CURVA DE CRESCIMENTO DE CODORNAS DE CORTE POR MEIO DE MODELOS DE REGRESSÃO NÃO-LINEARES

Objetivou-se avaliar diferentes modelos de regressão não-linear para descrição da curva de crescimento de codornas de corte, machos e fêmeas. Foram utilizados 30.410 registros de peso corporais, originalmente mensurados semanalmente de codornas de corte, do 1º ao 42º dia de idade, participantes do Programa de Melhoramento Genético da Universidade Federal dos Vales do Jequitinhonha e Mucuri. O peso corporal das aves foram agrupados em machos ou fêmeas e submetidos aos modelos de regressão não-lineares de Brody, Gompertz, Logístico, MMF (Morgan-Mercer-Flodin), Richards, e van Bertalanffy. Os modelos foram avaliados quanto ao ajuste das curvas de crescimento preditas em relação aos valores observados. Não se obteve convergência com o modelo Brody. Os demais modelos apresentaram bons valores de IA (índice assintótico), sendo o modelo MMF o mais adequado para predizer o peso dos machos com IA 33,59, enquanto que o modelo Gompertz com IA 36,100, apresentou-se como mais adequados para predizer o peso das fêmeas. Portanto, no presente estudo os modelos de Gompertz e MMF apresentaram melhor ajuste aos dados para machos e para fêmeas; com R2aj acima de 0,92. Os resultados indicam a utilização de ambos modelos para descrever o crescimento dos animais, independente do sexo.

SIMULAÇÃO DA EVOLUÇÃO DO REBANHO CONSIDERANDO POTENCIAL DE CRESCIMENTO E HABILIDADE MATERNA COMO CRITÉRIOS DE SELEÇÃO EM BOVINOS DE CORTE

The aim of this study was to verify, by simulation, the result of twenty years of selection for maternal ability and growth in productivity in a selection Nellore herd raised in the savannah biome. Data were reported to the DECI (Decision Evaluator for the Industry Cattle) simulation model reflecting the real situation of registered purebred Nellore herd of the Embrapa Cerrados (Nellore BRGN). The simulation model DECI was effective to predict the response to genetic selection for high growth rate and maternal ability, signaling direct improvement in the response of 5.5% in milk yield causing an increased pre-weaning weight gain (9.3%), and the weaning weight of calf (10%). However, were found increased, the average maturity weight (465 kg), the weight of the cow in the moment of the partum (476 kg), and the weaning weight of the cow (520 kg). These results indicate higher costs for herd maintenance due to the increase in body size and together, the requirements for maintenance of these animals. The increased milk yield of mothers caused a decrease in body condition of delivery (9.3%) and weaning (3.9%). Under the simulated conditions, the adoption of the management techniques resulted from the simulation may increase the productive rates of the Nellore Embrapa Cerrados herd.O objetivo deste trabalho foi verificar, por meio de simulação, o resultado de vinte anos de seleção para crescimento e habilidade materna na produtividade de um rebanho Nelore puro de origem (PO), marca BRGN (Nelore BRGN), criado no bioma Cerrado. O modelo de simulação utilizado foi o DECI (Decision Evaluator for the Industry Cattle), ao qual foram informados os dados de forma a refletir, o mais fielmente possível, o sistema de produção do rebanho Nelore da Embrapa Cerrados. O modelo de simulação DECI foi eficaz em predizer a resposta à seleção genética para habilidade materna que obteve como resposta direta o aumento de 5,5% na produção de leite, proporcionando maior ganho de peso pré-desmama (9,3%) e aumento no peso do bezerro a desmama (10%). No entanto, foram verificadas maiores médias para peso à maturidade (465 kg), peso da vaca ao parto (476 kg), e peso da vaca na desmama (520 kg), indicando maiores custos de manutenção do rebanho devido ao aumento no tamanho corporal e nas exigências de mantença desses animais. A maior produção de leite das mães acarretou diminuição na condição corporal ao parto (9,3%) e à desmama (3,9%). Sob as condições estudadas, a adoção das técnicas de manejo resultantes da simulação poderá aumentar as taxas produtivas do rebanho Nelore da Embrapa Cerrados

