title: Productive performance, meat quality and fatty acid profile of steers finished in confinement or supplemented at pasture.
abstract: Thirty Aberdeen Angus crossbred steers (281 ± 16 kg) were used to test the effect of finishing feeding system on growth performance, meat quality and fatty acid (FA) profile in intramuscular fat. Steers were fed in confinement (forage:concentrate ratio of 50 : 50; DM basis) or with different levels of energy supplementation (0, 0.4, 0.8 and 1.2% BW) at pasture (Avena strigosa Schreb and Lolium multiflorum L.). There were no differences between treatments for ADG (average=1.60 kg/day), hot carcass weight (HCW) (average=229 kg) and subcutaneous fat depth (average=3 mm). Dressing % (P=0.06; tendency) and carcass ADG (P=0.02) linearly increased with level of supplementation for pasture steers. No differences were observed between treatments for tenderness, marbling, pH, color b*, or cooking loss and drip loss in samples of Longissimus dorsi. However L* increased linearly (P=0.05) with level of supplementation. The concentrations of myristic, palmitic, estearic and linoleic FA did not differ among treatments. The concentration of n-3 FA increased (P<0.001) in steers at pasture compared with confinement, but n-6 FA concentrations did not differ between feeding system. Supplementation up to 0.4% BW increase (P<0.001) conjugated linoleic acid (CLA) and linolenic FA concentrations in intramuscular fat when compared with confinement. The level of supplementation on pasture linearly decreased (P<0.001) n-3 and CLA and linearly increased (P=0.001) the n-6 : n-3 ratio. Finishing of steers grazing winter pasture with energy supplementation or in confinement fed a medium-concentrate diet did not affect meat quality (tenderness, marbling, parameter b* on the CIE L*a*b* scale, cooking and drip losses) except for a* and L*. However, intramuscular fat of animals finished at pasture with moderate level of supplementation compared to animals fed in confinement had greater concentration of CLA, linolenic, and n-3, and lower n-6 : n-3 in intramuscular fat.
authors.affiliation: 1Departamento de Pós Graduação em Zootecnia,Universidade Federal do Rio Grande do Sul (UFRGS; Av. Bento Gonçalves,7712,CEP 91540-000,Porto Alegre, RS),Brazil.
authors.forename: H O
authors.initials: HO
authors.lastname: Patino
authors.affiliation: 2Brazilian Angus Association,General Manager of Certified Angus Beef (Largo Viasconde Cairú,12,CEP 90030-110,Porto Alegre,RS),Brazil.
authors.forename: F S
authors.initials: FS
authors.lastname: Medeiros
authors.affiliation: 1Departamento de Pós Graduação em Zootecnia,Universidade Federal do Rio Grande do Sul (UFRGS; Av. Bento Gonçalves,7712,CEP 91540-000,Porto Alegre, RS),Brazil.
authors.forename: C H
authors.initials: CH
authors.lastname: Pereira
authors.affiliation: 3Department of Animal Science,North Dakota State University(NDSU Dept 7630 PO Box 6050,Fargo,ND),USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Swanson
authors.affiliation: 4Faculdade de Agronomia e Medicina Veterinária,Universidade de Brasília (UnB; Campus Universitário Darcy Ribeiro, CEP 70910-900, Brasília, DF),Brazil.
authors.forename: C
authors.initials: C
authors.lastname: McManus
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D001835:Body Weight; D001938:Brazil; D002417:Cattle / Q000254:growth & development / Q000502:physiology*; D004032:Diet / Q000662:veterinary; D019587:Dietary Supplements; D005227:Fatty Acids / Q000378:metabolism*; D008297:Male; D008460:Meat / Q000032:analysis / Q000592:standards*; D050151:Subcutaneous Fat / Q000378:metabolism*
chemical_list: D005227:Fatty Acids
keywords:       n-3; CLA; Confinement; beef quality; pasture