Desempenho de cordeiros Santa Inês puros e cruzas Santa Inês com Texel, Ile de France e Bergamácia

O trabalho foi desenvolvido com o objetivo de estudar o efeito do sexo dos animais, do grupo genético e do peso de abate no desempenho de animais confinados. Foram utilizados 103 cordeiros, machos e fêmeas, Santa Inês puros (SS) e cruzas Santa Inês com Texel (TS), Ile de France (FS) e Bergamácia (BS), confinados em gaiolas individuais. Mediram-se a dieta fornecida e as sobras diárias, para cálculo do consumo de matéria seca (MS), energia metabolizável (EM), proteína digestível (PD) e fibra em detergente neutro (FDN). Os cordeiros foram abatidos em quatro pesos: 15, 25, 35 e 45 kg de peso vivo. Avaliaram-se o ganho de peso diário (GPD), o número de dias no confinamento (ND), a conversão alimentar (CA) e o consumo de MS, PD, em e FDN, nas três fases de crescimento: 15 a 25 kg (1), 25 a 35 kg (2) e 35 a 45 kg (3). Também foram avaliados as idades de abate (IA), o peso do corpo vazio (PCVZ) e rendimento de carcaça (RC). Aos 35 e 45 kg, os cordeiros TS e FS apresentaram IA inferiores e as cordeiras SS, IA superiores. O ND dos cordeiros BS de 35 a 45 kg foi maior que dos TS. Aos 35 e 45 kg, o PCVZ dos cordeiros TS e FS foram menores. Os melhores GPD foram dos cordeiros TS, seguidos do FS e SS. Os consumos de MS, PD, em e FDN foram semelhantes entre os grupos genéticos, nas fases 1 e 2 de crescimento. Verificou-se que os cordeiros TS tenderam a aumentar o consumo, com o incremento de peso, enquanto os outros grupos tenderam a diminuir. A CA elevou-se com o aumento de peso, com exceção dos machos FS. Os machos não apresentaram diferenças na CA entre os grupos genéticos, entretanto, as fêmeas TS e FS apresentaram valores melhores. Aos 35 e 45 kg, as fêmeas apresentaram maiores RC que os machos. Aos 35 kg, os melhores RC foram dos machos TS.

Fontes de óleo vegetal na dieta de cordeiros em confinamento

Objetivou-se avaliar a ingestão de matéria seca, o ganho de peso diário, a conversão alimentar, o peso vivo ao abate e o período de confinamento em cordeiros Santa Inês puros e ½Dorset ½Santa Inês, alimentados com dietas isoenergéticas (76,59% de NDT) e isoprotéicas (17,48% de PB) contendo diferentes fontes de óleo vegetal (óleos de soja, canola e linhaça) e uma dieta controle (sem inclusão de óleo vegetal). A relação volumoso:concentrado foi de 30:70 e utilizou-se feno de aveia como volumoso. Realizou-se também um ensaio de digestibilidade, utilizando quatro cordeiros não-castrados, distribuídos em delineamento quadrado latino, avaliando-se ingestão, excreção fecal e digestibilidade total dos nutrientes das rações. A ingestão de matéria seca, expressa em porcentagem do peso vivo, foi menor nos cordeiros que receberam dieta contendo óleo de canola que naqueles que receberam dieta controle. Porém, todas as rações proporcionaram ganhos de peso e conversão alimentar satisfatórios. Os valores de digestibilidade total da matéria seca (76,02%) e matéria orgânica (76,82%) da dieta controle foram superiores aos da dieta contendo óleo de linhaça (72,11% e 72,97%, respectivamente), embora não tenham diferido das dietas contendo óleos de soja (72,94 e 73,71%) e canola (73,45 e 74,25%). A digestibilidade do extrato etéreo foi menor na dieta controle (84,02%), enquanto as demais dietas apresentaram valor médio de 91,98%. Os óleos vegetais reduziram a digestibilidade da matéria seca e da matéria orgânica, não afetando a ingestão e digestão dos demais nutrientes.

