する際 and 穴埋め meaning along with として


>
> 初めは番組を編成する際の穴埋めとして放映されていたのだが、番組の数が増え,年月を経るうちに、子どもたちにとって生まれたときから存在しているアニメは、今やなくてはならない娯楽となっている.

My attempt to translate that would be something like

> In the beginning, when broadcasts were created by filling the gap (???) were
> televised but, as they grew in numbers and time past, the anime that existed
> since when we were born as kids, they became a must amusement.

which is incomprehensible for me. The key seems to be the clauses in the title
but I figured out midways that the translation of the last part with kids
being raised with animes e.t.c. doesn't really make sense too.




You can parse it like this:

> 初めは[{(番組を編成する際の)穴埋め}として]放映されていたのだが、

番組を編成する際の modifies 穴埋め, "fillers (between programs) used when editing TV
programs / planning program schedule." So I think it's like "In the beginning,
anime were broadcasted as fillers inserted when organising TV programmes,
but..."

> 番組の数が増え、年月を経るうちに、

as they(=TV programs) grew in numbers and time passed,

> 子どもたちにとって(、)[生まれたときから存在している]アニメは、

The relative clause 生まれたときから存在している modifies アニメ. The subject for 生まれた is
子どもたち. **Edit:** I think it'd be more natural to think the 子どもたちにとって modifies
(アニメは)なくてはならない娯楽となっている.  
"for children, anime, which have existed ever since they were born,"

> 今やなくてはならない娯楽となっている.

... have become an indispensable entertainment by now.

(Sorry I can't translate it into natural English, but hopefully this might be
of some help.)




You can parse it like this:

> 初めは[{(番組を編成する際の)穴埋め}として]放映されていたのだが、

番組を編成する際の modifies 穴埋め, "fillers (between programs) used when editing TV
programs / planning program schedule." So I think it's like "In the beginning,
anime were broadcasted as fillers inserted when organising TV programmes,
but..."

> 番組の数が増え、年月を経るうちに、

as they(=TV programs) grew in numbers and time passed,

> 子どもたちにとって(、)[生まれたときから存在している]アニメは、

The relative clause 生まれたときから存在している modifies アニメ. The subject for 生まれた is
子どもたち. **Edit:** I think it'd be more natural to think the 子どもたちにとって modifies
(アニメは)なくてはならない娯楽となっている.  
"for children, anime, which have existed ever since they were born,"

> 今やなくてはならない娯楽となっている.

... have become an indispensable entertainment by now.

(Sorry I can't translate it into natural English, but hopefully this might be
of some help.)

