title: Performance of the Santa Ines breed raised on pasture in semiarid tropical regions and factors that explain trait variation.
abstract: This study aimed to evaluate sex, the number of lambs per birth, and the family effects on production traits in the Santa Ines breed of sheep by estimating the least square means and coefficient of variance for those traits. A total of 484 lambs were evaluated for the following traits: weight at birth, at weaning, and at 240 days of age; weight gain during the pre-weaning and post-weaning periods; height, width, and length of different body regions; and rib eye area and fat thickness between the 12th and 13th ribs. We observed coefficients of variation higher than 10 % for several traits. Generally, males were larger than females (P < 0.05), while lambs from single and double births were larger than lambs from triple births (P < 0.05). Family effect was significant (P < 0.05) for most traits and explained the highest percentage of residual variance. The results showed good development of Santa Ines sheep, especially during the pre-weaning period but no in post-weaning. Our study also showed that there is an effect of sex, birth type, and family, which must be included in any statistical model for the estimation of least square means and residual variance in ANOVA.
authors.affiliation: Escola de Medicina Veterinária e Zootecnia, Universidade Federal da Bahia, Av. Adhemar de Barros, 500, 40170-110, Salvador, BA, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: de Farias Jucá
authors.forename: Juliana Cantos
authors.initials: JC
authors.lastname: Faveri
authors.forename: Geraldo Magalhães
authors.initials: GM
authors.lastname: Melo Filho
authors.forename: Antônio
authors.initials: A
authors.lastname: de Lisboa Ribeiro Filho
authors.forename: Hymerson Costa
authors.initials: HC
authors.lastname: Azevedo
authors.forename: Evandro Neves
authors.initials: EN
authors.lastname: Muniz
authors.forename: Luís Fernando Batista
authors.initials: LF
authors.lastname: Pinto
mesh_terms: D000367:Age Factors; D000704:Analysis of Variance; D000821:Animal Feed; D000818:Animals; D001835:Body Weight / Q000235:genetics / Q000502:physiology; D001837:Body Weights and Measures / Q000662:veterinary; D001938:Brazil; D001947:Breeding / Q000379:methods*; D005260:Female; D016018:Least-Squares Analysis; D008297:Male; D008460:Meat / Q000032:analysis* / Q000592:standards; D010641:Phenotype; D012098:Reproduction / Q000502:physiology*; D012756:Sheep / Q000235:genetics* / Q000254:growth & development*; D014329:Tropical Climate; D015430:Weight Gain / Q000235:genetics / Q000502:physiology