Feed efficiency of Nellore cattle selected for postweaning weight

Foram comparados dois rebanhos Nelore, um selecionado para maior peso pós-desmame e outro controle, selecionado para a média de peso pós-desmame, para avaliar os efeitos de 29 anos de seleção sobre a eficiência alimentar. Sessenta machos Nelore com 205 kg e 267 dias de idade (41 selecionados e 19 controle), foram avaliados em baias individuais durante a prova de ganho de peso. O desempenho e o consumo de matéria seca foram utilizados para determinar as seguintes medidas de eficiência: conversão alimentar; consumo alimentar residual; ganho residual; eficiência parcial de crescimento; taxa de crescimento relativo; e taxa de Kleiber. Após o período experimental de 112 dias, os animais controle apresentaram menor peso vivo final em comparação aos selecionados, contudo, não diferiram quanto ao consumo de matéria seca (% do peso vivo), à área de olho-de-lombo e às espessuras de gordura subcutânea na altura da 12ª costela e na região da picanha. O consumo de matéria seca (kg/dia) e o ganho médio diário dos animais selecionados foram, respectivamente, 19,4 e 26,4% superiores aos dos controle. O maior ganho médio diário dos animais selecionados promoveu melhora significativa, em torno de 6%, na conversão alimentar; 70 g/dia no ganho residual; e de 17% na taxa de Kleiber. As demais medidas de eficiência (consumo alimentar residual, eficiência parcial de crescimento e taxa de crescimento relativo) não diferiram entre os rebanhos. Os 29 anos de seleção para peso pós-desmame não afetaram a eficiência alimentar de bovinos Nelore.

Test post-weaning duration for performance, feed intake and feed efficiency in Nellore cattle

O objetivo neste estudo foi determinar o melhor período de avaliação para medidas de desempenho, consumo e eficiência alimentar. Durante 112 dias, 60 machos da raça Nelore, recém-desmamados, submetidos à prova de ganho de peso, foram alimentados em baias individuais para determinação do consumo alimentar e do desempenho. O peso corporal dos animais foi determinado a cada 28 dias, depois de jejum de 16 horas de líquidos e sólidos. As alterações na variância, variância relativa e correlações de Pearson e Spearman entre os dados dos períodos de avaliação reduzidos (28, 56 e 84 dias) e período total (112 dias) foram usados para determinar a melhor duração do período de avaliação. A duração do período de avaliação para ganho médio diário, consumo de matéria seca, conversão alimentar e consumo alimentar residual pode ser reduzida para 84, 28, 84 e 84 dias, respectivamente, pois tal redução não diminui significativamente a confiabilidade das avaliações em animais alimentados em baias individuais.

Residual feed intake and relationships with performance of Nellore cattle selected for post weaning weight

Objetivou-se com este trabalho avaliar desempenho, parâmetros de eficiência e correlações fenotípicas entre medidas de eficiência energética de animais Nelore selecionados para peso pós-desmame e classificados quanto ao consumo alimentar residual, calculado pela diferença entre o consumo observado e o predito, com base no peso vivo médio metabólico e no ganho médio diário. Assim, os animais foram classificados em três grupos: alto (> média + 0,5 desvio-padrão; menos eficientes); médio (± 0,5 desvio-padrão da média); e baixo (< média - 0,5 desvio padrão; mais eficientes) consumo alimentar residual. Não foram observadas diferenças nos pesos vivos inicial e final, no ganho médio diário e no consumo de matéria seca entre os grupos. Animais com baixo consumo alimentar residual mostraram-se também com melhor eficiência alimentar, conversão alimentar e eficiência parcial de crescimento e não apresentaram diferenças em relação aos outros grupos quanto à taxa de crescimento relativo e taxa Kleiber. O consumo alimentar residual apresentou correlação significativa com eficiência alimentar (_0,25), conversão alimentar (0,25), eficiência parcial de crescimento (_0,37) e consumo de MS (0,16) e não apresentou correlação significativa com peso vivo (0,04), ganho médio diário (_0,02), taxa de crescimento relativo (_0,03) e taxa de Kleiber (_0,05). Foram encontradas correlações significativas entre conversão alimentar e peso vivo inicial (0,34) e ganho médio diário (_0,46). Eficiência parcial de crescimento apresentou correlação significativa comtodos os outros parâmetros de eficiência analisados. O consumo alimentar residual, em comparação às demais medidas de eficiência energética, apresenta grande potencial na eficiência produtiva, sendo independente de crescimento e tamanho dos animais.

Automatic identification of terpenoid skeletons by feed-forward neural networks

Feed-forward neural networks (FFNNs) were used to predict the skeletal type of molecules belonging to six classes of terpenoids. A database that contains the (13)C NMR spectra of about 5000 compounds was used to train the FFNNs. An efficient representation of the spectra was designed and the constitution of the best FFNN input vector format resorted from an heuristic approach. The latter was derived from general considerations on terpenoid structures. (c) 2006 Elsevier B.V. All rights reserved.

