95 degrees Fahrenheit
The cold brooder conserves the body heat of the chickens and keeps them warm. A brooder suitable for up to 50 two-day-old chickens consists of a frame 100 mm deep, 750 mm long and 600 mm wide. The bottom of the frame is covered with wire mesh, and can be set above the litter on adjustable legs. In addition to noting your chicks’ positions in the brooder, a thermometer is a great tool. Brand new baby chicks prefer temperatures just under 100 degrees. However, their need for heat decreases about 5 degrees per week until they are about 10 weeks of age. Brooders. The chick's first home will be the brooder. For brooder designs and ideas see our chicken brooders section. The size of the brooder will depend on the number of chicks you have. Aim for at least 2.5 sq feet per chick, if possible, more is better. The bottom of the brooder should have a layer of clean litter (pine shavings or similar). Brooders should keep chicks at the proper temperature. Newly hatched chicks need to be maintained at 95 degrees Fahrenheit (F) for the first week of their lives. After the first week, chicks can tolerate temperatures 5 degrees F cooler for each week until they are four weeks old. Theoretically, chick brooder temperature is measured with a thermometer placed 2 inches (5 cm) above the brooder floor (and at the outer edge of a hover), but you shouldn’t need a thermometer. Just watch the chicks, and adjust the temperature according to their body language. Brooder Lamp. You'll need a brooder lamp to keep the chicks at the right temperature. Purchase a 250-watt infrared heat lamp, preferably a red bulb instead of a white. You can find these at feed and hardware stores.
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0013/203521/small-scale-brooding-rearing-chickens.pdf http://www.nutrenaworld.com/knowledge-center/poultry/heat-lamps-for-chicks/index.jsp http://www.backyardchickens.com/a/how-to-raise-baby-chicks-the-first-60-days-of-raising-baby-chickens http://edis.ifas.ufl.edu/an182 http://www.motherearthnews.com/homesteading-and-livestock/raising-chickens/raising-chicks-brooder-temperature-zebz1305zstp.aspx http://smallfarm.about.com/od/farmanimals/a/chickbrooder.htm
what temperature does a chicken brooder need to be