On the reproductive strategies post-colony foundation: major termite pest species with distinct ecological habits differ in their oviposition dynamics.

Termite colony foundation precedes the incipient stage, when the first oviposition cycle takes place, followed by months of reproductive inactivity. The royal couple is supposed to cease oviposition during this period, investing energy to care for the first brood. When a suitable number of alloparents differentiate, egg-laying resumes. Here we followed oviposition dynamics, embryo development and queen/king body changes in laboratory colonies of the major pest species Coptotermes gestroi (Rhinotermitidae) and Cryptotermes brevis (Kalotermitidae) during 9 months. We show that they differ in these oviposition dynamics, as C. gestroi queens displayed an uninterrupted oviposition whereas C. brevis laid a cohort of eggs and ceased oviposition during a 3-month period (lag phase). C. gestroi oviposition dynamic was remarkable and suggests that occurrence of progeny was not a limiting factor, thus queens and kings were able to concomitantly invest energy in reproduction and parental care. These findings contrast those reported for rhinotermitids from temperate areas, and we discuss the likely reasons for such a condition, including endogenous rhythms, avoidance of a high mortality rate of the first progeny and adaptation to the weather conditions of the Neotropical region. Oviposition dynamic in C. brevis resembled those of several termite species, in which the royal couple cease reproduction to care for the first brood. Rearing conditions did not influence oviposition dynamics (egg-laying cycle followed by a lag phase), thus our results on the oviposition of C. gestroi and C. brevis correspond to different reproductive strategies post-foundation adopted by these pest species.

Vegetable lipid sources in the diet of japanese quails in the rearing phase and effects on the initial phase of production / Fontes lipídicas vegetais na alimentação de codornas japonesas em fase de recria e sua repercussão na fase inicial de produção

This study aims to evaluate the residual effect of different lipid sources in the diet of Japanese quails (Coturnix japonica) in the rearing phase on the performance and egg quality in the initial phase of egg-laying. In the first stage, 400 Japanese quails aged 21 days were used, being distributed in a completely randomized experimental design, with five treatments and ten replicates of eight birds/replicate Treatments consisted of basal ration (BR) with 2.5% soybean oil; BR with 2.5% corn oil; BR with 2.5% cottonseed oil; BR with 2.5% sunflower oil; and BR with 2.5% canola oil.At 42 days, maintaining the initial design, all quails received a basal ration with soybean oil, in order to evaluate the residual effect of the previous phase on the performance and egg quality in the initial phase of egg-laying (43 - 84 days). The different lipid sources did not affect the performance of quails in the initial phase of production. For egg quality, yolk height, yolk diameter, yolk index, gravity, and Haugh unit (HU) showed better results in the treatment using sunflower oil. There was a residual effect of the use of lipid sources of vegetable origin in the rearing phase diet of Japanese quails on egg quality traits. Lipid sources from soybean, corn, cottonseed, canola, and sunflower seeds can be used as energy sources in the rearing diet of egg-laying quails for not being harmful to their initial performance. The longevity in egg production of quails fed with different lipid sources in the rearing phase was similar.

A pesquisa foi conduzida com objetivo de avaliar o efeito residual de diferentes fontes lipídicas na dieta de codornas japonesas (Coturnix japonica) na fase de recria sob o desempenho e a qualidade de ovos na fase inicial de postura. Na primeira etapa foram utilizadas 400 codornas japonesas com idade de 21 dias, as aves foram distribuídas em tratamentos seguindo um delineamento inteiramente casualizado com dez repetições, de oito aves, em cinco tratamentos: ração basal (RB) com 2,5% de óleo de soja, RB com 2,5 % de óleo de milho, RB com 2,5% de óleo algodão, RB com 2,5% de óleo de girassol e RB com 2,5% de óleo de canola. Aos 42 dias mantendo o delineamento inicial, todas aves receberam ração basal com óleo de soja, para que fosse avaliado o efeito residual da fase anterior sobre o desempenho e a qualidade dos ovos na fase inicial de postura (43 - 84 dias). As diferentes fontes lipídicas não afetaram o desempenho das aves na fase inicial de produção. Para a qualidade dos ovos, os parâmetros de altura, diâmetro e índice de gema, gravidade e UH foram melhores no tratamento com utilização de óleo de girassol. Houve efeito residual da utilização de fontes lipídicas de origem vegetal na dieta em fase de recria de codornas japonesas sobre as características da qualidade dos ovos. As fontes lipídicas oriundas das sementes de soja, milho, algodão, canola e girassol podem ser utilizadas como ingredientes energéticos na dieta de recria de codornas poedeiras por não serem prejudiciais ao desempenho inicial das aves. A longevidade na produção dos ovos das aves alimentadas com diferentes fontes lipídicas na fase de recria foi semelhante.

