RESUMO

This study assessed the effects of combined supplementation with canthaxanthin (Cx) and 25-hydroxycholecalciferol (25-OH-D3) on incubation performance, fertility, and chick quality in European quail breeders. A total of 240 birds were distributed in a completely randomized design with 5 diets and 8 replicates. The animals were fed a basal diet containing 50 µg of vitamin D3 or the basal diet supplemented with 3 ppm Cx and 34.5 µg 25-OH-D3, 6 ppm Cx, and 69 µg 25-OH-D3, 9 ppm Cx and 103.5 µg 25-OH-D3, or 12 ppm Cx and 138 µg 25-OH-D3. Incubation performance was analyzed in 2 periods (32 and 38 wk). Breeders aged 32 wk produced eggs with higher hatchability (P = 0.024), hatchability of fertile eggs (P = 0.026) and lower initial plus mid embryonic mortality (P = 0.021), whereas 38-week-old breeders generated chicks with a higher length at hatching (P < 0.001) and lower final plus pipped embryonic mortality (P = 0.021). In both age groups, Cx + 25-OH-D3 levels had a quadratic effect on egg fertility (P < 0.001), hatchability of total (P < 0.001), and fertile eggs (P < 0.001). The fertility and the number of sperm cells in the perivitelline membrane was analyzed in two periods (26 and 40 wk). A quadratic effect of diet and days after mating on both parameters (P < 0.05) was observed. Eggs from supplementing breeders showed a high fertility (P < 0.001) and sperm cell counts (P < 0.001) for up to 7 and 3 d after mating, respectively, then the control group. Moreover, the supplementation of quail breeder diets with 6 ppm Cx + 69 µg 25-OH-D3 enhances sperm cell longevity in sperm storage tubules, hatchability of total and fertile eggs, fertility, and chick quality, especially in older quail's breeders and reduces embryonic mortality.

Assuntos

RESUMO

Abstract Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P 0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P 0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.

Resumo A seleção pode impactar a forma de crescimento, mudando o desempenho e os valores assintóticos. No entanto, existem poucas informações sobre o crescimento das famílias em programas de criação de peixes. O objetivo deste estudo foi examinar o desempenho e as curvas de crescimento de famílias de tilápia-do-Nilo AquaAmérica. Foram avaliadas 20 famílias AquaAmérica cultivadas em tanques-rede (13,5 m3) por 181 dias. O modelo de regressão não linear de Gompertz foi ajustado aos dados pelo método dos mínimos quadrados ponderados, tomando o inverso da variância do peso nas diferentes famílias e nas diferentes idades como variável de ponderação. O modelo foi ajustado para descrever o crescimento em peso e características morfométricas. Duas famílias apresentaram pesos maiores (P 0,05) em 133 dias (família AA10: 743,2 g; família AA16: 741,2 g) e 181 dias (família AA10: 1422,1 g; família AA16: 1393,4 g) de experimento em relação a outras famílias. Em ambos os períodos experimentais, os machos apresentaram maior peso, com maior contraste entre os sexos ocorrendo aos 181 dias. A análise das três famílias mais contrastantes (AA1, AA9 e AA14) mostrou que o valor assintótico para o peso foi maior (P 0,05) na família AA9 (3926,3 g) do que na família AA14 (3251,6 g), mas a taxa de crescimento específica e a idade no ponto de inflexão não diferiu significativamente entre as famílias. Em conclusão, duas das 20 famílias eram muito superiores; machos exibiram um maior crescimento, principalmente no período de 181 dias; e a curva de crescimento diferiu entre as famílias, principalmente quanto ao peso assintótico.

RESUMO

Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P<0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P<0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.(AU)

