Resumo em Inglês:

Using biotechnology to increase the growth rates of fish is likely to reduce production costs per unit of food. Among vertebrates, fish appear to occupy a unique position, when growth patterns are considered. With few exceptions, fish species tend to grow indeterminately, implying that size is never fixed. Both hyperplasia and hypertrophy contribute to post-larval muscle growth in fish. Growth hormone (GH) - Insulin-like Growth Factor I (IGF-I) is the most important growth axis in fish. Our experimental model, the pejerrey, Odontesthes bonariensis (Ateriniformes) is a South American inland water fish considered to be a promising species for intensive aquaculture. However, one major drawback to achieve this goal is its slow growth in captivity. In order to understand how growth is regulated in this species, our first objective was to characterized pejerrey GH- IGF-I axis. We first cloned and characterized pejerrey (pj) GH, IGF-I and the growth hormone receptors (GHRs) I and II. In addition to providing valuable data for evolutionary comparison of GH, investigation of GH action in teleosts is particularly important because of its potential application in aquaculture. GH can not only promote the somatic growth in fish but also lower dietary protein requirements. A prerequisite for providing sufficient amounts of GH for basic research and aquaculture application is a large-scale production of GH. For that purpose, recombinant pjGH was expressed in a bacterial system. Protocols for solubilization and proper folding were achieved. Activity of recombinant pjGH was assessed in fish by measuring the liver IGF-I response to different doses of GH. IGF-I transcript was measured in the liver after pjGHr in vivo stimulation by means of quantitative real-time PCR assays. A dose-dependent response of IGF-I mRNA was observed after pjGHr administration, and reached a 6 fold IGF-I maximum increase over control group when 2.5 µg pjGH /g-body weight were injected. Temporal analysis of hepatic IGF-I mRNA levels showed that administration of a single dose of pjGHr into juvenile pejerrey resulted in a significant increase (P<0.02) 9 hours post injection. These results demonstrates that recombinant pjGH could promote a dramatic response in liver, increasing the IGF-I mRNA level. We also study the effect of GH on muscle growth after oral administration. A significant association between GH doses and mean fiber area (MFA) was observed even with a caloric restrictive diet. MFA increased 3.7 µm² per each unit of GH supplied indicating that GH promoted white muscle hypertrophy. These preliminary data indicates that GH could be absorbed by the intestine in an active form and promote somatic growth.

Resumo em Inglês:

Initial success in sperm cryopreservation occurred at about the same time for aquatic species and livestock. However, in the 50 plus years since then cryopreserved sperm of livestock has grown into a billion-dollar global industry, while cryopreserved sperm of aquatic species remains a research activity with little commercial application despite work in more than 90 species and more than 200 published reports. Most research work has focused on large-bodied culture and sport fishes, such as salmon, trout, carp, and catfish, and mollusks such as commercially important oyster and abalone species. However, only a few studies have addressed sperm cryopreservation in small fishes such as zebrafish, or in endangered species. Overall, this work has yielded techniques that are being applied with varied levels of success around the world. Barriers to expanded application include a diverse and widely distributed literature base, technical problems, small sperm volumes, variable results, a general lack of access to the technology, and most importantly, a lack of standardization in practices and reporting. The benefits of cryopreservation include at least five levels of improvements for existing industries and for creation of new industries. First, cryopreservation can be used to improve existing hatchery operations by providing sperm on demand and simplifying the timing of induced spawning. Second, frozen sperm can enhance efficient use of facilities and create new opportunities in the hatchery by eliminating the need to maintain live males, potentially freeing resources for use with females and larvae. Third, valuable genetic lineages such as endangered species, research models or improved farmed strains can be protected by storage of frozen sperm. Fourth, cryopreservation opens the door for rapid genetic improvement. Frozen sperm can be used in breeding programs to create improved lines and shape the genetic resources available for aquaculture. Finally, cryopreserved sperm of aquatic species will at some point become an entirely new industry itself. A successful industry will require integrated practices for sample collection, refrigerated storage, freezing, thawing, rules for use and disposal, transfer agreements, and database development. Indeed the development of this new industry is constrained by factors including the technical requirements for scaling-up to commercial operations during the transition from research, and the absence of uniform quality control practices, industry standards, and appropriate biosecurity safeguards.

Resumo em Português:

O mercado de alimentos para cães e gatos absorve importante quantidade de proteínas e carboidratos, apesar disso poucos estudos existem sobre digestibilidade e energia metabolizável destes ingredientes. Arroz e milho têm sido considerados as melhores fontes de amido, mas demonstra-se que o sorgo é igualmente bem digerido por cães. Na interpretação dos estudos, deve-se distinguir os que empregaram farinhas ou amidos purificados dos que empregaram ingredientes moídos, como utilizado na fabricação de alimentos para animais de companhia. Além de sua digestibilidade e valor energético, amidos interferem na glicemia de cães, o que torna interessante se empregar, para animais em condições específicas, fontes de carboidrato que levem à menores respostas de glicose e insulina. Devido a elevada necessidade de proteína, ingredientes protéicos são importantes nas formulações. Proteínas de origem animal apresentam maior variação em composição química, qualidade e digestibilidade que as de origem vegetal. Farinhas de origem animal podem apresentar excesso de matéria mineral, limitando sua inclusão na fórmula, enquanto derivados protéicos vegetais apresentam diversos fatores anti-nutricionais que devem ser inativados durante seu processamento. Demonstra-se que proteínas vegetais apresentam boa digestibilidade e energia metabolizável para cães e gatos, sendo sua inclusão interessante para reduzir a matéria mineral da dieta, controlar o excesso de bases do alimento e manter adequada a digestibilidade do produto, neste sentido soja micronizada e o farelo de glúten de milho 60% se destacam em digestibilidade e teor de energia metabolizável. A farinha de vísceras de frango, dentre as proteínas de origem animal secas demonstra-se como a de melhor digestibilidade e energia metabolizável.

