Relação proteína: carboidrato no desempenho e metabolismo de juvenis de pacamã (Lophiosilurus alexandri) / Ratio protein: carbohydrate on performance and metabolism of Juvenile (Lophiosilurus alexandri)

Objetivou-se neste estudo verificar o melhor nível de inclusão entre proteína e carboidrato no desempenho e algumas respostas metabólicas em juvenis de pacamã (Lophiosilurus alexandri). Testaram-se quatro dietas com as relações proteína/carboidrato (PB:CHO) 1,24; 0,84; 0,51 e 0,33 durante 60 dias. Foram utilizados 240 juvenis de pacamã pesando inicialmente 1,90g, alimentados duas vezes ao dia (8% da biomassa). Avaliou-se o ganho de peso total, taxa de crescimento específico, consumo de ração aparente, conversão alimentar aparente, rendimento de carcaça e gordura visceral. Glicemia, aminoácidos totais livres no plasma e glicogênio hepático também foram avaliados. A relação PB:CHO influenciou (P<0,05) os parâmetros de desempenho e metabolismo, exceto o glicogênio hepático. Maiores concentrações de glicose e aminoácidos totais livres no plasma foram observadas nos peixes que se alimentaram com a dieta contendo a maior relação PB:CHO (1,24). Além disso, observaram-se melhores médias de ganho de peso, taxa de crescimento específico e conversão alimentar aparente. Maiores percentuais de gordura visceral e menor rendimento de carcaça foram observados nos animais submetidos à dieta composta pela menor relação PB:CHO (0,33). Pode-se concluir que a dieta com a relação PB:CHO de 1,24 promoveu melhor desempenho e respostas metabólicas em juvenis de pacamã...

The aim of this study was to determine the best level of inclusion between protein and carbohydrate on performance and some metabolic responses in juvenile pacamã (Lophiosilurus alexandri). We tested four diets regarding protein/carbohydrate (PB: CHO) 1.24, 0.84, 0.51 and 0.33 for 60 days. The experiment was conducted with 240 juvenile pacamã initially weighing 1.90g, fed twice daily (8% of the biomass). We evaluated the total weight gain, specific growth rate, feed intake, feed conversion, carcass yield and visceral fat. Glucose, total plasma free amino acids and liver glycogen were also evaluated. The relationship PB: CHO influenced (P <0.05) the performance and metabolism parameters except the liver glycogen. Higher concentrations of glucose and total plasma free amino acids were observed in fish that were fed the diet containing the highest ratio PB: CHO (1.24); and we also observed better mean weight gain, specific growth rate and feed conversion. A higher percentage of visceral fat and lower carcass yield were observed in animals treated with diet composed by the lower ratio PB: CHO (0.33). We can conclude that a diet with a ratio PB: CHO of 1.24, promotes better performance and metabolic responses in juvenile pacamã...

Frequência de alimentação para juvenis de tambaqui / Feeding frequency for tambaqui juveniles

Objetivou-se nesta pesquisa avaliar qual frequência alimentar promove o melhor desempenho em juvenis de tambaqui. Foram testadas quatro frequências alimentares (duas, quatro, seis e oito vezes ao dia) em intervalos regulares. Foram estocados alevinos de tambaqui com peso médio inicial de 15,74±0,28g em 16 aquários de vidro transparentes com capacidade de 70L de volume útil, em um delineamento inteiramente ao acaso, com quatro tratamentos e quatro repetições. O período de alimentação foi de 30 dias, e utilizou-se uma ração comercial contendo 45 por cento de proteína bruta para peixes onívoros, com taxa de arraçoamento de 6 por cento da biomassa total dos peixes de cada aquário. Os resultados médios de pH, temperatura (°C) e condutividade elétrica (mS/cm) para manhã e tarde foram, respectivamente: 6,91; 6,96; 25,85; 27,69; 0,65; e 0,65. Foram avaliados os índices de desempenho: ganho de peso, conversão alimentar aparente, taxa de crescimento específico, sobrevivência, e também foi analisada a glicose sanguínea. Não foram detectadas diferenças significativas para as variáveis estudadas. Recomenda-se a frequência de alimentação de duas vezes ao dia para juvenis de tambaqui, principalmente visando minimizar mão de obra...

