Farrowing rates : going back to basics and paying attention to detail

Gilt stimulation_opt.jpegMaximizing farrowing rate requires a focus on the basic aspects of management and close attention to detail, Steinbach, Manitoba-based veterinarian Dr. Blaine Tully told delegates at the recent Red Deer Swine Technology Workshop.

He was describing the findings from his work carrying out fertility assessments on swine farms across Canada over the last three years. “Very few of our conclusions reveal ‘new’ information about sow reproduction,” he said. “In other words, 95 per cent of farms with suboptimal fertility and therefore reduced farrowing rates have very similar deficiencies in the execution of basic breeding barn tasks.” This applies to all types and sizes of farm, whether using natural service or AI, he added.

Tully stressed the importance of farrowing rate on overall breeding herd output and profit. “Maximizing farrowing rate and achieving a consistent level allows breeding targets to be set and achieved, driving uniform pig flow for customers downstream, right through to the packer,” he pointed out.

“Suboptimal farrowing rate will increase the cost of production by increasing non-productive days (NPDs). On many farms, we also find a link between reduced farrowing rate and litter size.” He noted that the opportunity cost of a five per cent reduction in farrowing target on a 1,000-sow unit was about $71,000 annually in the breeding herd alone.

Tully said that the value of the fertility audit was in viewing procedures with an outside set of eyes and providing a different perspective. It also allows the relevant farm protocols to be reviewed in the light of what is observed on farm and the results achieved.

It’s the boar’s fault!

Boar management is top of Tully’s list of five key areas of management that are found to need improvement on the farms he has surveyed. Too often the boar is blamed for poor outcomes, when in reality he is not being managed properly.

“The boar has three main jobs — stimulation of the female brain, help with heat detection and stimulation during and after insemination, which assists semen transportation up the reproductive tract,” he explained. “In order for the boar to perform all of these tasks well, he needs to be trained and managed from an early age to drive a high libido.”

Tully stressed the importance of using boars that produce a large amount of frothy saliva, containing pheromones which stimulate the sow’s brain and impact the release of reproductive hormones. The Chinese Meishan breed is an ideal boar for stimulation as it is smaller and early maturing, has a very high libido and produces lots of pheromones, Tully said. In addition, he suggested, a number of different boars should be used for heat detection, because sows show varying levels of attraction for different boars.

It is essential to allow boars used for heat detection and stimulation in AI systems to serve sows or gilts naturally once per week, Tully believes. This helps to maintain libido and keep them keen, he says.

Sow and gilt management

Second on Tully’s list is management of the sow after weaning, in particular maximizing feed intake from weaning to breeding.

“Feed a lactation diet with a higher energy and protein level than the gestation diet, feed sows twice per day and group sows by condition to prevent the bigger sows stealing from thinner sows,” he advised. “Much of the success in the breeding barn will depend on the energy balance and body condition of weaned sows following lactation.”

Tully also recommended boar stimulation of weaned sows daily following weaning, in order to stimulate the onset of estrus. He noted that this also results in more effective detection of sows with a short wean-to-estrus interval.

The gilt development program is the third important area of management and farms should have a well-defined protocol, which includes acclimatization procedures, boar exposure, recording of dates of estrus, feeding and weight/age at breeding, Tully said. “Boar exposure should be provided from 180 to 210 days of age and the date of observed estrus recorded,” he suggested.

Breeding techniques and protocols

Problem area No. 4 is the techniques used during insemination, notably hygiene, sow stimulation and semen storage.

“The stockperson should provide the stimulation given by the boar during natural service,” Tully said. “This includes back pressure and kneading the sow’s flanks. Another good stimulus is to rub the udder, which releases oxytocin, which stimulates sperm transport.” Once insemination is complete, he advised that a ‘followup’ boar is placed in front of sows for further stimulation.

Finally, Tully said, breeding protocols and the way in which they are being implemented should be reviewed periodically.

“Veterinarians visit many farms where the intended protocol, be that for biosecurity, vaccination, feeding or breeding is not actually followed through consistently by all farm staff,” he noted. “I find that helping staff to understand some of the basic reproductive physiology behind the breeding protocols helps to keep motivation high, and prevent deviation from some of the intended procedures. Once a level of understanding about why we do certain things in the barn is reached, then fine tuning of the procedures can take place.”



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