Dr. John W. Mabry Iowa Pork Industry Center Iowa State University Closed Herd Systems: Genetic Systems, Genetic Cost of Production and BLUP Sow Indexing Dr. John W. Mabry Iowa Pork Industry Center Iowa State University Iowa Pork Industry Center

Replacement Rates in Sow Herd It is a biological certainty that in a swine herd, females will go out of service on a regular basis due to age, soundness, death, disease, etc The annual replacement rates of sows has increased dramatically in the past few years PRRS, more reproductive and fragile genetics Iowa Pork Industry Center

Traditional Production Systems (Genetic Aspect) Purchase parent stock (PS) females from genetic supplier Purchase GP females and make PS females within herd Purchase GGP females and make GP and PS females within herd Iowa Pork Industry Center

Roles of Genetic Supplier and Pig Farm Genetic supplier provided the genetic progress in the form of healthy animals plus AI Pig farm simply multiplied the market pigs Then came PRRS Many herds now want to be closed to all live animal introductions, will allow AI from PRRS negative studs Iowa Pork Industry Center

Closed Herd Genetic Systems Maintain purebred GGP females and make GP and PS females using maternal AI lines Problem in managing purebred females Problem in managing replacement females through the production system Iowa Pork Industry Center

Iowa Pork Industry Center GGP Closed Herd GGP L x L X X Grandparent Y x L X Parent Duroc x F1 Y/L Market Hogs Iowa Pork Industry Center

Closed Herd Genetic Systems Rototerminal cross system using maternal AI lines Problem in lost maternal heterosis in herd Problem in managing replacement females through the production system Iowa Pork Industry Center

best Y x L crossbred sows Roto-terminal Mating System Grandparent best Y x L crossbred sows mated to GGP Y or L semen X Parent Duroc x LW/LR cross Market Hogs Iowa Pork Industry Center

Relative Genetic Cost of Production ?? Cash or out of pocket costs purchase breeding stock or semen or supplies produce breeding stock Salvage value of culled breeding stock Interest rate on capital spent on purchases Royalties or selection fees In-herd multiplication costs Iowa Pork Industry Center

In-Herd Multiplication Costs A parent female with 100% heterosis is replaced with a maternal line female mated to a maternal line boar potentially less maternal heterosis (< P/S/Y) maternal offspring grow slower, have a lower lean percentage and poorer feed conversion These are not out of pocket costs, but are hidden costs that must be accounted for Iowa Pork Industry Center

Iowa Pork Industry Center GENCOST Iowa Pork Industry Center

Genetic COP with Alternative Replacement Female Systems Iowa Pork Industry Center

Iowa Pork Industry Center Can the Pig Farm Maintain the Same Level of Genetic Improvement While Making Their Own Females ?? Purchase terminal semen and GGP semen from seedstock supplier Utilize the most effective technology currently being used by your seedstock supplier (Computerized BLUP technology) Is your current multiplier doing more? Iowa Pork Industry Center

Genetic Technologies Used by Genetic Suppliers Quantitative Genetics BLUP based BV estimation systems phenotypic selection on structural and reproductive soundness Molecular Genetics Marker assisted selection Transgenics Which can be used at the farm?? Iowa Pork Industry Center

Requirements to Do BLUP Indexing PigWin or PigChamp or equivalent data management system Computer with math co-processor (486DX or higher CPU) Pedigree information entered on the sows (her sire and dam) preferable BLUP system that can be made extremely user friendly to use at the farm Iowa Pork Industry Center

Iowa Pork Industry Center BLUP Sow Indexing Estimate the breeding value of animals for litter size, litter weight and wean to estrous interval Create an SPI from the BV estimates for use in selection Iowa Pork Industry Center

Demonstrate On-Farm BLUP System Iowa Pork Industry Center

Iowa Pork Industry Center BLUP Sow Indexing Purebred GGP system: At weaning, decide which GGP and GP sows to breed pure and which to breed cross and which to cull Rototerminal system At weaning, identify the top 15% of sows to breed maternally to make replacement females Breed the rest terminally or cull Iowa Pork Industry Center

Genetic Progress Example Iowa Pork Industry Center

Genetic Progress Example Iowa Pork Industry Center

Iowa Pork Industry Center BLUP Sow Indexing Primary reproductive traits are farrowing rate, number born alive, litter weaning weight and wean to estrous interval Farrowing rate is confounded with boar fertility and not clean to measure Other traits are lowly heritable Therefore, BLUP genetic evaluation system is needed to make genetic progress Iowa Pork Industry Center

Managing Replacement Gilts in Your Production System 1. Must identify potential replacement females at birth (date of birth, genetics, sire and dam) 2. Must keep track of potential replacement females through your production system 3. Should pen these gilts separately 4. Must develop them for maximum reproduction Iowa Pork Industry Center

Frequency of Maternal Matings Make replacement gilts weekly or monthly? 12% of one weeks matings or 50% of a months matings Weekly matings steady flow of gilts, greatest selection pressure, harder to manage small group of gilts Monthly matings larger group of gilts to manage, less selection pressure, monthly groups What’s best for your farm? Iowa Pork Industry Center

Management of Gilts for Maximum Reproduction Maximum growth, maximum leanness, ??? NPB Maternal Line Genetic Evaluation Program trials examined four different nutritional programs and effects on future reproduction High protein-High energy diets did not result in best reproduction Better to develop the gilts below their growth potential for best reproduction Iowa Pork Industry Center

Iowa Pork Industry Center Summary Closed herd management systems offer the potential for an improved health status Internal multiplication of females offers the potential for cost savings Internal multiplication of females requires more management by the farm A genetic supplier with high quality genetics and health and AI is still required Iowa Pork Industry Center

Iowa Pork Industry Center Summary Health concerns have forced some farms to move to a closed herd management system Economic concerns force them to try to capture all the genetic improvement possible It is possible for the better managed farms to use BLUP technology plus phenotypic selection Improvement from molecular technology still must come from genetic supplier Iowa Pork Industry Center

Iowa Pork Industry Center