Reproductive performance of red-winged tinamous (Rhynchotus rufescens) using different mating strategies in captivity - case report / [Desempenho reprodutivo de perdizes (Rhynchotus rufescens) utilizando diferentes estratégias de acasalamento em cativeiro - relato de caso]

The aim of this study was to evaluate the reproductive performance of red-winged tinamous in captivity using different mating systems during three breeding seasons. The data were collected from August to March during three breeding seasons of the species. Ten couples and four groups of red-winged tinamous were randomly selected for formation of the monogamous and polygynous mating system, respectively, with egg collection from both systems. The traits evaluated were number of eggs per female, egg breaking and egg fertilization. Data were statistically analyzed by the least square method and logistic regression. Animals in couples mating strategy were superior (P<0.05) in terms of number of eggs per female compared to the group mating strategy. High egg breaking rate (P<0.05) in the red-winged tinamous groups was observed. Eggs of animals in couples mating strategy were 5.24 and 11.5 more likely to be fertilized than those of group strategy in two breeding seasons. In general, the reproductive efficiency in terms of low egg breaking, high egg production and fertility was observed for red-winged tinamous from the monogamous mating system.

O objetivo deste estudo foi avaliar o desempenho reprodutivo dos perdizes de asas vermelhas em cativeiro utilizando diferentes sistemas de acasalamento durante três épocas de reprodução. Os dados foram coletados de agosto a março, durante três épocas de reprodução da espécie. Dez casais e quatro grupos de perdizes de asas vermelhas foram selecionados aleatoriamente para a formação do sistema de acasalamento monogâmico e poliginoso, respectivamente, com coleta de ovos de ambos os sistemas. Os traços avaliados foram o número de ovos por fêmea, a quebra dos ovos e a fertilização dos ovos. Os dados foram analisados estatisticamente pelo método dos mínimos quadrados e pela regressão logística. Os animais na estratégia de acasalamento de casais foram superiores (P<0,05) em termos de número de óvulos por fêmea, em comparação com a estratégia de acasalamento do grupo. Foi observada uma alta taxa de quebra de ovos (P<0,05) nos grupos perdizes de asas vermelhas. Ovos de animais em estratégia de acasalamento de casais foram 5,24 e 11,5 mais propensos a serem fertilizados do que os de estratégia de grupo em duas épocas de reprodução. Em geral, a eficiência reprodutiva em termos de baixa quebra de ovos, alta produção de ovos e fertilidade foi observada para os tinâmicos de asas vermelhas do sistema de acasalamento monogâmico.

Human tumor necrosis factor alpha affects the egg-laying dynamics and glucose metabolism of Schistosoma mansoni adult worms in vitro.

Several studies have described the effects of human tumor necrosis factor alpha (hTNF-α) on Schistosoma mansoni. hTNF-α affects the worm's development, metabolism, egg-laying, gene expression and protein phosphorylation. The available data on the influence of hTNF-α on egg-laying in S. mansoni are controversial, but understanding the mechanism of egg-laying regulation in this species is essential in combating schistosomiasis. We characterized the effects of in vitro treatment of S. mansoni adult worms with different doses of hTNF-α (5, 20 and 40 ng/ml) for 5 days. We explored the effects on egg-laying rate, glucose levels, ATP metabolism, and messenger RNA (mRNA) expression levels of lactate dehydrogenase, glucose transporters and the parasite gene which acts as an hTNF-α receptor, SmTNFR. hTNF-α influenced egg-laying in a time- and dose-dependent manner: at a dose of 40 ng/ml, egg-laying increased on day 2 and decreased on days 3 and 4; at 20 ng/ml, egg-laying decreased on day 3; while at 5 ng/ml, egg-laying decreased on day 4. The total number of eggs produced was not affected by the different treatments, but the egg-laying dynamics were: the median egg-laying time decreased significantly with treatment, and egg developmental stages and size were also affected. At 5 and 20 ng/ml hTNF-α, lactate production diminished on day 3 up to day 5, while glucose uptake increased on day 5. At 40 ng/ml, glucose uptake diminished on day 1 up to day 3, while ATP accumulation was detected on day 5. No significant changes in mRNA expression were detected in any of the treatments. We found that crosstalk involving hTNF-α and parasite signaling plays a role in the fine-scale regulation of the worm's metabolism and physiology, and points to new strategies for disease control.

Anthropogenic impact on the reproductive health of two wild Patagonian fish species with differing reproductive strategies.