A seleção pode impactar a forma de crescimento, mudando o desempenho e os valores assintóticos. No entanto, existem poucas informações sobre o crescimento das famílias em programas de criação de peixes. O objetivo deste estudo foi examinar o desempenho e as curvas de crescimento de famílias de tilápia-do-Nilo AquaAmérica. Foram avaliadas 20 famílias AquaAmérica cultivadas em tanques-rede (13,5 m3) por 181 dias. O modelo de regressão não linear de Gompertz foi ajustado aos dados pelo método dos mínimos quadrados ponderados, tomando o inverso da variância do peso nas diferentes famílias e nas diferentes idades como variável de ponderação. O modelo foi ajustado para descrever o crescimento em peso e características morfométricas. Duas famílias apresentaram pesos maiores (P <0,05) em 133 dias (família AA10: 743,2 g; família AA16: 741,2 g) e 181 dias (família AA10: 1422,1 g; família AA16: 1393,4 g) de experimento em relação a outras famílias. Em ambos os períodos experimentais, os machos apresentaram maior peso, com maior contraste entre os sexos ocorrendo aos 181 dias. A análise das três famílias mais contrastantes (AA1, AA9 e AA14) mostrou que o valor assintótico para o peso foi maior (P <0,05) na família AA9 (3926,3 g) do que na família AA14 (3251,6 g), mas a taxa de crescimento específica e a idade no ponto de inflexão não diferiu significativamente entre as famílias. Em conclusão, duas das 20 famílias eram muito superiores; machos exibiram um maior crescimento, principalmente no período de 181 dias; e a curva de crescimento diferiu entre as famílias, principalmente quanto ao peso assintótico.(AU)

Assuntos

RESUMO

Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P<0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P<0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.

A seleção pode impactar a forma de crescimento, mudando o desempenho e os valores assintóticos. No entanto, existem poucas informações sobre o crescimento das famílias em programas de criação de peixes. O objetivo deste estudo foi examinar o desempenho e as curvas de crescimento de famílias de tilápia-do-Nilo AquaAmérica. Foram avaliadas 20 famílias AquaAmérica cultivadas em tanques-rede (13,5 m3) por 181 dias. O modelo de regressão não linear de Gompertz foi ajustado aos dados pelo método dos mínimos quadrados ponderados, tomando o inverso da variância do peso nas diferentes famílias e nas diferentes idades como variável de ponderação. O modelo foi ajustado para descrever o crescimento em peso e características morfométricas. Duas famílias apresentaram pesos maiores (P <0,05) em 133 dias (família AA10: 743,2 g; família AA16: 741,2 g) e 181 dias (família AA10: 1422,1 g; família AA16: 1393,4 g) de experimento em relação a outras famílias. Em ambos os períodos experimentais, os machos apresentaram maior peso, com maior contraste entre os sexos ocorrendo aos 181 dias. A análise das três famílias mais contrastantes (AA1, AA9 e AA14) mostrou que o valor assintótico para o peso foi maior (P <0,05) na família AA9 (3926,3 g) do que na família AA14 (3251,6 g), mas a taxa de crescimento específica e a idade no ponto de inflexão não diferiu significativamente entre as famílias. Em conclusão, duas das 20 famílias eram muito superiores; machos exibiram um maior crescimento, principalmente no período de 181 dias; e a curva de crescimento diferiu entre as famílias, principalmente quanto ao peso assintótico.

Assuntos

RESUMO

Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P<0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P<0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.

A seleção pode impactar a forma de crescimento, mudando o desempenho e os valores assintóticos. No entanto, existem poucas informações sobre o crescimento das famílias em programas de criação de peixes. O objetivo deste estudo foi examinar o desempenho e as curvas de crescimento de famílias de tilápia-do-Nilo AquaAmérica. Foram avaliadas 20 famílias AquaAmérica cultivadas em tanques-rede (13,5 m3) por 181 dias. O modelo de regressão não linear de Gompertz foi ajustado aos dados pelo método dos mínimos quadrados ponderados, tomando o inverso da variância do peso nas diferentes famílias e nas diferentes idades como variável de ponderação. O modelo foi ajustado para descrever o crescimento em peso e características morfométricas. Duas famílias apresentaram pesos maiores (P <0,05) em 133 dias (família AA10: 743,2 g; família AA16: 741,2 g) e 181 dias (família AA10: 1422,1 g; família AA16: 1393,4 g) de experimento em relação a outras famílias. Em ambos os períodos experimentais, os machos apresentaram maior peso, com maior contraste entre os sexos ocorrendo aos 181 dias. A análise das três famílias mais contrastantes (AA1, AA9 e AA14) mostrou que o valor assintótico para o peso foi maior (P <0,05) na família AA9 (3926,3 g) do que na família AA14 (3251,6 g), mas a taxa de crescimento específica e a idade no ponto de inflexão não diferiu significativamente entre as famílias. Em conclusão, duas das 20 famílias eram muito superiores; machos exibiram um maior crescimento, principalmente no período de 181 dias; e a curva de crescimento diferiu entre as famílias, principalmente quanto ao peso assintótico.