The use of extruded feed in fish food

In our country, the intensive culture of fish has been making progress due to the availability of extruded rations, which are characterized by the way they have been formulated to assist the nutritional demands of the tropical species and for facilitating a better practice of alimentary handling. This process checks the extruded product density and the desirable physical/chemical aspects to a diet that should be handled in the water, the critical factor of this activity. It is important to emphasize that this product stays to the surface of the water, facilitates the consumption control and the observation of the general aspects of the school of fish, as well as guaranteeing that no deterioration of the physical/chemical characteristics of the water occurs. The floating characteristic of the extruded ration is preferable for farmers because most of the tropical species feed at the surface of the water. In some cases, in the function of the alimentary habit, the thermal conditions of the water and the handling system produce granules with different densities. This is due to the humidity and the applied cooking heat, which modifies the time of hydration, and consequently the ability to float. To establish the physical presentation idea for a ration for tropical fishes, it is necessary that the pellets come in sizes, textures, humidities and densities in order to allow for the different phases of the lives of the fishes. This ration should be the result of characteristics of the species, such as the anatomophysiologics particularities, alimentary habits, digestive capacity and alimentary behavior. Only in this way is it possible to offer to those fishes a ration whose nutritious value and physical presentation facilitate the best biological and economic answers.Those aspects need to be reviewed because the tropical species that are cultivated in our country present selective behavior in relation to the size of the pellet. Generally, this has access to the digestive system without waste; the digestibility, therefore, is dependent upon the size of the particles and the physical aspects of the pellets. They should still consider that those granules could be less abrasive and softer. The extruded rations available in the national market present a qualitative reference to its proteic level, whose consequence allows us to infer that those are overestimated for the final phase of those fishes. Thus, the final cost of production is made unfeasible. In this point of view of the development of the national fish culture, and the growing adoption of the intensive system of production, it can link that such progress is a function of the availability of the rations in the extruded form. Although this technique of processing of rations has revolutionized the market in such a way that has been seen as preferable for farmers, some feel that there is a lack of products best suited for the initial phases of fingerlings production.

A COMPARATIVE-STUDY OF 4 DIFFERENT STAINING METHODS FOR ESTIMATION OF LIVE YEAST FORM CELLS OF PARACOCCIDIOIDES-BRASILIENSIS

A comparative study of four different staining methods for estimation of live yeast form cells of Paracoccidioides brasiliensis was carried out. The staining methods used were fluorescent staining, vital dye exclusion tests with erythrosin B and by Janus green and lactophenol cotton blue staining. Colony forming units (cfu) of the yeast form of eight P. brasiliensis isolates on brain heart infusion agar (BHIA) supplemented with 4% horse serum plus 5% P. brasiliensis cell extract (BHIA + HS + EXT) were examined for reliability of staining in determining the number of live fungal units in eight different isolates. Cfu on BHIA + HS + EXT plates showed an excellent plating efficiency over 96% in all isolates tested. The percentage of the live cells indicated by fluorescent staining (FL) or vital dye exclusion test with erythrosin B (EB) or Janus green (JG-1) was lower than that of cfu. By contrast, the percentage due to modified dye exclusion test with Janus green (JG-2) and that due to lactophenol cotton blue staining (LPCB) showed a close correration to that of cfu. Our results indicate that the modified dye exclusion test with Janus green and lactophenol cotton blue staining are useful for estimating cell viability of yeast form cells of P. brasiliensis.

Determination of the betaine content of feed ingredients using high-performance liquid chromatography

A series of studies was conducted to establish a methodology for the accurate and efficient determination of betaine in different feed ingredients. The final methodology involves an extraction step in which the feed sample is heated for 3h in a methanolic KOH solution using a Goldfisch apparatus. Impurities are removed by the addition of activated charcoal and concentrated (36%) HCl. After centrifugation the extractant is passed through a strong cation exchange resin (Dowex 50W-X12, H+). The betaine retained in the column is eluted with 1.5 N HCl. A 2 nil aliquot of the elute is air dried and reconstituted with 1 ml of deionised water. HPLC separation with a cation exchange column (Partisil SCX-10) is used for the separation of betaine from other compounds. The mobile phase is kept constant at 50mm KH2PO4 in water, and eluted compounds are detected by UV absorbance (200nm). The flow rate is maintained at 1.5ml min(-1). This assay is very accurate over the range of betaine concentrations from 15 to 650 mug ml(-1), with a lower detection limit in feeds of approximately 500 mug g(-1) when 4g of sample is extracted. Recovery assays done with standard betaine hydrochloride and hard red wheat resulted in a consistent recovery of 80%. Betaine content was quantified in several feed ingredients, including alfalfa (1.77 mg kg(-1)), wheat (3.96 mg kg(-1)), wheat middlings (4.98 mg kg(-1)) and poultry meal (0.77 mg kg(-1)). Betaine in corn and soybean meal was not detectable by this method, even when 16g of sample was used (<125 mg kg(-1)). Betaine present in several feed ingredients should influence choline supplementation to animal feeds and may have implications for human health. (C) 2002 Society of Chemical Industry.