A particularly concerning outcome of environmental pollution is the disturbance of reproductive processes. However, studies on the impacts of pollution on the reproductive health of fish inhabiting South American environments are limited. We studied the impact of anthropogenic pollution on the reproductive health of two sympatric Patagonian marine fish species with different reproductive strategies: the live-bearing rockfish Sebastes oculatus and the egg-laying Brazilian sandperch Pinguipes brasilianus. Our findings reveal that both species presented some degree of reproductive disturbance when inhabiting an affected site, but the specific alterations differed depending on the species, sex, and season. During the reproductive season, 17ß-estradiol levels were elevated in females of both species living in polluted areas, while no differences in androgen levels were observed in either species or season. The gonadosomatic index (GSI) was affected in both sexes of S. oculatus during the non-reproductive season, while the gonadal stages were mainly affected in both sexes of P. brasilianus. No signs of intersex condition were observed. Our results highlight the importance of including diverse reproductive parameters to better understand anthropogenic effects on wild animals. Long-term studies including other fish species and including offspring (to evaluate possible transgenerational effects) will be necessary to determine the consequences of the documented reproductive alterations, particularly whether fish species inhabiting Patagonian marine reef areas will be able to reproductively adapt to increasing marine anthropogenic disturbances.

Multivariate analysis of sources of polyunsaturated fatty acids, selenium, and chromium on the productive performance of second-cycle laying hens

An experiment was conducted to evaluate the effect of the intake of a mixture of fish and sacha inchi oils (iOM), organic selenium (iSe), and organic chromium (iCr) on egg production (EP) and feed conversion ratio (FCR) of Isa Brown second-cycle laying hens (SCLH) for 16 weeks (91-106 weeks old). Egg production and FCR were evaluated using multivariate models that included conventional equations and artificial neural networks (ANN) to study multiple nutritional interactions as alternatives to univariate dose-response models. Based on the best models, iOM, iSe, and iCr levels were optimized, and a global sensitivity analysis was implemented to quantify their influence on EP and FCR. The modified logistic model was selected as the best strategy to represent EP. In the case of FCR, an ANN model with a feed-forward architecture and softmax transfer function was selected as the best alternative. One of the scenarios to simultaneously optimize EP (89.1%) and FCR (1.94 kg feed/kg egg) at 16 weeks of production was established with 3.3 g/hen·day of iOM, 0.132 mg/ hen·day of iSe, and 0.176 mg/hen·day of iCr. However, optimization considering only FCR results in much lower optimal iCr levels (between 0.083 and 0.105 mg/hen·day) with a slight decrease in EP (87.9%). The global sensitivity analysis showed that iSe is an essential factor associated with the increase in EP, and iCr is the most influential factor for the decrease in FCR. When both criteria were taken into account simultaneously from a desirability function, iSe was the most critical factor.(AU)

Effect of Dietary Tetramethylpyrazine on Egg Production, Nutrient Retention and Cecal Bacterial Diversity in Aged Laying Hens

This study aimed to investigate the effect of tetramethylpyrazine (TMP) supplementation on egg production, nutrient retention and cecal microbiota diversity using 288 commercial Hy-Line brown hens as of wk 75 to 86. Four treatments consisted of TMP addition at 0 (control, basal diet), 100, 150 and 200 mg/kg of diet. The results showed that diets supplemented with TMP addition improved egg-laying rate as of wk 77 compared to the control, which led to an increase (p<0.001) of egg mass by 97-225 g/hen throughout the whole trial, and a linear increase (p=0.003) of egg mass to the incremental TMP doses was found. At wk 86, the apparent digestibilities of dry matter and crude protein were enhanced (p<0.05), exhibiting consistent linear increases (p≤0.033) with the TMP doses. However, TMP did not cause alpha and beta diversity of cecal microbiota. The results suggest that TMP can be an additive to improve egg production and nutrient digestibility of aged laying hens.(AU)

Superdosing Phytases in the Diets of Light Laying Hens: Productive Performance and Bone Quality

Two experiments were carried out with the objective of evaluating the effect of superdosing of two phytases on performance, egg quality, digestive organ biometry and bone quality of light hens in the first (58 weeks) and second (87 weeks) productive cycle. In the first cycle, 270 light hens were used, in which a completely randomized design was adopted in a 2 x 2 + 1 factorial scheme (bacterial phytase or fungal phytase x 450 FTUs or 900 FTUs + control diet). In the second cycle, 270 hens were used, following the same design as the previous experiment. The performance and quality of the eggs were evaluated in both cycles, and the biometry of the digestive organs and bone characteristics were also evaluated in the first experiment. There was no effect in the comparison between the means for the performance and egg quality (in both experiments), or for the biometric variables and bone characteristics (first experiment). There was no significant interaction between the factors for any of the variables in the two experiments. In the first experiment, egg production was higher with bacterial phytase and egg weight with fungal phytase. The mineral matter showed greater value with 450 FTUs. It is recommended to use bacterial phytase produced from Escherichia coli as it improves the performance of light laying hens. The dosage of 450 FTUs improves the mineral content of light laying hens and the use of phytase in the laying hen diet implies a lower feed cost.

