title: Effects of high concentrations of dietary crude glycerin on dairy cow productivity and milk quality.
abstract: An increasing worldwide interest in alternative fuel sources and in a more diversified energy matrix has provided incentives for the biodiesel industry, generating large amounts of the by-product crude glycerin, a potential alternative feed for dairy cows. A replicated 3×3 Latin square study was conducted to evaluate the effects of high concentrations of crude glycerin on dry matter intake, milk yield and composition, milk fatty acid profile, and blood metabolites of medium-yield cows. Ruminally cannulated Holstein cows (n=6; 587 ± 39 kg of body weight; 114 ± 29 d in milk; and 20 ± 1.5 kg/d milk yield) were used in the study. The experimental period included 2 wk for adaptation and 1 wk for data collection. Cows were fed diets containing 0 (control), 15, or 30% crude glycerin (83% glycerol). Cows were milked, milk weights were recorded twice daily, and milk samples were collected for milk quality analyses at d 18 and 19 in each experimental period. Feeding cows with crude glycerin linearly decreased dry-matter intake, the 3.5% fat-corrected milk, and the solid-corrected milk yield. Hepatic enzymes were not affected by dietary treatments, except gamma-glutamyl transferase, which was decreased with the 15% crude glycerin diet. Serum glucose and albumin showed quadratic effect with increasing inclusion of crude glycerin. Plasma cholesterol as well as total protein linearly decreased with increasing inclusion of crude glycerin. Milk fat concentration and yield showed a quadratic effect of treatments. Solid yield decreased linearly with increasing inclusion of crude glycerin. Odd-chain fatty acids and conjugated linoleic acid in milk fat linearly increased with addition of crude glycerin in the diets. Together, these results suggest that crude glycerin has potential to replace corn; however, feeding diets in which corn is replaced with crude glycerin at 30% of dietary DM greatly reduces animal performance.
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900.
authors: J M B
authors: JM
authors: Ezequiel
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900.
authors: J B D
authors: JB
authors: Sancanari
authors: Department of Animal Production, São Paulo State University, Botucatu, Brazil 18610-307.
authors: O R
authors: OR
authors: Machado Neto
authors: Agricultural and Environmental Sciences Center, Federal University of Maranhão, Chapadinha, Brazil 65500-000.
authors: Z F
authors: ZF
authors: da Silva
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900.
authors: M T C
authors: MT
authors: Almeida
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900.
authors: D A V
authors: DA
authors: Silva
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900.
authors: F O S
authors: FO
authors: van Cleef
authors: Department of Animal Science, São Paulo State University, Jaboticabal, Brazil 14884-900. Electronic address: ericvancleef@gmail.com.
authors: E H C B
authors: EH
authors: van Cleef
mesh_terms: D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002417:Cattle / Q000502:physiology*; D003612:Dairying; D004032:Diet / Q000662:veterinary*; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D005990:Glycerol / Q000008:administration & dosage / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects; D044243:Linoleic Acids, Conjugated / Q000032:analysis; D008892:Milk / Q000187:drug effects* / Q000378:metabolism / Q000592:standards
chemical_list: D005227:Fatty Acids; D044243:Linoleic Acids, Conjugated; D005990:Glycerol
keywords: blood metabolite; crude glycerin; fatty acid; milk production