Pig Production: Gilt Management
Gilts for breeding are usually selected when they 4 to 6 months old either on farm or from other reputable breeding farms. They are bought at 6 months to provide for quarantine and acclimatization periods in our farm. Once in the farm, they are observed for heat occurrence. Every cycle is recorded such that we can determine whether the gilt is a regular heater or not. It is very important to note the date of every estrus because breeding is done on the 2nd or 3rd period. Breeding is done when they are 8 months of age and weighing 130 to 140 kgs.
Goal in Efficient Female Breeders Management (FBM)
Efficiency in breeding is the heart and soul of swine farming worldwide.
Maximize the number of piglets / litter
Maximize total piglets born alive per year
Optimize the piglet birth and weaning weight, sow productivity and longevity
Heat stress in the first 30 days of pregnancy reduces the number piglets born per litter and decreases conception rate and farrowing rate
Feeding Gilts
Gilts need adequate feed to support long productive life. Well-fed gilts can reach 130 kgs at 7 months of age and a backfat thickness of about 18-20 mm. Two weeks before breeding, each is given a ration of 3-4 kgs of a feed with 3000-3200 kcal DE. Housing the gilts in group of 5-10 per pen promotes stimulation in the occurrence of heat due to social contact. Each is provided with floor space of 1.1 m2 and should be housed at least 1.5 m away from the boar. They also need a light exposure of at least 14 hours a day.
Sufficient exposure to light enable the gilts to reach puberty earlier, such that reproductive phenomenon is achieved at lighter weight among gilts. However, there is no difference in ovulation rate compared to the unexposed gilts but both gilts and boars tend to become sexually more active.
Gilts Housing
Exposure to boars is a one of the most effective management tool in stimulating the gilts to come into heat early. However, this should be carefully carried out otherwise each effect will turn negative. Very young gilts of less than 160 days of age should not be exposed. A mature boar more than 10 months of age is better used than younger ones. Limiting the exposure to 10-15 minutes usually give better results either direct or at fence line. Rotating the boars can also eliminate the negative effect of gilts and boars becoming familiar hence less stimulation is achieved.
Weak or Shy Heater Management
This phenomenon is brought about by late puberty, extremely hot weather, overcrowding, bullying and gilts becoming too fat. Corrective measure for this include:
Do not rear own-herd replacement close to the boars
Use 6-8 gilt pool (maximum of 10-12)
Excitement and competition stimulate estrus
Put smelly, friendly boars in a group of weak-heaters
Move weak-heaters to previously occupied boar pen
Check lighting adequacy
Anestrous or failure to come into heat is a reproductive problem which needs considerable attention. Gilts under this condition are profit eaters hence necessary measures should be done. Among the known remedies of anestrous are:
Keep the gilts outside on a paddock or a “run” for few hours each day
Provide at least 14 hours of light per day
Examine the under-development of external genitalia or anatomical anomalies
Create good health
Acclimatize new gilts
Create good nutrition
Satisfy the gilts’ physiological needs