Multivariate modeling strategies to predict nutritional requirements of essential amino acids in semiheavy second-cycle hens

An experiment with 23 diets was performed to evaluate the effect of digestible lysine (Lys), digestible methionine + cysteine (Met+Cys), and digestible threonine (Thr) on egg production of H&N Brown second-cycle laying hens (SCLH) for 20 weeks (92-111 weeks of age) in cages under environmental conditions. Body weight (BW), feed intake (FI), feed conversion ratio (FCR), egg weight (EW), number of hen-housed eggs, and livability were also evaluated during the experiment. Diets were formulated from a central composite design that combined five levels of Lys, Met+Cys, and Thr ranging from 727 to 1159, 662 to 1055, and 552 to 882 mg/kg, respectively. Egg production (EP) data were evaluated through three different modeling strategies: egg production models, multivariate polynomial models, and artificial neural networks (ANN). A cascade-forward neural network with logsigmoid transfer function was selected as the best model according to goodness-offit statistics in both identification and validation data. One of the best scenarios for EP of H&N Brown SCLH under specific outdoor conditions was established at Lys, Met+Cys, and Thr levels of 1138, 1031, and 717 mg/hen·day, respectively. The ANN model may be an appropriate tool to study and predict EP of H&N Brown SCLH based on the combination of three different levels of essential digestible amino acids. The strategies included in this work may contribute to improving poultry performance based on modeling techniques to study other production parameters in terms of different nutritional requirements and productive conditions.

Superdosing Phytases in the Diets of Light Laying Hens: Productive Performance and Bone Quality

Two experiments were carried out with the objective of evaluating the effect of superdosing of two phytases on performance, egg quality, digestive organ biometry and bone quality of light hens in the first (58 weeks) and second (87 weeks) productive cycle. In the first cycle, 270 light hens were used, in which a completely randomized design was adopted in a 2 x 2 + 1 factorial scheme (bacterial phytase or fungal phytase x 450 FTUs or 900 FTUs + control diet). In the second cycle, 270 hens were used, following the same design as the previous experiment. The performance and quality of the eggs were evaluated in both cycles, and the biometry of the digestive organs and bone characteristics were also evaluated in the first experiment. There was no effect in the comparison between the means for the performance and egg quality (in both experiments), or for the biometric variables and bone characteristics (first experiment). There was no significant interaction between the factors for any of the variables in the two experiments. In the first experiment, egg production was higher with bacterial phytase and egg weight with fungal phytase. The mineral matter showed greater value with 450 FTUs. It is recommended to use bacterial phytase produced from Escherichia coli as it improves the performance of light laying hens. The dosage of 450 FTUs improves the mineral content of light laying hens and the use of phytase in the laying hen diet implies a lower feed cost.(AU)

High Speed Video Documentation of the Mosquito Sabethes albiprivus Egg-Catapulting Oviposition Behavior (Diptera: Culicidae).

The oviposition behavior of mosquitoes varies between species. We documented the unusual mechanism of egg laying in the mosquito Sabethes albiprivus Theobald with the aid of high speed video recordings in the laboratory. A sapucaia (Lecythis pisonis Camb.) nut oviposition trap, described herein, was used to simulate a tree hole with a small opening, which is the natural larval habitat of Sa. albiprivus. We showed that females approach the opening and perform a sequence of rapid, short up-and-down flights before egg laying. At this time, the egg is already visible externally, being held at the very tip of the abdomen. Females catapult one egg at a time by rapidly curling their abdomen downward, sending the egg through the opening while their legs are positioned in different configurations throughout the event. The estimated velocity of the catapulted eggs was almost 1 m/s.

Effect of green propolis on the productivity, nutrient utilisation, and intestinal morphology of Japanese laying quail

In this study, we evaluated the effects of dietary inclusion of ethanolic extract of green propolis (EEGP) on productivity, egg quality, nutrient utilization, and duodenal morphology of 120 Japanese laying quail. The quail were randomly distributed into five treatment groups: one group with no EEGP in the diet (control diet) and four groups with increasing EEGP levels (500, 1000, 1500, and 2000 mg EEGP/kg diet) in the diets. Excreta and diet samples were collected on day 40 and were analyzed for dry matter (DM), crude protein (CP), ether extract (EE), ash, gross energy (GE), calcium, and phosphorus to evaluate the nutrient and energy use. At the end of the study period, productive performance, egg quality, and duodenum morphology were evaluated. Duodenal sections were obtained from four birds per treatment and were processed for optical microscopy. The EEGP did not affect DM, GE utilization, apparent metabolizable energy, ash retention, feed intake, feed conversion, egg mass, egg quality, crypt depth, or villus height:crypt depth ratio in the duodenum. However, EEGP did increase laying rate, CP, EE, calcium, and phosphorus utilization, as well as villus height and absorption surface area in the duodenum when provided to birds at 1500 and 2000 mg/kg in the diet. Thus, the inclusion of EEGP at 1500 ppm in the diet of Japanese laying quail improves productivity, egg quality, nutrient utilization ability, and duodenal morphology.(AU)

