title: Responses of lactating dairy cows to protected fats or whole cottonseed in low or high forage diets.
abstract: Thirteen treatments to compare effects of dietary fat on milk yield and composition were control, 15% whole cottonseed, and 2 and 4% Ca-tallowate factorially distributed in low forage (35% corn silage DM) with 14 or 18% CP and high forage (66% corn silage) diets with an additional diet of 8% Ca-tallowate. Different treatments were fed to 36 cows in each of three 28-d periods. Feeding 2 and 4% Ca-tallowate improved milk yield with high forage, although DM intake was slightly depressed; compared with 4% Ca-tallowate, DM intake and milk yield were depressed by 8% Ca-tallowate. Across all diets, whole cottonseed depressed DM intake and milk yield more than when nearly equal fat came from Ca-tallowate (4%). Calcium-tallowate depressed milk fat percentage linearly. Milk fat from cows fed whole cottonseed or Ca-tallowate contained unsaturated fatty acids (mostly C18:1) and lesser quantities of short-chain fatty acids. In a subsequent experiment, Ca-tallowate depressed milk fat percentage, whereas Megalac (calcium salts of fatty acids from palm oil) did not. In a field study, one trial with 210 cows in midlactation showed no effect on milk yield and composition from .54 kg of Megalac/d for 60 d, nor was there any effect detected with 121 cows in early lactation from feeding of .45 kg of Megalac/d for 90 d.
authors.affiliation: Dairy Science Department, University of Florida, Gainesville 32611.
authors.forename: D
authors.initials: D
authors.lastname: Lubis
authors.forename: H H
authors.initials: HH
authors.lastname: Van Horn
authors.forename: B
authors.initials: B
authors.lastname: Harris
authors.forename: K C
authors.initials: KC
authors.lastname: Bachman
authors.forename: S M
authors.initials: SM
authors.lastname: Emanuele
mesh_terms: D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000502:physiology*; D003369:Cottonseed Oil; D004041:Dietary Fats / Q000378:metabolism*; D005260:Female; D007774:Lactation / Q000502:physiology*; D016014:Linear Models; D008892:Milk / Q000737:chemistry / Q000378:metabolism; D011897:Random Allocation; D015430:Weight Gain
chemical_list: D003369:Cottonseed Oil; D004041:Dietary Fats