title: Effect of protein level and source in molasses slurries on the performance of growing cattle fed hay during winter.
abstract: Four molasses slurries of varying protein level and source were fed in two performance trials (Year 1, 105 d; Year 2, 92 d) to growing cattle (Year 1, 230 kg; Year 2, 247 kg). Treatments were CONTROL (hay only), MOL (molasses-corn meal), MOL-UREA (molasses-urea-corn meal), MOL-SBM (molasses-soybean meal), and MOL-BF (molasses-urea-corn meal blood meal-hydrolyzed feather meal). Animals on all treatments were offered bermudagrass hay (Year 1: 12.8% CP, 50% TDN; Year 2: 12.8% CP, 54% TDN) and a complete mineral mixture free choice. Each treatment was fed to three pens each year with seven animals/pen. Slurries were offered at 2.1 kg/d (DM) and effects on forage intake, ADG, condition score (1 to 9), hip height, and plasma urea nitrogen were monitored. Treatment effects for Years 1 and 2 were analyzed separately due to treatment x year interactions (P < .15) with respect to ADG, hip height change, condition score change, and feed cost of gain. Supplementation increased (P < .001) ADG over CONTROL in Year 1 (.41 vs .06 kg/d) and Year 2 (.69 vs .25 kg/d), increased hip height change by .02 cm/d (P < .001) in Year 1 and by .01 cm/d (P = .012) in Year 2, and decreased (P < .001) loss of body condition in Years 1 and 2. Molasses-urea showed no advantage over MOL in Years 1 and 2. Natural protein (MOL-SBM and MOL-BF) increased ADG by .10 kg/d in Year 1 (P = .001) and by .06 kg/d in Year 2 (P = .077) compared with MOL-UREA. Daily gain was improved by MOL- BF by .05 kg/d (P = .109) in Year 1 and by .08 kg/d (P = .063) in Year 2 compared with MOL-SBM. Results indicate that growing cattle fed bermudagrass hay during winter respond positively to energy supplementation in the form of molasses. The addition of animal source protein enhanced this response.
authors.affiliation: Department of Animal Science, University of Florida, Gainesville 32611, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Stateler
authors.forename: W E
authors.initials: WE
authors.lastname: Kunkle
authors.forename: A C
authors.initials: AC
authors.lastname: Hammond
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000592:standards*; D000818:Animals; D002417:Cattle / Q000254:growth & development* / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000032:analysis; D005527:Food, Fortified; D008297:Male; D008965:Molasses / Q000032:analysis / Q000592:standards*; D006109:Poaceae; D011897:Random Allocation; D012621:Seasons; D013025:Glycine max / Q000592:standards; D014508:Urea / Q000097:blood; D003313:Zea mays / Q000592:standards
chemical_list: D004044:Dietary Proteins; D014508:Urea