greater (P< 0.0001) for C (2) and PG (2) gilts than for OG (1) and PG+OG (1) gilts. Of gilts inseminated, the percentage, which returned to estrus at 21 days after AI, was greater (P< 0.01) for OG (17) and PG+OG (20) gilts than for C (3) and PG (4) gilts. Total number of piglets born/semen dose was greater (P< 0.04) for OG (8.4) and PG+OG (7.3) gilts than for C (6.3) and PG (5.2) gilts. Total born alive (all litters) and piglet index were greatest for C (553 & 922) followed by OG (466 & 777), PG+OG (375 & 625) and PG (374 & 623) gilts. The remaining parameters were not different among all gilts. When comparing OG and PG+OG gilts, MATRIX to estrus (P< 0.03) was greater for OG than for PG+OG gilts. Piglet index was greater for OG than for PG+OG gilts. However, duration of estrus (P< 0.04) and mummies/litter (P< 0.01) were greater of PG+OG than for OG gilts. The remaining parameters were not different for OG and PG+OG gilts. Thus, OvuGel containing 200 ug triptorelin given at 120 hours after last feeding of MATRIX effectively synchronized ovulation after estrous cycle synchronization with MATRIX in gilts and PG failed to improve precision of ovulation synchronization. OBJECTIVE D: The percentage of sows, which expressed estrus, was greater (P< 0.03) for PG+OG (99) and PG (95) sows than for C (89) and OG (89) sows. Hours from weaning to estrus (P< 0.05) and days from weaning to estrus (P< .0001) were greater for C (114 & 4.6) and OG (111 & 4.2) than for PG+OG (103 & 4.1) and PG (101 & 4.0) sows. Duration of estrus (hours) was shortest for OG (50.8) sows, followed by PG+OG (52.6), C (53.8) and PG (58.5) sows (P< 0.05). Percentage of sows in estrus at AI was greater (P< 0.01) and doses of semen/sow inseminated was greater (P< 0.0001) for C (100 & 1.9) and PG (100 & 1.8) sows than for OG (91 & 1.0) and PG+OG (97 & 1.0) sows. Percentage returns at 21 days of sows inseminated was greater (P< 0.02) for PG (9.7) sows than for C (0), OG (4.6) and PG+OG (1.9) sows, however, percentage pregnant at 30 days and percentage farrowed, of sows allotted, were similar among treatments. Total born per semen dose was greater (P< 0.0001) for OG (12) and PG+OG (12.2) than for C (7.5) and PG (7.9) sows. Piglet Index was greatest for C (893) sows followed by PG+OG (869), PG (822) and OG (742) sows. The percentage of sows, which had ovulated by each ultrasound examination after treatment, was not different among treatments. These data are consistent with previous trials showing no difference in farrowing rate and litter size between OG and C sows. P.G. 600 reduced interval to estrus, but failed to impact farrowing rate or litter size.
Publications
- No publications reported this period
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Progress 09/01/08 to 08/31/09
Outputs
OUTPUTS: Objective A and E are completed and Objective B and F have not started. Objective C and D were conducted and subsequent farrowings are in progress. Controls were untreated and inseminated as normally practiced and OvuGel (OG) contained 200 mcg triptorelin acetate in all studies. Gilts displayed at least one estrus and were individually fed MATRIX for 14 days. The last feeding of MATRIX and day of weaning = Day 0. Objective A was performed in six separate weaning groups. Sows were weaned at 17 - 22 days of lactation and 63 each assigned to one of 4 treatments: Controls or OG at 96 hours; at 100 hours or at 104 hours after weaning. Treated sows were inseminated between 8 and 10 am the day following treatment whether or not they showed signs of standing estrus. Untreated Control sows were observed from Day 4 until Day 7 after weaning for behavioral estrus and inseminated the day they were observed to be in estrus and at 24 hour intervals for the duration of standing heat (normal farm procedures). Pregnancy rate, date of farrowing, farrowing rate, total number of pigs born and the number of piglets born alive, interval (hours) from weaning to estrus and percentage of sows bred by 8 days post weaning were recorded. Objective C consisted of 11 replicates. Gilts were fed MATRIX for 14 days. On Day 0, 60 gilts each were assigned to: PG 600 vehicle on Day 1 + OG vehicle on Day 4; PG 600 vehicle on Day 1 + OG on Day 4; PG 600 on Day 1 + OG on Day 4 or PG 600 on Day 1 + OG vehicle on Day 4. A subset of 31-33 gilts from each group were examined for ovarian follicle size and time of ovulation using transrectal real-time ultrasound at the time of OG or vehicle gel treatment and at 8-hour intervals for 56 hours. In Objective D, 296 sows in 13 replicates were weaned and 74 each were assigned to: PG 600 vehicle on Day 1 + OG vehicle on Day 4; PG 600 on Day 1 + OG vehicle on Day 4; PG 600 on Day 1 + OG on Day 4 or PG 600 on Day 1 + OG vehicle on Day 4. Subsets of 20-21 sows from each group were examined for ovarian follicle size and time of ovulation as in Objective C. Objective E was conducted as a GLP study and data have been submitted to FDA for review. Additional studies may be required pending FDA response. Sows were weaned and 8 each were assigned to the following treatments: 2 ml of OG, 14 ml of OG or 2 ml of OG vehicle 96 hours after weaning. Changes in behavior, respiration, food and water intake, urination or defecation frequency, vaginal irritation or infection and effects on the condition of skin, hair, eyes, mucous membranes and nervous system were monitored. Blood serum was analyzed for hematological, chemical and hormonal parameters. All external surfaces, orifices and internal organs were examined and tissue samples representing all body systems were collected for histopathology at necropsy. PARTICIPANTS: Dr. Stephen Webel is the Principle Investigator of this proposed research project. Dr. Webel is Director of Reproduction Research and Development at JBS United, Inc., which is one of the founding partners of the joint venture company, Pennatek LLC. He has over 40 of years of experience in research, teaching, consulting and administration in swine reproductive physiology. Dr. Webel is also an Officer at Pennatek LLC and serves as the company's Vice President of Research. Dr. Robert Kraeling, L&R Research Associates, Inc., is a co-principle investigator/collaborator on this research project. He has over 35 years of experience in research, teaching and administration in swine reproductive physiology. Dr. Kraeling retired