The aim of this research was to assess how often food promotes better performance in tambaqui. We tested four food frequencies (two, four, six and eight times a day) at regular intervals. Tambaqui fingerlings with initial weight of 15.74±0.28g were stocked in 16 transparent glass tanks with a capacity of 70L of usable volume in a completely randomized design with four treatments and four replications. The feeding period was thirty days and a commercial diet containing 45 percent crude protein for omnivorous fish and a feeding rate of 6 percent of the total biomass of fish for each experimental unit was used. The average results of pH, temperature °C and electrical conductivity mS/cm for morning and afternoon were respectively 6.91 and 6.96; 25.85 and 27.69; 0.65 and 0.65. We evaluated the performance indices: weight gain, feed conversion, specific growth rate, survival, and also blood glucose. No significant differences were detected for the variables studied. It is recommended that the frequency of feeding be 2 times a day for tambaqui, mainly to minimize labor...

Farelo de licuri em dietas para alevinos de tambaqui (Colossoma Macropomum, Cuvier, 1818) / Licuri meal in diets for tambaqui (Colossoma Macropomum, Cuvier, 1818)

A busca de alimentos alternativos para a fabricação de ração para peixes tem se tornado constante. No entanto, é essencial que, além de ter ótimo aproveitamento pela espécie, este alimento esteja disponível ao longo do ano. Deste modo, o objetivo do presente trabalho foi avaliar o efeito da substituição do farelo de milho pelo farelo de licuri sobre o desempenho de alevinos de tambaqui. Três tratamentos de níveis de substituição de milho pelo farelo de licuri (33,33 por cento; 66,66 por cento e 100 por cento) foram avaliados e comprados com a dieta controle. Os alevinos, com peso inicial médio de 3,18±0,5g, foram distribuídos em caixas de água de 250L, contendo cada uma, inicialmente, 16 animais. Os alevinos foram alimentados três vezes ao dia, a uma taxa de 5 por cento da biomassa total, durante o período de 50 dias. A cada 10 dias eram realizadas biometrias. Ao final do experimento, foram avaliados parâmetros de desempenho zootécnico e foi feita avaliação bromatológica da carcaça. Não houve diferença significativa entre os tratamentos, para os parâmetros: peso final, ganho de peso, conversão alimentar, eficiência alimentar, sobrevivência e crescimento, somente para o consumo de ração, que foi significativamente menor quando houve 100 por cento de substituição. Neste tratamento também houve maior porcentagem de proteína bruta e menor teor de extrato etéreo na carcaça...

The search for alternative ingredients for fish feed has become constant, therefore it is essential that the ingredients have total use by the specie. Beyond this, the ingredient should be available throughout the year. The aim of this study was to evaluate the effect of the corn meal replacement by licuri meal over tambaqui juvenile performance. Three replacement treatments were evaluated and compared to the control diet (33.33 percent; 66.66 percent and 100 percent). Sixteen fish (initial weight = 3.18 ± 0.5 g ) were placed in 250 L tanks. Fish were fed three times a day at the average of 5 percent of total biomass. Every ten days fish were weighed and measured. At the end of the trial, performance and carcass composition were evaluated in each treatment. There was no significant difference among treatments for final weight, weight gain, feed conversion, feed efficiency, survival and growth. However, there was significant difference for feed consumption, which was significantly lower where 100% of corn meal was replaced by licuri meal. Is this treatment higher carcass protein content and lower carcass fat was also significant...

