Gabrimar Araújo Martins

Efeitos genéticos aditivos e não-aditivos para características produtivas e reprodutivas em vacas mestiças Holandês × Gir

A partir de registros de genealogia e controle leiteiro e reprodutivo fornecidos pela Associacao Brasileira dos Criadores de Girolando, foram estimados os efeitos de diferenca genetica aditiva entres as racas Holandesa e Gir, de dominância e de recombinacao, alem das herdabilidades e repetibilidades, para as caracteristicas producao de leite por lactacao (PL), producao de leite ate os 305 dias de lactacao (PL305), duracao da lactacao (DL), intervalo de partos (IDP), idade ao primeiro parto (IPP) e producao de leite por dia de intervalo de partos (PL/IDP). Foram utilizados 4.805 registros de PL, PL305 e DL e 2.222, 1.408 e 2.363 registros de IDP, IPP e PL/IDP, respectivamente. Analises unicaracteristicas foram realizadas considerando os efeitos de diferenca genetica aditiva entre as racas, de dominância e de recombinacao como covariaveis. As estimativas para a diferenca genetica aditiva entre as duas racas foram significativas para todas as caracteristicas, exceto para o IDP, e foram estimadas em 3.115 ± 273 kg, 2.574 ± 226 kg, 98 ± 13 dias, -236 ± 67 dias e 7,5 ± 0,9 kg/dia para PL, PL305, DL, IPP e PL/IDP, respectivamente. Os efeitos de dominância (heterose) tambem foram significativos para todas as caracteristicas, exceto para a DL. Foi verificada significativa perda por recombinacao para PL e PL305. As estimativas de herdabilidade foram de 0,25 ± 0,05, 0,21 ± 0,04, 0,12 ± 0,04, 0,05 ± 0,05, 0,33 ± 0,09 e 0,21 ± 0,07 para PL, PL305, DL, IDP, IPP e PL/IDP, respectivamente, enquanto as estimativas de repetibilidade foram de 0,49 ± 0,05; 0,47 ± 0,04; 0,18 ± 0,04; 0,09 ± 0,06; e 0,37 ± 0,07 para PL, PL305, DL, IDP e PL/IDP, respectivamente.

Período de gestação em rebanho Nelore na Amazônia Oriental

The evaluated animals were raised in grazing system without supplementation in the dry season, from 1988 to 1996. A total of 587 observations of days open (DO) was taken from the archives of the regional technical office of ABCZ (Escritorio Tecnico Regional da ABCZ) in Fortaleza – CE and from zootechical registers of the Farm Entre Rios. The GLM procedure of the SAS Program was used to analyze the data. The model included the sire of the cow random effect, [...]

Intervalo de partos em rebanho Nelore na Amazônia Oriental

A study was conducted to evaluate calving interval (CI) in the Nellore breed, using a total of 578 data of calving interval from animals raised in pasture, from 1988 to 1996. The GLM procedure of the SAS Program was used to analyze the data. The model included the sire of the cow random effect, the fixed effects of genetic group of last calf, of the year and the month of the last calving and the interactions between last genetic group and month of the last calving, genetic group and year of the last calving, and the age of the cow at calving as covariate. The sire of the cow and last year of calving influenced the IDP. The estimated minimum square mean and its respective error standard (EP) and coefficient of variation (CV) were 431.83 ± 142.76 days and 33.06%, respectively. The environment in addition of the sire of the cow effect, influenced the calving interval. The reproductive performance of the studied herd, for the tropical climate conditions, could be considered as satisfactory, and is in accordance with the parameters obtained by other authors in different regions.

Predição do peso vivo a partir de medidas corporais em animais mestiços Holandês/Gir

O objetivo deste estudo foi investigar as relacoes entre o peso corporal e as medidas corporais altura de garupa (ag), comprimento de garupa (cg), comprimento corporal (cc) e perimetro toracico (pt), em bovinos oriundos principalmente do cruzamento das racas Holandes e Gir. Foram utilizados dados de 483 vacas, 469 novilhas e 62 machos, de tres rebanhos distintos, analisados separadamente para cada categoria a fim de estabelecer equacoes polinomiais dos pesos em relacao as medidas corporais. As correlacoes simples do peso corporal com pt, cc, cg e ag foram respectivamente 0,807; 0,440; 0,187 e 0,504 para vacas; 0,928; 0,735; 0,819 e 0,880 machos, e 0,942; 0,748; 0,902 e 0,573 para novilhas. Embora as regressoes de peso corporal em relacao ao cc e cg tenham sido significativas (P<0,05), o aumento da porcentagem de explicacao das variacoes do peso corporal obtido com a inclusao destas medidas, em adicao ao pt, nao parece justificar o custo das medicoes. As equacoes de predicao do peso corporal em funcao do pt foram as seguintes: para vacas, peso = 12.174 - 187,410 pt + 0,97196960 pt² - 0,00162382 pt³, para novilhas, peso= 1.717-35,167 pt + 0,238978 pt² - 0,00046260 pt³ e, para machos, peso = -3.862+76,014 pt-0,488837 pt²+ 0,00109755 pt³.

