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Effect of Rescue Decks on Pre-Weaning Mortality in a Prolific Sow Herd

15 December 2011, at 12:00am

The Rescue Deck system produces extra pigs weaned, however, the profitability of the system is dependent on the margin over weaner, grower and finisher feed costs for these extra pigs, according to a report on a project supported by a BPEX Innovation Fund grant. Based on the performance during the trial and prevailing costs at the time, the pay-back period for the Rescue Deck investment was less than two years.

Background to the Project

Genetic advances in pig breeding have increased litter size, leading to greater nutritional demands on sows and gilts to rear these extra pigs. Larger litters of piglets are often linked with higher levels of pre-weaning piglet mortality, due in part to increased competition within the litter for viable teats at the udder. Stockmen responsible for the farrowing section often use piglet cross-fostering and even shunt-fostering whole litters after colostrum uptake to try to rear surplus piglets. Keeping sows back for longer lactations reduces the farrowing index and moving whole litters can upset all-in all-out farrowing rooms, to the detriment of pig unit health control. Also, weaning pigs that are less nutritionally developed than others in the batch can lead to problems post-weaning. The object of Rescue Decks is to rescue piglets that otherwise might die and improve the overall efficiency of the breeding herd by rearing more pigs per sow per year. With support from a BPEX Innovation Fund Grant, a 10-deck system was installed on Stuart Bosworth’s 270-sow farrow-to-finish pig unit, to evaluate the system for the benefit of the wider pig industry.

The long term report for the breeding herd shows a steady improvement of two extra pigs born alive per litter over the past 10 years, from closed herd grandparent selection to Large White or Landrace criss-cross damline AI. Despite these larger litters, the results show that higher pre-weaning piglet mortality prevented the full potential of these larger litters to be realised. Early weaning pigs and shunt fostering of whole litters was used regularly to reduce piglet mortality in the weekly batch farrowing system. In early 2011, one Nurtinger nursery per week was also used to rear surplus pigs, as a pilot trial to support the decision to install a Rescue Deck system. The pig unit needed to make progress in numbers reared, which had been stuck between 11.1 and 11.2 pigs reared per litter for each of the last three years.

The farrowing rooms each have 12 places, and despite the recommendation of one deck per 10 to 24 farrowing places, it was decided to employ two decks in each farrowing room, to give the stockman two opportunities to ‘rescue’ piglets. By mounting the decks above the farrowing places, the weekly batch of pigs would remain in the all-in all-out accommodation until weaning. A room was constructed as a kitchen area for food storage and preparation, housing a compressor, air dryer, pneumatic milk pump and milk mixing tank, as well as a hot water system for mixing milk at the recommended 55°C. An electricity meter in the kitchen recorded energy use to run the system.

The target is to rear and sell more pigs per sow per year to exceed the BPEX target of selling more than two tonnes deadweight per sow per year, to keep production at competitive levels with other European countries.

The Project

The first pigs entered the Rescue Decks on 13 June 2011 at 10 days of age to test the new system. These pigs were well established on the sow and only one deck was used for this weekly batch. Whilst feed, water, electricity, cleaning costs and weight gain were recorded from 13 June 2011, the ability of the decks to rescue piglets was recorded from the following batch, which was weaned on 7 July 2011. It was assumed that these initial eight piglets (average: 4.37kg at 10 days) entering the first deck would have survived on the sow to weaning.

All piglets were weighed in and out of the decks and milk, pre-starter meal and starter creep feeds were recorded over the period from 13 June 2011 to 3 November 2011. In all, 102 pigs were weighed after weaning to compare post-weaning growth rates of Rescue Deck pigs and suckled pigs. As Rescue Deck piglets were effectively weaned off the milk system at three weeks of age, and on solid creep feed and water for the last week in the decks, they were nutritionally more advanced than suckled piglets supplemented with creep feed.

