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Exponential model for population growth (exponential model) is a foundation to evaluate population dynamics in Population Ecology field. Here, we used a didactic experiment to teach exponential model for an undergraduate course of Population Ecology. We built nine populations of weevils with three different initial population sizes: eight, 16, and 32 individuals with three replicates each. We provided equal food resource availability, and counted their population sizes weekly for 12 weeks. We estimated the intrinsic growth rate (i.e., r parameter), by trials and errors with an exponential model build in an Excel spreadsheet. The population growth rate (i.e., dN/dt parameter) was estimated using r values. Replicates with eight and 16 individuals reached the highest values of r and dN/dt, while replicates with 32 individuals reached the lowest values. Beyond of exponential model, two density dependency issues acting in populations were observed. First, in the lowest initial population sizes we observed the effect of demographic stochasticity acting in both r and dN/dt in one of the three populations. Second, we observed the intraspecific competition reducing r values in largest initial populations. Therefore, we highlight the importance of didactic experiment into learning exponential model in Population Ecology course, both for teaching and learning practices.(AU)

Resumo

This study estimated the growth of body, carcass, primal cuts, edible offal, and feathers of Japanese quail reared in two thermal environments, receiving three nutritional plans, from one to 39 days of age. A total of 576 one-day-old female chicks (Coturnix japonica) with an average initial weight of 7.51±0.75g/bird were evaluated in a completely randomized design with a 3 × 2 factorial arrangement (three nutritional plans × two temperatures). The animals were housed in two climatic chambers, at 25 ºC and 35 ºC, using 12 replications with eight birds per experimental unit. Nutritional plans (NP) were as follows: NP1: one diet from 1-21days and another from 22-39 days; NP2: one diet from 1-14 days and another from 15-39 days; and NP3: a single diet from 1-39 days. The growth curves and growth rates of body, carcass, primal cuts, feathers, and edible offal were evaluated using the Gompertz mathematical model. Quail fed NP3 showed higher growth curves and rates for body, carcass, drumstick +thigh, and feather. There was an effect on maturity rate, which was lowest in quail housed at 35 ºC. Among the animals kept at 25 ºC, the group fed NP3 exhibited the highest growth rate and breast weight. The nutritional plan consisting of a single diet offered from 1 to 39 days, formulated based on the tables for Japanese and European quail, is the most suitable for estimating the growth curves (Gompertz model) of Japanese quail housed at 25 ºC or 35 ºC.

Objetivou-se estimar o crescimento corporal, carcaça, cortes nobres, vísceras comestíveis e penas de codornas japonesas criadas em dois ambientes térmicos e alimentadas com três planos nutricionais de um a 39 dias. Foram utilizadas 576 pintainhas (Coturnix japônica), fêmeas, com um dia de idade, com peso médio inicial 7,51 ± 0,75g/ave, distribuídas em delineamento inteiramente casualizado em esquema fatorial 3 × 2 (três planos nutricionais x duas temperaturas), alojadas em duas câmaras climáticas de 25º e 35 ºC, com 12 repetições e oito aves por unidade experimental. Os planos nutricionais foram: plano nutricional um (PN1) - uma dieta de 1-21 dias e uma dieta de 22-39 dias; plano nutricional dois (PN2) - uma dieta de 1-14 dias e uma dieta de 15-39 dias; e plano nutricional três (PN3) - dieta única de 1-39 dias. Foram avaliadas as curvas e taxas de crescimento corporal, carcaça, cortes nobres, penas e vísceras comestíveis, através do modelo matemático de Gompertz. Codornas alimentadas com PN3 apresentaram maiores curvas e taxas de crescimento corporal, de carcaça, coxa + sobrecoxa e penas. Houve efeito para taxa de maturidade, sendo inferior para codornas alojadas em 35 ºC. Nas aves mantidas em 25 ºC, observou-se maior taxa de crescimento e peso de peito nas codornas alimentadas com PN3. O plano nutricional composto por uma única dieta ofertada durante o período de um a 39 dias, formulado com base nas recomendações das tabelas para codornas japonesas e europeias, é o mais indicado para estimar curvas de crescimento no modelo de Gompertz de codornas japonesas alojadas em 25 ºC ou 35 ºC.

Resumo

Genipa americana (Rubiaceae) is a fruit tree with broad phytogeographic domain and suitable for different silvicultural systems in the tropics. The knowledge associated with the relative growth rate of species such as G. americana, provides important guidelines for the effective establishment and survival of seedlings after planting in the field. In this study we investigated differences in growth, biomass allocation and photosynthesis of seedlings originating from different mother plants of G. americana in southern Bahia, Brazil. For this, we evaluated fifteen variables associated with carbon balance at the whole plant and leaf scales of twelve G. americana progenies. All seedlings grew over a period of 198 days under similar microclimatic conditions with approximately 65% full sun. Our results showed significant differences in the relative growth rates (RGR), with the highest and lowest mean values being 29.0 and 38.0 mg g-1 day-1, respectively. Differences in RGR between G. americana progenies were highly related to differences in biomass allocation at both whole plant and leaf scales. From a practical point of view, we demonstrate that the selection of mother plants to produce seedlings with higher growth rates, and consequently greater establishment capacity in field plantings, can be made from evaluations of growth and biomass allocation variables at the whole plant scale.

