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.
In May 2004, first-calf heifers in a dairy with 650 milking cow Holsteins experienced an outbreak of late third- trimester abortions and premature live births with skeletal and neurologic deformities. Over a 4-week period, 19 of 37 heifers in their last month of gestation aborted or gave birth to calves approximately 2-4 weeks early. In the first week of May, 7 of 7 premature stillborn and live calves had notably shortened mandibles and appeared undersized for