Litter weight of over 115 kg possible, says research 

 

Sows can wean litter weights of over 115 kilogrammes at 28 days of age, and pigs with low birth weights can have feed efficiency ratios under 2.4 during the finishing period, recent research at the Agri-Food and Bioscience Institute (AFBI) has found.

The Northern Irish research institute added that in comparison, commercial litter outputs rarely exceed 105 kg and the average feed efficiency of finishing pigs in Northern Ireland is approximately 2.7. 

"The superior performance outputs achieved at AFBI were driven by a combination of nutrition and management and demonstrate the high potential that both sows and low-birth-weight pigs can achieve", the high-technology R&D institute said.

Due to significant increases in litter sizes over recent years, piglet birth and wean weights have reduced. However, the weaning weight of a pig is a critical factor in determining its lifetime performance, and therefore a conflict in terms of productivity has arisen.

Dr Aimee Craig, under the supervision of Dr Elizabeth Magowan, has demonstrated the superior yields and performance that sows and piglets can achieve under targeted feeding and management strategies.

Craig addressed this issue as part of her postgraduate work at Hillsborough, which aimed to develop nutritional and managerial strategies to increase piglet and litter wean weights and optimise the lifetime performance of low-wean-weight piglets.

Craig's studies showed that, when a basal diet was offered, sows were able to produce a litter weight of 101 kg over a 28-day lactation. However, when a diet containing high energy and lysine was offered at the same intake level (7.5kg/day) sows were able to produce a litter weight of 112kg. 

Over the series of trials, the treatment that had the greatest average litter weaning weight (115 kg) was when sows were offered a diet containing 15.8 DE MJ (megajoule of digestible energy)/kg and 1.3% total lysine at an intake of 7 kg/day. The total litter weaning weight of 115 kg represented a litter of 13 piglets weighing on average 8.8 kg. 

The trials found that litter weight was mostly driven by sow feed intake (intakes of over 7 kg/day on average over a 28-day lactation). However, when intake was lower (6 kg), an increase in diet specification, increased energy and lysine contents, resulted in litter weaning weights above 100 kg.

As to post-weaning piglet management, two main rearing practices were compared. Small pigs (around 5.5 kg) were allowed to either suckle the sow for an extra three weeks (i.e. weaned at 7 weeks of age), after which they were offered a commercial dietary regime. However, due to the three-week delay in weaning, diet changes took place three weeks later than the comparator group, which were weaned as normal at four weeks of age and offered the same commercial dietary regime. Most of the mortality occurred in the extended suckled group before they were 10 weeks of age, but for the "normal" group most of the mortality occurred in the finishing period. 

The extended suckled group also had superior finishing pig performance than the "normal" group. The economics of extended suckling and delayed dietary changes was better by £5.40 (US$7.50) per pig than the practice of weaning small pigs at four weeks and offering a special starter diet regime. The adoption of such a practice is, however, difficult to manage in an "all in/all out" situation, according to the study.

The study concluded that offering lactating sows a high-energy and -lysine diet at an intake of 7.5 kg per day will drive superior litter performance. The estimated value of this extra performance is at least £1 million ($1.4 million) for the Northern Ireland pig industry. 

Improving the environment of the farrowing house to encourage high feed intakes will also improve piglet weaning weight. Furthermore, there could be economic advantages associated with offering small pigs at weaning (less than 6 kg) extended suckling coupled with lifetime dietary changes that match weight development. "Further work is required to establish the risk of adopting such practices on disease transfer between batches", the study said, however.

The study was funded by the Department of Agriculture, Environment and Rural Affairs and the work was completed at AFBI Hillsborough in conjunction with Queens University Belfast.

 

 

Dr Aimee Craig, under the supervision of Dr Elizabeth Magowan (AFBI) has demonstrated the superior yields and performance which sows and piglets can achieve under targeted feeding and management strategies