Genipa americana (Rubiaceae) é uma árvore frutífera com amplo domínio fitogeográfico e adequada para diferentes sistemas silviculturais nos trópicos. O conhecimento associado à taxa de crescimento relativo de espécies como G. americana fornece diretrizes importantes para o estabelecimento e sobrevivência de mudas após o plantio no campo. Neste estudo investigamos diferenças no crescimento, alocação de biomassa e fotossíntese de mudas originárias de diferentes plantas-mãe de G. americana no sul da Bahia, Brasil. Para isso, foram avaliadas quinze variáveis associadas ao balanço de carbono em escala de planta inteira e escala foliar de doze progênies de G. americana. Todas as mudas cresceram durante um período de 198 dias sob condições microclimáticas semelhantes com aproximadamente 65% de pleno sol. Nossos resultados mostraram diferenças significativas nas taxas de crescimento relativo (RGR), sendo os valores médios mais altos e mais baixos 29.0 e 38.0 mg g-1 dia-1, respectivamente. As diferenças na RGR entre as progênies de G. americana foram altamente relacionadas às diferenças na alocação de biomassa tanto na planta inteira quanto em escala foliar. Do ponto de vista prático, demonstramos que a seleção de plantas matrizes para produção de mudas com maiores taxas de crescimento, e consequentemente maior capacidade de estabelecimento em plantios em campo, pode ser feita a partir da avaliação de variáveis de crescimento e alocação de biomassa em escala de planta inteira.

Resumo

The present study was carried out with the objective of determining the requirements for digestible lysine in Nile tilapia during the 500 to 600 g live weight stage. Isocaloric and isonitrogenous diets were tested with increasing amounts of digestible lysine. L-lysine HCl (78%) were used to replace glutamic acid at increasing levels, resulting in treatments of 9.3, 12.3, 15.3, 18.3 and 21.3 g kg-1 of digestible lysine. Three hundred Nile tilapias with an average weight of 519 ± 27.23 g were used and distributed among 25 tanks. The physical and chemical parameters of the water were pH, dissolved oxygen, salinity, conductivity and temperature. The mortality rate was registered daily. Two slaughters were performed at 28 and 50 days after the beginning of the experiment. It was estimated that an amount of 13.1 g kg-1 of digestible lysine was ideal for obtaining higher WG. Fish slaughtered after 50 days, the digestible lysine requirements were determined to be 14.5 g kg-1 for the lowest carcass humidity and 14.6 g kg-1 for the greatest carcass ethereal extract. Nile tilapias with live weight between 500 and 600 grams require 13.1 g kg-1 of digestible lysine in the diet for greater WG (90.53 g) and better FCR (2.55).(AU)

Resumo

The objective of this study was to describe the growth curve of Brazilian Creole chickens of the Canela-Preta breed raised in two different rearing systems using non-linear growth models. A total of 400 birds were divided into two groups of 200 animals (of both genders), which were kept in confined or semi-confined systems. The confined birds were housed in an experimental masonry shed and the semi-confined animals were housed in another shed with access to pasture from 29 days of age. Birds were individually weighed every seven days during six months for determination of the growth curves of body weight using 10 non-linear models. The parameters of the models were estimated using the Gauss Newton method. The performance of the models was assessed using mean squared error (MSE), coefficient of determination (R2), percentage of convergence, and residual mean absolute deviation (MAD). With the exception of the Inverse Polynomial, all the other models had R2 values close to one. Therefore, the best models were chosen based on the lowest MSE and MAD values, with the Richards model ranking first followed by the Von Bertalanffy model. Gender and rearing system effects significantly influenced (p<0.05) some parameters of the Richards model. In conclusion, the Richards model was the most adequate to describe the growth of Canela-Preta chickens. Gender and rearing system significantly influenced the growth of the birds. The growth rates observed indicated that management strategies can be performed to increase the production efficiency of Canela-Preta chickens.(AU)

Resumo

The study aimed to evaluate performance and growth curves of broilers fed different nutritional relations. A total of 1,440 Cobb-500 male day-old chicks were assigned to eight treatments in a 2 x 2 x 2 factorial arrangement with six replicates of 30 birds each. The main factors were nutritional density (control and high), lysine source (HCl and sulfate), and calcium pidolate (presence and absence). Analyses were made for body weight gain (BWG), and feed conversion rate (FCR) at 21, and 42 days of age. The growth curves were adjusted by weighing a bird per plot every three days. Data for BWG were tested by ANOVA to evaluatethe effects of treatments and their interactions at 5% significance, and the Gompertz model was adjusted by NLS. Birds fed a high nutritional density had higher BWG and lower FCR. Calcium pidolate and different sources of lysine did not influence the FCR of broilers, however a triple interaction was evidenced for BWG at 1 to 42 days of age. The day with maximum gain adjusted by Gompertz of all treatments was at the 32ndday of age and the maximum weight (A) was around 5.85 kg.(AU)

Resumo

The research was conducted during the 2018/19 hunting year at three hunting grounds: "Barajevska reka" - "Takovo" and "Jadar". The average density of Roe deer in hunting grounds varied from 48.67 to 74 individuals per 1,000 ha of hunting-productive area. However, when observing the number of individuals per 1,000 ha of total hunting area, the density varies from 16.07 individuals to 34.72 individuals. The determined gender ratio at the hunting ground "Jadar" was (M: F = 1: 0.93). At the hunting ground "Takovo", the gender ratio was (M: F = 1: 1.22), while at the hunting ground "Barajevska reka" the ratio was (M: F = 1: 1.59). The average fertility of Roe deer was 1.67 embryos per individual, or 1.75 embryos per pregnant female. Depending on the study area, the real growth varied from 0.54 to 0.73 fawns per female. Loss in Roe deer are caused mostly by biotic factors. The determined average age of shot individuals varied depending on the hunting ground from 3.53 to 5.24 years. The current state of Roe deer populations in Serbia varies between analyzed hunting grounds, but the overall situation is quite unsatisfactory, especially in terms of density, gender ratio and age structure of culled individuals.

