I used to have a customer who required seven diet changes for raising his piglets from 11 lb (5 kg) to 60 lb (27 kg) body weight. Another one only used one for pigs between 6 and 20 kg body weight. The majority, however, will use the prescribed three-phase feeding program. So, what is the correct number of feed changes for any growing animal?
In my opinion, starting from what the books suggest is a good initial point. In the above cases, a three-phase program ensures the following by phase:
- By using an expensive feed piglets start to eat soon
- By switching to a less expensive feed piglets remain healthy
- By moving to a simple economical diet the producer remains profitable
But, that’s not always true. Take for example the first example given above. That producer was placing 5,000 piglets per week on a different nursery building. He was ordering feed each week, and he had seven different group ages at a time. So, why not take advantage of his ordering system and offer him a less expensive diet for each week? As for the second example, that was a 100-sow, one-man operation. It is easy to understand why logistics had to be simplified, even at a cost!
The end point I am trying to make today is that the correct number of feed changes should be determined not only on pig age or weight, but also on logistics that are very different from farm to farm. Certainly animal appetite increases faster than their requirement for nutrient intake, so offering them more feed changes with progressively less dense (and less expensive) diets makes absolute sense, but there might be practical limits to this. On the other hand, a very clever system that uses only two feeds (one expensive high-end, the other least-cost, low-end) and mixes the two at certain ratios according to a prescribed growth rate curve can deliver a different diet each day -- and it works with dry and liquid feeds.