Unidentified cartoon spots from late 1980s

How are you certain these are from another source?

Well, I'd also imagine that there weren't all too many animations being done in Brazil at the time to take footage from, though they did exist since at least 1917 & couple from the 50s & 60s still survive.

The one for Mother's Day could've been made in-house, but the first one looks like it came from one of those obscure direct-to-video animations that would be made here in the US. I'm going to assume that OP is Brazilian & therefore would likely know a bit more about the Brazilian animation industry around this time.

• The network did not commission other known pieces of animation for any of its programming.
  
• The visuals are disconnected from Brazilian climate, language, architecture... 
  
• One of the shorts of the group differs radically in style.
  
• Brazilian animation was is tiny and restricted to advertisement with virtually no cartoon series or animated features being produced. Never was a 2D powerhouse.
  
• And trying to contact any company about poorly documented things they did more than 30 years ago will result in nothing as workers retire and take knowledge with them.

Take these points in consideration for better skepticism inquiries.

Brazil could not even import animation celluloid in the 80s, said Brazilian animator Mauricio de Sousa. They made animation shots and reused cells after cleaning them. Brazil is almost completely ruled out as the source country.

Hey there! Brazilian here. I can clarify a few things:

1) The head of TVS/SBT, Sílvio Santos, was very clever and knew very well how to export foreign content that was successful internationally and adapt it for the Brazilian audience. Some examples include the channel's jingle, "Quem Procura Acha Aqui", which is actually a licensed version of the NBC promotional song "Let's All Be Here". He also adapted the song "Ritmo de la Noche" into Portuguese to be the musical theme for one of his television programs. The title was “Ritmo de Festa”.



2) Actually, Brazil has a very rich history in animation. Our first pieces of animation were produced in the late 1910s ("The Kaiser", from 1917 is the oldest one known) but unfortunately they were lost over time. Since then, it has developed more and more. Of course, not with the same frequency as the US or European countries but it happened.
The 80s were a good year for Brazilian animation. Here, great pieces were born, such as the short films by Marcos Magalhães ("Meow" from 1981 is an example) that were awarded internationally and something that I legitimately don't know how the OP could forget - the animated series of Turma da Mônica, a famous Brazilian comic strip. The animation is good (and even very smooth at times), it had a decent budget and the stories told are iconic, continuing to be remembered by us Brazilians. Below is a compilation of episodes from the 80s season. I recommend you watch the last one in this video, "A Estrelinha Mágica". It presents some fluid animations very well and also has a killer soundtrack accompanying the visuals.



3) That animated series you linked here, "Os Detetives - Bandeira e Antunes", is (surprisingly) very good. It tells the story of two detectives from Rio, Antunes and Bandeira, who are respectively a tapir and an anteater. The characters' names are puns on the names of animals in Portuguese - tapir is "anta", so anta becomes Antunes, which is a common surname in Brazil. Anteater is "tamanduá", but there is a common species here called "tamanduá-bandeira", and so the name Bandeira comes from there, but it is also a common surname. Bandeira is the typical "malandro carioca", a naughty guy, who always has a trick up his sleeve and speaks street slang. Antunes is a foolish buffoon, who is always hungry and is loyal to his fellow detective. The script and dialogue are very funny and informal, and make reference to various facts and points about the city of Rio de Janeiro and its urban culture. Maybe I can subtitle it in the future.
The only problem is the cartoonist who created the characters, Stil, had to produce the series in an incredibly small studio (Quaddro Produções) and with an even smaller budget. So much so that the characters are animated in rather crude cutouts and the background music is composed of stock or copyright-free songs (for example, "In the Hall of the Mountain King" plays for 2/3 of the episode "O Lobo se Estrepa").
Stil, on other occasions, has done much better animation work. For example, an animated series about his character Asdrúbal, a handyman teenager, made in the late 70s. Below is the episode "O Que Há com seu Peru" (translated, it would be something like "What's Up With your Cock ". Yes, in Portuguese this title also has a double meaning.) Read more about Stil here.



4) Brazilian animated commercials or advertising campaigns always sought a more original style, without these "americanized" features and traces. This TVS/SBT campaign was definitely not produced in Brazilian territory, analyzing those spots. See some examples below and you will understand what I mean.

   

5) Yes, mainly in Rio de Janeiro, Christmas is synonymous with infernal heat. Mainly because of Summer. There's no way anyone would animate a Christmas bumper in Brazil with snow and cold in it!

6) As we are talking a lot about Brazilian animation, I want to pay my respects to Ziraldo, legendary Brazilian cartoonist, father of the Menino Maluquinho, who died 91 this Sunday in his sleep.
    Adeus, mestre Ziraldo. Nunca te esqueceremos!