A pesquisa foi realizada durante o ano de caça de 2018/19 nos três locais de caça: "Barajevska reka" - "Takovo" e "Jadar". A densidade média de cabrito-montês em áreas de caça variou de 48,67 a 74 indivíduos por 1.000 ha de área produtiva de caça. Entretanto, ao observar o número de indivíduos por 1.000 ha de área total de caça, a densidade varia de 16,07 indivíduos a 34,72 indivíduos. A razão de gênero determinada no terreno de caça "Jadar" foi (M: F = 1: 0,93). No terreno de caça "Takovo", a proporção de gêneros era (M: F = 1: 1,22), enquanto no terreno de caça "Barajevska reka" (M: F = 1: 1,59). A fertilidade média do cervo Roe era de 1,67 embriões por indivíduo, ou 1,75 embriões por fêmea grávida. Dependendo da área de estudo, o crescimento real variou de 0,54 a 0,73 fulvos por fêmea. As perdas em cabrito-montês são causadas principalmente por fatores bióticos. A idade média determinada dos indivíduos abatidos variou de 3,53 a 5,24 anos, dependendo do terreno de caça. O estado atual das populações de cabrito-montês na Sérvia varia entre os locais de caça analisados, mas a situação geral é bastante insatisfatória, especialmente em termos de densidade, proporção de gênero e estrutura etária dos indivíduos abatidos.

Resumo

This study aimed to evaluate the vegetative growth of the species Coffea canephora from the orthotropic and plagiotropic branches of coffee plants of the botanical varieties Conilon and Robusta under irrigated and non-irrigated conditions during the rainy and dry seasons. The experiment was conducted in the municipality of Ouro Preto do Oeste, Rondônia, Brazil, during two periods defined between October 2019 and October 2021. Branch growth rates (mm day−1) were obtained every 14 days and seasonal growth was plotted in series graphs. Average growth rates for each type of branch were compared by Tukey's test (p ≤ 0.05). Vegetative growth was seasonal during the evaluation periods and seasons and varied according to genetic material and irrigation use. Growth rates were higher in the rainy season, regardless of water management and botanical variety. Irrigation of coffee plants conducted during periods of high temperatures and strong water deficit provided higher growth relative to non-irrigated plants. Furthermore, the growth of coffee plants subjected to non-irrigation was held back during the drought period and was compensated by high growth rates during the rainy season. Plants of the botanical variety Robusta tended to grow more than those of the variety Conilon under water availability conditions (rain or irrigation), considering the climate conditions of the South-Western Amazon.(AU)

Neste estudo objetivou-se avaliar o crescimento vegetativo da espécie Coffea canephora, a partir dos ramos ortotrópicos e plagiotrópicos dos cafeeiros das variedades botânicas Conilon e Robusta, em condições irrigada e não irrigadas, durante as estações de chuva e estiagem. O experimento foi conduzido no município de Ouro Preto do Oeste, Rondônia, Brasil, durante dois períodos definidos entre os meses de outubro de 2019 a outubro de 2021. As taxas de crescimentos dos ramos (mm dia-1) foram obtidas a cada quatorze dias e o crescimento sazonal foi plotado em gráficos em série. As médias das taxas de crescimento para cada tipo de ramo foram comparadas pelo teste de Tukey (p ≤ 0,05). O crescimento vegetativo foi sazonal durante os períodos de avaliação e estações do ano e, variou conforme o material genético e uso da irrigação. As taxas de crescimento foram superiores no período chuvoso, independentemente do manejo hídrico e da variedade botânica. A irrigação de cafeeiros realizada durante as épocas de altas temperaturas e forte déficit hídrico proporcionou maior crescimento em relação a plantas não irrigadas. Além disso, o crescimento dos cafeeiros não irrigados ficou represado durante o período da estiagem e foi compensado pelas altas taxas de crescimento no período das chuvas. As plantas da variedade botânica Robusta, em condições de disponibilidade hídrica, mediante chuva ou irrigação, tenderam a crescer mais do que as da variedade Conilon, considerando as condições climáticas da Amazônia Sul-Ocidental.(AU)

