Navegando por CNPq "CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS"

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Acesso aberto (Open Access)
Características fenotípicas e manejo genético de búfalos (Bubalus bubalis) leiteiros: ranqueamento de reprodutores
(Universidade Federal do Pará, 2015-08-10) MARQUES, Larissa Coelho; MARQUES, José Ribamar Felipe; http://lattes.cnpq.br/0104908318773676
The buffalo is an animal that can compete with differentiated products on internal and world markets, which presents own features and great performance when processing by-products and derivatives. Despite this, buffalo agribusiness resents of enhancers animals proved and / or tested to meet a demand that is vital for better genetic pattern. This study aimed to evaluate phenotypic characteristics of production milk and reproduction efficient of buffalo and perform genetic analyzes determining parameters and genetic index aimed at selection of buffalo to prepare a ranking of genetically superior breeding, increasing production chain of buffaloes in the Amazon region. We used 2,459 phenotypic records of Murrah, Mediterranean and half-blood buffaloes of EMBRAPA - CPATU herd from period between 1953 to 2013. The characteristics evaluated were: total milk production (TMP), fat percentage (F), age at first calving (AFC), calving interval (CI) and service period (SP). The descriptive analysis began with the editing of the data worked in the environments of Excel spreadsheet and SAS package. The overall results were: TMP = 1741.00 ± 496.48 kg, F = 7.07 ± 0.86%, AFC = 49.39 ± 7.37 months, CI = 13.16 ± 0.79 months and SP = 91.52 ± 24,22 days. In the analysis of variance for TMP the most significant effects were the birth order and the degree of blood from female, and to F was degree of female blood and AFC was calving season and birth order and CI and SP were station childbirth and the calf sex. The phenotypic correlations between TMP and F was 0.034, between TMP and AFC 0.118, between TMP and CI 0.070, between TMP and SP 0.070, between F and AFC -0.113, between F and CI -0.025, -0.025 between F and SP, among AFC and CI 0.445, 0.445 between AFC and SP and between CI and SP 1.00. Genetic analysis began with the editing of the data discussed in the environments of Excel spreadsheet and the SAS package and genetic analyzes were performed by WOMBAT software. For estimation of genetic parameters we used the animal model with two-trait analysis. The TMP was regressed depending on length of lactation and the regression coefficient was used for correction of lactation in 305 days (PL305). Fixed effects were contemporary group and linear and quadratic effects of birth female age as (co) variable. AFC and SP model was the same as described above with the exclusion of the term of the maternal permanent environmental effect. The heritability estimates for Murrah were: 0.49 for TMP; 0.59 for F; 0.75 for AFC; 0.006 for CI and 0.06 for SP; for the Mediterranean race were 0.31 for TMP; 0.08 for F; 0.78 for AFC; 0.90 for CI and 0.90 for SP. Genetic correlations between TMP and other features in the Murrah were 0.065 TMP and F; TMP and AFC 0.097, -0.450 TMP and CI and 0.079 TMP and SP for the Mediterranean were: -0.267 TMP and F; 0,629 TMP and AFC; 0.559 TMP and CI and 0.624 CI TMP and SP. The ranking of bulls / breeding was based on predictions of probable transmission ability (PTA's), using the SAS package which allows editing a bulls catalog of buffalo species of EMBRAPA Amazônia Oriental in that period. Based on the results the variability of the studied herd is likely to be crafted with the genetic management for both production characteristics as to the reproductive efficiency.
Acesso aberto (Open Access)
Estudo da interação genótipo-ambiente em rebanhos da raça Nelore na Amazônia Legal
(Universidade Federal do Pará, 2011-07-22) MATOS, Amanda de Sousa; MARQUES, José Ribamar Felipe; http://lattes.cnpq.br/0104908318773676; MARCONDES, Cíntia Righetti; http://lattes.cnpq.br/9955818501759983
Data from adjusted weights at 120 (P120), 210 (P210), 450 (P450) days of age, scrotal circumference at 450 days of age (PE450) and age at first calving (IPP), for 211,744 records from Nelore herds located in the Legal Amazon region, were used in the analysis. The effect of genotype-environment interaction was studied through heritability estimates and correlations between ranks, comparing the Legal Amazon animals with the general basis of animals – PMGRN Nelore Brazil. Bi-trait analyses considered P120 as anchor-trait, with P210, P450 and PE450 as another one. Model considered contemporary group of P120, P210, P450 and age-of-dam classes as fixed effects and direct maternal, additive and residual as random effects. Analyses of P120 with P450 and PE450 not included maternal effect in the model. Covariance additive-maternal was fixed at zero, as protocol in PMGRN – Nelore Brazil analysis. IPP has been analyzed separately in single-trait analysis and considering GCIPP as fixed and additive and residual effects as random. Comparisons between ranks, through the procedure PROC CORR option spearman of SAS were obtained. Estimates of heritability for P120, P210, P450, PE450 and IPP on the data of the Legal Amazon were: 0.20 to 0.49; 0.21; 0.48; 0.45; and 0.21, respectively, and in general data of PMGRN – Nelore Brazil were: 0.23; 0.25; 0.34; 0.43 and 0.11, respectively. Correlations between rank for P120, P210, P450, PE450 and IPP were equal to 0.77; 0.79; 0.82; 0.78 and 0.38, respectively. The analysis of genotype-environment interaction have demonstrated greater effects on maternal, IPP and P450, while correlations between classifications showed strong evidence in almost all traits studied.