Gestation lenght of Nellore cattle in the Oriental Amazônia

The evaluated animals has been bred fed only with grass, without any complementary alimentation during the dry season from 1988 to 1996. A total of 1206 observations of the gestation lenght (LG) was taken from the archives of the regional technical office of ABCZ (Escritório Técnico Regional da ABCZ) in Fortaleza CE and from zoo-technical registers of the farm. For the statistical analyses of the data was used the SAS (Statistical Analysis System, 1990), through procedure GLM (general linear model). Had been includ in the model the random effect of the sire of the cows, the fixed effects of the genetic group of the calf, month and year of calving, Sex of calf and the interactions between groups of the sex beyond he age of the cow at used as covariat. The LG was influenced by month of the calving, year of the calving and by the calf sex. The estimated average by minimum square and its respective standard error (EP) and coefficient of variation (CV) had been, 284.73 ± 3.65 days and 1.28%. The gestation length generally did not suffer significant influences from the environment, except on the determination of the calf sex , such as occurred in this work. The estimated average for the gestation length obtained can be considered normal for the species and the studied breed.The evaluated animals has been bred fed only with grass, without any complementary alimentation during the dry season from 1988 to 1996. A total of 1206 observations of the gestation lenght (LG) was taken from the archives of the regional technical office of ABCZ (Escritorio Tecnico Regional da ABCZ) in Fortaleza - CE and from zoo-technical registers of the farm. For the statistical analyses of the data was used the SAS (Statistical Analysis System, 1990), through procedure GLM (general linear model). Had been includ in the model the random effect of the sire of the cows, the fixed effects of the genetic group of the calf, month and year of calving, Sex of calf and the interactions between groups of the sex beyond he age of the cow at used as covariat. The LG was influenced by month of the calving, year of the calving and by the calf sex. The estimated average by minimum square and its respective standard error (EP) and coefficient of variation (CV) had been, 284.73 ± 3.65 days and 1.28%. The gestation length generally did not suffer significant influences from the environment, except on the determination of the calf sex , such as occurred in this work. The estimated average for the gestation length obtained can be considered normal for the species and the studied breed.

Estimativas de parâmetros de cruzamentos para peso de fêmeas Holandês/Gir

Monthly weights (18.089) of 412 females on a demonstration farm in the Zona da Mata, Minas Gerais State, were used to develop a model to describe the liveweight of cows, heifers and calves. The data were analyzed using Proc Mixed of the SAS package, separately for the following categories: a) cows, b) heifers older than 12 mo., c) heifers 70-d to 12 mo-old and d) female calves up to 70 d. For each of these, the regression equations of weight on age (mo) were, respectively, Y i = 267.730 24.319 q + 81.025 z + 1.152 x 0.007 x2 + 3.908 qx + 0.958 zx 0.017 qx2; Y i = -230.446 + 205.033 q + 76.206 z + 27.304 x 0.278 x2 11.806 qx + 0.166 qx2; Y i = -58.167 + 99.107 q + 47.627 z + 16.730 x + 0.093 x2 4.928 qx and Y i = 17.286 + 20.343 q + 11.023 z + 0.680 x + 4.117 x2 + 3.663 qx, where q is the proportion of Holstein genes and z the breed heterozygocity. The average weight maintained by cows during their herd life was estimated by integration of the predicted weight (v) between the ages at first calving and at disposal. Heterosis had important effect on this weight.

Desempenho Reprodutivo de Ovelhas SPRD Acasaladas com Reprodutores de Raças Especializadas para Corte no Estado do Ceará

c aracteristicas reprodutivas e suas correlacoes em ovelhas SPRD acasaladas com reprodutores Santa Ines, Somalis brasileira, Texel e Dorper foram estudadas entre 1995 a 2002, no Ceara. As caracteristicas foram: taxa de fertilidade (F), prolificidade (P), taxa reprodutiva (TR), numero e peso medio dos cordeiros nascidos e desmamados por ovelha exposta (NCN, NCD, PCN e PCD, respectivamente), peso medio da ninhada ao nascimento (PNN) e ao desmame (PND) por ovelha exposta e a taxa de sobrevivencia dos cordeiros ao desmame (TSD). As medias gerais observadas foram: 82,78 + 15,66%, 1,09 + 0,08, 1,47 + 0,21, 1,60 + 0,24, 1,47 + 0,21, 4,93 + 0,52, 18,20 + 1,01, 6,09 + 0,44, 18,78 + 1,07 e 82,40 + 15,81%, respectivamente. A produtividade global da ovelha pode ser obtida por meio do peso medio dos cordeiros ao desmame (PCD ). As correlacoes fenotipicas sinalizam que a melhoria no manejo reprodutivo das femeas pode incrementar o numero de cordeiros viaveis ao nascimento e, consequentemente, ao desmame, aumentando assim, a produtividade global da ovelha.