Resumo

This study focuses on incubation parameters, egg morphometrics, and body mass development, hatching, and behavioral adaptations to heat stress within a colony of freshwater-breeding Black Skimmers (Rynchops niger) located in the private nature reserve of Serviço Social do Comércio (SESC) in the northern Pantanal, Mato Grosso, Brazil. Temperatures of nest, eggs, and surface substratum, as well as the development of embryos, were surveyed using thermal imaging, a method allowing digital recording from a distance and in a fraction of the time of traditional measuring techniques. The mean egg dimensions (n = 71) were 4.48 (± 0.13) × 3.27 (± 0.07) cm; the mean mass at hatching was 24.3 (± 1.9) g, with a significant decrease over incubation time. The mean surface temperature of eggs varied from 30.9℃ to 39.7℃, while the sand surface temperature was 20℃ at 06:00 h, rising to 47.7℃ at 11:00 h. There was a significant increase (7%) in egg surface temperature throughout incubation. Incubation-bout durations (n = 2108) were correlated with the microclimatic conditions of the substratum, becoming shorter with increasing sand-surface temperature around midday. Egg hatching lasted one day, and siblings hatched no more than 24 h apart. The mean body mass on Day 1 after hatching was 16.8 (± 1.6) g (n = 6). Three days after hatching, chicks moved to new sand depressions provided by parents near the original nest, where they remained motionless or tried to hide under riparian vegetation. The single chick that fledged had a growth rate of K = 0.117 and a t10₋90 value of 37.3 days. On Day 7, dorsal pintail feathers and primaries appeared, which were open on Day 15. After 14 days, the chick was able to regulate its body temperature, and no more feeding by parental birds during the daytime was observed. On Day 21, the immature plumage was fully developed. Fledging was completed on Day 27. Our study demonstrates that thermal imaging is a useful method of surveying egg and embryo development in the Black Skimmer, reducing nest disturbance and observation efforts.(AU)

Resumo

The main objective of this study was to determine the effects of milking system on growth, reproduction, and milk yield and composition of East Friesiancross (Tahirova) dairy sheep that were milked in the evening during the suckling period. A total of 43 Tahirova ewes and 58 lambs were used in the present study. One of the groups was milked in the evening (evening milked; EM) before coming together with their lambs, and the other group was not (not milked in the evening; NEM). Morning milking was performed in both groups during the study. Lambs in both groups were individually weaned at the age of 60 days. There was no statistical difference between the lambs' live weight at weaning in the EM and NEM groups, determined to be 23.46 and 24.11 kg, respectively. Live weight values of lambs were similar in the groups at ages of up to 180 days. The reproductive characteristics of ewe lambs in the EM and NEM groups, having similar growth rates and a similar live weight and body condition in the first estrus stages, were also similar. The return rate and frequency of return were close in both groups of ewe lambs. Milk yield of the NEM group was significantly higher than that of the EM group before and after weaning. However, in groups with similar lactation milk yield and length, the total marketable milk yield was higher in the suckling period of the EM group. The milking system in suckling period of Tahirova ewes does not significantly affect growth, average daily gain, and reproductive characteristics. Milk yield in the NEM group before and after weaning was significantly higher than the EM group, but the total marketable milk yield was higher in the EM group.(AU)

Resumo

The growth of generations of the Genomar Supreme Tilapia (GST) strain, specifically G20 and G25, was evaluated. Tilapias 8 g were reared in a recirculating aquaculture system with 0.25 m³ tanks, 80 fish m-³, with four replicates. During growth, eight fish from each tank were weighed and measured at day 1, 30, 60, 90, 120, 150, 180 and 210. Survival, weight gain, feed conversion and batch homogeneity were determined. Weight-age data were fit to Gompertz model. In addition, absolute and relative growth rates and weight and age at inflection were determined. Final weight showed 26.7% higher in G25 when compared to G20 (920.05 and 725.87 g, respectively). The feed conversion and homogeneity indexes were better in G25 than G20. The estimate of asymptotic weight was higher in G25 (1202.0 g) when compared to G20 (912.7 g). G20 presented smaller weight (335.76 g), age (108.87 days) and absolute growth rate (4.87 g day-1) when compared with G25 (442.19 g, 113.77 days and 6.41 g day-1). Carcass characteristics were similar, but G25 presented about 25% higher fillet weight than G20. After five years in the GST breeding program, results indicated that a sustained improvement of harvest weight was achieved, as well as 6 to 10% gain in performance by generation.(AU)

Resumo

For the proper growth of fish, it is necessary to feed the fish with a proper and balanced diet. A study was conducted to find out the effect of different protein-based diets on fingerlings of Tor putitora (mahseer). A feed with dietary protein levels of 35%, 40%, 45%, and 50% were prepared. The effect of different protein-based feed on weight gain, standard growth rate (SGR), food conversion ratio (FCR), percent weight gain, food conversion efficiency (FCE), and protein efficiency ratio (PER) was studied. An increase was observed in the growth rate with an increase in protein concentration up to 45%. The fingerlings fed a 45% protein diet shown the highest growth, followed by 50%, 40%, and 35%. The SGR value was greatest for 45% protein diet (8.56) followed by 50% and 40%, while the least values were observed for 35% protein feed (1.57). The same trend was observed for FCE. The highest PER values was observed in fishes fed 45% protein-based feed (0.65) followed by 50% (0.56), 40% (0.38) and35% (0.17). The food conversion ratio was lowest for 45% protein diet (3.41), while the greatest for 35% protein feed (16.85). It was concluded that a 45% protein-based diet was the best feed formulation for higher production of Tor putitora. However, research on the same percentage of protein diet is recommended for yearlings.

