Think about your most productive sows in any farm. They’re in good body condition, they’re sound, they’re good mothers and they wean quality pigs. They were likely set up for success as gilts.
Modern gilt eligibility targets prepare gilts for a solid first parity and to be constently good perfomers in their subsequent litters. Ultimately, that leads to an optimal lifetime performance.
PIC defines gilt eligibility using these four elements:
• Age at puberty
• Age at first breeding
• Bodyweight at first breeding
• Number of estrus at first breeding
Hitting all targets on each gilt serviced is vital to optimize cost-efficiency, longevity and reproductive performance. Research shows meeting just two or three of the targets will not have the same positive results. When only one of the elements is achieved, the farm’s biological and financial results could be serioulsy compromised for the next two years.
Follow these four gilt eligibility targets to start gilts on the right path:
Age at first puberty: Encourage first estrus before 195 days of age
Gilts that have their first estrus before 195 days (28 weeks) of age tend to have higher lifetime performance.
Manage gilts to stimulate early puberty onset by starting boar exposure when gilts are between 24–26 weeks of age. Introduce the boar into the gilt pen for up to 15 minutes daily using nose-to-nose contact. Carefully monitor and record gilts in estrus to plan the breeding groups that will be breed within the next 3 to 6 weeks.
Age at first breeding: Strive for 200 to 225 days of age
Gilts older than 225 days of age are likely overweight. Consistently breeding gilts over 240 days of age show decreased litter sizes in second parity, longer wean-to-service intervals and overall shorter production lives, especially when they are systematically heavier than 350 pounds.
Bodyweight at first breeding: Breed gilts between 300 to 350 pounds
Aim for 90% or more of gilts to be bred between 300–350 pounds (135–160 kg). Gilts should gain between 1.32–1.76 pounds (600–800 grams) per day to reach their target breeding weight around 200 to 225 days.
Hitting this target sets gilts up for ideal weight at farrowing and overall lifetime maintenance demands.
Gilts bred below the target weight tend to have smaller litter sizes in their first farrowing and decreased performance during their first lactation. Gilts over 350 lbs. (160 kgs.) at first breeding are likely to remain heavy and will be more expensive to feed and maintain in the herd. Heavier gilts are prone to locomotion issues in subsequent parities and have a higher probability to be removed from the farm at a young age.
If you choose to breed a heavy gilt, closely monitor her through gestation and farrowing. Adjust management strategies like daily feed allowance if you identify challenges during gestation.
Weight is commonly the most challenging component of gilt eligibility to measure. Visual estimates tend to be inaccurate and most farms consistently underestimate weights. That’s why PIC developed an easy-to-understand and action-driven “flank to flank” tape in collaboration with Kansas State University. The tool is color-coded for quick decision-making to determine if a gilt is within the ideal weight range.
Estrus cycle at first breeding: Aim to breed at second estrus
It is important to accurately track estrus and breed on the second estrus. Research shows breeding during the second estrus has a positive effect on litter size. Only delay breeding to the third estrus if a gilt is too light to meet the minimum weight recommendation.
Entering the breeding herd is a crucial step for the gilt in a lifetime of productivity. Follow gilt eligibility targets to start gilts on the right path. Then, ensure those gilts stay in your herd with these eight strategies to improve sow retention rates.
Contact your PIC team to talk more about reaching gilt eligibility targets for lifetime sow performance.
