Since this question has already been answered already in two separate questions, provided in "Related Questions" below, the answer would be the same: around 280 to 285 days in length.
The inclusion of the Angus bull is irrelevant to this question since the bull has no control nor part in the length of a cow's gestation period. Expect a Hereford-cross cow to have an average gestation period of around 285 days long, plus or minus a few days.
Domestic Cattle, often informally refered to as a Cow or Cows Aberdeen Angus is a beef cattle breed.
For a tiger, the gestation period averages around 100 days. For a cow, the gestation period averages around 285 days.
The gestation period of a Gelbvieh cow averages around 260 to 280 days long.
The gestation period of a mini cow is around 285 days, which is the same length for a full-sized cow.
The gestation for a cow that's been AI'd would have the same gestation period as a cow that has been naturally bred: around 285 days, plus or minus. Artificial Insemination does NOT affect the length of gestation of a cow, it only affects what her offspring is going to be.
The gestation period of a Red Pol cow is around 285 days long, plus or minus a few days.
The cow has the longest gestation period of the two species: A dog is pregnant for around 60 days, whereas a cow is pregnant for around 285 days.
The gestation period of a Dutch Belted is around 285 days long.
It's a scottish breed Full name is Aberdeen Angus Think stereotypical Highland Cow Chris fae Glasgow
Angus cattle tend to have short gestation periods, ranging from 260 to 280 days in length. However, this can be the exception rather than the rule. Because Angus are so popular and wide-spread, it shouldn't come to a surprise that some strains may have average or slightly long gestation periods ranging from 280 to 290 days long.
Charolais tend to have a long gestation period, which is around 287 to 293 days long.