Para o bom crescimento dos peixes, é necessário alimentá-los com uma alimentação adequada e balanceada. Um estudo foi realizado para descobrir o efeito de diferentes dietas à base de proteínas em alevinos de Tor putitora (mahseer). Foi preparado um alimento com níveis de proteína dietética de 35%, 40%, 45% e 50%. O efeito de diferentes alimentos à base de proteína no ganho de peso, taxa de crescimento padrão (SGR), taxa de conversão alimentar (FCR), ganho de peso percentual, eficiência de conversão alimentar (FCE) e taxa de eficiência proteica (PER) foi estudado. Foi observado um aumento na taxa de crescimento com um aumento na concentração de proteína de até 45%. Os alevinos alimentados com dieta de 45% de proteína apresentaram o maior crescimento, seguidos de 50%, 40% e 35%. O valor de SGR foi maior para dieta com 45% de proteína (8,56), seguido de 50% e 40%, enquanto os menores valores foram observados para ração com 35% de proteína (1,57). A mesma tendência foi observada para FCE. Os maiores valores de PER foram observados em peixes alimentados com 45% de ração à base de proteína (0,65), seguido por 50% (0,56), 40% (0,38) e 35% (0,17). A taxa de conversão alimentar foi menor para a dieta com 45% de proteína (3,41), enquanto a maior para a dieta com 35% de proteína (16,85). Concluiu-se que a dieta à base de proteína de 45% foi a melhor formulação alimentar para maior produção de Tor putitora. No entanto, a pesquisa sobre a mesma porcentagem de dieta proteica é recomendada para animais de um ano.

Resumo

Abstract For the proper growth of fish, it is necessary to feed the fish with a proper and balanced diet. A study was conducted to find out the effect of different protein-based diets on fingerlings of Tor putitora (mahseer). A feed with dietary protein levels of 35%, 40%, 45%, and 50% were prepared. The effect of different protein-based feed on weight gain, standard growth rate (SGR), food conversion ratio (FCR), percent weight gain, food conversion efficiency (FCE), and protein efficiency ratio (PER) was studied. An increase was observed in the growth rate with an increase in protein concentration up to 45%. The fingerlings fed a 45% protein diet shown the highest growth, followed by 50%, 40%, and 35%. The SGR value was greatest for 45% protein diet (8.56) followed by 50% and 40%, while the least values were observed for 35% protein feed (1.57). The same trend was observed for FCE. The highest PER values was observed in fishes fed 45% protein-based feed (0.65) followed by 50% (0.56), 40% (0.38) and35% (0.17). The food conversion ratio was lowest for 45% protein diet (3.41), while the greatest for 35% protein feed (16.85). It was concluded that a 45% protein-based diet was the best feed formulation for higher production of Tor putitora. However, research on the same percentage of protein diet is recommended for yearlings.

Resumo Para o bom crescimento dos peixes, é necessário alimentá-los com uma alimentação adequada e balanceada. Um estudo foi realizado para descobrir o efeito de diferentes dietas à base de proteínas em alevinos de Tor putitora (mahseer). Foi preparado um alimento com níveis de proteína dietética de 35%, 40%, 45% e 50%. O efeito de diferentes alimentos à base de proteína no ganho de peso, taxa de crescimento padrão (SGR), taxa de conversão alimentar (FCR), ganho de peso percentual, eficiência de conversão alimentar (FCE) e taxa de eficiência proteica (PER) foi estudado. Foi observado um aumento na taxa de crescimento com um aumento na concentração de proteína de até 45%. Os alevinos alimentados com dieta de 45% de proteína apresentaram o maior crescimento, seguidos de 50%, 40% e 35%. O valor de SGR foi maior para dieta com 45% de proteína (8,56), seguido de 50% e 40%, enquanto os menores valores foram observados para ração com 35% de proteína (1,57). A mesma tendência foi observada para FCE. Os maiores valores de PER foram observados em peixes alimentados com 45% de ração à base de proteína (0,65), seguido por 50% (0,56), 40% (0,38) e 35% (0,17). A taxa de conversão alimentar foi menor para a dieta com 45% de proteína (3,41), enquanto a maior para a dieta com 35% de proteína (16,85). Concluiu-se que a dieta à base de proteína de 45% foi a melhor formulação alimentar para maior produção de Tor putitora. No entanto, a pesquisa sobre a mesma porcentagem de dieta proteica é recomendada para animais de um ano.

Resumo

For the proper growth of fish, it is necessary to feed the fish with a proper and balanced diet. A study was conducted to find out the effect of different protein-based diets on fingerlings of Tor putitora (mahseer). A feed with dietary protein levels of 35%, 40%, 45%, and 50% were prepared. The effect of different protein-based feed on weight gain, standard growth rate (SGR), food conversion ratio (FCR), percent weight gain, food conversion efficiency (FCE), and protein efficiency ratio (PER) was studied. An increase was observed in the growth rate with an increase in protein concentration up to 45%. The fingerlings fed a 45% protein diet shown the highest growth, followed by 50%, 40%, and 35%. The SGR value was greatest for 45% protein diet (8.56) followed by 50% and 40%, while the least values were observed for 35% protein feed (1.57). The same trend was observed for FCE. The highest PER values was observed in fishes fed 45% protein-based feed (0.65) followed by 50% (0.56), 40% (0.38) and35% (0.17). The food conversion ratio was lowest for 45% protein diet (3.41), while the greatest for 35% protein feed (16.85). It was concluded that a 45% protein-based diet was the best feed formulation for higher production of Tor putitora. However, research on the same percentage of protein diet is recommended for yearlings.

