
BPEX AI meeting State of the art in conventional AI on Danish farms ___ Mads Thor Madsen DVM, Certificate in Swine Herd Health 14th of February 2005
Agenda – BPEX AI-meeting • Welcome and presentation • Rules for Danbred AI stations • AI research projects – preliminary results • State of the art in conventional AI • Future co-operation
Heat detection Ovulation Riding test Strenght of heat Riding test + 4 boars Time Mounting No mounting (mod.e. Langendijk et al.)
Average and interval of oestrus duration and time of ovulation after onset of heat
Optimal insemination Total born piglets per litter Total born n = 75 X = 12,8 (4-25) Ref.: Anne Kirstine Nissen, 1995
Human stimulation Oxytocin - lab trial Investigated with 3 groups of sows • high stimulation • low stimulation • mating with boar (control) Blood sampling and hormone analysis All sows had the possibility of nose contact with a boar
Human stimulation Oxytocin – Herd trial Investigated with 2 groups of sows • high stimulation • low stimulation Farrowing rate and total born piglets per litter
Human stimulation Oxytocin – Herd trial Farrowing rate – a difference of 5.9 % in favour of the high stimulation group No difference in total born piglets per litter
Stress and implantation • Implantation defined as day 0 – 34 after first insemination • Stress in part of the implantation will result in loss of embryos or return to oestrus • When and what stressors - we do not know?
Stress and implantation • Transport of embryos – high stress • Day 10 – 12 maternal contact – low stress • Day 12 – 14 embryo production of estrogens – low stress • Until day 16 – low immune response – low stress • Until day 25 – heat stress causes death of embryos
Stress and implantation Conclusion A Danish average sow will be most sensitive to stress day 10 – 25 of the implantation period
Stress and implantation • Stress releases a hormone from the pituitary gland • The hormone consists of ACTH and beta-endofine • ACTH releases cortisol and adrenaline, while beta-endofine is the problem • Beta-endofine inhibits the hormone responsible for ovulation (LH)
Stress and implantation Direct stress – lab trial Sows in 3 groups treated every 4 hours during oestrus with - CRH - ACTH - Saline Blood sampling and analyses of hormones
Stress and implantation Direct stress – lab trial - Delayed LH peak and a more broad peak • Delayed ovulation (8 hours) • Unaffected length of heat (60 hours)
Stress and implantation Ovulation BPT Delayedovulation Oestrus BPT + 4 boars Mounting No mounting Time
Stress and time after AI Herd trial Rest after AI in boxes in 2 groups of sows which were • Within the box for at least 2 hours after AI • Forced out of the box immediately after AI Farrowing rate and total born piglets per litter
Stress and time after AI Herd trial No difference overall between the 2 groups in farrowing rate and total born piglets per litter But age dependent !
Stress and time after AI Farrowing rate and age
Stress and time after AI Total born piglets per litter and age
Strategic use of boar at stimulation Herd trial Investigated with 2 groups of sows: - Constant boar contact - Only boar contact the first 2 days after weaning and at the day of expected insemination Farrowing rate and total born piglets per litter Time for heat detection and insemination
Strategic use of boar at stimulation No differences in farrowing rate and total born piglets per litter Reduction of time for heat detection and insemination (approx. 2 minutes) in favour of the low boar exposed group
Miscellaneous • Avoid blood on tip of catheter • Avoid the use of catheter gels • Avoid preheating of semen before use • Use a higher concentration of Yorkshire semen when used on Yorkshire sows • Use a shorter life-span when using Hampshire semen • Re-inseminate if peristaltic contractions (2 hours later) • Boars for smell has to be > 10 month of age
Prostaglandin (PGF2alfa) release during AI PROSTAGLANDIN – TRIAL Investigated with 3 groups of sows • high stimulation • low stimulation • boar stimulation Blood sampling and analyses of hormones