Utilization of Whole Cottonseed and Hay in Beef Cow Diets

Whole cottonseed (WCS) have become a very popular by-product feed for dairy cattle and for wintering beef cows in the Southern USA. The product is locally available to many producers across the region, and in most years WCS are competitively priced with other feedstuffs. Over time, ruminant nutritionists have recommended that WCS should be fed at about 0.5% of average body weight (BW), or about 2.3 to 3.2 kg WCS/cow daily (Rogers et al., 2002). The WCS provide both energy and protein (96% TDN and 23% CP, NRC, 1996; Feedstuffs, 2001). Research has indicated that WCS has a value similar to a 20% CP mixture of corn and soybean meal (Poore and Rogers, 1998). Beef cows can utilize WCS and hay very well, but younger growing cattle had diminished performance on WCS/hay diet compared with a corn/WCS meal diet (Hill et al., 2003; 2004), and performance decreased when WCS were fed at greater than 15% of diet DM in heifer diets (Poore, 1994). Feeding WCS at dietary levels higher than 0.5% of cow BW will supply excess fat in the diet, which could interfere with fiber digestion of the hay being fed. While ruminants have a fairly high tolerance for gossypol in WCS, excessive feeding of WCS could cause devastating effects on metabolism and health of cows. Nevertheless, some producers attempt to self-feed WCS, without actual knowledge of what intake levels may be, without regard to wasted money spent on WCS that was not consumed because it was trampled, refused because of being wet after rains, and not efficiently utilized because of over-consumption. After decades of feeding trials and producer usage of WCS as a supplement, few if any documented research trials have been conducted to determine how much WCS mature beef cows will consume.