Substituição do farelo de milho pela farinha de manga no desempenho da tilápia-do-nilo / Replacement of corn meal by mango in the dietary in performance of fingerlings of Nile-tilapia

Avaliou-se nesta pesquisa o efeito de diferentes fontes de carboidratos no desempenho de alevinos de tilápia. Foram testadas quatro dietas isoproteicas com diferentes concentrações de farinha de manga 0; 33, 66, e 100 por cento em substituição ao milho. O período de alimentação foi de 45 dias, e a taxa de arraçoamento foi de 8 por cento da biomassa. Foram utilizados 360 alevinos de tilápia-do-nilo, com peso médio inicial de 2,08±0,13g, distribuídos em 12 caixas de 500L, em um sistema de recirculação de água com biofiltro. Foram avaliados índices de desempenho, consumo de ração, rendimento de carcaça e sobrevivência. Os resultados obtidos demonstraram que o ganho de peso individual, o ganho médio diário, a taxa de crescimento específico, o consumo de ração aparente, a conversão alimentar aparente e a sobrevivência não foram afetados pelas fontes de carboidratos testadas. O rendimento de carcaça foi influenciado pela farinha de manga na ração. Concluiu-se que o milho na dieta pode ser substituído 100 por cento pela farinha de manga para a tilápia, sem prejudicar o desempenho.

The aim of this study was to evaluate the effect of different carbohydrates on the performance of Tilapia fingerlings. Four isoproteic diets with different concentrations of mango meal (0, 33, 66 and 100 percent) were tested to replace the cornmeal. The feeding period was 45 days and the feeding rate was 8 percent of the biomass. Three hundred and sixty nile tilapia fingerlings with initial average weight of 2.08±0.13g, distributed into 12 500L experimental units, in a water recirculating system with biofilter were used. Performance indicators such as feed intake, carcass yield and survival rate were also evaluated. The results showed that the individual weight gain, average daily gain, specific growth rate, apparent feed intake, apparent feed conversion and survival were not affected by the two sources of carbohydrates tested. The carcass yield was influenced by mango meal in the diet. It was concluded that the replacement of maize in the diet can be done with 100 percent mango meal for Tilapia.

Phenology and pollination biology of eight Peperomia species (Piperaceae) in semideciduous forests in southeastern Brazil.

Data on flowering phenology and pollination of Peperomia species are virtually non-existent. This study presents data on the pollination biology of eight Peperomia species from south-eastern Brazil, including the flowering phenology, pollination system, and reproductive success. Data on flowering phenology were recorded weekly and exclusion experiments on inflorescences provided data on autonomous self- and wind pollination. Direct visual observations were made and insect visits were recorded. Four Peperomia species showed continuous flowering, while the others were seasonal and flowered in the wet season. Pollination by wind and Syrphidae was confirmed for two self-incompatible Peperomia species. The remaining species are self-compatible and their high fruit set may be accounted for by autonomous self-pollination and perhaps agamospermy. Although the floral morphology of Peperomia species suggests wind- and/or insect pollination, most of the species studied exhibit autogamy and perhaps agamospermy as the main method of reproduction.

Ants visit nectaries of Epidendrum denticulatum (Orchidaceae) in a Brazilian rainforest: effects on herbivory and pollination

Epidendrum denticulatum (Orchidaceae) produces nectar on the petioles of buds, flowers, and fruits (extrafloral nectaries) but no nectar is found on its flowers, and it is probably a deceptive species. In the Brazilian Atlantic rainforest, some aspects of both the ecology and behavior of Camponotus sericeiventris (Formicinae) and Ectatomma tuberculatum (Ponerinae), two ant species foraging on E. denticulatum extrafloral nectaries, were investigated. Both experiments, using termites as baits and field observations, suggest that these ant species are able to prevent reproductive organ herbivory, without affecting pollinator behaviour. Since a low fruit set is often cited as a characteristic of the family, especially for deceptive species, ants attracted to orchid inflorescences protect reproductive structures and increase the probability of pollination success. Epidendrum denticulatum flowers were visited and probably pollinated by Heliconius erato (Nymphalidae) and Euphyes leptosema (Hesperiidae).

Ants visit nectaries of Epidendrum denticulatum (Orchidaceae) in a Brazilian rainforest: effects on herbivory and pollination.