Effects of different proteases on commercial laying hens at peak production

We evaluated the effect of adding proteases in diets of laying hens at peak production on the performance, egg quality, relative weight of digestive organs, and intestinal morphometry. Hy-Line W36 layer hens (390; 28-39 weeks old) were distributed in five treatments, with 13 animals each, with six replicates. The treatments were: control (standard formulation without nutritional reduction or protease inclusion), negative control A - NCA (nutritional reduction according to protease A matrix, without protease), negative control B - NCB (nutritional reduction according to protease B matrix, without protease), NCA + protease A, and NCB + protease B. The experimental period lasted 12 weeks, divided into three cycles of 28 days. Hens subjected to treatments (NCA and NCB) showed a decrease in feed intake. However, the addition of proteases A and B promoted improvement in this trait. The diets NCA and NCB had a negative influence on the production rate of the hens, but the diet supplementation with protease B resulted in significant improvement on egg laying rate. Hens subjected to nutritional reduction presented the worst results regarding mass and conversion by egg mass. However, the addition of enzymes reversed these results. Although the diets did not affect the relative weights of yolk, albumen, eggshell, Haugh unit, and specific gravity of the eggs, a higher eggshell thickness was observed in hens that received NCA, NCB, and NCB + protease B diets. The diets did not influence the relative weights of digestive organs and the small intestine morphometry. Hens fed diets supplemented with A and B have performance recovered in relation to those that received diets with reduced levels of nutrients.(AU)

The influence of a light and dark cycle on the egg laying activity of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

BACKGROUND The epidemiological importance of the mosquito Aedes aegypti as a vector of multiple human pathogens has generated a growing number of studies on the physiology and behaviour of its blood-feeding females. The activity of oviposition is one of the critical elements contributing to the expansion of Ae. aegypti's populations. Although there is a vast literature about oviposition behaviour, significant specific knowledge about egg viability and female fertility under light and dark conditions is still lacking. OBJECTIVES We studied, in controlled laboratory conditions, the effect that light and dark cycles have on the efficiency of oviposition by Ae. aegypti females. METHODS Physiological assays were performed using synchronised eggs obtained from forced egg laying. The number and viability of eggs was analysed under three different light/dark regimes: LD12:12 (12 h of light and 12 h of dark), DD (constant darkness) and LL (constant light). FINDINGS and CONCLUSIONS Our results show that females prefer to lay their eggs in dark conditions, but maximising the number and viability of eggs requires the occurrence of a light/dark cycle. Ongoing research on this theme has the potential of contributing to the proposition of new strategies for control based on the failure of egg laying and hatching.

Chelated minerals and two limestone particle sizes on production of layers in the second laying cycle / Minerais quelatados e duas granulometrias de calcário sobre a produção de poedeiras em segundo ciclo produtivo

The aim of this experiment was to evaluate the performance, egg quality, and bone quality of commercial white-egg layer hens in the second production cycle fed diets containing organic and inorganic minerals and two limestone particle sizes. A total of 215 birds with an average weight of 1.527 ± 0.092 kg were distributed in a completely randomized design in a 2 × 2 factorial arrangement (two mineral sources and two limestone particle sizes) with six replicates. The following four treatments were tested: T1 = inorganic minerals + 100% fine limestone; T2 = inorganic minerals + 50% fine limestone + 50% coarse limestone; T3 = organic minerals + 100% fine limestone; and T4 = organic minerals+ 50% fine limestone + 50% coarse limestone. No significant interaction occurred between the studied factors for any variable. Egg production, egg mass, bone resistance and bone deformity were higher with organic supplementation. Eggshell weight, percentage of eggshell, and specific gravity were higher in the treatments with the fine+coarse limestone association. In conclusion, organic mineral supplementation improves the performance based on egg production and egg mass. The association between fine and larger-sized limestone improves the external quality of eggs. The use of organic minerals improves the bone quality of birds in the second production cycle.

