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| Schmidt,GS; Figueiredo,EAP. |
| This experiment aimed at evaluating the effect of genetic selection on embryo development of two male broiler lines (LL and LLc). LL line was selected for eight generations for growth, carcass, and reproduction traits. The LLc line was derived from LL line in 1985, and kept under a random mating system with no selection. Fertile eggs were collected and individually weighed for four periods of five consecutive days, with two-week intervals. For every period, a total of 960 eggs/line were identified and separated in four groups of 240 eggs, and then stored for subsequent incubation. At 9 (P9), 11 (P11), 13 (P13), 15 (P15), 17 (P17) and 21 (P21) days of incubation, eggs and embryos were weighed (EmW). Egg weight (EgW) was similar between the two lines. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Correlation; Egg weight; Embryo weight; Genetic gain; Meat lines. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2009000100003 |
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| Schmidt,GS; Figueiredo,EAP de; Ledur,MC; Alves,HJ. |
| This study used 300 females and 30 males with 36 weeks of age from the selected PP and control PPc maternal broiler lines. PP has been selected for heavy body weight (PC) and high egg production for eight generations. Fertile eggs were collected and weighed individually for 4 periods of 5 consecutive days at two-week intervals. In each period, a total of 960 eggs/line were identified and separated in groups of 240 eggs, and stored for later incubation. Embryo weight (PE) was evaluated at 9 (P9), 11 (P11), 13 (P13), 15 (P15), 17 (P17) and 21 (P21) days of incubation. The objective was to estimate the effect of selection on embryo development. Egg weight (PO) was similar between the two lines. The differences in PE were significant from P15 on, resulting in... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Correlation; Egg weight; Embryo weight; Genetic gain; Meat lines. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2003000200006 |
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| Schmidt,GS; Figueiredo,EAP; Saatkamp,MG; Bomm,ER. |
| A total number of 300 females and 30 males of two experimental broiler lines, TT (male) and PP (female), with 39 and 36 weeks of age, respectively. Experiment 1 (TT) evaluated the effect of storage time (ST) on hatchability and embryo mortality (EM). Eggs were stored for 2 (ST1), 4 (ST2), 6 (ST3), 8 (ST4), 10 (ST5), 12 (ST6), and 24 (ST7) days and EM was assessed in the periods of 0 to 6 (EM1), 7 a 13 (EM2), 14 to 17 (EM3), 18 to 21 (EM4), and 0 to 21 (TEM) days. Experiment 2 (PP) evaluated the effect of egg weight (EW) on embryo development. Eggs were individually collected and weighed. Embryos were collected and weighed on days 9 (EW9), 11 (EW11), 13 (EW13), EW15, 17 (EW17) days of incubation and at hatching (EW21). ST linearly influenced hatchability... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chick weight; Broiler breeders; Embryo development; Embryo mortality; Egg weight; Incubation. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2009000100001 |
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| Schmidt,GS. |
| This study included 35 farmers contracted by a broiler integrator company. Each farmer owned an average of seven poultry houses, housing six flocks per year per farmer, summing up 4.0 million broilers housed. Live performance was evaluated in flocks housed in three densities (D1<12, 12<D2<14, and D3>14 birds/m2), and included the following parameters: market age (MA), average flock weight (AFW), average daily gain (DWG), feed conversion ratio (FCR), livability (LB), production efficiency index (PEI) and carcass yield/m2 (CY). Production costs and gross margin were calculated with birds housed at two densities (11.5<D4<12.4 and 14.5<D5<15.5birds/m2), standardizing MA to 44 days. The economic evaluation included 15 farmers and 1.0... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broilers; Density; Economic indices; Integration; Performance parameters. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2008000300002 |
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| Schmidt,GS; Coutinho,LL; Figueiredo,EAP de; Ledur,MC; Alves,HJ. |
| Two paternal broiler lines (LL and LLc, originated from the same stock in 1998) of Embrapa Suinos e Aves genetic program were used. Line LL had been selected for eight generations for rapid growth while LLc had been mated randomly, without selection, as a control line. In the last generation, 30 males and 240 females were used in hierarchical matings with pedigree control to determine sire effect. The same number of birds were used, but matings were at random for LLc. Eggs of both lines were incubated and embryos were collected in different development stages (40, 45, 50, 55 and 60 hours after setting) in order to determine somite number (NOS). The number of evaluated embryos were 1,967 and 498 for LL and LLc, respectively. This study aimed to determine... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Genetic; Heritability; Selection; Somite. |
| Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2003000300003 |
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| Schmidt,GS; Figueiredo,EAP. |
| The objective of this study was to report the response to selection for fertility and hatchability in white egg layers strains, based on sire and dam performance, and the effects of inbreeding on these traits. Two selected white egg strains (CC and DD) from Embrapa´s poultry program under multiple trait selection were compared to a control strain (CCc). The control strain was established by randomly mating one male from each sire family to a non-related female from each dam family and was used to monitor genetic change in the selected lines. CC and DD were selected using family and individual information on hen-day egg production up to 40 weeks of age, egg weight, sexual maturity and 16-week-old body weight over five generations. Independent culling levels... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Egg production; Inbreeding; Reproductive traits; Selection culling levels. |
| Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2005000400006 |
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| Schmidt,GS. |
| In the present study, 35 farmers contracted by an integration company were selected. Each farmer owned an average of seven poultry houses, and housed six flocks per year, with a total of 4.0 million housed broilers. Birds were grouped into 5 market ages (MA1=<43, 43<MA2=<44, 44<MA3=<45, 45<MA4=<46, MA5>46 days), and the following parameters were measured: average flock body weight (AFW), feed conversion ratio (FCR), livability (L), production efficiency index (PEI), production cost, and farmer's gross margin. MA significantly influenced all parameters, except production cost/kg broiler. The effects of farm and farm*MA interaction were not significant. Each day of MA increase resulted in increases of 68.43g and 0.039 units in AFW and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Broiler; Cost; Integrated companies; Performance. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2008000400005 |
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