Data/hora: 25/06/2024 05:29:44

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 10/08/1999
Data da última atualização: | 04/04/2012
Autoria: | FIGUEIREDO, E. A. P. de.
Título: | Potential breeding plans developed from observed genetic parameters and simulated genotypes for Morada Nova sheep in northeast Brazil.
Ano de publicação: | 1986
Fonte/Imprenta: | College Station: Texas A & M University, 1986.
Páginas: | 178p.
Idioma: | Inglês
Notas: | Tese Doutorado. Contem informacoes tecnicas fornecidas pela Embrapa Caprinos.
Conteúdo: | Analyses of the environmental factors and estimation of the genetic parameters concerning characters related to the Morada Nova breed, were conducted. A simulation experiment with a factorial structure of three genetic potentials for mature size (WMA) (30, 40 and 50 kg), three .genetic potentials for milk production (GMLKL) (1.125, 1.500 and 1.875 kg of milk per ewe at the peak day of lactation) and three genetic potentials for ovulation rate (OVR) (1.65, 2.20 and 2.75 ova per ovulation), for a total of 27 genotypic combinations, was also conducted. Data were obtained from 1669 lambs sired by 88 rams, and out of 560 ewes and from 2128 ewe records from the Morada Nova flock at Iracema Farm - EPACE - Quixada, Ceara, Brazil, from 1979 to 1985. The characters studied were age and weight at the first estrus cycle (AFEC and WFEC, respectively), breeding rate (B), lambing rate (1), prolificacy (T), weaning rate (W), total weight born (TWB), total weight weaned (TWW), breeding weight (WB), lambing weight (LW), ; birth weight (BW), weaning weight (WW), seven-month weight (7MW), yearling weight (YW), slaughter age (SA) and preweaning survivability (S) . The parameters estimated were heritability, repeatability and genetic and phenotypic correlations. The estimates of heritability were .20+.O6, .33+.O8, 19+O9 and 30t.O9 for BW, WW, 7MW and YW, respectively, and .52+34, .22+3l, 24+3l, 06+29, .33+32, .14+5l and .66t.30 for WB, LW, L, W, TWB, TWW and T, respectively. The simulation results indicated that efficiency of sheep meat production for Northeast Brazil (total weight sold/total dry matter consumed by the flock/year) increases with increases in genetic potential for ovulation rate and with increases in genetic potential increasing genetic for mature size as compared to the characteristics of the base genotype. The most efficient simulated genotype was the one with medium WMA, medium GMLKL and high OVR, followed closely by the genotypes with medium WMA, low GMLKL and high OVR, and by low WMA, medium GMLKL and high OVR. Selection indices were constructed to rank individuals based on a range of available information on their own performance, as well as on their relatives to estimate breeding values for prolificacy and for weaning weight (direct and maternal).
Palavras-Chave: | Brasil; Morada Nova; Nordeste.
Thesagro: | Genótipo; Melhoramento Genético Animal; Ovino; Parâmetro Genético.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
Exemplares: | CNPC - (1399-1) - UPC - TS - PP - TS 1986.00005 - FIG - 1986.00005 - DIS