Assuntos

RESUMO

Selection can affect growth, changing performance and asymptotic values. However, there is little information about the growth of families in fish breeding programs. The aim of this study was to evaluate the performance and growth of families of Nile tilapia AquaAmérica. Twenty AquaAmérica families cultivated in a net cage (13.5 m3) for 181 days were evaluated. The nonlinear Gompertz regression model was fitted to the data by the weighted least squares method, taking the inverse of the variance of weight in different families and at different ages as the weighting variable. The model was adjusted to describe the growth in weight and morphometric characteristics. Two families showed highest (P<0.05) weights at both 133 days (family AA10: 743.2 g; family AA16: 741.2 g) and 181 days (family AA10: 1,422.1 g; family AA16: 1,393.4 g) of the experiment. In both experimental periods, the males showed a heavier weight, with the greatest contrast between the sexes occurring at 181 days. The analysis of the three most contrasting families (AA1, AA9 and AA14) showed that the asymptotic value for weight was higher (P<0.05) in family AA9 (3,926.3 g) than in family AA14 (3,251.6 g), but specific growth rate and age at the inflection point did not differ significantly between families. In conclusion, two of the 20 families were superior; males exhibited a greater growth, mainly in the period of 181 days; and the growth curve differed between the families, especially for asymptotic weight.

Assuntos

RESUMO

The aim of this study was to evaluate the reproductive traits of the non-inbred and inbred AquaAmérica, GIFT and AquaAmérica × GIFTgenetic groups. Six fish from each genetic group were used (2 females:1 male). Females were examined for the presence of eggs in their mouth at every four days, for 12 weeks. Reproduction occurred in all genetic groups (GIFT: 100%; non-inbred AquaAmérica and AquaAmérica ×GIFT: 75%; inbred AquaAmérica: 50%). Female weight, female standard length, total spawning weight, absolute fecundity, relative fecundity, spawn index and hatching rate did not differ significantly between the genetic groups. However, the non-inbred AquaAmérica variety showed lower values (P<0.05) for egg diameter (2.4mm) and egg weight (4.2mg) and higher values (P<0.05) for relative number of eggs (247.6 eggs/g of egg) than GIFT (egg diameter: 2.8mm; egg weight: 5.7mg; relative number of eggs: 175.4 eggs/g of egg) and AquaAmérica ×GIFT (egg diameter: 2.8mm; egg weight: 5.9mg; relative number of eggs: 168.8 eggs/g of egg). In conclusion, the non-inbred AquaAmérica variety produces smaller, lighter eggs but a higher relative number of eggs than the GIFT variety and the AquaAmérica ×GIFT cross; and inbreeding negatively affects spawning rate.(AU)

O objetivo deste estudo foi avaliar as características reprodutivas dos grupos genéticos AquaAmérica não endogâmicos e endogâmicos, GIFT e AquaAmérica × GIFT. Foram utilizados seis peixes de cada grupo genético (duas fêmeas:um macho). As fêmeas foram examinadas quanto à presença de ovos na boca a cada quatro dias, durante 12 semanas. A reprodução ocorreu em todos os grupos genéticos (GIFT: 100%; AquaAmérica não endogâmica e AquaAmérica × GIFT: 75%; AquaAmérica endogâmica: 50%). Peso e comprimento padrão de fêmea, peso total de desova, fecundidade absoluta, fecundidade relativa, índice de desova e taxa de eclosão não diferiram significativamente entre os grupos genéticos. Entretanto, a variedade não endogâmica da AquaAmérica apresentou valores mais baixos (P<0,05) para diâmetro do ovo (2,4mm) e peso do ovo (4,2mg) e maiores valores (P<0,05) para número relativo de ovos (247,6 ovos/g de ovo ) que GIFT (diâmetro do ovo: 2,8mm; peso do ovo: 5,7mg; número relativo de ovos: 175,4 ovos/g de ovo) e AquaAmérica × GIFT (diâmetro do ovo: 2,8mm; peso do ovo: 5,9mg; número relativo de ovos: 168,8 ovos/g de ovo). Em conclusão, a variedade AquaAmérica não endogâmica produz ovos menores e mais leves, mas um número relativo maior de ovos que a variedade GIFT e o cruzamento AquaAmérica × GIFT; a consanguinidade afeta negativamente a taxa de desova.(AU)

