Oestrus in the Gilt
The gilt is the fuel that run the farm.
Pig flow is about a well managed gilt pool.
Stockmanship
It is the stockperson who detects the receptive
female and places her in front of a fertile boar and then ensures an
effective service takes place. The effect of the stockperson can be
demonstrated in table 1. Despite as many variables as possible being
stabilized (i.e. boar effects, number of sows/gilts, their age, time
of year, feeding routines etc.) a significant difference was seen
between 6 different stockpeople.
Table 1:
Effect of stockmanship on fertility (Flowers, 1992)
Stockperson |
Farrowing rate |
Total born alive |
Live piglets |
1 |
90.6 |
11.0 |
2348 |
2 |
89.8 |
11.1 |
2413 |
3 |
89.1 |
10.8 |
2346 |
4 |
85.9 |
11.2 |
2310 |
5 |
81.6 |
11.0 |
2153 |
6 |
67.8 |
9.3 |
1371 |
Factors that can affect reproduction:
The Gilt
- The gilt should be healthy and physically fit
- Use boars only over 150 days of age to
stimulate
- She should be over 210 days at first service
- She should be over 120 kg body weight
- She should have 20 mm back fat P2
- She should be served on her 2nd or 3rd heat
- She should receive 15 minutes or supervised
physical direct boar exposure daily
- She should not receive constant boar exposure
as this can reduce the intensity of estrus
- She should be moved to the breeding area or
boar pen rather than the boar moved to the gilt pen
- All mating should be supervised
- Intense estrus in a gilt only lasts 7 to 10
minutes
- There can be periods of up to 1 hour when the
gilt is less receptive, even in the middle of estrus
- To enhance signs of estrus remove all boar
contact for one hour before checking
- The boar used to stimulate should be >11 months
- Do not carry out any fearful tasks during heat
checking
Environment
Water
- Supply clean cool water 24 hours a day with a
flow rate of 1.5 to 2 liters per minute ideally from a bowl or
trough
Feed
- At point of introduction feed a lactator diet
for 2 weeks.
- Then feed 2 kg of a standard dry sow ration
from 100 kg until 14 days pre-breeding then ad lib feed, ideally a
lactator diet.
- Provide lactator feed to all gilts equally
through a single spaced feeder to remove all aggression
Flooring
- Provide at least 1m2 total area per gilt.
- House in groups of 4 to 8. Have good non
abrasive flooring.
Air
- Provide a draught free environment
- Provide an ambient air temperature of 18-22 C
- Provide cooling systems if >30 C
- Provide good quality air (ammonia >20 ppm can
reduce signs of estrus
Light
- Provide 16 hours of day light and 8 darkness
- The light intensity should be sufficient to
easily read these notes (500 lux needed)
Stress
- Especially with home bred gilts, ensure they
receive a transport stress to introduce estrus load them onto a
truck and transport them around the farm for 15 minutes
Estrus synchronizaton/stimulation
- Transport/movement provides a stress factor.
Transport for 15 minutes at least
- Chemical using Regumate of PG600. Consult your
veterinarian
- Within a group gilts synchronize themselves.
Therefore, care must be taken with group size within the gilt pool
to provide weekly replacements. Note 95 kg gilts take at least 6
weeks introduction.
- Order gilts in time both to introduce and plan
the order to meet requirements.
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