Carlos Antonio Lopes de Oliveira

Estimates of covariance components for hygienic behavior in Africanized honeybees (Apis mellifera)

Genetic and phenotypic parameters considering the genetic effect on hygienic behavior of queen and workers from 40 Africanized honeybees colonies were estimated separately. Maternal origin of queens was controlled whereas the paternal was unknown, and different groups of workers were considered in three seasons, October 2006, April 2007 and August 2007, but with the same queen. Colonies were 21 honey producers and 19 royal jelly producers. After the method of freezing capped brood, hygienic behavior was determined by the ratio between the number of dead capped brood removed at 24, 48 and 72 hours and the total number of capped brood at zero hour. Data was submitted to single and three traits analyses using Bayesian inference. Estimates of direct heritability at 24, 48 and 72 hours (0.10, 0.11 and 0.11) were identical to the motherly ones. Estimates by three trait analysis of direct heritability were 0.28, 0.15, 0.24, and of maternal heritability were 0.23, 0.29, 0.27, at 24, 48 and 72 hours, respectively. Correlations between maternal and genetic effects were 0.12, 0.09 and - 0.08 at, 24, 48 and 72 hours, respectively. Correlation between 24 and 48 hours was 0.49; between 24 and 72 hours, 0.40; and between 48 and 72 hours, 0.47. Moderate genetic correlations with the number of capped brood removed until 48 and 72 hours indicate that after the selection of a few generations, these traits can become an efficient criterion for selection in 24 hours.

Genotype × environment interaction for milk yield of Holstein cows among dairy production units in the state of Paraná

It was analyzed 117,082 complete lactation records adjusted for 305 days in milk yield (MY305) of 49,676 Holsteins cows from 308 herds distributed among seven dairy production units in the state of Parana, Brazil. The objective was to verify the genotype × environment interaction to MY305 of Holsteins cows between dairy production units in the state of Parana using the Bayesian inference. All animals were officially controlled by the Servico de Controle Leiteiro Mensal of Associacao Paranaense de Criadores de Bovinos da Raca Holandesa, between January/1992 and December/2003. The (co)variance components and genetic parameters were estimated using one and multiple-trait analysis, where MY305 of each dairy production unit was considered as a different variable. Means and standard deviations for MY305 (kg) for dairy production units of Castro, Carambei, Witmarsum, Arapoti, Sul, Norte and Oeste, were 8,414 ± 1,825; 8,481 ± 2,010; 7,636 ± 1,594; 7,850 ± 1,795; 8,617 ± 2,050; 7,401 ± 1,809 and 7,336 ± 2,456, respectively. The highest heritability estimated was obtained for the Oeste unit (0.39) while Carambei unit presented the lowest value (0.23). Genetic correlations were low (0.09 to 0.57) between dairy production units. Pearson and Spearman correlations were lower for the Oeste unit, when compared with other dairy production units, which ranged from 0.37 to 0.41, and from 0.37 to 0.49, respectively. These results show the presence of genotype × environment interaction between dairy production units in the state of Parana.

Effect of an homeopathic complex on fatty acids in muscle and performance of the Nile tilapia (Oreochromis niloticus)

BACKGROUND The homeopathic complex HomeoAqua Mega 3(®) was designed to stimulate fish liver function resulting in enhanced lipid metabolism and improved overall performance. The effect of the complex in fatty acid compounds in the muscle tissues and the performance of Nile tilapia (O. niloticus) were evaluated. METHODS A control diet with 40 mL of alcohol solution (30° Gay Lussac (GL) alcohol) per kg of feed and another diet with 40 mL/kg of the homeopathic complex were analysed in sex-reversed juvenile male Nile tilapia with mean initial weights of 89.54 g (±7.97) and 89.74 g (±8.83) and initial total mean lengths of 16.93 cm (±0.56) and 16.85 cm (±0.56) for the control and homeopathy-treated fish, respectively. Overall, 200 fish were distributed into 10 water tanks, with 20 specimens in each 600 L tank, they were kept for 63 days. Monitoring of the waters physical and chemical parameters was performed. Additionally, the percentage chemical composition and the composition of the muscle tissue fatty acids were determined, and fish performance was evaluated. RESULTS No significant differences (p > 0.05) were found between treatments with regard to the waters physical and chemical parameters, moisture, ashes, proteins of the Nile tilapia muscular tissue and mean rates of total weight and length of the animals in the final period of the assay. The total lipid (TL) rates of the tilapia muscle tissue were 1.133 ± 0.2% at the start (control and homeopathy) and 0.908 ± 0.14% (control) and 0.688 ± 0.14% (homeopathy) at the end of the experiment (p < 0.06). The sum total of the SFAs (saturated fatty acids) was 338.50 ± 0.15 at the start (control and homeopathy) and 271.49 ± 0.34 mg/g of the TLs for the control and 226.12 ± 0.77 mg/g of TL for the homeopathy at the end of the experiment (p < 0.05). The n-6/n-3 ratio was also lower for the homeopathy-treated fish (8.45 ± 0.40) compared with the control fish (9.60 ± 0.14), (p < 0.05) at the end of the 63-day period. CONCLUSION Nile tilapia juveniles that received the HomeoAqua Mega-3(®) in their diets had a decrease in the TL rates, mainly for the SFAs, and the n-6/n-3 ratio, compared with the control group, without any changes in the animal performance during the experimental period.