Para o bom crescimento dos peixes, é necessário alimentá-los com uma alimentação adequada e balanceada. Um estudo foi realizado para descobrir o efeito de diferentes dietas à base de proteínas em alevinos de Tor putitora (mahseer). Foi preparado um alimento com níveis de proteína dietética de 35%, 40%, 45% e 50%. O efeito de diferentes alimentos à base de proteína no ganho de peso, taxa de crescimento padrão (SGR), taxa de conversão alimentar (FCR), ganho de peso percentual, eficiência de conversão alimentar (FCE) e taxa de eficiência proteica (PER) foi estudado. Foi observado um aumento na taxa de crescimento com um aumento na concentração de proteína de até 45%. Os alevinos alimentados com dieta de 45% de proteína apresentaram o maior crescimento, seguidos de 50%, 40% e 35%. O valor de SGR foi maior para dieta com 45% de proteína (8,56), seguido de 50% e 40%, enquanto os menores valores foram observados para ração com 35% de proteína (1,57). A mesma tendência foi observada para FCE. Os maiores valores de PER foram observados em peixes alimentados com 45% de ração à base de proteína (0,65), seguido por 50% (0,56), 40% (0,38) e 35% (0,17). A taxa de conversão alimentar foi menor para a dieta com 45% de proteína (3,41), enquanto a maior para a dieta com 35% de proteína (16,85). Concluiu-se que a dieta à base de proteína de 45% foi a melhor formulação alimentar para maior produção de Tor putitora. No entanto, a pesquisa sobre a mesma porcentagem de dieta proteica é recomendada para animais de um ano.

Resumo

The discontinuous seed hydration enables the acquisition of tolerance to environmental stresses, causing a stress imprint. It may modify metabolic patterns and lead to improved stress responses. This study aims to evaluate the effects of discontinuous hydration on germination and on seedling growth of Triplaris gardneriana Wedd. under intermittent drought. The seeds have gone through cycles (0, 1, 2 and 3) of hydration and dehydration (HD). The seedlings produced were subjected to water deficit (daily watering and intervals of seven and fourteen days between watering). Seed germinability parameters and, relative growth rate (RGR) of seedling, leaf area, dry matter yield and leaf relative water content (RWC) were evaluated. The HD cycles did not benefit germination, but two HD cycles induced a better biomass accumulation and increased leaf area in seedlings under moderate water deficit, while three HD cycles promoted an increase in RGR and influenced the RWC values. Severe stress affects seedling growth, but subjection to HD cycles minimizes the deleterious effects of drought, suggesting discontinuous hydration acts leading stress imprint in plants.

Resumo

This study aimed to evaluate the growth of Arthrospira (Spirulina)platensiscultivated in Zarrouk culture medium and effluent from Nile tilapia (Oreochromis niloticus) reared in biofloc system. Four treatments were used: Control (100% Zarrouk), E50 (50% Zarrouk + 50% Tilapia effluent), E75 (25% Zarrouk + 75% Tilapia effluent), and E100 (100% Tilapia effluent), and the experiment lasted 10 days. Growth parameters such as maximum cell density (MCD), doubling time (DT), and growth rate (K) were daily evaluated, as well aspH and water temperature. In addition, the concentrations of total ammonia nitrogen (TAN), nitrite-N (NO2-N), and nitrate-N (NO3-N) were analyzed in order to compare nitrogen absorption. Among treatments, E50 and E75 obtained higher maximum cell densities and presented an exponential growth rate similar to the control treatment. Regarding the concentrations of nitrogen compounds, a significant reduction was observed in all treatments, with an NO3-Nuptake of 99%, followed by 80% of TAN and 90% of NO2-N. Thus, giving the results obtained, besides being able to grow in wastewater, A. platensis can also be used in bioremediation processes, confirming the potential of this species.

Resumo

Camelina sativa (L.) Crantz is an emerging oil seed crop and research information on its response to different levels of phosphorous (P) fertilizer is lacking. The two years study was performed to investigate the response of C. sativa to various rates of P fertilizer. The experiments were laid out in Randomized Complete Block Design (RCBD) with factorial arrangement having four replications. The P was applied in soil at the rate of 0, 30, 40 and 60 kg ha-¹ to two C. sativa accessions namely Canadian and Australian. Soil applied phosphorus rates had significant effects on the growth, yield and quality of C. sativa and two accessions were varied to each other. Australian accession performed better in terms of quality traits and Canadian was superior in terms of seed yield. An increase in P rate improved growth, yield and quality and 60 kg P ha-¹ resulted in maximal crop growth rate (6.79), seed yield (1239 kg ha-¹), total P uptake (0.67%) and oil contents (39.8%). The regression model estimated that each increment in P rate increased the seed yield by 11.5 and 11.2 kg ha-¹ in Canadian and Australian accessions, respectively. Conclusively, increases in P rates (0 to 60 kg ha-¹) impart a positive impact on C. sativa accessions and 60 kg P ha-¹ was most effective to achieve optimum yield and profitability.

