This is a great question, and I want to answer it as completely as I can. This is going to be a rather lengthy response, but I hope that you find it interesting enough to stay with it.
I’m not sure how old this USDA poultry management practice is, but here is what I am going to say about old research…at the time of this research, this may have been a good option considering how the birds were fed and managed along with the genetics of those birds. Research like this is a great foundation to build off of. As time goes by, the ingredients being fed to animals changes. The way we manage the birds changes. The way we feed the bird changes. The genetics of the animal changes. Overtime, researchers in all of these areas have improved the way the crops are grown, harvested and processed to get to your animal to make sure that the best nutrition of those ingredients is still there. A tremendous amount of research goes into understanding the nutrient requirements of the animals at various stages of growth and development. Vitamins are discovered. The importance of various minerals are understood. We evaluate the amount of each vitamin and mineral to understand what inclusion rate is needed to support proper growth, development and health of the animal. We understand the role that amino acids (building blocks of protein) play, and what the right amounts of each and what ratios of each will drive your bird to grow at the appropriate rate. When this research was started, I am sure the birds were not being raised as intensively as they are now, so their nutrient requirements were different then. As we brought birds into buildings in which we could control their environment, we discovered new ways to manage them in a way that they could grow faster or develop at the proper rate to ensure a productive life. As management changes, so to does the nutrient requirements of the birds. At the same time, geneticists have been working to select the best performing animals to become breeding stock in order to pass on their genes to future generations. For example, in the early 1900’s, it would take about 112 days to get a broiler chicken to market weight. Today, we can do it in 35-42 days. There are lots of components that allow us to make such a huge improvement on the performance of those animals.
I understand that the backyard farmer isn’t looking for similar results to this, but we can take that understanding of the high performing animal and apply it to your setting. I would not want to “rotate” my diets like that because I feel that you would be feeding a great diet to your birds one week, and then you would be feeding them a “snack food” diet for a week. Would you feed your children a healthy, complete diet one week, and then the next week feed them a diet that consists of candy? Scratch grains are full of calories, not a lot of protein (maybe 12-14% depending on the grains used), and very little vitamins and minerals. We understand what level of each nutrient the animal needs to grow at the proper rate to be ready for egg laying when the time comes. We can do that by feeding them a complete feed for 18 weeks. In a laying chick, it is important that the bird grows at the proper rate so that her skeletal structure develops at the proper rate to enable her to lay eggs without complications. Feeding a scratch diet, is likely to push that bird to deposit fat, which can interfere with her ability to lay eggs. Instead of “stair-stepping” her nutrition – feeding her a complete feed one week followed by a scratch diet the next week and so on – would it not make sense to take the “average” of those two diets and provide that to her over that same 2 week period? This would provide her with the proper levels of vitamins and minerals, which are very important early on in life, along with the protein/amino acids that are necessary for her to grow muscle, bone, reproductive tract, etc.
Commercial operations are also using light and nutrition to help stimulate the birds to begin to lay eggs. There are many things done at that level that the majority of backyard farmers are never going to attempt for the reason you already mentioned. These birds aren’t your source of income; they are part of your family. It is not uncommon for a commercial producer to feed up to 5 or 6 diets to their developing pullets during those first 18 weeks of life to prepare her for a life of egg laying at the highest level. At Purina, we have developed Purina Start & Grow as a diet that will provide your developing layers to grow at the necessary rate so that their body is prepared for egg laying around 18 weeks of age. I feel that providing your hen with the necessary nutrition everyday of her life will provide you with a hen that will have the opportunity to produce high quality eggs for the duration of her egg-laying life. Don’t forget that nutrition is just a small part of what is needed to have a hen that will produce high-quality eggs over a long period of time. As the flock owner, your role may play an even bigger part by providing her with an environment that is safe and healthy and allows her to thrive and be successful throughout her life.