Ovopel and Carp Pituitary Extract as Spawning Inducers in Males of the Amazon Catfish Leiarius marmoratus (Gill, 1970)

The objective of this study was to evaluate Ovopel and carp pituitary extract as spawning inducers in the males of the Amazon catfish L. marmoratus. The following treatments, applied in a single dose, were studied: 0.2, 0.4 and 0.6 Ovopel pellet/kg live weight, and 2.5 mg carp pituitary extract/kg live weight. Each treatment was repeated four times. No significant difference in sperm volume, motility and vigor, time of motility, sperm count, or percentage of normal and abnormal spermatozoa was observed between the treatments. There was also no significant difference in terms of primary or secondary sperm defects, except for the secondary defect of loose heads, which was less frequent in the treatments using 0.4 and 0.6 Ovopel pellet/kg live weight. It was concluded that Ovopel could replace carp pituitary extract for induction spawning in the males of the Amazon catfishL. marmoratus.

Associação entre características de desempenho de tilápia-do-nilo ao longo do período de cultivo

The objective of this work was to estimate the structure and heritability of genetic correlations between the performance traits of Nile tilapia (Oreochromis niloticus) of the GIFT lineage during different stages of the production cycle. The Nile tilapias were grown in net cages. Daily total weight gain, live weight, and daily weight gain were measured in four periods, in approximately 30-day intervals. One-trait analyses were performed for all biometric measurements, and, in the two-trait analyses, measurements of the same traits were combined in pairs and to daily total weight gain. Estimated heritabilities ranged from 0.15 to 0.11 for live weight, from 0.16 to 0.09 for daily weight gain, and from 0.17 to 0.12 for daily total weight gain in the one-trait analyses. Estimated values of genetic correlation for live weight and daily weight gain, associated with daily total weight gain, ranged from 0.37 to 0.98 and from 0.74 to 0.88, respectively. The high genetic correlation estimated between live weight in intermediate biometric measurements and daily total weight gain suggests that selection for growth rate may be performed earlier.

Mechanically separated fillet and meat nuggets of Nile tilapia treated with homeopathic product

The homeopathic product Homeopatila 100 in the diet of Nile tilapia reduces stress during production and improves the well-being of fish. The objective of this study was to develop nuggets of tilapia fed with Homeopatila 100 and to assess their quality. Physical, chemical, microbiological and sensory analyses were performed on three formulations with 25, 50 and 75% mechanically separated meat (MSM) for each of the treatments. The nuggets with 75% MSM revealed a higher pH (5.89 ± 0.02), the tissue was softer (1.29 N ± 0.04), and they had a higher lipid value (15.96% ± 0.05). With 50 and 75%, the color (L) was darker (60.76% ± 0.91 and 60.03% ± 0.78), and there were lower protein amounts (15.54% ± 0.31 and 13.55% ± 0.35). Nuggets had an acceptable value of lipid oxidation (0.672 ± 0.007 mg MDA/kg). The microbiological analyses demonstrated that the product met the requirements of legislation. Nuggets with 25 and 50% MSM were deemed acceptable. There was no difference (p > 0.05) between the control treatment group and the Homeopatila 100 group for the analysis undertaken. The results indicated that the use of Homeopatila 100 in the diet of the Nile tilapia did not change the physical, chemical, microbiological and sensorial quality characteristics of the nuggets, ensuring consumer acceptability.