Camelina sativa (L.) Crantz é uma cultura de sementes oleaginosas emergente e faltam informações de pesquisa sobre sua resposta a diferentes níveis de fertilizante de fósforo (P). O estudo de dois anos foi realizado para investigar a resposta de C. sativa a várias doses de fertilizante P. Os experimentos foram dispostos em blocos casualizados em arranjo fatorial com quatro repetições. O P foi aplicado em solo na proporção de 0, 30, 40 e 60 kg ha-¹ em dois acessos de C. sativa, canadenses e australianos. As doses de P aplicadas no solo tiveram efeitos significativos sobre o crescimento, rendimento e qualidade de C. sativa e dois acessos foram variados entre si. O acesso australiano teve melhor desempenho em termos de características de qualidade e o canadense foi superior em termos de rendimento de sementes. O aumento na taxa de P melhorou o crescimento, rendimento e qualidade e 60 kg P ha-¹ resultou em taxa máxima de crescimento da cultura (6,79), rendimento de sementes (1239 kg ha-¹), absorção total de P (0,67%) e teor de óleo (39,8 %). O modelo de regressão estimou que cada incremento na dose de P aumentou a produtividade de sementes em 11,5 e 11,2 kg ha-¹ nos acessos canadense e australiano, respectivamente. Conclusivamente, aumentos nas doses de P (0 a 60 kg ha-¹) conferem um impacto positivo sobre os acessos de C. sativa e 60 kg P ha-¹ foram mais eficazes para atingir rendimento e lucratividade ideais.

Resumo

Abstract Poppiana dentata (Randall, 1840) is widely distributed throughout riverine habitats in Trinidad. However, there is a scarcity of information on the biology of this species. This study provides the first baseline examination that describes growth aspects for P. dentata. Juvenile crabs were obtained from berried females collected in northwest Trinidad. Carapace width (CW), length (CL), moult incident, intermoult period and qualitative aspects were recorded for crabs (N = 23) over 9 months. CW, CL and intermoult period were used to derive percentage size increment, specific growth rate (SGR) and size at structural maturity for both sexes. Growth curves and logistic equations were also generated for each sex. Hatched crabs ( 5 mm CW) underwent rapid hardening after their first moult, indicating a fast turnover of moult cycles. SGR and CW percent increment were also the highest for this initial moult (P 0.05). CW, CL, intermoult period, size increment and SGR did not differ between sexes (P > 0.05), with logistic equations expressed as CW = 32.81 (1+exp (1.481 0.031t))-1 for males and CW = 34.07 (1+exp (1.516 0.027t))-1 for females. Yet, breakpoint analyses indicated dissimilar sizes for structural maturity (male: 28.40 mm CW; female: 16.84 mm CW). These patterns reflect a shorter life span for this species in comparison to what has been reported for other trichodactylid relatives. This can have implications for P. dentata populations residing in anthropogenically disturbed habitats; thus, highlighting the need for conservation strategies to ensure preservation of native wild stock.

Resumo O Poppiana dentata (Randall, 1840) está amplamente distribuído nos habitats fluviais de Trinidad. Existem, porém, poucas informações sobre a biologia dessa espécie. Este estudo fornece a primeira análise de referência que descreve aspectos do crescimento do P. dentata. Caranguejos jovens foram obtidos a partir de fêmeas em desova na região noroeste de Trinidad. A largura da carapaça (LC), o comprimento da carapaça (CC), a incidência de muda, o período de intermuda e aspectos qualitativos foram registrados para caranguejos (N = 23) ao longo de mais de nove meses. A LC, o CC e o período de intermuda foram utilizados para obter o aumento porcentual, a taxa específica de crescimento (TEC), e o tamanho na maturidade estrutural para os dois sexos. Curvas de crescimento e equações logísticas foram também geradas para cada sexo. Os caranguejos que nasceram (com largura de carapaça 5 mm) apresentaram um endurecimento rápido depois de sua primeira muda, o que indica uma rápida rotação dos ciclos de muda. A TEC e o aumento da porcentual da LC foram também os mais altos para esta muda inicial (P 0,05). Não houve variação da LC, CC, do período de intermuda, aumento do tamanho e da TEC entre os sexos (P > 0,05), e as equações logísticas foram expressas como: LC = 32,81 (1+exp (1,481 0,031t))-1 para machos, e LC = 34,07 (1+exp (1,516 0,027t))-1 para fêmeas. Porém, as análises de quebra indicaram tamanhos diferentes para maturidade estrutural (LC para macho: 28,40; para fêmea: 16,84 mm). Esses padrões refletem um período de vida mais curto para esta espécie em comparação com o que tem sido registrado para outras famílias de Trichodactylidae. Isso pode ter implicações para as populações de P. dentata que residem em habitats modificados antropogenicamente; destaca-se, assim, a necessidade de estratégias de conservação para assegurar a preservação das populações selvagens nativas.