Neste experimento objetivou-se de avaliar o desempenho, qualidade dos ovos e qualidade óssea das poedeiras comerciais leves em 2° ciclo de produção, submetidas às dietas contendo minerais orgânicos e inorgânicos e duas granulometrias do calcário. Foram utilizadas 216 aves, com peso médio de 1,527 ± 0,092 kg, distribuídas em um delineamento inteiramente casualizado em um esquema fatorial 2 × 2 (duas fontes de minerais e duas granulometrias do calcário), com seis repetições. Foram empregados quatro tratamentos a seguir: T1 = minerais inorgânicos + 100% de calcário fino; T2 = minerais inorgânicos + 50% de calcário fino + 50% de calcário grosso; T3 = minerais orgânicos + 100% de calcário fino e T4 = minerais orgânicos + 50% de calcário fino + 50 % de calcário grosso. Não houve interação significativa entre os fatores estudados para nenhuma variável. A produção de ovos, massa de ovo, resistência e deformidade óssea foram melhores com a suplementação orgânica. O peso da casca, percentagem da casca e a gravidade específica foram melhores nos tratamentos com a associação do calcário fino + grosso. Concluiu-se que suplementação mineral orgânica melhora o desempenho com base na produção de ovos e massa dos ovos. A utilização da associação do calcário fino com o de maior granulometria melhora a qualidade externa dos ovos. A utilização de minerais orgânicos melhora a qualidade óssea das aves, em 2° ciclo produtivo.

Glycerin from biodiesel in the feeding of red-egg layers / Glicerina oriunda do biodiesel na alimentação de poedeiras de ovos vermelhos

The aim of this study was to evaluate the effects of vegetable glycerin on performance and egg quality of red-egg layers in the second production cycle. A total of 252 Hy-Line Brown layers weighing 1.919 ± 0.095 kg, at 90 weeks, were used in a completely randomized design with six treatments and seven birds per replication. The experiment lasted 84 days. Treatments consisted of a control diet (no glycerin) and five diets with increasing levels of vegetable glycerin (2, 4, 6, 8, and 10%). The following variables were evaluated: feed intake (g/bird/day); egg production (%); egg weight (g); egg mass (g/bird/day); conversion per egg mass (kg kg) and per dozen eggs (kg/dz); percentages of albumen, yolk, and shell; eggshell thickness (mm); and egg specific gravity. (Y = 67.69 + 54.23X, R2 = 0.78) and egg mass (Y = 44.84 + 42.87X, R2 = 0.66) improved linearly with the glycerin levels. A quadratic effect was observed (Y = 114.11 + 336.96 X 3,169.6 X2, R2 = 0.52) on feed intake. In conclusion, glycerin can be used to partially replace corn in diets for layers in the second production cycle at inclusion levels of up to 10%.(AU)

Objetivou-se avaliar os efeitos da glicerina vegetal sobre o desempenho e qualidade dos ovos de poedeiras de ovos vermelhos em segundo ciclo de produção. Foram utilizadas 252 poedeiras Hy-Line Brown, pesando 1,919 ± 0,095 kg com 90 semanas, em um delineamento inteiramente casualizado com seis tratamentos e sete aves por repetições. O experimento teve duração de 84 dias. Os tratamentos consistiram em uma dieta controle (sem glicerina), e cinco dietas com níveis de glicerina vegetal (2, 4, 6, 8 e 10%). As variáveis avaliadas foram: consumo de ração (g/ave/dia), produção de ovos (%), peso do ovo (g), massa de ovos (g/ave/dia), conversão por massa de ovos (kg/kg), conversão por dúzia de ovos (kg/dz), percentual de albúmen, gema e casca, espessura de casca (mm) e gravidade específica dos ovos. A produção (Y = 67.69 + 54.23X, R2 = 0.78) e massa de ovos (Y = 44.84 + 42.87X, R2 = 0.66) melhoraram linearmente com os níveis de glicerina. Foi observado efeito quadrático (Y = 114.11 + 336.96 X 3.169.6 X2, R2 = 0.52) sobre o consumo de ração. Conclui-se que a glicerina pode ser utilizada em substituição parcial ao milho, nas dietas para poedeiras em segundo ciclo de produção, no nível de até 10% de inclusão.(AU)

Chelated minerals and two limestone particle sizes on production of layers in the second laying cycle / Minerais quelatados e duas granulometrias de calcário sobre a produção de poedeiras em segundo ciclo produtivo

The aim of this experiment was to evaluate the performance, egg quality, and bone quality of commercial white-egg layer hens in the second production cycle fed diets containing organic and inorganic minerals and two limestone particle sizes. A total of 215 birds with an average weight of 1.527 ± 0.092 kg were distributed in a completely randomized design in a 2 × 2 factorial arrangement (two mineral sources and two limestone particle sizes) with six replicates. The following four treatments were tested: T1 = inorganic minerals + 100% fine limestone; T2 = inorganic minerals + 50% fine limestone + 50% coarse limestone; T3 = organic minerals + 100% fine limestone; and T4 = organic minerals+ 50% fine limestone + 50% coarse limestone. No significant interaction occurred between the studied factors for any variable. Egg production, egg mass, bone resistance and bone deformity were higher with organic supplementation. Eggshell weight, percentage of eggshell, and specific gravity were higher in the treatments with the fine+coarse limestone association. In conclusion, organic mineral supplementation improves the performance based on egg production and egg mass. The association between fine and larger-sized limestone improves the external quality of eggs. The use of organic minerals improves the bone quality of birds in the second production cycle.(AU)

