Discoid Roach Nutrition Guide
Good feeder. Limited species-specific data.
Discoid roaches are an important staple feeder for many reptile keepers, particularly in Florida.
They're also an excellent example of why we built these Nutrition Guides differently.
There are plenty of clean-looking discoid nutrition charts online. The problem is finding the research behind the numbers.
Our review located only one peer-reviewed nutritional analysis that explicitly included Blaberus discoidalis, and the accessible publication reports nutritional ranges pooled across three feeder cockroach species, rather than giving us a clean discoid-only row.
So that's what we show.
What the published research supports
These values are reported on a dry-matter basis.
| Nutrient | Subadults | Adults |
|---|---|---|
| Crude protein | 48.9–54.7% | 60.2–67.8% |
| Fat | 23.6–36.3% | 14.5–21.4% |
| Ash | 3.6–4.0% | 4.2–5.1% |
| Chitin | 5.3–8.6% | 5.3–8.6% |
| Ca:P ratio | 0.043:1–0.53:1 | 0.043:1–0.53:1 |
Important: These are dry-matter figures. Our Cricket Nutrition Guide also reports dry matter, so the two can be read alongside each other; as-fed figures, such as those on our Mealworm Nutrition Guide, cannot be compared directly with either. The ranges come from Kulma et al. 2016 and cover three feeder cockroach species, including Blaberus discoidalis. They should not be interpreted as measurements of our individual colony.
Life stage makes a real difference
One finding is particularly useful despite the limitations of the dataset:
Adults were higher in protein and lower in fat than subadults.
Across the three cockroach species studied, adults contained approximately 60–68% crude protein on a dry-matter basis, while subadults were approximately 49–55%.
The direction reversed for fat: subadults were substantially higher.
So size and maturity can matter nutritionally — but the published evidence doesn't justify assigning a unique protein or fat percentage to every commercial discoid size we sell.
Why you won't find an as-fed discoid table here
We don't have reliable published Blaberus discoidalis-specific moisture data from the accessible research.
Without moisture, converting the dry-matter values to as-fed values would require making an assumption.
We won't do that simply to make the chart look complete.
Related feeder roaches such as dubia can provide useful context, but dubia data are not discoid data, and we label them accordingly whenever they're discussed.
Calcium still needs attention
The available cockroach research reports an inverse Ca:P ratio, consistent with the broader feeder-insect literature.
That is expected. Like crickets and mealworms, cockroaches do not have a mineralized skeleton and naturally contain relatively little calcium compared with phosphorus.
Calcium supplementation therefore remains part of responsible insectivore husbandry.
Roaches respond strongly to gut loading
The strongest controlled gut-loading data we have are actually from the related dubia roach.
In one study, 24-hour-fasted dubia began at a Ca:P ratio of 0.15:1. Feeding a commercial diet containing 8.3% calcium on a dry-matter basis raised the ratio to approximately 1.4:1 after 12 hours, 1.7:1 after 24 hours and 2.1:1 after 48 hours.
Those are dubia results — not discoid measurements — but they demonstrate something important about feeder roaches generally:
What is in the gut can dramatically change the calcium delivered when the insect is eaten.
Where discoids fit
Discoid roaches are a useful staple feeder for many insectivorous reptiles and an excellent way to build variety into a feeding rotation.
We simply won't pretend their laboratory record is more complete than it is.
Explore: Discoid Roach Care & Storage · Feeder Size Guide · Gut Loading Feeder Insects
About our nutrition data
Feeder-insect composition can vary with species, life stage, diet, gut contents, rearing conditions and laboratory method. We identify whether figures are as-fed or dry-matter, publish ranges when the research gives ranges, and leave values unpublished when reliable species-specific data aren't available.