Comparison of digestibility, nutritive value, and storage characteristics of different forms of cottonseed in diets fed to lactating dairy cows.
Thirty-two Holstein cows averaging 70 d postpartum were used to compare digestibility of whole short staple cottonseed (SS) to whole Pima (WP), coarsely cracked Pima (CrP), and ground Pima (GP) cottonseeds and their effects on lactational performance. Cottonseed was fed at 15% of diet DM. Milk and solids-corrected milk (SCM) yields were higher for cows fed GP than for cows fed CrP or WP but were not different from yields of cows fed SS. Feed efficiency (SCM/DMI) was higher for cows fed GP and SS than for those fed WP. Milk of cows fed GP was lower in stearic acid but higher in linoleic and linolenic acids than milk of cows fed SS. Whole seeds passing into the feces (percentage of consumed) were higher for WP (12.3%) than for SS (6.2%). Total tract digestibility of ether extract was lower for WP than for other diets. Digestibilities of other nutrients were not different. To test storage characteristics, samples of cottonseed were incubated at 32 degrees C and 30% relative humidity for 0, 10, 20, and 30 d, or stored at ambient temperatures in covered buckets for 9 mo. No differences in amount of free fatty acids between incubated samples were noted, and only CrP stored in buckets for 9 mo was significantly higher in free fatty acids than initial or frozen seed. No differences in aflatoxin were detected, and levels were very low. Milk yield of cows fed GP diets was similar to that of cows fed SS diets and slightly higher than those of cows fed CrP or WP diets. Processing the Pima seed increased feed efficiency.
Sullivan
J L
JL
Department of Animal Sciences, University of Arizona, Tucson 85721.
Huber
J T
JT
Price
R L
RL
Harper
J M
JM
D000821:Animal Feed / Q000592:standards; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003369:Cottonseed Oil / Q000737:chemistry / Q000378:metabolism*; D004043:Dietary Fiber / Q000032:analysis; D004063:Digestion; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D007774:Lactation / Q000502:physiology*; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D009753:Nutritive Value; D011897:Random Allocation
D003369:Cottonseed Oil; D004043:Dietary Fiber; D005227:Fatty Acids