Neste experimento objetivou-se de avaliar o desempenho, qualidade dos ovos e qualidade óssea das poedeiras comerciais leves em 2° ciclo de produção, submetidas às dietas contendo minerais orgânicos e inorgânicos e duas granulometrias do calcário. Foram utilizadas 216 aves, com peso médio de 1,527 ± 0,092 kg, distribuídas em um delineamento inteiramente casualizado em um esquema fatorial 2 × 2 (duas fontes de minerais e duas granulometrias do calcário), com seis repetições. Foram empregados quatro tratamentos a seguir: T1 = minerais inorgânicos + 100% de calcário fino; T2 = minerais inorgânicos + 50% de calcário fino + 50% de calcário grosso; T3 = minerais orgânicos + 100% de calcário fino e T4 = minerais orgânicos + 50% de calcário fino + 50 % de calcário grosso. Não houve interação significativa entre os fatores estudados para nenhuma variável. A produção de ovos, massa de ovo, resistência e deformidade óssea foram melhores com a suplementação orgânica. O peso da casca, percentagem da casca e a gravidade específica foram melhores nos tratamentos com a associação do calcário fino + grosso. Concluiu-se que suplementação mineral orgânica melhora o desempenho com base na produção de ovos e massa dos ovos. A utilização da associação do calcário fino com o de maior granulometria melhora a qualidade externa dos ovos. A utilização de minerais orgânicos melhora a qualidade óssea das aves, em 2° ciclo produtivo.(AU)

Aggregated oviposition in Rhodnius prolixus, sensory cues and physiological consequences.

Females of the haematophagous bug Rhodnius prolixus attach their eggs in clusters on substrates related to their hosts, such as nests or avian feathers. Because the hosts are an enormous food resource as well as potential predators, the choice of the site and pattern of oviposition could have an important adaptive value. Here we investigated proximate and a potential ultimate cause of this aggregated pattern of laid eggs. First, we studied proximal causes by analyzing the use of chemical or physical cues associated with aggregated oviposition in R. prolixus. For all terrestrial organisms there is a trade-off between exchange of respiratory gases and water loss. Particularly, insect eggs are highly susceptible to this trade-off because they do not obtain water from the environment, hence our second objective is to study the possible mechanisms involved in dehydration resistance in this species. Therefore we examined the dynamics of change in CO2 release rate (MCO2), and water loss rate (MH2O) in relation to embryo development as energetic demands increase, and tested the energetic or hygric efficiency hypothesis as a potential ultimate cause of aggregated oviposition. This hypothesis states that grouped eggs consume less energy or lose less water than equal numbers of isolated eggs, the latter being more susceptible to dehydration. Results indicated the use of physical external cues such as dummy eggs or edges of the oviposition substrates, but we did not find any chemical cues associated with the aggregated pattern of oviposition. There are no energetic or hygric benefits associated with egg's aggregated pattern. However, when we analyzed the MCO2 and MH2O change in relation to embryo development, we found a fairly constant and low MH2O albeit a clear increase in MCO2, suggesting a tightly control of egg's desiccation tolerance. This high resistance to desiccation coupled with a temporal strategy of hatching allows R. prolixus embryos to successfully develop and hatch under harsh environmental conditions.

Glycerin from biodiesel in the feeding of red-egg layers / Glicerina oriunda do biodiesel na alimentação de poedeiras de ovos vermelhos

The aim of this study was to evaluate the effects of vegetable glycerin on performance and egg quality of red-egg layers in the second production cycle. A total of 252 Hy-Line Brown layers weighing 1.919 ± 0.095 kg, at 90 weeks, were used in a completely randomized design with six treatments and seven birds per replication. The experiment lasted 84 days. Treatments consisted of a control diet (no glycerin) and five diets with increasing levels of vegetable glycerin (2, 4, 6, 8, and 10%). The following variables were evaluated: feed intake (g/bird/day); egg production (%); egg weight (g); egg mass (g/bird/day); conversion per egg mass (kg kg) and per dozen eggs (kg/dz); percentages of albumen, yolk, and shell; eggshell thickness (mm); and egg specific gravity. (Y = 67.69 + 54.23X, R2 = 0.78) and egg mass (Y = 44.84 + 42.87X, R2 = 0.66) improved linearly with the glycerin levels. A quadratic effect was observed (Y = 114.11 + 336.96 X 3,169.6 X2, R2 = 0.52) on feed intake. In conclusion, glycerin can be used to partially replace corn in diets for layers in the second production cycle at inclusion levels of up to 10%.

