03115naa a2200241 a 450000100080000000500110000800800410001902400850006010000170014524501520016226000090031452023350032365000230265865000160268165000100269765000140270765000100272165300240273165300230275565300180277870000170279677300600281315185082026-01-15       1997    bl uuuu     u00u1 u    #d7 ahttps://doi-org.ez103.periodicos.capes.gov.br/10.1016/S0921-4488(96)01000-02DOI1 aSINHA, N. K.  aGenetic and phenotypic parameters of body weights, average daily gains and first shearing wool yield in Muzaffarnagri sheep.h[electronic resource]  c1997  aAbstract: Data on 953 Muzaffarnagri lambs, progeny of 41 rams, born between 1987 and 1993 at the Central Institute for Research on Goats, were utilized to estimate genetic and phenotypic parameters for BW at birth, 3 and 6 months, first-shearing wool yield and average daily gain (ADG) for the periods 0–3 (ADG1), 3–6 (ADG2) and 0–6 (ADG3) months of age. The effects of sire, year of birth and type of management on weight at birth, 3 and 6 months, first-shearing wool yield and ADG were all appreciable. Season of birth affected BW at 6 months, ADG2 and ADG3. Sex of lambs affected all traits except birth weight. The linear regression effect of age of ewe at lambing was significant for birth weight, ADG2 and ADG3, while linear and quadratic regression effects of weight of ewe at lambing were significant for all traits studied, except ADG3. Least squares means were 3.48 ± 0.07, 16.82 ± 0.37, 25.16 ± 0.41 kg and 511.0 ± 11.9 g for weight at birth, 3 and 6 months and first-shearing wool yield, respectively. The mean values for ADG1, ADG2 and ADG3 were 148.2 ± 3.9, 92.5 ± 3.2 and 120.5 ± 2.3 g, respectively. Male lambs attained heavier weights and grew faster than females; similarly, lambs maintained in feedlot had better ADG and higher weights than those kept in group. Heritability estimates for weight at birth, 3 and 6 months of age and wool yield were 0.32 ± 0.10, 0.43 ± 0.12, 0.27 ± 0.09 and 0.15 ± 0.07, respectively. The h2 of ADG1, ADG2 and ADG3 was 0.44 ± 0.12, 0.34 ± 0.10 and 0.29 ± 0.10, respectively. Birth weight had low to moderate phenotypic (rp) and genetic (rg) correlations with other traits, while standard errors of rg were high. BW at 3 months was highly and positively correlated with 6-month weight and wool yield, both at genetic and phenotypic scales. The rp between 6-month BW and wool yield was 0.354 and the rg with ADG2 was 0.14 ± 0.30. ADG1 had negative genetic and phenotypic correlations with ADG2, indicating that lambs growing faster from 0 to 3 months grew at a slower rate from 3 to 6 months. High heritability of BW at 3 months and ADG2, and their high and positive correlations with 6-month weight indicated that selection for BW could be practised at 3 months of age or these traits could be included in an index for improving 6-month weight and wool yield.  aAverage daily gain  aBody weight  aSheep  aFenótipo  aOvino  aFirst-shearing wool  aParamento Genetico  aPeso Corporal1 aSINGH, S. K.  tSmall Ruminant Researchgv. 26, n. 1/2, p. 21-29, 1997.