For sows weaned after day 2, return to estrus should occur in 6 to 10 days. Split weaning of the litter may promote earlier breeding in early weaned sows, says Britt, particularly during summer, when postweaning anestrus delays breeding. The average wean-to-estrus interval (WEI) on commercial farms is approximately 5 days with most sows bred within 7 days of weaning (Knox et al., 2013). Due to the energy and amino acid demands during lactation, many sows and gilts will have lost weight (body condition) during lactation. Weaning-to-estrus interval In study 1, the mean weaning-to-breeding interval was 7.6 days and the median was 5 days. Seventy percent of all breedings occurred on or before day 6 postweaning, while 12.6% of the sows were bred between days 7-10 postwean- ing.Sows consuming 12 mega-calories per day lost 50% as much weight and backfat and over 91% exhibited estrus by Day 8 after weaning. Sows consuming 16 mega-calories per day lost even less weight and backfat and 96% were in estrus within 8 days after weaning.
How long after weaning does a sow come into heat?
Most sows weaned at 18+ days after farrowing should be in heat within 4-6 days after weaning, on average.
Why do sows come on heat 3 7 days after weaning the piglets?
Following weaning, the surge in energy that occurs as milk production stops trips off a different hormonal pathway centred around insulin and insulin-like growth factor that stimulates heat. The normal aim would be to re-serve the sow 3-7 days after weaning – a period usually regarded as the peak fertile time.
What is weaning to estrus interval?
The weaning-to-estrus interval (WEI) corresponds to the period between the day of weaning (Day 0) and the first day sow is showing standing heat, being part of the normal reproductive cycle of the female.
How long is weaning stage of pigs?
Weaning pigs at approximately 21 days has become a common practice in the U.S. Farm economics and productivity, sow and piglet welfare, and available facilities will dictate the best weaning age on a given farm.
When do sows return to estrus after weaning?
Sows that returned to estrus in less than 9 days after weaning on Day 28 of lactation had higher circulating concentrations of LH at 14, 21 and 28 days postpartum than sows that required more than 15 days to return to estrus.
How long do sows stay in heat after weaning?
After weaning, sows will come into heat again as quickly as 3 days but 4-7 days is more typical with an average return to heat of 5 days after weaning. Gilts are not so predictable and must be checked for heat daily until a standing heat is determined.
What is the weaning-to-estrus interval for sows?
The percentage of sows displaying estrus within 10 days after weaning differed (P .09) among groups (Figure 1). Among groups, sows displaying estrus during this period had a similar (P .1) weaning-to-estrus interval (approximately 5.7 days).
How fast do sows lose weight after weaning?
Sows consuming 12 mega-calories per day lost 50% as much weight and backfat and over 91% exhibited estrus by Day 8 after weaning. Sows consuming 16 mega-calories per day lost even less weight and backfat and 96% were in estrus within 8 days after weaning.