from a 34 year career with ARS, USDA in 2004. Dr. Robert Knox, Associate Professor of Animal Science, University of Illinois, is a co-principle investigator/collaborator on this research project. He has over 15 years of experience in research, teaching and extension in swine reproduction, including specific expertise in transrectal ultrasound techniques used to monitor ovulation in swine. Mark Swanson, Vice President of Development at Pennatek, is a co-principal investigator/collaborator on this research project. He has over 21 years of experience in research and administration in the pharmaceutical and biotechnology industries. Chris Anderson, an employee of Pennatek, has overseen the management of data in several swine studies over the past five years. This project provided training opportunities to graduate students; primarily, Jessica Taibl and Shawn Breen, and undergraduate students; primarily, Anne Visconti and Cody Skees, under the direction of Dr. Knox. These graduate students as well as undergraduate students assisted in the experimental design, data analysis, and report preparation. They also assisted with execution of ultrasonography. TARGET AUDIENCES: There are approximately 67,000 pig producers in the U.S. Of these, 25 producers maintain more than 25,000 sows/gilts and represent approximately 40% of production. These largest producers will be our primary target. Our secondary target will be the 130 producers with 2,500 - 25,000 sows/gilts who account for approximately 20% of production. We will also market to the 2,400 producers with 250 - 2,500 sows/gilts who account for 28% of production. The key players involved in the purchase decision, in order of likely influence, will include swine veterinarians, pig production operators, and purchasing personnel. Swine veterinarians may be employed by the producer or serve as independent consultants. We will also target pork producers in the U.S., Canada and the EU. When the results from this project are published, other scientists in academia and the animal pharmaceutical industry will use this information as a basis for further research and university extension personnel will use this information to make swine producers aware of this new technology. PROJECT MODIFICATIONS: Objective B has not begun. Based on a review of previous ovulation data after OvuGel in weaned sows (Objective A, SBIR II) and Matrix fed gilts (Objective A and B, SBIR I), we concluded that additional data on time of ovulation following either placebo or OvuGel in Matrix fed gilts (Objective C) were needed before proceeding with Objective B. These additional data will be used to more definitively select the times for OvuGel administration and AI after feeding MATRIX to gilts, which Objective B was designed to investigate. Therefore, objective B has been delayed and the specific treatments may be modified based on additional ovulation data obtained. OvuGel treatment at 104 hr. after last Matrix feeding appeared to be the most logical time between 96 and 120 hr. because it still permits OvuGel treatment to be administered during the normal farm staff work day. Therefore, we proceeded with Objective C. The fourth treatment group of PG 600 + OvuGel vehicle was added to Objective C and D in order to improve the experimental design.
Impacts
Data were collected from 252 sows (63 sows per treatment) for Objective A. There were no treatment by cohort interactions for any of the variables tested. As expected, there was a significant difference among treatment groups in the percentage of sows in estrus at insemination (P<.05; 100 % for controls vs. approximately 80% for OvuGel-treated sows) and number of inseminations per sow (P<.01; 1.56 for controls vs. 1.00 for OvuGel-treated sows) since control sows were inseminated daily during estrus, whereas OvuGel-treated sows were inseminated once at a fixed time regardless of estrus behavior. The farrowing rate was not different among treatments (P=.67), which agrees with results from our previous trials. Thus, we conclude that a single insemination following OvuGel results in farrowing rates comparable to controls inseminated multiple times during estrus. The number of piglets born per semen dose was greater (P<.01) for OvuGel-treated sows (12.3 for OG96, 11.4 for OG 100 and 10.7 for OG 104) than for controls (6.7). Such a large difference in piglets born per semen dose after OvuGel will permit production of more piglets from higher indexing boars with greater genetic merit. Litter size was greater (P<.05) for TG 96 compared to TG 104, but not significantly different from the other treatments. Total piglets born (piglet index) were 477, 487, 422 and 404 for Control, OG96, OG 100 and OG 104 sows, respectively. Based on these results, we conclude that the optimal time for OvuGel treatment is at 96 hours after weaning. For Objective C, farrowing for the first 8 replicates started on October 15, 2009 and will conclude in December, 2009. The final 3 replicates will begin farrowing February 11, 2010. Therefore, all data collection should be completed by March 1, 2010. Farrowing for Objective D began October 15, 2009 and all data collection should be completed by January 25, 2010. All data for Objective E have been submitted to FDA for analysis. Application of this method to precisely control ovulation in both weaned sows and Matrix treated gilts will revolutionize how pigs are mated. Synchronized ovulation facilitates the use of fixed-time, single service AI, while eliminating the labor previously required for detection of estrus. This synchronized estrus and ovulation system allows for insemination of all females in a particular group at the same time and at the peak time of fertility. Adoption of this system will result in increased genetic progress because sires of higher genetic merit will be used across the entire breeding herd. The labor costs associated with operation of the replacement gilt pool will be reduced due to elimination of estrus detection during the combined estrous cycle synchronization and ovulation synchronization procedures. This needle free administration system will reduce the risk of needle shafts in pork carcasses and the need to trim pork cuts due to the presence of needle injection sites.
Publications
- No publications reported this period
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