Consulta: creatorFacets:"Schmidt,GS"
Registros recuperados: 9
Data/hora: 10/06/2024 11:12:05

Characterization of selection effects on broiler lines using DNA fingerprinting
Provedor de dados: 89
Autores: Schmidt,GS; Hellmeister Filho,P; Zanella,EL.
The objective of this study was to evaluate the effect of selection for body weight on the genetic variability and diversity in broiler lines. Two paternal broiler lines (LL and LLc) were used. LL line was selected for 12 generations for growth and carcass and reproduction characteristics. The LLc line was established from LL line in 1985 and mated at random. Blood samples from six chickens per line were collected and used for molecular analysis. Also, a DNA pool was made for each line to compare effects between lines. Data were analyzed considering the collected information on the presence or absence of DNA bands. Band sharing scores were calculated using the DICE coefficient. The pattern of the 21 most representative bands was used. DNA fingerprinting...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Body weight; Fingerprinting; Molecular markers; Variability.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2003000200005

Evaluation of the technical and economic impacts of high-density broiler production in an integrated system
Provedor de dados: 89
Autores: 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&lt;12, 12&lt;D2&lt;14, and D3&gt;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&lt;D4&lt;12.4 and 14.5&lt;D5&lt;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

Selection for reproductive traits in white egg stock using independent culling levels
Provedor de dados: 89
Autores: 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

Effect of selection for productive traits in broiler maternal lines on embryo development
Provedor de dados: 89
Autores: 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

Morphological genetic markers for selection of broiler lines
Provedor de dados: 89
Autores: 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

Effect of storage period and egg weight on embryo development and incubation results
Provedor de dados: 89
Autores: 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

Genetic gain for body weight, feed conversion and carcass traits in selected broiler strains
Provedor de dados: 89
Autores: Schmidt,GS; Figueiredo,EAP; Ledur,MC.
The Brazilian Swine and Poultry Research Center (Embrapa Suínos e Aves) maintains a chicken breeding program for meat production since 1985. Two control lines (LLc and PPc) are maintained, whereas two male lines (TT and ZZ) and three female lines (PP, VV and KK) have been selected. This paper reports the genetic gain after 15 generations of combined selection (mass and independent culling levels) in order to develop the commercial broiler stocks Embrapa 021 and Embrapa 022. Selection pressure has been exerted on weight gain, carcass traits and fertility. In addition, female lines have also been selected for egg production, whereas males have been selected for feed efficiency since 1992. All lines have been selected for breast area instead of carcass traits...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Control line; Crossbreeding; Genetic gain; Meat production; Production; Selection.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2006000100004

The effect of broiler market age on performance parameters and economics
Provedor de dados: 89
Autores: 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=&lt;43, 43&lt;MA2=&lt;44, 44&lt;MA3=&lt;45, 45&lt;MA4=&lt;46, MA5&gt;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

Effect of selection for productive traits in broiler male lines on embryo development
Provedor de dados: 89
Autores: 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