Prior to weaning piglets are suckled by the sow approximately every hour throughout the day and night. The frequent suckling of small amounts of highly digestible milk ensures that the small gut is not overloaded with indigestible material. At weaning, pigs must move from frequent and regular liquid food to solid food. They must also adapt to changes in the pattern of food intake. The ability of the pig to adapt to these changes is directly dependent on its size and age at weaning.
The weaned pig requires a more mature digestive system than a suckling pig to digest the less digestible post weaning diets. The time it takes the pig to have its digestive system adapt to solid feed is one of the limitations affecting post weaning performance. The key to good post weaning performance is a highly digestible diet. Diet digestibility is a function of the selection of dietary ingredients appropriate to the digestive competence of the pig. These digestible ingredients can be expensive. The provision of a good water supply to these newly weaned pigs is also crucial. Lack of water or poor availability of water leads quickly to dehydration.
In Ireland, we have a higher feed cost per kg of pigmeat produced than our European counterparts. This is partly due to our island status and the requirement that a portion of feed ingredients be transported into the country. The combination of diets that are used on Irish pig units is also a factor in this higher feed price. In this paper I wish to concentrate on the diets fed to first stage weaner pigs and to identify where savings can be made.
It is important to grow the pig fast, but at the same time it is important to get value for money. Lawlor and Kavanagh (1995) emphasised that the sooner one can move a pig on to a lower density diet the lower the cost of feeding the pig. For this reason target usage levels for starter and link feed should be set for weaned pigs. A feed budget sets down how much of the different diets should be fed per pig.
Table 1 below shows the usage of three diets in the weaner section on Irish farms over the past four years.
What is a reasonable target usage of starter diet (16 MJ DE per kg;1.6% lysine)? In practice, for pigs weaned at 28 days a reasonable intake of 200 gram/day fed for 10 days after weaning would amount to 2.0kg of starter diet per pig. If we make an allowance for 200g/pig (2kg/litter) to be fed in the farrowing rooms it would bring the total starter diet to 2.2 kg/pig.
The Pigsys figures show that farmers are using more starter diet than this target figure. The 3.7 kg fed in 2006 is 1.5 kg in excess of this target. If this were replaced with weaner ration the saving is 1.5 kg by 89 cent/kg less 1.7 kg by 29 cent/kg = 84 cent/pig. This calculation has assumed that the feed conversion on weaner diet will be poorer because the energy content (14.4MJ DE per kg) is lower .
A reasonable target of link feed usage is 5kg / pig weaned at 28 days. This is below the 7.1 kg figure recorded in 2006. Achieving the target would save 2.1 kg of link at 56 cent/kg versus a cost of 2.2 x 29 cent = 53 cent / pig. Note: The above calculations are based upon commercial feed prices at the end of August, 2007 (time of writing).
The research shows that feeding lower levels of starter and link diets did not affect subsequent performance for pigs weaned at reasonable weaning weights. Table 2 shows work from Moorepark comparing a low usage of starter (1.5kg/pig) and link diet (3kg/pig) with a higher
usage (ie 3kg starter diet and 6kg of link).
Table 2: Response to quantity of starter/link
When analysing performance it is important to look at the figures from weaning to transfer/sale. Looking at figures over a shorter period may not give a true picture. Over emphasis can often be placed on maximising performance by feeding high levels of expensive starter and link diets. Pigs fed only moderate levels of these diets have the ability to exhibit compensatory growth after the starter phase and reach 30kg in the same length of time but at a reduced cost (Kavanagh, 1994).
The only way to control feed usage is to measure the usage of each diet. In practice the best method is to count the bags of starter diet that is required for each weeks weaning and only feed that amount to that group of pigs. This may mean that the larger pigs go onto the link diet sooner than the smaller pigs in the group. This is where the stockman has a clear role to play.
If you are purchasing the link diet in bags you should count out the bags required for the group of pigs and this will help reduce the risk of over-feeding this more digestible but expensive diet. Where link feed is being purchased in bulk there is a temptation to keep pigs on this diet until they are transferred to the second stage weaner house. This needs to be monitored closely. Again the stockman has to decide when the pigs are suitable for weaner diet and get them eating it as soon as possible.
Table 3: Cost per kilogram liveweight gain on starter diet
Management Tips to optimise weaner feed costs
1. Base decisions on a cost/kg liveweight gain basis ultimately cost per kg dead
2. Change pigs to less expensive diets as soon as possible
3. Keep feed fresh and palatable to maximise intakes
4. Adjust feed hoppers to minimise feed wastage
5. Replace or repair old feeders that are wasting feed
In order to improve costs, current figures for feed use and efficiencies must be prepared for your unit. New targets should be set and a plan agreed with all staff involved on how to achieve these target figures. Costs may be reduced by supplying the animal according to its requirements. Over or under supply of nutrients can present hidden costs. The aim is to minimise feed cost per pig.