Epidendrum denticulatum (Orchidaceae) produces nectar on the petioles of buds, flowers, and fruits (extrafloral nectaries) but no nectar is found on its flowers, and it is probably a deceptive species. In the Brazilian Atlantic rainforest, some aspects of both the ecology and behavior of Camponotus sericeiventris (Formicinae) and Ectatomma tuberculatum (Ponerinae), two ant species foraging on E. denticulatum extrafloral nectaries, were investigated. Both experiments, using termites as baits and field observations, suggest that these ant species are able to prevent reproductive organ herbivory, without affecting pollinator behaviour. Since a low fruit set is often cited as a characteristic of the family, especially for deceptive species, ants attracted to orchid inflorescences protect reproductive structures and increase the probability of pollination success. Epidendrum denticulatum flowers were visited and probably pollinated by Heliconius erato (Nymphalidae) and Euphyes leptosema (Hesperiidae).

Synchronization of ovulation in beef cows (Bos indicus) using GnRH, PGF2alpha and estradiol benzoate.

The objective of this study was to evaluate protocols for synchronizing ovulation in beef cattle. In Experiment 1, Nelore cows (Bos indicus) at random stages of the estrous cycle were assigned to 1 of the following treatments: Group GP controls (nonlactating, n=7) received GnRH agonist (Day 0) and PGF2alpha (Day 7); while Groups GPG (nonlactating, n=8) and GPG-L (lactating, n=9) cows were given GnRH (Day 0), PGF2alpha (Day 7) and GnRH again (Day 8, 30 h after PGF2alpha). A new follicular wave was observed 1.79+/-0.34 d after GnRH in 19/24 cows. After PGF2alpha, ovulation occurred in 19/24 cows (6/7 GP, 6/8 GPG, 7/9 GPG-L). Most cows (83.3%) exhibited a dominant follicle just before PGF2alpha, and 17/19 ovulatory follicles were from a new follicular wave. There was a more precise synchrony of ovulation (within 12 h) in cows that received a second dose of GnRH (GPG and GPG-L) than controls (GP, ovulation within 48 h; P<0.01). In Experiment 2, lactating Nelore cows with a visible corpus luteum (CL) by ultrasonography were allocated to 2 treatments: Group GPE (n=10) received GnRH agonist (Day 0), PGF2alpha (Day 7) and estradiol benzoate (EB; Day 8, 24 h after PGF2alpha); while Group EPE (n=11), received EB (Day 0), PGF2alpha (Day 9) and EB (Day 10, 24 h after PGF2alpha). Emergence of a new follicular wave was observed 1.6+/-0.31 d after GnRH (Group GPE). After EB injection (Day 8) ovulation was observed at 45.38+/-2.03 h in 7/10 cows within 12 h. In Group EPE the emergence of a new follicular wave was observed later (4.36+/-0.31 d) than in Group GEP (1.6+/-0.31 d; P<0.001). After the second EB injection (Day 10) ovulation was observed at 44.16+/-2.21 h within 12 (7/11 cows) or 18 h (8/11 cows). All 3 treatments were effective in synchronizing ovulation in beef cows. However, GPE and, particularly, EPE treatments offer a promising alternative to the GPG protocol in timed artificial insemination of beef cattle, due to the low cost of EB compared with GnRH agonists.

Estrous behavior and the estrus-to-ovulation interval in Nelore cattle (Bos indicus) with natural estrus or estrus induced with prostaglandin F2 alpha or norgestomet and estradiol valerate.