Objetivou-se avaliar os efeitos da glicerina vegetal sobre o desempenho e qualidade dos ovos de poedeiras de ovos vermelhos em segundo ciclo de produção. Foram utilizadas 252 poedeiras Hy-Line Brown, pesando 1,919 ± 0,095 kg com 90 semanas, em um delineamento inteiramente casualizado com seis tratamentos e sete aves por repetições. O experimento teve duração de 84 dias. Os tratamentos consistiram em uma dieta controle (sem glicerina), e cinco dietas com níveis de glicerina vegetal (2, 4, 6, 8 e 10%). As variáveis avaliadas foram: consumo de ração (g/ave/dia), produção de ovos (%), peso do ovo (g), massa de ovos (g/ave/dia), conversão por massa de ovos (kg/kg), conversão por dúzia de ovos (kg/dz), percentual de albúmen, gema e casca, espessura de casca (mm) e gravidade específica dos ovos. A produção (Y = 67.69 + 54.23X, R2 = 0.78) e massa de ovos (Y = 44.84 + 42.87X, R2 = 0.66) melhoraram linearmente com os níveis de glicerina. Foi observado efeito quadrático (Y = 114.11 + 336.96 X 3.169.6 X2, R2 = 0.52) sobre o consumo de ração. Conclui-se que a glicerina pode ser utilizada em substituição parcial ao milho, nas dietas para poedeiras em segundo ciclo de produção, no nível de até 10% de inclusão.

Variation in honey yield per hive of Africanized bees depending on the introducing time of young queens / Variação na produção de mel por colmeias de abelhas africanizadas em função da época de introdução de rainhas jovens

The objective of this research was to evaluate the honey production per hive and the egg laying rates of queens produced in 2007, 2008 and 2010. Thirty colonies initiated with a queen per colony at each climatic season were used during the three years. The years, started on January (summer), April (autumn), July (winter) and October (spring) and ended 12 months later, at the same periods related to each season of the later years. Honey supply were weighed before and after centrifugation to evaluate the quantity of the stored honey. Colonies with queens introduced during autumn and winter in the three years produced 57.2±6.0kg and 60.7±7.5kg of honey, respectively. In the first year of production activity, after the introduction of queens in the initial colonies, values were significantly higher than those obtained in colonies with queens introduced in the summer (39.3±7.6kg) and spring (41.8±3.7kg). Egg laying rates of queens were higher in spring (98.2±3.9%) and summer (88.4±7%), indicating greater food flow (flowerings) in these seasons compared to the averages in autumn (30.3±8.1%) and winter (24.5±7.2%). Produce and introduce queens of Africanized Apis mellifera in colonies initiated during autumn and winter was found to be economically feasible. Honey production of colonies initiated in these periods were higher and they had greater population stability in times of scarcity of flowerings.(AU)

O objetivo deste trabalho foi avaliar a produção de mel por colmeia e as taxas de postura de ovos das rainhas produzidas nos anos de 2007, 2008 e 2010. Foram utilizadas 30 colônias iniciadas com uma rainha/colônia por estação climática, durante os três anos. A cada ano, iniciou-se em: janeiro (verão), abril (outono), julho (inverno) e outubro (primavera) e encerrou-se doze meses depois, nos mesmos períodos referentes a cada estação dos anos posteriores. As melgueiras foram pesadas antes e depois da centrifugação para avaliar a quantidade do mel estocado. As colônias com rainhas introduzidas durante o outono e o inverno nos três anos produziram 57,2±6,0kg e 60,7±7,5kg de mel, respectivamente, no primeiro ano de atividade de produção após a introdução das rainhas nas colônias iniciais, valores significativamente superiores aos obtidos para as colônias com rainhas introduzidas no verão (39,3±7,6kg) e na primavera (41,8±3,7kg). As taxas de postura de ovos das rainhas foram mais altas na primavera e no verão (98,2±3,9% e 88,4±7%, respectivamente), indicando maior fluxo de alimento (floradas) nessas épocas, quando comparadas às médias do outono e inverno (30,3±8,1% e 24,5±7,2%, respectivamente). Constatou-se que é economicamente viável produzir rainhas e introduzir em colônias iniciais de Apis mellifera africanizada durante o outono e inverno. Além da produção de mel das colônias iniciadas nesses períodos ser superior, elas terão maior estabilidade populacional em épocas de escassez de floradas.(AU)