SEASONAL fertility issues in sows can cause reduced conception and farrowing rates but when a cost-effective energy-boosting product is included into a daily diet, piglet numbers can be increased.
Sunpork Farms researcher Dannielle Glencorse recently conducted a trial using dextrose sugar in feed programs to address sow fertility issues and help identify its effects on litters.
"Finding a solution is better than just coping with an issue repeatedly," she said.
There are many expressions of seasonal fertility but the most obvious on-farm impact to recognise is reduced conception and farrowing rates, according to Ms Glencorse.
"The effects are more pronounced in the litter but the issue actually begins with the luteinising hormone that causes growth and maturation of the oocyte follicle, an immature egg," she said.
"In summer there is a large reduction of developed follicles as well as smaller follicles and a variation in size."
Ms Glencorse said on-farm, that translated to a lower litter size and a varied litter birthweight.
"It also impacts further down the line too, small piglets will die and be smaller at weaning," she said.
"Essentially, it affects a piglet at the start of life and continues to impact it."
Ms Glencorse said the trial's aim was to focus on piglet performance to measure how seasonal infertility impacted production.
"Obviously producers can mate more sows to counteract a lower farrowing rate but will there be enough?" she said.
"It is a big procedure to do that and it is a lot of work."
Another focus was on the entire litter, to see the effects of infertility on the uniformity of piglets.
But Ms Glencorse said producers needed to better understand when piglet birthweight was determined.
"Birthweight is established by day 55 gestation and the focus needs to be on sows at weaning, mating and the early stage of gestation," she said. "That is the high-risk point for determining if piglets that do not suit your system are produced.
"But how can producers do this? The alternative we came up with was to include a dextrose supplement in the sow's diet.
"It supplements the high energy requirement of sows during oocyte maturation. We hoped to help follicle growth and ensure the embryo that results after is viable."
Ms Glencorse conducted a single comparison trial during summer and winter between a control diet and one with a 5 per cent dextrose introduction.
The supplement was fed to sows from weaning until mating.
"The addition of dextrose directly impacts on insulin production and that is depleted during heat stress and impacts follicle development," Ms Glencorse said.
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SUPPLEMENT LIFTS PIGLET NUMBERS
AFTER conducting a diet supplement trial to improve seasonal fertility in sows, SunPork's Dannielle Glencorse revealed increased piglet numbers could be achieved through including dextrose into a sow's daily diet.
Ms Glencorse said the trial showed that during summer there was a 25 per cent reduction of farrowing rates.
"That is extreme and it is too difficult to replace those animals at that stage," she said.
"That could cause a big drop in production."
Sows that were fed a diet including dextrose increased the total number of piglets born by one and increased its litter size by 0.6 per cent.
"By adding an extra piglet, it means follicles produced are viable and sustained through the pregnancy," Ms Glencorse said.
"The results varied in summer and winter after a higher litter variation was recorded in summer.
"A larger litter size will generally cause small and low viability piglets at the end, but we did not find that.
"That's a good sign that dextrose was able to reverse seasonal fertility and boost piglet performance."
Ms Glencorse also said piglets of a consistent size were produced from the larger litters.
"It is a cheap dietary addition - it costs about $1 for each sow," she said.
"The only issue to be mindful of is the amount of storage required for the supplement."
