First, some questions on his test:
Did he show starting weights for each individual baby, and then final weights? Because a hatchling that starts at 5 grams isn't going to gain as much weight as a hatchling starting at 8 or 9 grams.
Was each group a single clutch or a mixed bag of clutches? If a single clutch each group, that doesn't rule out genetic tendencies towards faster growth.
Unnecessary vitamin supplementation can be detrimental to health; you can overdose on vitamins and minerals and considering the 'safe' doses are typically measuring in IUs per *kilogram* dosing a hatchling appropriately is going to be extremely difficult and you'll already be giving it more than it actually needs as it's getting that from its food already. Too much vitamin A, for example, and the snake basically continually sheds over and over, back to back, using up vital resources. Too much calcium and they can build up calcium deposits in the skin that cause tissue irritation and even ulcerate- this is a chronic condition from long-term excess calcium called calcinosis cutis.
There is also medical concerns with feeding too large and too frequent prey items; it might actually be decreasing our snakes' lifespans.
http://jeb.biologists.org/content/219/13/1969
Also anecdata from an exotics vet where one of their clients had seen a significant decrease in lifespan for their snakes:
Quote:
It is well known that after snakes eat their metabolisms are kicked into high gear to help digest the meal. Studies in Burmese pythons show that their hearts actually grow larger in size after a meal to accommodate the increase need for oxygenation of the tissues and to supply more blood to the GI tract. I never really paid much attention to this as a clinician until I had a client who breeds several species of python tell me that his snakes just aren’t living as long as they did when he first got into the business. After spending several days pouring over all of his data (he keeps meticulous records on each snake) and running diagnostics on a few snakes and necropsies on those that had died, I only really found one main issue- he was feeding larger prey items more often starting about a decade ago. I looked into the literature and spoke with some other herp vets and found that animals that are fed more often age faster than those that eat less.
Who cares right? The difference seems only to be a few years in longevity. For breeders whose main goal is producing young to sell, it probably is insignificant. But for people that own snakes just for their own enjoyment or those in zoological institutions those extra years may really matter, especially for endangered species. I see a lot more obesity in reptiles than I used to due to over feeding so not only are we making reptiles fat which causes health problems, we are shortening their lives just be speeding up their metabolisms.
Below are a few of the articles if you would like to read them and form your own conclusion.
Eating increases oxidative damage in a reptile.
J Exp Biol. July 2016;219(Pt 13):1969-73.
Michael W Butler 1, Thomas J Lutz 2, H Bobby Fokidis 3, Zachary R Stahlschmidt 4
Effects of meal size on postprandial responses in juvenile Burmese pythons (Python molurus)
Am J Physiol. March 1997;272(3 Pt 2):R902-12.
S M Secor 1, J Diamond
The effects of fasting duration on the metabolic response to feeding in Python molurus: an evaluation of the energetic costs associated with gastrointestinal growth and upregulation
Physiol Biochem Zool. 2002 Jul-Aug;75(4):360-8.
Johannes Overgaard 1, Johnnie B Andersen, Tobias Wang
Physiology: postprandial cardiac hypertrophy in pythons
Nature. March 2005;434(7029):37-8.
Johnnie B Andersen 1, Bryan C Rourke, Vincent J Caiozzo, Albert F Bennett, James W Hicks
Respiratory consequences of feeding in the snake Python molorus
Comp Biochem Physiol A Mol Integr Physiol. November 1999;124(3):359-65.
J Overgaard 1, M Busk, J W Hicks, F B Jensen, T Wang
|
And a thing of note with obesity; you only see external signs of obesity once the body cavity has reach max fat storage capacity. A snake that visually appears to be in good body condition could still be obese.