Results

From weekly weaning on 7 July 2011 to 3 November 2011 inclusive, a total of 2,633 pigs were weaned from 223 litters, averaging 11.81 weaned per litter. Records show that in the previous 12 months to the end of June 2011 before the effects of Rescue Decks, an average of 11.25 pigs were reared per litter using one Nurtinger nursery per week to rear some of these piglets.

The Rescue Deck system raised numbers reared by 0.56 pigs per litter over the course of the trial period. The 270 productive sow herd has averaged 640 farrowings per year over the last four years on a weekly batch farrowing system. If the results of the trial period are replicated for a full year, an extra 358 piglets will be weaned by the Rescue Deck system, almost seven extra pigs weaned per week. The detailed results shows that the more that the stockman used the system, the better the results that were achieved. July and August averaged 11.61 and 11.67 weaned per sow, respectively, whilst September and October weaned an average 11.90 and 11.98 per sow, respectively. It soon became apparent that the best results were achieved by placing good pigs in the decks and rounding up the smalls for suckling, usually on a gilt for best teat presentation, size and functionality.

Pre-weaning piglet mortality was 9.14 per cent for the trial period recording 223 litters which averaged exactly 13.0 pigs born alive per litter. In the 12 months ending June 2011, pre-weaning mortality was 10.34 per cent from 12.55 pigs born alive per litter. Rescue Decks are very effective at reducing piglet mortality in a herd of prolific sows.

Overall quality of weaned pigs was improved by using Rescue Decks because there were less piglets suckling on ineffective back teats, particularly on older parity sows.

Sow condition at weaning was visibly improved to the extent that mid-gestation feed levels have now been reduced for sows. The reduced sow feed costs have not been accounted for in the financial benefits of the project, as at this stage it is not certain if this is a long-term benefit. Also, litter size in late October and early November has increased to average more than 14 born alive per litter. This may be due to less nutritional drain on the suckling sows where Rescue Decks have been used to rear about 15 per cent of the piglets from their previous farrowing. It is not possible to judge at this stage if this is a long-term benefit of using Rescue Decks.

There are two points to note. Rescue Decks are not a substitute for poor nutritional management of farrowing sows. Before using Rescue Decks, the sows’ lactations were optimised by using dietary electrolyte balance through mineral supplementation to enhance the release of calcium ions into the sow’s blood circulation, and feed levels were changed slightly for a better lactation. The second point is that stockmanship and farrowing house management have to be first-rate to get the best from the Rescue Deck system. As always, attention to detail is imperative for best results and this is particularly important in hygiene and proper and regular cleaning of the milk line system.

The results from weighing 51 Rescue Deck pigs and 51 suckled pigs and monitoring growth rates in the first 27 days post-weaning show that on average, Rescue Deck weaners were 0.11kg lighter than suckled pigs at weaning, despite often being the stronger pigs in the batch on entry into the decks.

However, because Rescue Deck pigs are fed creep pellets and water from three weeks of age in the decks, they have been through their post-weaning growth check before the rest of the suckled pigs in the same weekly batch. Data from the comparison of 51 Rescue Deck pigs and 51 suckled pigs shows that despite being lighter at weaning, the Rescue Deck pigs grew at 406g per day in the first 27 days from weaning compared to 370g per day growth rate for suckled pigs. At just under eight weeks of age, the 51 Rescue Deck pigs weighed on average 17.41kg compared to the 51 suckled pigs weighing on average 16.54kg.

These results show a clear advantage in growth rate for Rescue Deck pigs post-weaning. However, because it is based on two relatively small samples of only 51 pigs under the same environmental conditions, no financial advantage has been accounted towards the Rescue Deck system from these results.

Costs and Evaluation

On 3 November 2011, piglets remaining in Rescue Decks at one, two and three weeks of age were weighed and recorded. Over the period of the trial, pigs stayed in the decks for an average of 23 days. Using pig days as a method of calculation, the remaining 71 pigs in six decks on 3 November equated to 40 pigs averaging 23 days in the six decks. For accurate costs and evaluation, 40 pigs were added to 394 pigs weaned from the decks during the trial period, giving an equivalent total of 434 pigs through the decks for the trial period.





December 2011