Desempenho Produtivo de Animais de Quatro Raças Zebuínas, Abatidos em Três Estádios de Maturidade. 1. Ganho de Peso e de Carcaça e Eficiência de Ganho

This research was conducted to evaluate the productive performance (live weight gain and carcass weight gain and gain efficiency) of animals from four zebu breed slaughtered in three maturity stages. Thirty-six bulls from Gyr, Guzera, Mocho Tabapua and Nellore with twenty-four months of average age and average initial live weight of 357.6, 362.0, 368.6 and 376.4 kg, respectively, were used. The bulls, from each breed, were randomly assigned to individual pens and were full-fed a diet containing 50% concentrate (DM basis) and distributed to three category (1, 2 and 3) of slaughter weights. The bulls from category 1, 2 and 3 were slaughtered when reached the individual live weight of 405, 450 and 500 kg, respectively. At slaughter the empty body weight was determined. The Nellore breed bulls showed greater average empty body weight gain and carcass gain in relation to the other breeds, which did not differ among themselves. There were no differences among breeds regarding to feed efficiency (empty body weight gain efficiency and carcass gain efficiency per unit of metabolizable energy intake). The slaughter weight did not influence the empty body weight gain and carcass gain, but animals slaughtered at higher slaughter weights showed lower gain efficiency and spent more time in feedlot.

A note on carcass characteristics of rabbits fed on a restricted system

Thirty four 65 days old New Zealand White female rabbits. weighting 1900 +/- 40 g, were separated in 3 groups and caged individually. One group was slaughtered when 70 days old (reference group, n=14). The second group was slaughtered 50 days later after ad libitum feeding (n = 6), and the third group was slaughtered also when 120 days old, but after restricted feeding since 70 days old i.e. 50% of the spontaneous feed intake of the 65-70 days period (restricted group n=14). Whole carcass weight and carcass cuts weights were measured after 24 hours storage at +4 degrees C. For each of the 3 groups in the previous order, slaughter live weight was 1992 - 2988 and 1887g; Chilled carcass percentage were 47.9 - 51.0 and 50.1. Feed restriction decreased the loin proportion of the carcass lower than that of the reference group (27.0 - 26.1 and 22.8% for the 3 groups in the same order) but increased the posterior limbs proportion (36.5 - 36.6 and 40.1).

Feeding habit of the Amazon river prawn Macrobrachium amazonicum larvae

To investigate the feeding habit of Macrobrachium amazonicum, three experiments were carried out assessing the stage at which larvae start exogenous feeding, the acceptance of inert food by different larval stages and the ratio between live and inert diet ingested by larvae at each larval stage. In the first experiment, newly hatched larvae were kept in 500-mL beakers and fed from stages I, II or III onward. Larval survival was not affected by the larval stage at which exogenous feeding started, but mean weight gain was lower when food was offered from stage III onward. In the second experiment, 60 larvae from each stage (I to IX) were fasted for 2 h and then fed on inert diet in excess. Only larvae from stage IV onward accepted this inert diet. In the last experiment, newly hatched larvae were stocked in a larviculture tank and fed daily on both Artemia nauplii and inert diet. After 15 min, food content in the digestive tract of individual larvae was analyzed under stereomicroscopy. Larvae in stage I did not feed, while live food was accepted from stage II onward and inert food from stage III onward. Larvae in stages IV, V and VI accepted both foods with no preference, while inert food was predominant in stages VII to IX In conclusion, to feed M amazonicum larvae on Artemia before stage II or on inert diet before stage IV is unnecessary. It increases production costs and may impair water quality. From stages IV to VI, feeding on Artemia and inert diet is probably necessary, while inert diet should be the main food item from stage VII onward. This schedule may optimize feeding management and production costs. (c) 2007 Elsevier B.V. All lights reserved.