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WILD PIG REPRODUCTION IN LOUISIANA …… JUST THE FACTS. Kim Marie Tolson , ULM James M. LaCour , LDWF. Misconceptions in the Media. Misconceptions in the Media. “Adult sows can produce three litters a year.”. Misconceptions in the Media. “Adult sows can produce three litters a year.” - PowerPoint PPT Presentation
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WILD PIG REPRODUCTION IN LOUISIANA …… JUST THE FACTS
Kim Marie Tolson, ULM James M. LaCour, LDWF
Misconceptions in the Media
Misconceptions in the Media
“Adult sows can produce three litters a year.”
Misconceptions in the Media
“Adult sows can produce three litters a year.”
“one female can have 300 piglets in two years”
BIOLOGY OF WILD PIGS•Habitat generalists• Low natural mortality•Opportunistic omnivores•High reproductive potential
BIOLOGY OF WILD PIGS•Habitat generalists• Low natural mortality•Opportunistic omnivores•High reproductive potential
BIOLOGY OF WILD PIGS•Habitat generalists• Low natural mortality•Opportunistic omnivores•High reproductive potential
BIOLOGY OF WILD PIGS•Habitat generalists• Low natural mortality•Opportunistic omnivores•High reproductive potential
BIOLOGY OF WILD PIGS•Habitat generalists• Low natural mortality•Opportunistic omnivores•High reproductive potential
Wild Pig Breeding Biology• Early reproductive maturity• Gestation period ~114 days– 3 months, 3 weeks, 3 days– potential multiple litters/yr
• Capability to produce large litters
HIGH REPRODUCTIVE POTENTIAL!!
OBJECTIVES
• Characterize the breeding biology of wild pigs in Louisiana– Determine average litter size– Calculate reproductive efficiency– Determine peak breeding dates– Compare data with other populations of feral hogs
METHODS
• Collection May 2010 to June 2011• Reproductive tracts removed: ovaries & uterus•
- Collection Date- Location (Parish)- Weight- Notes- Tracts frozen
METHODS
• OVARIES– Preserved in 10% buffered formalin– Sliced in 1-2 mm sections– Presence/number of follicles or corpora lutea (CL)
Ovary with follicles Ovary with CLPhotos courtesy Meg O’Boyle
METHODS
• UTERI– Number and gender of fetuses– Crown-rump measurements (avg. for litter)– Extrapolate breeding and farrowing dates
(Henry 1968)
RESULTS
• 87 Reproductive Tracts– 80 Adults + 7 Sub-adults– 47 lb. sow with follicular development
RESULTS
• 87 Reproductive Tracts– 80 Adults + 7 Sub-adults– 47 lb. sow with follicular development
RESULTS
• 35 Pregnant 43.75%• 40 Developing follicles 50.00%• 2 CL in ovaries 2.50%• 3 No repro activity 3.75% 80 Adult sows
(77/80 showed repro activity in ovaries)
RESULTS
• 35 Pregnant 43.75%• 40 Developing follicles 50.00%• 2 CL in ovaries 2.50%• 3 No repro activity 3.75% 80 Adult sows
(77/80 showed repro activity in ovaries)
RESULTS
CL Fetuses RE*__Sum 229 176 76.85%----------------------------------------------------------------Mean 6.54 5.03----------------------------------------------------------------Range (4-10) (2-10)----------------------------------------------------------------*RE = (# fetuses / # CL) x 100
COMPARISON OF LITTER SIZE_____________________________________________________________________________________________Location n Mean # of fetuses (range) Reference_____________
Louisiana 35 5.03 (2-10) Tolson and LaCour (2013) Georgia 17 6.20 (?-9) Hagen and Kephart (1980) (penned) Georgia 35 5.89 (3-11) Jolley (2007) (free ranging) South Carolina 8 7.40 (5-12) Sweeney et al. (1979) Tennessee 20 4.65 Henry (1968) Texas 64 5.40 (2-11) Delgado-Acevedo et al. (2010) (southern and central counties) Texas 21 6.30 Taylor et al. (1998) -South Texas Plains (western) Texas 18 5.60 Taylor et al. (1998) -Gulf Coast Prairie (eastern) New Zealand 291 6.20 (1-11) Dzieciolowski et al. (1992) Spain 52 3.58 (1-7) Fernandez-Llario and Mateos-
Quesada (1998)__________
Conception Dates
Farrowing Dates
Breeding Biology of Wild Pigs in Louisiana
• Average litter size is 5-6• Conception and farrowing occurs year round• Two peaks in conception:– Broad peak from Sept. through Dec.– Narrow peak in Feb. – Mar.
