First-litter reproductive performance determines the rest of her life: how to raise high-performance replacement gilts
Five key management points:
1. Short-term flushing of replacement gilts
2. Lighting for replacement gilts
3. Feed restriction during gestationTechnology
4. Management from farrowing to the next mating
5. Adequate boar exposure for estrus stimulation in sows
1. Short-term flushing of replacement gilts
Replacement gilts should be fed ad libitum before mating; the traditional practice of restricted feeding must be completely overturned, because a sow's lifetime reproductive performance is closely related to her body weight at first mating.
To achieve the highest reproductive performance in replacement gilts, they need to be fed as close to ad libitum as possible during the rearing period, while completing all vaccinations and other acclimation procedures at least 3 weeks before mating, and providing at least 14 days of short-term flushing before mating.
In addition, before mating, replacement gilts should be moved into gestation stalls at least 15 days in advance to adapt. If replacement gilts are mated soon after being moved into the stalls, their average number of live-born piglets in the first litter will decrease; see the figure below for details.
At the same time, after being moved into the stalls, replacement gilts that were fully flushed before mating had 1 more piglet in total born per litter in the first litter than those that were restrictively fed.
A sow's first-litter production performance determines her lifetime reproductive capacity; therefore, the feeding and rearing of replacement gilts is extremely important!
Complete data from 5,100 sows from parity 1 to parity 5 in the Midwestern United States
As can be seen from the table above, the variation in piglets born in the first litter is the largest. A sow's lifetime productivity is determined by her first litter. A difference of 1 piglet in the first litter means a difference of 0.4 piglets per litter across parities 1-5.
2. Lighting requirements for replacement gilts
Replacement gilts require no less than 16 hours of light per day, with a light intensity greater than 150 lx. At least one light every 2 m is required in the gilt house, with no shadows in any corner of the barn (small print in a newspaper should be legible in every corner of the barn). The brightness should be no lower than that shown in the figure below (most pig farms neglect lighting management):
3. Feed restriction during gestation
Throughout gestation, body condition should be kept at a score of 2.5-3, relatively on the lean side; at present, gestating sows in China are generally too fat.
Throughout gestation, sows should be in a restricted-feeding state. For normal replacement gilts after mating, the feeding amount is 1.8 kg/day from day 0-90 and 2.7 kg/day from day 90-114; for multiparous sows in early gestation, 2.25 kg/day from day 0-28; in mid-gestation, 2.0 kg/day from day 29-90; and in late gestation, 3.2 kg/day from day 90-114.
Of course, the feeding amount for sows is not set in stone; it should be adjusted appropriately according to factors such as parity, breed and season. In summary, the feed amount should be appropriately increased or decreased according to the sow's body condition. Within the last 5 weeks of gestation, bring 85-90% of sows to normal body condition, and maintain a standard body condition score of 3 throughout gestation until farrowing.
It must be emphasized that one designated person on the farm should evaluate the body condition of all sows once every two weeks, make necessary adjustments to the feeding amount based on body condition, and keep the proportion of sows with abnormal body condition within 10%.
4. Management from farrowing to the next mating
Management principles during lactation and from weaning to the next mating: sows should be given short-term flushing as much as possible.
01
Maximize feed intake during lactation;
Where conditions permit, farrowing houses should preferably use ad libitum feeders so that sows can eat freely during lactation. Ad libitum feeding can effectively increase feed intake during lactation, reduce body weight loss during lactation, increase the average weight of weaned piglets, raise the mating rate within 7 days after weaning, and improve the litter performance of the next parity.
While maximizing feed intake during lactation as much as possible, attention should also be paid to the sow's water intake: the water flow rate should be 2 L/min; wet mash can also be fed to increase the sow's feed and water intake.
Experience (based on measured data from more than 1 million sows) shows that during lactation, between 4.5-8.2 kg per day, for every additional 0.45 kg of feed intake, the next farrowing adds 0.4 piglets to the total number born per litter.
If the number of lactation days is insufficient, it will affect the sow's reproductive performance. The minimum number of lactation days should not be less than 18 days, and preferably 21-23 days.
02
Achieving short-term flushing from weaning to mating:
After weaning, sows should receive the maximum feeding amount starting from the day of weaning. The maximum feeding amount after weaning has a direct effect on the weaning-to-estrus interval:
Starting the maximum feeding amount on the day of weaning significantly shortens the weaning-to-estrus interval compared with feeding 1.8 kg on the day of weaning and then feeding the maximum amount.
Maximizing feed intake from weaning to estrus and mating not only shortens the weaning-to-mating interval, 5.3 d vs 4.4 d,but also increases the mating rate within 7 days after weaning and the litter performance of the next parity (92.8% vs 97.5%).
5. Estrus stimulation in sows
If a pig farm has well-equipped facilities, estrus stimulation of sows (both replacement gilts and multiparous sows) can be carried out very effectively. It is recommended that the mating facility set up fully separate pen gates every 5 pigs, so that boars and sows have ample nose-to-nose contact time, which is very important for estrus stimulation in sows.