Estrous behavior and the estrus-to-ovulation interval are essential for estimating the best time to artificially inseminate cattle. Because these parameters are not well characterized in the Nelore breed (Bos indicus), the main purpose of the this study was to determine the estrus-to-ovulation interval in Nelore heifers and cows with natural estrus or with estrus induced by treatments with PGF2 alpha or norgestomet and estradiol valerate (NEV). The cows and heifers were observed continuously (24 h a day) to determine the onset of estrus and to study estrous behavior in the cows. Ten hours after the start of estrus the ovaries were scanned every 2 h by ultrasonography to monitor the dominant follicle until ovulation. Blood samples were collected periodically to determine progesterone levels by RIA. Administration of PGF2 alpha (2 injections, 11 days apart) did not induce estrus in most Nelore females in spite of the presence of functional CL, indicated by progesterone concentrations above 6.0 ng/ml in 25 of 28 animals. Treatment with NEV induced high sexual receptivity in cows (10/11), but only 66% ovulated. Cows with natural or induced estrus exhibited behavioral estrus of 10.9 +/- 1.4 h, and ovulation occurred 26.6 +/- 0.44 h (n = 26) after the onset of estrus. In most of the cows (53.8%) estrus began at night (between 1801 and 600 h), and 34.6% it started and finished during the night. It is concluded that in Nelore females ovulation occurs approximately 26 h after the onset of estrus. Additionally, estrous behavior is shorter than in European breeds, and there is a high incidence of estrus at night, which makes it difficult to detect and, consequently, impairs Al in Nelore cattle. The observation that a high percentage of Nelore females with an active CL did not respond to usual dosages of PGF2 alpha warrants further investigation.

Ovarian follicular dynamics in Nelore breed (Bos indicus) cattle.

The most common beef cattle raised in Brazil is the Nelore breed (Bos indicus). Information obtained by ultrasonography on follicular growth in Bos taurus cattle has been accumulating rapidly. However, there are few publications to date on follicular development in Bos indicus breeds. The follicular dynamics in Nelore heifers and cows during natural or prostaglandin (PG)-induced estrous cycle were studied. From the detection of estrus onward, all animals were examined daily by ultrasonography for one (n = 35) or two (n = 10) consecutive estrous cycles. The follicular dynamic in Nelore cattle was characterized by the predominance of 2 follicular waves in the cows (83.3%, n = 18, P < 0.05) and 3 waves in the heifers (64.7%, n = 16, P < 0.05). Most of the cattle observed over 2 consecutive estrous cycles presented the same pattern of follicular waves in the first and second cycle, and only 30% showed variation in the number of waves from one cycle to the other. Most of the follicular parameters analyzed were not affected by PG treatment or age but were altered by follicular waves. Consequently, data on cows and heifers were combined according to the number of follicular waves. The ovulatory follicle was larger than the other dominant follicles (P < 0.05), and the ovulatory wave was shorter than the preceding waves (P < 0.05). The interovulatory interval was longer in animals showing 3 waves than those exhibiting 2 waves (P < 0.05). Maximum diameter of the dominant follicle (around 11 mm) and of the corpus luteum (CL, approximately 17 mm) were smaller than those reported for European breeds. In conclusion, the results demonstrate that although the dominant follicle and corpus luteum are smaller than in European breeds, the follicular dynamics in Nelore cattle were similar to those observed in European breeds and were characterized by 2 or 3 follicular waves for cows and heifers, respectively, during the natural or prostaglandin-induced estrous cycle.

Hexokinase polymorphism in Apis mellifera and its use for africanized honeybee identification

Neste trabalho é descrito o alto grau de polimorfismo da hexoquinase (HK) em abelhas africanizadas do Brasil e confirmado o monomorfismo deste sistema em abelhas de origem européia. A detecçäo da alozima 87 em abelhas africanizadas do Brasil é explicada pela introduçäo de Apis mellifera scutellata no país em 1956. A frequência do gene HK nas populaçöes brasileiras analisadas é maior em Luiz Antonio, Estado de Säo Paulo, localidade próxima a Rio Claro, centro inicial de dispersäo dos enxames africanos. A frequência deste alelo diminui à medida que populaçöes situadas a uma maior distância deste centro säo amostradas, particularmente, em áreas mais ao sul do país, onde a atividade apícola com base em abelhas européias foi mais intensa. A detecçäo deste polimorfismo se reveste de significativa importância para o rastreamento de genes africanos em populaçöes de Apis mellifera existentes no continente americano