Unit 7- Management and nutrition of the replacement gilt Flashcards
What do we select for in gilts?
Genetically superior lines
Good profligacy
Good mothering ability
Good health
What is the least % replacement rate?
20%
A gilt must get no boar exposure before approximately …
168 days (5-6 months)
What is the prefered floor space for a gilt house?
1.2 – 1.5 m2/gilt
What is the gilt house temp?
17-25°C
What is considered a sufficient trough space to prevent fighting?
30cm per gilt
What is the factors influencing gilt lifetime production?
- Growth rate during rearing
- Nutritional levels
- Ovulation rate at oestrus
- Weight (condition) at first service
- Age at successful mating
- First litter size
- Ability to successfully rebreed
What are the expected farrowing rates for gilts?
> 90%
What are the expected number of piglets born form gilts?
> 13.5
What are the expected number weaned on first parity?
> 11.5
What do we expect from gilts?
- Farrowing rates (gilts) > 90%
- Total born >13.5
- Weaned/first parity > 11.5
- Retention rate from P1 to P2 >90%
- No “second litter dip” problems
What is the appropriate weight for a gilt to start mating?
140 - 150 Kg
What is the appropriate age for a gilt to start mating?
220-240 days
At what oestrus should a gilt breed?
Between 2nd and 3rd but never at 1st oestrus
What amount of fat stores must a gilt have on mating and farrowing?
13 - 15 mm P2 at mating
15 - 16 mm P2 at farrowing
What is the “boar effect” on gilts?
Boars accelerate and synchronize puberty in gilts through:
1. Priming pheromones (3α-androstenol) in saliva of boar
2. Tactile stimuli
3. Auditory stimuli
4. Visual stimuli
Until when does a gilt still deposit lean tissue?
3rd parity
What happens when energy stores are tapped during lactation?
Infertility will follow
What is the difference between feeding a gilt over a finishing slaughter pig?
- Lower level of feeding to slow growth and limit body size to improve bone development
- Lower lysine in diet
- Higher Ca and P levels than for growing pigs (0.82% Ca; 0.73% P in the diet)
- Maximise bone mineralization to improve reproductive longevity
What is the body weight gain from birth to mating for a gilt?
550-650g per day
What happens when a gilt has a weight gain of <550g/day?
Negatively affect ova maturation and follicle size
Delayed puberty
Poor udder development
Poor lifetime productivity
What is the effect of too fast growth rate in gilts?
- Higher feed cost due to high maintenance requirements
- Structure problems
What is the basic feed program?
- The rearing program start at 25 kg till first service
- A min of three dietary phases used during rearing!
- Ensure that there is a smooth transition between diets.
- Minimize the use of by-products or any high-risk ingredients!
- Flush sows at least 10 to 14 days before first service.
Name the different feeding systems?
- Long trough – Liquid feeding
- Long trough – Dry feeding
- Single space – Dry feeding
What is flush feeding in gilts?
Feed gilts ad libitum 10 to 14 days with special flush feed before insemination
What is the effect of flush feeding in gilts before mating?
- Increase LH release
- Increase ovulation rate
- Increase uniformity and quality of ovum’s
- Stimulate fat deposition
How do we assess pigs body condition?
- Body weight
- Body condition scoring
- Ultrasound estimate of back fat depth
- P2 measurement at last rib
What is the difference between 2nd cycle vs the 1st cycle?
Known as the Second litter syndrome
1. Lower pregnancy rate
2. Lower farrowing rate
3. Lower litter size
Resulting from relatively high weight losses during first lactation
How do we overcome Second litter syndrome?
- Feed intake during first lactation needs to be improved
- Optimize pre-farrowing nutritional management
- Optimize lactational nutritional management
