Nelson José Laurino Dionello

Genotype by environment interaction characterization and model comparison for post weaning gain adjustment of Devon cattle via reaction norms

The objectives of this study were to verify the presence of the genotype by environment interaction and to compare different models to fit Devon cattle post weaning gain standardized to 345 days, via reaction norms obtained by random regression. Data from 14,973 calves collected by the beef cattle improvement program from 1980 to 2005 were used. The INTERGEN program was used for data analysis. First, a standard animal model (AM) was fitted to serve as comparison basis and to provide estimates of the environmental gradient, based on contemporary group (CG) deviations and, next, the reaction norms hierarchical models with homogeneous (RNHM) and heterogeneous (RNHMH) residual variances were run. In these last two models, fixed effects of age of dam and age of calf at yearling and random contemporary group and genetic effects (level and slope of animals reaction norms) were included. For the RNHM estimates of residual variance, reaction norm level and slope additive genetic variances and their genetic correlation were, respectively, 272.02 ± 8.51; 340.38 ± 17.11; 0.119 ± 0.006 and 0.83 ± 0.01, while for the RNHHM were 401.96 ± 11.91; 177.86 ± 16.60; 0.076 ± 0.006 and 0.72 ± 0.02, respectively. The heritability asa well as the genetic variance increased on the environmental gradient, characterizing that there is genotype by environment interaction. Based on the Deviance Information Criterion, Bayes Factors and Pseudo Bayes Factors, the NRHM provided superior fit to the data, being the most appropriate model to consider the genotype by environmental interaction of this population.

Exigência de proteína bruta e energia metabolizável para codornas de corte EV1

The crude protein and metabolizable energy requirement for weight gain, body weight, feed consumption, and feed consumption : weight gain ratio during three periods (7- 21; 21-42 and 7-42days of age) of the growing phase of meat type quail (EV1) were estimated in a completely randomized design, with eight treatments and six replicates of 12 quails per experimental unit. The treatments consisted in a factorial combination 4 x 2 (22, 24, 26 e 28% PB x 2900 e 3100kcal de EM/kg). Body weight and weight gain from 7 to 21 days of age were quadratic affected by protein level of diets. Feed consumption linearly decreased with the increasing of diet energetic level. Feed: weight gain ratio increased linearly with crude protein level and decreased with metabolizable energy level of diets. Body weight at 42 days of age was not affected by metabolizable energy and crude protein levels of the diets. From 7 to 42 days of age the protein and metabolizable energy of diets did not affect quail body weight and feed: weight gain ratio. Quails fed on 2900kcal of EM/kg of diet showed higher feed consumption in comparison to quails fed on 3100kcal of EM/kg diets. Maximum performance of EV1 quails are reached in diets with 27% of crude protein (CP) and 2900kcal of ME/kg of diet in the initial period (7-21 days of age) and 22% of CP and 2900kcal of ME/kg of diet in the whole period (7-42 days of age).

Exigência de metionina + cistina total para codornas de corte em crescimento

Total methyonine + cystine requirements during the initial (7-21 days of age) and final period ( 22-42 days of age) of the growing phase were estimated for meat type quails in a completely randomized experimental design with six treatments, five replicates and 13 quails per experimental unit. Weight gain (g), body weight (g), feed consumption (g) and feed : weight gain ratio (g/g) were evaluated for quails fed on .73, .79, .85, .91, .97 and 1.03% methyonine + cystine diets. Meat type quails fed .95% and .73% methyonine + cystine diets during the initial (7-21days of age) and final period (22-42 days of age) of the growing phase show maximum weight gain.

Exigências em proteína bruta para codornas de corte EV1 em crescimento

Crude protein requirements for EV1 meat type quails were estimated using 288 quails of both sexes in a completely randomized experimental design with six crude protein levels (23, 25, 27, 29, 31 and 32%) and four replicates of 12 quails per experimental unit. The following traits were recorded in each experimental period (from hatch to 21 days and from hatch to 42 days of age): body weight (g), weight gain (g), feed intake (g), and feed:weight gain ratio. From hatch to 21 days of age quadratic effects of crude protein levels on live body weight, weight gain and feed intake were observed and maximum performances were estimated for quails fed 30.2; 30.1; and 30.8% crude protein diets, respectively. Quadratic effect of protein level on body weight at 42 days of age was significant and quails fed 30.2% crude protein diets showed maximum performance. Quails fed 29.5 and 32.6% crude protein diets from hatch to 42 days showed maximum weight gain and feed intake while feed:weight gain ratio was negative and linearly related to crude protein level of diet. Crude protein requirement for weight gain (male and female), from hatch to 21 days of age is estimated in 30.1% and from hatch to 42 days of age in 29.5%.

Exigências de proteína bruta e energia metabolizável em codornas de corte durante a fase de crescimento

Crude protein (CP) and metabolizable energy (ME) levels during five experimental periods of seven days each of the growing phase for European quail were determined. A total of 384 quails of both sexes were used in a completely randomized design in a 2×4 (energy and crude protein) factorial treatment with six replications of eight quails each. The metabolizable energy levels were 2900 and 3000kcal of ME/kg of diet and the crude protein levels were 22, 24, 26 and 28%. The analyzed variables were weight gain (g), accumulated weight (g), feed consumption (g), feed:gain ratio (g/g). Performance responses were evaluated by linear and quadratic regression of the traits on crude protein levels. Higher weight gains from the following protein and metabolizable energy levels combinations: 28.0% PB and 2900 kcal EM/kg (first period); 25.7% CP and 3100kcal ME/kg (second period); 27.9% and 2900kcal ME/kg (third period); 24.8% PB and 3100kcal/kg (fourth period) and 23.1% CP and 2900kcal/kg (fifth period).

Breeding objectives and economic values for traits of low input family-based beef cattle production system in the State of Rio Grande do Sul

The objectives of this study were to define breeding objectives and derive economic weights for production traits in family-based beef cattle systems, assess the sensitivity of these weights to changes in market and husbandry indicators and estimate the expected genetic changes in the selection criteria proposed. Based on data from the production systems, farms revenues and expenses, obtained from interviews and meetings with producers, a bioeconomic model was derived, relating biological traits of animals with the financial result of the production system based on calf-crop, selling male calves and culling cows for finishing. Traits considered in the model as breeding goals were weaning rate, weaning weight and cow weight. The economic weights, obtained by the partial derivative of the bioeconomic model with respect to the trait in question, assessed on the average value of the remaining traits, were R

Estimativas de parâmetros e tendências genéticas para algumas características de importância econômica em linhagem paterna de frangos de corte sob seleção

73.21% for weaning rate, R

Desempenho de codornas de corte EV1 alimentadas com diferentes níveis de lisina na dieta

17.07/kg for weaning weight and R

Estimação de parâmetros genéticos utilizando-se a produção de leite no dia do controle em primeiras lactações de vacas da raça Jersey

4.75/kg for cow weight. An index for joint selection of these three criteria would allocate 89.5% of importance to weaning rate, 6.9% for weaning weight and 3.6% for cow weight. In this way, for every R

Uso de redes neurais artificais na predição de valores genéticos para peso aos 205 dias em bovinos da raça Tabapuã

100.00 of genetic gain in this index, there would be an increase of 1.4% in weaning rate, but with reduction of 0.004 kg in weaning weight and 0.665 kg in cow weight due to negative genetic association between these traits. The proposed index and the relative importance identified for the economic traits can guide the selection decisions of smallholders, both in the choice of their animals and in the acquisition of bulls, cumulatively increasing the productivity of their herds.