Assuntos

RESUMO

Although the tambaqui (Colossoma macropomum) is the most cultivated native fish species in Brazil, estimated breeding values for growth traits are rarely used for selection of superior individuals in commercial fingerling production. This study aimed to estimate the (co)variance components of growth traits. Body weight, length and width of 2500 tambaqui were determined at tagging and at 6 and 12 months after tagging in a commercial breeding programme in Brazil. Heritability estimates were low for traits measured at tagging (0.10 to 0.19) and moderate to high for traits measured at 6 and 12 months (0.23 to 0.81). Common full-sib effects were high at tagging (>73%), low at 6 months and negligible at 12 months. Positive genetic correlations were found among growth traits at 12 months (0.84 to 0.99) and between growth traits at 6 and 12 months (0.80 to 0.92). These results show that animal selection can be performed at 6 months after tagging. Expected genetic gains for growth traits ranged from 8% to 31%. A simulation of the sex ratio was performed, as individuals did not reach sexual maturity during the experimental period. Because of the sexual dimorphism, more accurate heritability estimates were obtained when considering the female proportion to be 90% in the high-weight group. The findings indicate that it is possible to obtain considerable genetic gains in growth by selecting for growth traits. The development of a tool to determine the sex of animals at early stages can improve the response to selection in tambaqui.

Assuntos

RESUMO

BACKGROUND: Over the last ten years, Brazilian fish farming has become more focused, resulting in the development of genetic improvement programmes (GIP) for two South American species Colossoma macropomum (tambaqui) and Pseudoplatystoma reticulatum (cachara). OBJECTIVE: To describe the action plan used for setting up the GIP and to detail the germplasm bank composition. MATERIALS AND METHODS: Semen of both species was collected, frozen and transported between locations in Brazil. To start the programme, full and half-sib families of both species were established from 120 males and 60 females. RESULTS: New species-specific protocols for semen cryopreservation s were established of value to commercial application in fish farming. CONCLUSION: Germplasm banking has enabled the exchange of biological material and reduced the overall GIP costs. Germplasm banking can be very important to the dissemination of the selected genetic material of these species among fish farmers.

Assuntos

RESUMO

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.(AU)

Assuntos

RESUMO

The influence of age (85, 140, and 270 days) of European quails breeders on the egg quality and hatching, fertility and progeny performance was evaluated. The experimental design was completely randomized in a 3x3 factorial arrangement (females' age x males' age), with ten replicates and six birds per experimental unit (four females and two males). Egg production and quality were determined during 3 periods of 14 days and incubation parameters were evaluated in eggs obtained in five consecutive days. The live performance of the progenies was analyzed until 35 days. There was no effect of male age or any interaction between the age of males and females for the evaluated variable. The female's age influenced egg production, egg weight and chick weight, with better results obtained for 140-d-old breeders. The age of females reduced the hatchability, increased the late mortality in incubated eggs, and had no effect on fertility, total embryo mortality or eggshell structure, when analyzed by electron microscopy. The number of sperm trapped in the outer perivitelline layer (sptz/mm²) was determined in 10 fertile eggs per experimental unit. Young females fertilized by young males (80 days) had reduced sptz/mm². Progeny live performance was not affected by breeder's age. Breeders with 270 days retain fertility; however, their egg production, weight and hatchability of fertilized eggs is reduced. In conclusion, European quail breeders with 140 days of age have better egg quality, hatching and breeding results.

