Whole cottonseed in dairy cattle feeding: a review

Whole cottonseed (WCS) is an unusual feedstuff for ruminants. Due to its high content of fat and protein, it may be defined as a concentrate. On the other hand, its fiber is similar to that of forages in terms of effectiveness in the rumen. The response of dairy cattle milk production to WCS feeding is variable. A large part of the effect of WCS on milk production is related to ruminal effects, which depend upon the basal diet fermentation balance. The high degradability of crude protein (CP) in the rumen may be associated with high ammonia production. The low heat increment obtained with WCS feeding favors its supplementation at high environmental temperatures, but a possible effect of WCS fat, i.e. reduced microbial activity, and gossypol toxicity may limit the amount of WCS which can be given to high-yielding dairy cattle. Current recommendations are to include WCS at up to 150 g/kg of the diet. Processing, and especially heat treatment of WCS may aid in providing more non-rumen degraded fat and CP from WCS to the small intestine. Heat treatment may also be useful for reducing free gossypol in WCS, and is likely to enable increased supplementation of WCS in dairy cattle rations. Reducing WCS particle size and NaOH treatment may also improve overall WCS digestibility. The advantages of such treatments may be more marked in low-lint WCS.