title: Effects of flaxseed encapsulation on biohydrogenation of polyunsaturated fatty acids by ruminal microorganisms: feedlot performance, carcass quality, and tissue fatty acid composition.
abstract: The objective of this study was to evaluate the efficacy of protecting PUFA within ground flaxseed against ruminal biohydrogenation by encapsulating them in a matrix consisting of a 1:1 blend of ground flaxseed and dolomitic lime hydrate (L-Flaxseed). Crossbreed heifers ( = 462, 346 ± 19 kg) were blocked by weight and randomly assigned to pens. Pens were assigned to 1 of 6 dietary treatments in a randomized complete block design. Treatment 1 consisted of a combination of 54.6% steam-flaked corn (SFC), 30.0% wet corn gluten feed, 8.0% roughage, and supplement (0% flaxseed). In treatments 2 and 3, a proportion of SFC was replaced with 3 and 6% flaxseed, respectively; in treatments 4, 5, and 6, SFC was replaced with 2, 4, or 6% L-Flaxseed, respectively. Cattle were fed for 140 or 168 d and then harvested in a commercial abattoir where carcass data were collected. Approximately 24 h after harvest, carcasses were evaluated for 12th-rib fat thickness, KPH, LM area, marbling score, and USDA yield and quality grades. Samples of LM were also obtained for determination of long-chain fatty acid profiles. Cattle that were fed diets with 4 and 6% L-Flaxseed consumed less feed than other treatments ( < 0.05), which adversely affected ADG. Compared with cattle fed 0% flaxseed, cattle in these treatments had lower final BW (18 and 45 kg less for the 4 and 6% L-Flaxseed treatments, respectively), less ADG (0.16 and 0.48 kg/day less for the 4 and 6% L-Flaxseed treatments, respectively), and lower carcass weights, dressing percentages, LM areas, backfat thicknesses, and marbling scores ( < 0.05). The addition of flaxseed or 2% L-Flaxseed did not affect performance or carcass traits ( > 0.05). Supplementation with flaxseed increased ( < 0.05) the concentration of α-linolenic acid (ALA) in meat (0.173, 0.482, 0.743 mg/g for 0, 3, and 6% flaxseed, respectively). Furthermore, proportionate increases in the ALA content of muscle tissue were 47% greater when flaxseed was encapsulated within the dolomitic lime hydrate matrix (0.288, 0.433, 0.592 mg/g for 2, 4, and 6% L-Flaxseed, respectively). Both products showed a linear response in ALA concentration ( > 99%; increases for Flaxseed and L-Flaxseed of 0.095 and 0.140 mg of ALA/g of tissue for each percentage of flaxseed added). This study indicates that a matrix consisting of dolomitic lime hydrate is an effective barrier to ruminal biohydrogenation of PUFA; however, adverse effects on DMI limit the amounts that can be fed.
authors.forename: C A
authors.initials: CA
authors.lastname: Alvarado-Gilis
authors.forename: C C
authors.initials: CC
authors.lastname: Aperce
authors.forename: K A
authors.initials: KA
authors.lastname: Miller
authors.forename: C L
authors.initials: CL
authors.lastname: Van Bibber-Krueger
authors.forename: D
authors.initials: D
authors.lastname: Klamfoth
authors.forename: J S
authors.initials: JS
authors.lastname: Drouillard
mesh_terms: D000273:Adipose Tissue; D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D001823:Body Composition; D001835:Body Weight / Q000502:physiology; D002417:Cattle / Q000382:microbiology*; D004032:Diet / Q000662:veterinary*; D004043:Dietary Fiber; D005227:Fatty Acids / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D005260:Female; D019597:Flax / Q000737:chemistry*; D005511:Food Handling; D005983:Glutens / Q000494:pharmacology; D006799:Housing, Animal; D015430:Weight Gain; D003313:Zea mays / Q000737:chemistry
chemical_list: D004043:Dietary Fiber; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D005983:Glutens