Feature: Feed management the key to handling the modern sow

Tuesday, June 2, 2009

That's the message of speakers at the London Swine Conference to producers coping with today's 'hyperprolific' sow

by KATE PROCTER

The challenges of managing large litter sizes have become more common as sows have become more prolific. The race to increase litter size and pigs weaned per sow per year has left some wondering if piglet viability has been sacrificed. In addition, the sow of 2010 is not the same animal as she was 20 years ago; she requires specialized management techniques.

True "hyperprolificacy" arrived on the scene in 1987, Dr. Guy-Pierre Martineau, a researcher with the Department of Health, Production and Economics at the National Veterinary School in France, told participants at the London Swine Conference this April. In 2007, the goal of French producers was to wean 12 piglets per litter. After several years of adapting to more prolific sows, producers are currently evaluating how best to manage them.

"We are in evolution," said Martineau. Sows have gone through several distinct body types in the past few decades, he noted. In the 1990s, producers wrestled with "fat sow syndrome" and learned that body condition scores do not always correspond to the actual back fat of the sow. 

The modern French sow now has a higher proportion of muscle and requires different feeding and management.  French herds are weaning 11 pigs per litter, with the top 33 per cent of herds weaning 11.6 per litter. With this increase in the number of piglets born has come an increase in challenges.  

Piglet birth weight and the number of functioning teats on the sow are two of the major challenges associated with hyperprolific sows. Currently in France, over 40 per cent of litters have more than 14 live piglets born, which exceeds the "normal" number of teats, explained Martineau. While breeders are actively selecting for number of teats, producers need good solutions for extra piglets now and cannot wait for genetic improvements to reach the commercial level.

One of the larger obstacles, however, is the fact that as litter size increases, the number of piglets born that weigh less than one kilogram also increases. Martineau has found that an increase of 25 per cent in total number born results in a gain in total litter weight of only 16 per cent. He observed that, in large litters, between 20 and 25 per cent of piglets weigh less than one kilogram at birth.

Farrowing induction, a commonly used practice, is associated with higher levels of preweaning mortality (PWM). Even inducing one day earlier can result in lower-viability piglets and a decrease in high-quality colostrum.

Current research suggests that cross-fostering may be one aspect of management where less is more, explained Martineau. He referred to "over cross-fostering syndrome" and said that low birth weight piglets have a better chance of surviving in a litter with a smaller number of animals rather than in larger litters composed of small piglets.

Feeding the sow throughout her lifetime also affects piglet viability. Lean, modern sows require different feeding strategies and tactics than sows from 20 years ago, explained Martineau. Some research has shown that increasing the sow's ration for the last two weeks prior to farrowing by one kilogram per day may improve piglet viability and help the sow eat more in the farrowing room.

"Everything must be done to maximize lactating feed intake," Michel Vignola, Director of Swine Technology Application for Nutreco Canada Agresearch told those attending the conference. Feeding during gestation, lactation feed management, ambient temperature of the room and water supply are some of the main influencing factors on sow feed consumption. "Never overfeed a sow during gestation," said Vignola. "Sometimes overfeeding is unseen but can have very bad consequences." He recommended doing monthly checks on the amount of feed actually being given to make sure that sows are really getting the correct amount.

Feed management during farrowing is also important. Vignola suggested that, the day after farrowing, sows should be fed the same amount that was fed the last 14 days before farrowing. He also recommended rapidly increasing the daily amount of feed offered in the days following farrowing.

Rapidly increasing sow feed after farrowing has been thought by many people to cause a number of problems that don't necessarily occur in most sows, says Vignola. "Avoid restrictive feed allowance for the first five to 10 days and during the entire lactation," he advises. Research conducted at Kansas State University suggests that, when 20 per cent of sow feeders are empty at any time, this indicates that the sows are being restricted.

Vignola concluded by telling participants that lean, prolific sows require maximum feed intake.

"Sometimes it is necessary to overcome some inherent 'belief' that limits change by applying sound science to practical problems." BP