RESUMO
The aim of this study was to estimate (co)variance components and genetic parameters (heritability and genetic correlations) for meat fatty acid composition in Nellore cattle. The fatty acids analyzed were: conjugated linoleic acid - CLA (C18:2 trans-10 cis-12), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1 cis-9), linoleic acid (C18:2 cis- 9-12) and linolenic acid (C18:3). A total of 751 Nellore bulls, finished in feedlot for at least 90 days, with average age at slaughter of 24 months were used. The animals belong to eight farms located in the Southeast, Northeast and Midwest regions, of São Paulo State, which comprise three specific genetic breeding programs. The fatty acid determination was carried out at the Laboratory of Meat Science (LCC), Department of Animal Production and Nutrition FMVZ/USP. Samples from theLongissimus muscle were collected 48 hours after slaughter. The determination of meat fatty acid profile was performed by the method of Folch et al. (1957) and Kramer et al. (1997). Fatty acids were quantified by gas chromatography (GC-2010 Plus - Shimadzu AOC 20i auto sampler) using SP-2560 capillary column (100 m × 0.25 mm in diameter with 0.02 mm thickness, Supelco, Bellefonte, PA). To estimate the (co) variance components and genetic parameters, the model included the additive genetic effect as random effect, and the fixed effects of the contem
O artigo não apresenta resumo em português.
RESUMO
The aim of this study was to estimate (co)variance components and genetic parameters (heritability and genetic correlations) for meat fatty acid composition in Nellore cattle. The fatty acids analyzed were: conjugated linoleic acid - CLA (C18:2 trans-10 cis-12), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1 cis-9), linoleic acid (C18:2 cis- 9-12) and linolenic acid (C18:3). A total of 751 Nellore bulls, finished in feedlot for at least 90 days, with average age at slaughter of 24 months were used. The animals belong to eight farms located in the Southeast, Northeast and Midwest regions, of São Paulo State, which comprise three specific genetic breeding programs. The fatty acid determination was carried out at the Laboratory of Meat Science (LCC), Department of Animal Production and Nutrition FMVZ/USP. Samples from theLongissimus muscle were collected 48 hours after slaughter. The determination of meat fatty acid profile was performed by the method of Folch et al. (1957) and Kramer et al. (1997). Fatty acids were quantified by gas chromatography (GC-2010 Plus - Shimadzu AOC 20i auto sampler) using SP-2560 capillary column (100 m × 0.25 mm in diameter with 0.02 mm thickness, Supelco, Bellefonte, PA). To estimate the (co) variance components and genetic parameters, the model included the additive genetic effect as random effect, and the fixed effects of the contem
O artigo não apresenta resumo em português.
RESUMO
The objective of this study was to estimate heritability of carcass muscle index (MI) in yearling (MIy) and post-yearling (MIp) Nellore cattle. MI is the measure of longissimus muscle area (LMA) expressed in relation to body weight (MI=100×LMA/BW), being an indicative of animal muscularity. The records of LMA, obtained by ultrasound, and body weight (BW) were from the three Nellore herds reared at Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho-SP, born between 1999 to 2011, excepting 1998, 2000 and 2003. The measures were collected when the animals were on average 372 ± 26 days (yearling) and 562 ± 33 days (post-yearling) of age. The animals are progeny of 163 bulls and relationship matrix included 3436 animals. Variance components were estimated by REML in two single-trait analyses. The model included the fixed effects of contemporary group (herd-year-sex, i=1, , 48), month of birth (j=1, , 3) and dam age (linear and quadratic effects) and animal age at measurement (linear effect), and random effects of animal and residual. The average of LMA and BW were: 48.4 ± 10.7 cm² and 287±59 kg; 50.5 ± 9.2 cm² and 339 ± 64 kg, respectively for yearling and post-yearling. Despite the differences between yearling and post-yearling LMA and BW (plus 2.2 cm ² and 52 kg at post-yearling than yearling), the same was not observed for MI. BW has increased from yearling to po
O artigo não apresenta resumo em português.
RESUMO
The objective of this study was to estimate heritability of carcass muscle index (MI) in yearling (MIy) and post-yearling (MIp) Nellore cattle. MI is the measure of longissimus muscle area (LMA) expressed in relation to body weight (MI=100×LMA/BW), being an indicative of animal muscularity. The records of LMA, obtained by ultrasound, and body weight (BW) were from the three Nellore herds reared at Centro APTA Bovinos de Corte, Instituto de Zootecnia, Sertãozinho-SP, born between 1999 to 2011, excepting 1998, 2000 and 2003. The measures were collected when the animals were on average 372 ± 26 days (yearling) and 562 ± 33 days (post-yearling) of age. The animals are progeny of 163 bulls and relationship matrix included 3436 animals. Variance components were estimated by REML in two single-trait analyses. The model included the fixed effects of contemporary group (herd-year-sex, i=1, , 48), month of birth (j=1, , 3) and dam age (linear and quadratic effects) and animal age at measurement (linear effect), and random effects of animal and residual. The average of LMA and BW were: 48.4 ± 10.7 cm² and 287±59 kg; 50.5 ± 9.2 cm² and 339 ± 64 kg, respectively for yearling and post-yearling. Despite the differences between yearling and post-yearling LMA and BW (plus 2.2 cm ² and 52 kg at post-yearling than yearling), the same was not observed for MI. BW has increased from yearling to po
O artigo não apresenta resumo em português.