Assuntos

RESUMO

1. Two experiments were performed to study the supplementation of valine, isoleucine, arginine and glycine (Val, Ile, Arg, Gly) in low-protein diets for broiler chickens in the starter (1-21 d; Exp. 1) and grower (22-42 d; Exp. 2) phases. 2. A low-crude protein (CP) diet was formulated to meet the requirements of all amino acids (AA) supplied by the control diet except for Val, Ile, Arg and Gly. The other experimental diets were obtained by the isolated or combined supplementation of the studied AA in the low-CP diet. 3. Growth, serum parameters and litter characteristics were taken in both of the experiments. Carcass measurements were taken in Experiment 2. 4. In the starter and grower phases, low-CP diets without supplementation resulted in birds with a poorer weight gain and feed conversion than those of the birds that received the control diet. 5. In the starter phase, individual supplementation with Val and Gly, but not Ile and Arg, restored the weight gain of the birds, while diets with the addition of Val + Gly, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly restored their feed conversion. 6. In the grower phase, weight gain was re-established at the same rate as the control diet for the diets supplemented with Val + Ile, Val + Ile + Arg, Val + Ile + Gly and Val + Ile + Arg + Gly. However, the feed conversion was restored only in birds that received the diet supplemented with all studied AA. 7. The supplementation of Val and Gly in low-CP diets was sufficient to avoid adverse effects in the performance and serum parameters of broilers in the starter phase. However, birds in the grower phase required the combined supplementation of Val, Ile, Arg and Gly, to prevent compromised performance.

Assuntos

RESUMO

Estudou-se a resposta à seleção para características de desempenho e morfométricas de tilápia-do-nilo (Oreochromis niloticus) em diferentes períodos de cultivo. Realizaram-se análises unicaracter para todas as características estudadas e as análises bicaracter, associando-se o ganho de peso diário, mensurado em quatro biometrias, com as características morfométricas obtidas ao final do período de cultivo. As herdabilidades estimadas para peso vivo, altura e comprimento de cabeça foram mais altas em análises unicaracter do que as estimadas em análises bicaracter. Os valores de correlações genéticas, fenotípicas, Pearson e Spearman foram positivas e crescentes com o avanço da idade dos animais. As respostas à seleção indireta foram 87% mais altas que as obtidas pela resposta direta, indicando que a seleção pode ser realizada precocemente, utilizando como critério de seleção o ganho de peso diário total medido em biometrias intermediárias, sem apresentar perdas expressivas no ganho genético.

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.

Assuntos

RESUMO

Estudou-se a resposta à seleção para características de desempenho e morfométricas de tilápia-do-nilo (Oreochromis niloticus) em diferentes períodos de cultivo. Realizaram-se análises unicaracter para todas as características estudadas e as análises bicaracter, associando-se o ganho de peso diário, mensurado em quatro biometrias, com as características morfométricas obtidas ao final do período de cultivo. As herdabilidades estimadas para peso vivo, altura e comprimento de cabeça foram mais altas em análises unicaracter do que as estimadas em análises bicaracter. Os valores de correlações genéticas, fenotípicas, Pearson e Spearman foram positivas e crescentes com o avanço da idade dos animais. As respostas à seleção indireta foram 87% mais altas que as obtidas pela resposta direta, indicando que a seleção pode ser realizada precocemente, utilizando como critério de seleção o ganho de peso diário total medido em biometrias intermediárias, sem apresentar perdas expressivas no ganho genético.(AU)

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.(AU)

Assuntos

RESUMO

A study was conducted to evaluate Gly requirements in low-CP diets with different levels of digestible (dig) Thr, and their effects on performance, intestinal mucosal development, and nutrient utilization of broiler chickens from 21 to 35 d age. A total of 240 twenty-one-day-old Cobb-Vantress male broiler chickens were distributed in a completely randomized 4 × 2 factorial arrangement for a total of 8 treatments with 5 replicates of 6 birds each. The treatments consisted of 4 levels of Gly+Ser (1.47, 1.57, 1.67, or 1.77%) and 2 levels of dig Thr (0.70 or 0.77%, corresponding to 100 or 110% of Thr requirements, respectively). Common diets were fed to broilers until 20 d of age. At d 35, an interaction (P ≤ 0.01) was observed between the Gly+Ser and dig Thr levels for G:F. Glycine supplementation resulted in a linear increase (P < 0.05) in BW gain, G:F, intestinal mucin secretion, apparent digestibility of fat, and AME values of the experimental diets. Threonine levels greater than the levels required (0.77%) improved (P < 0.05) G:F and increased (P < 0.05) intestinal mucin secretion. However, intestinal morphometry and the number of goblet cells in the duodenum, jejunum, and ileum were not affected by the treatments. The dietary Gly+Ser level necessary to optimize G:F in low-CP diets containing 0.77% Thr for broiler chickens during growth was estimated to be 1.54%; however, this requirement may be greater than 1.77% in diets with 0.70% Thr. Supplemental Gly may be essential to support maximum performance for broiler chickens from 21 to 35 d of age when they are fed diets based exclusively on vegetable ingredients and with low protein levels. Glycine can directly or indirectly influence the proper function of the intestinal mucosa and improve dietary energy utilization.

