The term BA15 means Bayonet base with 15mm in diameter. A BA15 bulb is commonly known by industry standards as the following bulb size: 1156 7506 7527 1157 2057 2357 7528 P21W P21/4W, etc. These BA15 bulbs are commonly use for turn signal, tail/stop lights, reverse lights and daytime running lights.
Depending on the breed of the heifer, most heifers will start to show the first signs of heat when they are between 9 and 22 months of age. 1  The rate of sexual maturity or puberty is determinate of genes and breeding. A deep, long, and wide rump is a very good sign that that heifer is a keeper. 2  You will always know when a heifer or cow is ready to be bred when they go into heat. 3  Normal estrus periods last 24 hours and occur between 17 to 24 days.
That calf, provided it's a female (a heifer calf), will reach full maturity by the time it is 3 to 4 years of age. If she has been bred at ~15 months of age and has given birt â¦ h to a calf at 24 months of age, then she is considered a cow.