The UK pig industry is “haemorrhaging gilts” and should be doing more to see them through to parities 3-5 when optimum returns are seen from a sow, according to pig production consultant Stephen Hall.
Speaking at a recent AHDB Pork event, he and the other speakers outlined some practical tips for producers to improve gilt productivity.
1 Minimise stress
“Adrenaline is the enemy of all reproductive hormones,” says John Hayden, a vet from Integra Veterinary Services. Therefore, it is important to minimise adrenaline so that gilts will hold in-pig and have a successful farrowing.
Methods might include:
- Getting gilts settled in farrowing area a week before farrowing
- Making sure they are familiar with human contact and don’t just associate them with vaccinations or treatments. Hand feeding and letting animals run through AI system and farrowing pens can help
- No moving, mixing, feed changes or vaccinations in the first five weeks of gestation. This is a really critical time of pregnancy
2 Create the right environment for the gilt
Successful farrowing requires a cascade of hormones. Allowing a sow to nest can aid this cascade of hormones, so the provision of nesting materials can aid this.
Considering the direction and set up of outdoor huts is also important, as is sticking to a “one hut, one sow, one litter” rule, says Mr Hayden.
If the hut is facing the wrong way, a gilt will try and move her bed away from the prevailing wind, which can result in crushing of piglets.
Similarly, if her bed is damp, she may try to flip it, to find dry material, so using a wheat or rye-based underlayer with barley straw on top can keep it drier.
It’s also important to keep weaned gilts separate from older sows to prevent bullying or riding, which can put pressure on already weaker bones. Grooved flooring can help with footing, minimising the risk of bone damage from slipping.
3 Maintain good hygiene
It is important that all teats of a gilt are suckled, so that milk is directed to them in future lactations. Therefore, it can pay to put more piglets on her for the first seven days than she will be able to carry for the whole lactation.
Keeping piglets healthy is critical to this, so piglet numbers are up. Strong hygiene is important and keeping clippers and dockers clean and cutting and treating umbilical cords needs to be part of this.
“We want the sow to produce as much milk as possible for subsequent ovulations,” says Mr Hayden.
4 Restrict feed in mid pregnancy
Mr Hayden believes it is important to restrict feed intake in mid pregnancy, before increasing it again around three weeks prior to farrowing. This would follow the pattern of feeding high-low-high during gestation.
Targets for gilt service
- Bodyweight: 135-170kg
- Age: 220-270 days
- Body condition score: 3-3.5
“Something I strongly believe in, although it’s not a universal thought, is that sow lactation sensors respond to how much they’re fed in mid pregnancy,” he says.
“The temptation is to get them fat so that they can afford to lose weight, but actually, you want to get them fit so they milk off their food, not off their backs.”
The amount you may bump feed depends on your starting point, but Mr Hayden would typically look at increasing feed by 0.75kg/day for the last three weeks of gestation.
5 Get supplementation correct
During the flushing stage, it is important to feed a carbohydrate-rich diet, says Rosemarijn Gerritsen, a nutritionist for ForFarmers with a pHD in sow reproduction.
This increases blood glucose and insulin levels, which have a positive effect on the hormones responsible for the growth of follicles. This leads to a bigger viable litter.
Supplying extra energy in the form of Dextrose has been seen to have a positive effect on farrowing as well as neonatal survival and piglet viability.
Calcium is equally important, contributing to efficient muscle function for contractions during farrowing, and replenishing the calcium lost when milking, so that bones remain strong.
Because gilts are still growing and their feed intake may be limited due to pregnancy already, it is vital they have a specially formulated diet so that they are getting enough nutrients. Feeding a gilt a dry sow ration is not good enough, says Ms Gerritsen.
6 Feed a transition diet
In addition to the bump feeding recommended above, Rosemarijn Gerritsen says that at the end of gestation, particular attention is required to diet.
It is a demanding time on the gilt with mammary gland development, colostrum production and energy reserves used up for mother and piglet. It is a high-risk time for constipation, which can cause farrowing troubles, put stress on the gilt, and increase endotoxin levels in the blood, so it is important to provide enough fibre.
This fibre needs to be fermentable to maintain gut activity, so straw, which provides insoluble fibre, will not do the job alone.
It is good to have a high-fibre transition diet between gestation and a new diet at lactation, says Ms Gerritsen.
7 Farrow gilts early
It’s not for everyone because it is very dependent on born alive figures, but for some producers, syncing the gilts to farrow a week early can be an effective way of getting the gilts to produce bigger piglets and milk for longer, resulting in stronger heats.
They are then weaned back into sync with the rest of the herd, so it doesn’t affect pigs/sow/year numbers.
High born alive numbers can work for this system because any piglets that the gilts can’t carry can be fostered on to sows when they farrow a week later.
However, this is not suitable for producers who aren’t confident in born alive numbers because they will not have piglets from the rest of the herd to foster on to gilts with smaller litters.
8 Focus on the last week of lactation
Gilt care in the last week of lactation is critical to influence her next litter, says Ms Gerritsen. Ad-lib feeding at this time can help to grow the follicle pool and help stave off second litter syndrome, which sees more returns to service and a smaller litter size.
Good nutrition at this time will help improve the quality of follicles.