Estimativas de parâmetros genéticos para produção e composição do leite de vacas da raça Holandesa no estado do Paraná

The objectives of this study were to estimate heritabilities and genetic correlations for milk (MY), fat (FY) and protein (PY) yields and for percentages of fat (%F) and protein (%P) in milk of Holstein cows in Parana State. Data consisted of 117,082 lactation records for MY, FY and PY and 116,747 records for %F and %P from herds supervised by the Milk Recording Service of the Holstein Breeders Association of Parana from January 1992 to December 2003. Covariance components and genetic parameters were estimated by Bayesian inference using an animal model including the fixed effects of contemporary group, number of milking, linear and quadratic effects for calving age and the additive genetic, permanent environmental and residual random effects. Averages and respective standard deviations for MY, FY and PY (kg) were respectively 8,181.23 ± 1,903.51, 270.88 ± 67.58 and 249.01 ± 55.65 and for %F and %P they were 3.33 ± 0.45 and 3.06 0.19, respectively. Heritability estimates for MY, FY, PY, %G and %P obtained from single-trait analyses were 0.26, 0.28, 0.25, 0.60 and 0.58, respectively. They indicate that these traits may be improved by selection. Genetic correlation estimates between MY and FY, MY and PY, FY and PY, MY and %F, MY and %P and for %F and %P were 0.56, 0.89, 0.67, -0.42, -0.39 and 0.56, respectively. Selection for increasing MY will result in positive correlated genetic gains for kg of fat and protein but decrease their percentages in milk.

Genetic parameters and trends of morphometric traits of GIFT tilapia under selection for weight gain

The main factor considered in breeding programs for fish is growth, which can be assessed in terms of a gain in either weight or body measurements. This study was undertaken to evaluate the morphometric traits of GIFT strain tilapia (Oreochromis sp.) selected for weight gain. The data set used contained information on 6,650 animals. The genetic values of 8,590 animals in a relationship matrix of five generations were predicted. The following morphometric measurements were evaluated: standard length; body depth and body width. Body area and volume were also calculated. Bi-character analyses involving morphometric traits were used to estimate (co)variance components. Heritability, larval and fingerling common environmental effects were estimated for each trait, together with the genetic and phenotypic correlations between traits. Bayesian procedures were utilised by Gibbs chains, and the convergence of the chains was tested using the Heidelberger and Welch method. Genetic trends were estimated by segmented regression of the fish breeding values of the generations considered in this study. Estimates of heritability (0.28 a 0.31) had moderate to high magnitudes for all traits. Genetic correlations between traits were all above 0.8, and the genetic gains were satisfactory from the third generation onwards. From the estimates of the genetic parameters and genetic gain the morphometric traits evaluated have good potential for selection.

Growth curve by Gompertz nonlinear regression model in female and males in tambaqui (Colossoma macropomum)

Was evaluated the pattern of growth among females and males of tambaqui by Gompertz nonlinear regression model. Five traits of economic importance were measured on 145 animals during the three years, totaling 981 morphometric data analyzed. Different curves were adjusted between males and females for body weight, height and head length and only one curve was adjusted to the width and body length. The asymptotic weight (a) and relative growth rate to maturity (k) were different between sexes in animals with ± 5 kg; slaughter weight practiced by a specific niche market, very profitable. However, there was no difference between males and females up to ± 2 kg; slaughter weight established to supply the bigger consumer market. Females showed weight greater than males (± 280 g), which are more suitable for fish farming purposes defined for the niche market to larger animals. In general, males had lower maximum growth rate (8.66 g / day) than females (9.34 g / day), however, reached faster than females, 476 and 486 days growth rate, respectively. The height and length body are the traits that contributed most to the weight at 516 days (P <0.001).

Resposta à seleção de características de desempenho e morfométricas de tilápia-do-nilo ao longo do período de cultivo

The objective of this work was to study the selection response for performance and morphometrics traits in Nile tilapias (Oreochromis niloticus) in different measurements of farming. The one-trait analysis was performed for all traits studied and the two-traits analysis, were associated with the daily total weight gain in four measurement among performance and morphometrics traits in the fourth measurement. The heritabilities estimated for live weight, height and head length were higher in one-trait analysis than two-traits analysis. The genetic correlations, phenotypic, Pearson and Spearman among weight gain and all other measurements were higher along the farming. The indirect response was estimated at over 87% of direct response, which indicates that the selection may be performed early, using the daily total weight gain as selection criteria in intermediate measurement, without significant losses in genetic gain and contributing to reduction of cost production.