title: Changes in intramuscular fat, fatty acid profile and cholesterol content induced by zeranol implantation strategy in hair lambs.
abstract: BACKGROUND
  The effect of zeranol implantation strategy on intramuscular fat, fatty acid profile and cholesterol content of the longissimus dorsi muscle of hair lambs was studied. Four treatments were tested: C, control group; Z12, 12 mg zeranol; Z24, 24 mg zeranol in a single application; and RZ12, 12 mg zeranol given twice. One-way analysis of variance was employed to estimate the effect of treatments (P < 0.05). To separate the effect of the mean, orthogonal contrasts were tested: C1, C versus Z12 + Z24 + RZ12; C2, Z12 versus Z24 + RZ12; and C3, Z24 versus RZ12.
  
  
  RESULTS
  A decrease (P < 0.05) in intramuscular fat content was observed from implanting (C1 effect) and zeranol reimplantation (C3 effect). Implanted lambs exhibited an increase (P < 0.05) in monounsaturated fatty acids compared with control group (40.60% versus 35.35%). All contrasts were significant for the sum of n-6 and n-3, with values lower (P < 0.05) in the control (n-6: 0.84% and n-3: 1.38%) and higher in the RZ12 treatment (n-6: 7.55% and n-3: 14.9%). Cholesterol decreased by 78% with implantation and increasing the dose.
  
  
  CONCLUSIONS
  The results indicate that it is possible to induce favorable changes in the fatty acid profile and cholesterol content using a zeranol implantation strategy on hair lambs.
authors.affiliation: Laboratorio de Investigación en Carne y Productos Cárnicos, Centro de Investigación en Alimentación y Desarrollo AC, Hermosillo, Sonora 83000, México.
authors.forename: Nidia V
authors.initials: NV
authors.lastname: Valenzuela-Grijalva
authors.forename: Humberto
authors.initials: H
authors.lastname: González-Rios
authors.forename: Thalia Y
authors.initials: TY
authors.lastname: Islava
authors.forename: Martin
authors.initials: M
authors.lastname: Valenzuela
authors.forename: Gastón
authors.initials: G
authors.lastname: Torrescano
authors.forename: Juan P
authors.initials: JP
authors.lastname: Camou
authors.forename: Francisco A
authors.initials: FA
authors.lastname: Núñez-González
mesh_terms: D000818:Animals; D002791:Cholesterol, Dietary / Q000378:metabolism*; D004032:Diet; D004041:Dietary Fats / Q000378:metabolism*; D004968:Estrogens, Non-Steroidal / Q000008:administration & dosage / Q000494:pharmacology*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D006801:Humans; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000378:metabolism*; D034561:Sheep, Domestic; D015029:Zeranol / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D002791:Cholesterol, Dietary; D004041:Dietary Fats; D004968:Estrogens, Non-Steroidal; D005231:Fatty Acids, Unsaturated; D015029:Zeranol