Associations between reproductive and carcass traits in Nellore

The objective of this study was to estimate the genetic parameters and (co)variance of Nellore animals and to characterize the associations between these characteristics for the following carcass traits: weight (W), longissimus muscle area (LMA), rump fat thickness (RF) and fat thickness between the 12th and 13th ribs obtained by ultrasound (BF); also, the following reproductive traits: age at first calving (AFC), first calving interval (FCI), scrotal circumference at 450 and 550 days of age (SC450 and SC550). The genetic parameters were estimated by a single-trait and two traits animal model using Bayesian inference. The model used for all of the features included the genetic random effect and age as covariate assuming a quadratic effect. Additionally, sex, month and year of birth and management of creation and environmental effects identified were included for the carcass traits. For AFC, FCI and SC450 and SC550, we considered only the month and year of birth. The heritability estimates for all of the traits were higher in the two traits analysis, except for AFC and FCI, which showed 0.75 and 0.29, respectively, similar values in the single trait analysis. The two traits analyses resulted in heritability estimates for a posteriori for the features W, LMA, BF, RF, SC450 and SC550 of 0.49, 0.66, 0.74, 0.68 0.66 and 0.74, respectively, suggesting the possibility of genetic gains during a short period of time. The genetic correlations between AFC and carcass traits measured by ultrasound were close to zero. A similar trend was found for AFC, SC450 and SC550 days, indicating that the selection for these traits does not promote changes in AFC. High genetic correlations (0.92, 0.93 and 0.94) were observed between the characteristics LMA and W, BF and RF, and SC450 and SC550, respectively.</p

Núcleos de Ensino da Unesp: artigos 2007

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

NEOTROPICAL CARNIVORES: a data set on carnivore distribution in the Neotropics

Mammalian carnivores are considered a key group in maintaining ecological health and can indicate potential ecological integrity in landscapes where they occur. Carnivores also hold high conservation value and their habitat requirements can guide management and conservation plans. The order Carnivora has 84 species from 8 families in the Neotropical region: Canidae; Felidae; Mephitidae; Mustelidae; Otariidae; Phocidae; Procyonidae; and Ursidae. Herein, we include published and unpublished data on native terrestrial Neotropical carnivores (Canidae; Felidae; Mephitidae; Mustelidae; Procyonidae; and Ursidae). NEOTROPICAL CARNIVORES is a publicly available data set that includes 99,605 data entries from 35,511 unique georeferenced coordinates. Detection/non-detection and quantitative data were obtained from 1818 to 2018 by researchers, governmental agencies, non-governmental organizations, and private consultants. Data were collected using several methods including camera trapping, museum collections, roadkill, line transect, and opportunistic records. Literature (peer-reviewed and grey literature) from Portuguese, Spanish and English were incorporated in this compilation. Most of the data set consists of detection data entries (n = 79,343; 79.7%) but also includes non-detection data (n = 20,262; 20.3%). Of those, 43.3% also include count data (n = 43,151). The information available in NEOTROPICAL CARNIVORES will contribute to macroecological, ecological, and conservation questions in multiple spatio-temporal perspectives. As carnivores play key roles in trophic interactions, a better understanding of their distribution and habitat requirements are essential to establish conservation management plans and safeguard the future ecological health of Neotropical ecosystems. Our data paper, combined with other large-scale data sets, has great potential to clarify species distribution and related ecological processes within the Neotropics. There are no copyright restrictions and no restriction for using data from this data paper, as long as the data paper is cited as the source of the information used. We also request that users inform us of how they intend to use the data

Núcleos de Ensino da Unesp: artigos 2008

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq