Mr. Rory Lewandowski, Extension Educator, Wayne County, The Ohio State University
Young dairy calves spend a lot of their day lying down. Research from the University of Guelph indicates that calves from 10 days of age to 4 weeks can average 20.6 hr/day lying down over that period. Calf lying down time will average 18 hr/day from 30 to 39 days of age, 17 hr/day from 40 to 49 days of age, and 16 hr/day from 50 to 56 days of age. Group housing systems must provide adequate space to enable all the calves to lie down for 75 to 85% of the day. To stay healthy and comfortable during that lying down time requires that calves have a clean, dry surface to lay on with ventilation that removes any ammonia near the surface of the bedding. Ammonia levels above 5 ppm at the calf nose level are harmful.
Bedding material is an important factor in calf comfort and type of bedding material may need to vary depending upon conditions. During hot weather, bedding with sand can help to keep calves cool. In cool and cold weather, calves need a bedding material that they can nest into, typically wheat or oat straw, to be able to conserve body heat, so depth of bedding is important.
Top quality wood shavings, wood chips, and wheat or oat straw are all very good absorbent bedding materials. Corn stover, when shredded, and top quality sawdust are rated as moderate quality bedding materials. Chopping wheat, oat, or even mature hay will increase the absorbency potential.