Assuntos

RESUMO

The influence of the age of Japanese breeder quails was studied by the analysis of fertility and sperm-egg interactions on the perivitelline layer of fertile eggs along the reproductive lifetime. Thus, 10 quail couples were observed every 30 d from 70 to 430 d. In each analyzed period, the males remained with the females for 24 h, and the oviposited eggs were analyzed up to the laying of 3 consecutive infertile eggs. The eggs were examined, and their fertility and the number of sperm (sptz)adhering to the outer perivitelline layer over the germinal disc were determined and expressed as sptz/mm(2). The age of the males had no effect (P > 0.05) on the maintenance of fertility after mating and on the number of sperm in the fertile eggs. The age of the females influenced (P < 0.05) the sptz/mm(2), which decreased 8 d after copulation. The probability of the eggs being fertile diminished with the age of the females combined with the time after copulation, and this probability became lower than 20% after 9 d. The number of sperm trapped in the perivitelline layer overlaying the germinal disc was reduced as a function of the age of the females and the time after copulation. From 3 sptz/mm(2) and on, the quails presented a 95% probability of having their eggs fertilized in females up to 55 wk of age. For breeder Japanese quails, the age of the females represents an important factor for fertility maintenance.

Assuntos

RESUMO

Cryopreservation of fish gametes has been studied extensively in the last few decades, but the successful cryopreservation of fish embryos remains elusive. However, recent studies using short-term chilling techniques have shown that it is possible to store embryos at low temperatures with no significant loss in viability. Information on cryopreservation of Neotropical freshwater fish embryos has so far been very limited in the literature. In the present study, chilling protocols for storage of pacu embryos at -8°C for up to 24 h were studied using different concentrations of sucrose in methanol. Embryos tolerated the subzero temperature for up to 6 h with no adverse effects (P > 0.05). After 12 h chilling, hatching rate of 64.0 +/- 3.5 percent was recorded. Low temperature storage of pacu embryos by chilling is detailed here for the first time. Further studies are needed to extend the storage time and to improve the hatching rate.

Assuntos

RESUMO

The histomorphometric and proliferative characteristics of the collared peccary (Tayassu tajacu) placenta and uterus were analyzed. The material was examined by standard histological techniques and histochemistry (PAS, Perls and Alcian Blue pH 0.5 and 2.5%) and the cellular proliferation by AgNORs and flow cytometry. All the analyzed morphometric variables differed between pregnant and non-pregnant uteri in the luteal phase using the Dunnet test. Height and gland diameter of uterine glands increased linearly during pregnancy, with an intense positive PAS and Perls reaction in all stages. The cells with more than seven AgNORs per nuclei and the cells in the G2M cell cycle phase in the maternal tissue also increased after 70 days of pregnancy. The uteroplacental ridges had a linear increase in size with two distinct areas, base and top, with uterine epithelium and trophoblastic cells changing their morphology following the placental ridge development. Flow cytometry analysis showed the percentage of cells in each cell cycle phase with a quadratic behavior for stages G2/M in the maternal tissue, suggesting an increase in proliferative capacity of maternal tissue after 65 days of pregnancy. The same quadratic effect was observed in the G0/G1 phase in both maternal and fetal tissues. Cells in apoptosis showed cubic behavior in both tissues. The morphometric and cellular dynamic aspects observed in this study have not been previously described and they extend our knowledge of functions relating to maternal-fetal dynamics in this species.

