With diminishing egg yolk sac residual nutrients, broiler chicks require an alternative source of highly digestible nutrients.
Early broiler nutrition (first week post-hatch) remains a strong topic as genetic improvement places strains on days that can be lost due to inadequate nutrition (among other variables). Broiler super pre-starters and their design are frequent discussion points among nutritionists, whereas broiler producers have just started to realize these feeds will eventually become indispensable.
For those with an interest on the subject, I would recommend this very recent review on the subject of egg yolk residual sac utilization in the newly hatched chick. At the time of writing, it was still in press at the journal Poultry Science.
According to this review of studies from 1930 to 2018, it was concluded that:
- Residual egg yolk sac diminishes in quantity with each passing generation/decade, most likely as a result of genetic improvement that have increased metabolic rate during incubation, leaving thus less nutrients available to the newly hatched chick.
- The efficiency of utilization of nutrients from the egg yolk sac has not changed (as it would be expected by biology).
- Breeder age (and perhaps nutrition and other management issues) can affect the nutrient composition of residual egg yolk.
In other words, newly hatched chicks arrive in this world with even less backup nutrients than in previous times. This places great emphasis on providing them immediately with a highly digestible source of nutrients that can replace those missing and thus prevent a break in their development that can affect their performance up until marketing time.
Also, the realization that broiler nutrition depends heavily on breeder management becomes even more obvious and with each genetic improvement step, this will become even more important.
Of course, feeding a broiler super pre-starter remains an inexpensive investment, but apart from an investment, it is now evident that it is a necessary step to provide nutrients that are essential and cannot be easily digested and absorbed by normal feeds.