• Results not unexpected – parallels other hog populations across the south.
Reproductive Potential
• Age of Reproductive Maturity – around 6 months– 47 pounds!
• Number of Litters per Year– Commonly reported = 2/12 mos.– Actually = 2/15-18 mos.
• Number of offspring per Litter– Average = 5 to 6
Wildpiginfo.msstate.edu
www.flickr.com
Reproductive PotentialComparison of Large Mammals
White-tail Deer Wild PigReproductive maturity
Avg. # offspring
Frequency of breeding
Reproductive PotentialComparison of Large Mammals
White-tail Deer Wild PigReproductive 18 mo. ~ 6 mo. maturity
Avg. # offspring
Frequency of breeding
Reproductive PotentialComparison of Large Mammals
White-tail Deer Wild PigReproductive 18 mo. ~ 6 mo. maturity
Avg. # offspring 1.5 5-6
Frequency of breeding
Reproductive PotentialComparison of Large Mammals
White-tail Deer Wild PigReproductive 18 mo. ~ 6 mo. maturity
Avg. # offspring 1.5 5-6
Frequency of breeding 1/12 mo. 1/8-9 mo.
REPRODUCTIVE FACTS
• Both sexes can live 10-14 yrs (avg. is 4-8 yrs)• No reproductive senescence has been noted• Litters can be sired by more than 1 male• Males produce viable sperm year round• Synchronous estrous by females in a sounder
REPRODUCTIVE FACTS
• Both sexes can live 10-14 yrs (avg. is 4-8 yrs)• No reproductive senescence has been noted• Litters can be sired by more than 1 male• Males produce viable sperm year round• Synchronous estrous by females in a sounder
REPRODUCTIVE FACTS
• Both sexes can live 10-14 yrs (avg. is 4-8 yrs)• No reproductive senescence has been noted• Litters can be sired by more than 1 male• Males produce viable sperm year round• Synchronous estrous by females in a sounder
REPRODUCTIVE FACTS
• Both sexes can live 10-14 yrs (avg. is 4-8 yrs)• No reproductive senescence has been noted• Litters can be sired by more than 1 male• Males produce viable sperm year round• Synchronous estrous by females in a sounder
REPRODUCTIVE FACTS
• FEMALES:– Lactation may inhibit estrous for up to 2 months– May experience anestrous period in hot/dry mos.– Anestrous also reported in years of mast failure– Food resources can influence reproduction
REPRODUCTIVE FACTS
• FEMALES:– Lactation may inhibit estrous for up to 2 months– May experience anestrous period in hot/dry mos.– Anestrous also reported in years of mast failure– Food resources can influence reproduction
REPRODUCTIVE FACTS
• FEMALES:– Lactation may inhibit estrous for up to 2 months– May experience anestrous period in hot/dry mos.– Anestrous also reported in years of mast failure– Food resources can influence reproduction
REPRODUCTIVE FACTS
• FEMALES:– Lactation may inhibit estrous for up to 2 months– May experience anestrous period in hot/dry mos.– Anestrous also reported in years of mast failure– Food resources can influence reproduction
CONCLUSIONS
• Wild pigs may not be as prolific as they are often made out to be in the media
CONCLUSIONS
• Wild pigs may not be as prolific as they are often made out to be in the media
• BUT, their reproductive potential is greater than native large mammals
CONCLUSIONS
• Wild pigs may not be as prolific as they are often made out to be in the media
• BUT, their reproductive potential is greater than native large mammals
CONCLUSIONS
• Wild pigs may not be as prolific as they are often made out to be in the media
• BUT, their reproductive potential is greater than native large mammals
ACKNOWLEDGEMENTS
• Dr. James LaCour• Meghan O’Boyle• ULM Biology graduate students• USDA/APHIS-Wildlife Services personnel• LDWF personnel• USFWS personnel at Lake Ophelia NWR and
Upper Ouachita NWR• Barksdale AFB personnel