Assuntos

RESUMO

The equivalent of US$75 million is spent each year in Brazil to control Brevipalpus phoenicis, a mite vector of Citrus leprosis virus C (CiLV-C). In this study, we investigated the possibility that hedgerows and windbreaks normally found in citrus orchards could host CiLV-C. Mites confined by an adhesive barrier were reared on sweet orange fruit with leprosis symptoms then were transferred to leaves of Hibiscus rosa-sinensis, Malvaviscus arboreus, Grevilea robusta, Bixa orellana, and Citrus sinensis. Ninety days post infestation, the descendant mites were transferred to Pera sweet orange plants to verify the transmissibility of the virus back to citrus. Nonviruliferous mites which had no feeding access to diseased tissue were used as controls. Local chlorotic or necrotic spots and ringspots, symptoms of leprosis disease, appeared in most plants tested. Results generated by reversetranscription polymerase chain reaction with primers specific for CiLV-C and by electron microscope analyses confirmed the susceptibility of these plants to CiLV-C.

RESUMO

The objective of this study was to evaluate various pesticides used in citrus crops in regard to their toxicity to Brevipalpus phoenicis and Neoseiulus californicus, a potential predator of phytophagous mites in the crop. Bioassays were conducted using orange-tree leaf discs for N. californicus and fruits for B. phoenicis. A total of 35 adult females of the predator mite were used, along with 50 adult females of the phytophagous mites. Tests were carried out with 13 chemicals at concentrations recommended for the control of leprosis mites. The applications were made using a Potter tower, with 4 replications for each treatment. Assessments of the number of live and dead mites were observed 72 hours after application. Bioassays with spirodiclofen and etoxazole were performed on eggs of mites. Chlorfenapyr and pyridaben proved harmful to N. californicus, causing mortalities of 88 and 99% respectively. Abamectin caused mortality of 62%, considered high when compared to dinocap (2%), propargite (4.2%), sulfur (5%), fenpropathrin (12.4%) and acrinathrin (22%). Cyflumetofen oxide, fenbutatin and deltamethrin were harmless to N. californicus. Spirodiclofen did not cause egg mortality or larvae mortality in N. californicus, however etoxazole caused 100% mortality in larvae of the predator on contact with the residue of the product. For B. phoenicis, abamectin, chlorfenapyr, dinocap, cyflumetofen, fenbutatin oxide, pyridaben and propargite caused 100% mortality. Fenpropathrin (95%), acrinathrin (87%) and sulfur (76%) were less effective. Deltamethrin was not effective in controlling leprosis mites. Etoxazole and spirodiclofen caused 100% egg mortality for B. phoenicis.

O objetivo deste trabalho foi avaliar a toxicidade dos principais agroquímicos utilizados em citros em Brevipalpus phoenicis e Neoseiulus californicus, potencial predador de ácaros fitófagos na cultura. Os bioensaios foram realizados utilizando discos de folhas de laranjeira para N. californicus e frutos para B. phoenicis. Foram utilizadas 35 fêmeas adultas do ácaro predador e 50 fêmeas adultas do ácaro fitófago. Utilizaram-se 13 agroquímicos nas concentrações recomendadas para o controle do ácaro da leprose. As aplicações foram feitas por meio de torre de Potter, sendo realizadas quatro repetições para cada tratamento. As avaliações do número de ácaros vivos e mortos foram observadas 72 horas após a aplicação. Os bioensaios com espirodiclofeno e etoxazol foram realizados em ovos dos acarinos. Clorfenapir, e piridabem mostraram-se nocivos a N. californicus, causando mortalidades de 88,6 e 99%, respectivamente. Abamectina causou mortalidade de 62,1%, considerada elevada ao se comparar ao dinocape (2%), propargito (4,2%), enxofre (5%), fempropatrina (12,4%) e acrinatrina (22%). Cyflumetofen, óxido de fembutatina e deltametrina foram inócuos ao N. californicus. Espirodiclofeno não provocou inviabilidade de ovos e mortalidade nas larvas de N. californicus, contudo, etoxazole provocou 100% de mortalidade nas larvas do predador ao entrarem em contato como o resíduo do produto. Para B. phoenicis, abamectina, clorfenapir, dinocape, cyflumetofen, óxido de fembutatina, piridabem e propargito provocaram 100% de mortalidade. Fempropatrina (95%), acrinatrina (87%) e enxofre (76%) mostraram-se menos efetivos. O deltametrina não foi eficiente no controle do ácaro da leprose. Etoxazol e espirodiclofeno causaram inviabilidade em 100% dos ovos de B. phoenicis.