Resumo

Poppiana dentata (Randall, 1840) is widely distributed throughout riverine habitats in Trinidad. However, there is a scarcity of information on the biology of this species. This study provides the first baseline examination that describes growth aspects for P. dentata. Juvenile crabs were obtained from berried females collected in northwest Trinidad. Carapace width (CW), length (CL), moult incident, intermoult period and qualitative aspects were recorded for crabs (N = 23) over 9 months. CW, CL and intermoult period were used to derive percentage size increment, specific growth rate (SGR) and size at structural maturity for both sexes. Growth curves and logistic equations were also generated for each sex. Hatched crabs (< 5 mm CW) underwent rapid hardening after their first moult, indicating a fast turnover of moult cycles. SGR and CW percent increment were also the highest for this initial moult (P < 0.05). CW, CL, intermoult period, size increment and SGR did not differ between sexes (P > 0.05), with logistic equations expressed as CW = 32.81 (1+exp (1.481 ̵ 0.031t))-1 for males and CW = 34.07 (1+exp (1.516 ̵ 0.027t))-1 for females. Yet, breakpoint analyses indicated dissimilar sizes for structural maturity (male: 28.40 mm CW; female: 16.84 mm CW). These patterns reflect a shorter life span for this species in comparison to what has been reported for other trichodactylid relatives. This can have implications for P. dentata populations residing in anthropogenically disturbed habitats; thus, highlighting the need for conservation strategies to ensure preservation of native wild stock.

O Poppiana dentata (Randall, 1840) está amplamente distribuído nos habitats fluviais de Trinidad. Existem, porém, poucas informações sobre a biologia dessa espécie. Este estudo fornece a primeira análise de referência que descreve aspectos do crescimento do P. dentata. Caranguejos jovens foram obtidos a partir de fêmeas em desova na região noroeste de Trinidad. A largura da carapaça (LC), o comprimento da carapaça (CC), a incidência de muda, o período de intermuda e aspectos qualitativos foram registrados para caranguejos (N = 23) ao longo de mais de nove meses. A LC, o CC e o período de intermuda foram utilizados para obter o aumento porcentual, a taxa específica de crescimento (TEC), e o tamanho na maturidade estrutural para os dois sexos. Curvas de crescimento e equações logísticas foram também geradas para cada sexo. Os caranguejos que nasceram (com largura de carapaça < 5 mm) apresentaram um endurecimento rápido depois de sua primeira muda, o que indica uma rápida rotação dos ciclos de muda. A TEC e o aumento da porcentual da LC foram também os mais altos para esta muda inicial (P < 0,05). Não houve variação da LC, CC, do período de intermuda, aumento do tamanho e da TEC entre os sexos (P > 0,05), e as equações logísticas foram expressas como: LC = 32,81 (1+exp (1,481 ̵ 0,031t))-1 para machos, e LC = 34,07 (1+exp (1,516 ̵ 0,027t))-1 para fêmeas. Porém, as análises de quebra indicaram tamanhos diferentes para maturidade estrutural (LC para macho: 28,40; para fêmea: 16,84 mm). Esses padrões refletem um período de vida mais curto para esta espécie em comparação com o que tem sido registrado para outras famílias de Trichodactylidae. Isso pode ter implicações para as populações de P. dentata que residem em habitats modificados antropogenicamente; destaca-se, assim, a necessidade de estratégias de conservação para assegurar a preservação das populações selvagens nativas.

Resumo

Plant growth analysis can be used for soybean plants evaluation to identify morphologic changes caused by soil microbes after seed inoculation. The objective was to measure changes of inoculated soybean plants grown under regular field Brazilian production conditions. The experiment was carried out to compare 5 inoculation treatments: T1 (Bradyrhizobium japonicum and B. diazoefficiens), T2 (T1 and Azospirillum brasilense), T3 (T1 and Trichoderma asperellum), T4 (T1 and T. virens, and Bacillus amyloliquefaciens) and T5 (T1 and Penicillum bilaiae). Leaf area, shoot and root dry matter were measured at vegetative and reproductive growth stages. Results of this study validate the contribution of plant growth analysis of soybeans plants for identifying their responses promoted by the combined inoculation of their seeds with selected microbes. Also, the microbial effects on plant growth vary not only between microbes but also between parts of the plants and through the plant development stages. The introduction of different microbes in soybean rhizosphere combined with Bradyrhizobium sp. strains can contribute to increase crop dry matter productivity during its growing cycle.

Análise de crescimento de plantas pode ser utilizada para avaliação de plantas e identificação de mudanças causadas por microrganismos de solo, depois de serem inoculados nas sementes. O objetivo deste estudo foi medir as mudanças no crescimento de plantas de soja inoculadas em condição de cultivos extensivos de campo no Brasil. O experimento foi conduzido para comparar cinco tratamentos inoculados: T1 (Bradyrhizobium japonicum e B. diazoefficiens), T2 (T1 e Azospirillum brasilense), T3 (T1 e Trichoderma asperellum), T4 (T1 and T. virens, e Bacillus amyloliquefaciens) e T5 (T1 e Penicillum bilaiae). A área foliar e a massa seca da parte aérea e de raízes foram medidas nos estádios vegetativos e reprodutivos. Os resultados validam a contribuição da análise de crescimento de plantas de soja para identificar as respostas causadas pela inoculação de sementes com combinação de microrganismos selecionados. Os efeitos dos microrganismos no crescimento das plantas não variam apenas entre os microrganismos, mas também entre as partes das plantas e ao longo do seu desenvolvimento. A introdução de diferentes micróbios na rizosfera de soja, combinados com cepas de Bradyrhizobium sp. pode aumentar a produtividade de massa seca das culturas durante o seu ciclo de crescimento.