It is usually a younger animal, roughly two to three years old.

https://nickbowkerhunting.com/plains-game/impala-hunting

One of the farms we hunt on is near Tarkastad. The farmer believes this is an Eastern Cape thing as the horns of his impala seldom really separate and straighten out like they do in the northern parts of SA, even for fully mature animals. If this is true, I would guess that it's a nutritional issue but I'm by no means an expert.

He pointed out one fully mature animal to me in 2023 that had horn tips almost touching - bigger body and longer horns than many of the animals around it but tips less than an inch apart.

His farm was for all practical purposes unoccupied and unhunted for over a decade before he bought it so all breeding was "natural".

Anyway, he is trying to sort it what he regards as a problem by shooting anything mature with horns pointing inwards and charges them as a "meat" animal irrespective of horn length. Parallel horns are treated as and charged for as "trophy" animals even if their horns are relatively short.

I'm watching with interest.

Addo Kirkwood produces some incredible horns ? I thought that was because of diet ? I am not convinced in this regard, to many incredible horns from the area, I always said the white calcinate rock found in the area caused excess calcium which was then shown in horn size.
I am more inclined to believe in genetics and inbreeding, but yea i asked because I did not have answers.
The animal in the photo, am I correct to say that it will never be a open horned animal ? 

Any guess's what that Impala weighed ? Do not cheat - guess before looking.
Scroll to first photo, big or not ?
You got a weight ?

20241209_214201 by David Frank Allen, on Flickr

I was going to say 32kg carcass with feet, head and skin off.

Addo Kirkwood produces some incredible horns ? I thought that was because of diet ? I am not convinced in this regard, to many incredible horns from the area, I always said the white calcinate rock found in the area caused excess calcium which was then shown in horn size.
I am more inclined to believe in genetics and inbreeding, but yea i asked because I did not have answers.
The animal in the photo, am I correct to say that it will never be a open horned animal ? 

It could be genetics & inbreeding but we also hunt on another farm about 30km away where the farmer brings in impala from up north every few years (ie new genes) and the herd as a whole also tends strongly towards horns pointing inwards.

My benchmark for impala is the herds that I see at Kruger Park which we visit about every second year.

Based on my non-scientific empirical observations I don't think the animal in the photo would ever become an open horned animal.

PS: I've also seen kudu bulls in Addo Park that are bigger in body & horn length than anything I've seen on the farms I've hunted in the Eastern Cape. They obviously haven't been hunted there for decades, which lends credence to your genetics theory but could also be nutrition.

I've heard that inbreeding in Eland can result in the males having "moffie" horns, which are thin like those of a female. This is a comment made by hunters, so I have absolutely no idea if there are any real genetics studies done on this.

Answer from a game ranger:

"Daar is heelwaarskynlik ‘n tekort aan een of ander mineraal wat die horing groei beinvloed! Ek sal begin om die water te toets."

(A mineral deficiency of some sort - test the water.)

Addo Kirkwood produces some incredible horns ? I thought that was because of diet ? I am not convinced in this regard, to many incredible horns from the area, I always said the white calcinate rock found in the area caused excess calcium which was then shown in horn size.
I am more inclined to believe in genetics and inbreeding, but yea i asked because I did not have answers.
The animal in the photo, am I correct to say that it will never be a open horned animal ? 

It could be genetics & inbreeding but we also hunt on another farm about 30km away where the farmer brings in impala from up north every few years (ie new genes) and the herd as a whole also tends strongly towards horns pointing inwards.

My benchmark for impala is the herds that I see at Kruger Park which we visit about every second year.

Based on my non-scientific empirical observations I don't think the animal in the photo would ever become an open horned animal.

PS: I've also seen kudu bulls in Addo Park that are bigger in body & horn length than anything I've seen on the farms I've hunted in the Eastern Cape. They obviously haven't been hunted there for decades, which lends credence to your genetics theory but could also be nutrition.

***************************
yes, believe u are correct

Answer from a game ranger:

"Daar is heelwaarskynlik ‘n tekort aan een of ander mineraal wat die horing groei beinvloed! Ek sal begin om die water te toets."

(A mineral deficiency of some sort - test the water.)

********************************
not in the area I speak of, here the horns are bigger because of area, but not necessarily better shaped, I ask about shape only

Bigger, but not developing completely?

Google "Impala" and look at the many  photos. There are quite a few of narrow horns as well as those with a wide spread. Seems as though it might be genetics affecting isolated groups of animals.