Resumo em Inglês:

Although Pet food companies use important amounts of protein and carbohydrate sources, little scientific information was published about digestibility and metabolizable energy of these ingredients for dogs and cats. Rice and corn have been considered the better starch sources for these animals, but it was presented that sorghum is well digestible for dogs too. When interpreting scientific data the reader needs to consider the differences among studies that evaluated flour or refined starch or the usage of ground grain, as employed by pet food companies. Besides of digestibility and energy content, starch interferes on dogs glycemic response's, which presents an opportunity to select low insulin and glucose response starch sources to diets designed to animals in special conditions. Due to high protein requirements, these ingredients are important in food formulation for dogs and cats. Protein sources of animal origin have greater variation in chemical composition, quality and digestibility than vegetable proteins. Animals' meals can have high levels of ash, limiting the inclusion of these ingredients in pet food formulation. On the other hand vegetable proteins can have antinutritional factors that must be inactivated during manufacturing. It was demonstrated that vegetable proteins can have good digestibility and metabolizable energy for dogs and cats. Their utilization in food formulation can help in reduction of diet' ash level, control of food's base excess and keeping good diet digestibility. Micronized whole soybean and corn gluten meal with 60% protein are highlighted, showing good digestibility and energy content's values for dogs and cats. In relation to dry animal proteins, poultry by product meal have better digestibility and metabolizable energy values.

Resumo em Português:

As silagens de milho e de sorgo são importantes fontes de energia em rações utilizadas na bovinocultura leiteira, sendo que a estocagem desses volumosos é realizada em silos horizontais com ou sem a presença de paredes laterais (trincheira ou superfície, respectivamente), os quais são atrativos em razão do baixo custo de armazenamento, porém suas conformações determinam grande superfície de exposição, o que torna as silagens mais susceptíveis a deterioração aeróbia. Os maiores problemas envolvendo a qualidade microbiológica e nutricional em silagens, estão relacionados às práticas de manejo na colheita, no abastecimento e compactação da massa, na vedação e, principalmente, durante o desabastecimento do silo. O controle da deterioração aeróbia em silagens pode ser o principal ponto para melhorar a qualidade química, sensorial e higiênica em queijos e no leite fresco. A deterioração aeróbia causa perdas nutricionais e de matéria seca (MS), podendo provocar efeitos indiretos ao animal e ao homens pela transferência de microrganismos patogênicos e micotoxinas ao longo da cadeia alimentar. O presente trabalho tem por objetivo discutir práticas de manejo em fazendas que utilizam silos horizontais no armazenamento de silagem de milho e de sorgo e que produzem leite destinado à fabricação de queijos (tipo pasta dura) que possuem Denominação de Origem Protegida, além de definir aspectos ligados ao manejo na produção de silagens e no controle da deterioração aeróbia das mesmas.

Resumo em Inglês:

Maize and sorghum silages are good sources of energy for lactating dairy cows that produce milk destined for fresh and matured cheeses. Silages are usually stored in horizontal silos with or without side walls on commercial farms throughout the world. The main microbiological and nutritional quality problems are related to harvesting time, ensiling technology, and management practices during filling and feed-out. Aerobic deterioration is a key point that must avoided on farms in order to improve the hygienic, chemical and sensorial quality of milk and cheeses. Aerobic deterioration causes large losses of dry matter (DM) and quality, and it can cause health problems for animals and humans through the transfer of pathogens and mycotoxins from feed and livestock to food products. The objectives of the present work were to overview management practices connected to the storage of maize and sorghum in horizontal silos on farms producing milk for make Protected Designation of Origin (PDO) hard ripened cheese, to define good management practices that should be applied as the basis for safe silage production and to reduce the extent of aerobic deterioration.

Resumo em Inglês:

Forages are essential for the successful operation of animal production systems. This is more relevant to ruminants which are heavily dependant upon forages for their health and production in a cost-effective and sustainable manner. While forages are an economical source of nutrients for animal production, they also help conserve the soil integrity, water supply and air quality. Although the role of these forages for animal production could vary depending upon the regional preferences for the animal and forage species, climate and resources, their importance in the success of ruminant production is acknowledged. However with the increasing global human population and urbanisation, the sustainability of forage based animal production systems is sometimes questioned due to the interrelationship between animal production and the environment. It is therefore vital to examine the suitability of these systems for their place in the future to supply quality food which is safe for human consumption and available at a competitive price to the growing human population. Grassland and forage crops are recognised for their contribution to the environment, recreation and efficiency of meat and milk production,. To maintain sustainability, it is crucial that such farming systems remain profitable and environmentally friendly while producing nutritious foods of high economical value. Thus, it is pertinent to improve the nutritive value of grasses and other forage plants in order to enhance animal production to obtain quality food. It is also vital to develop new forages which are efficiently utilised and wasted less by involving efficient animals. A combination of forage legumes, fresh or conserved grasses, crop residues and other feeds could help develop an animal production system which is economically efficient, beneficial and viable. Also, it is crucial to use efficient animals, improved forage conservation methods, better manure handling, and minimum fertilisers to maximise animal production without damaging the environment. The sensible use of supplements and herbal additives as the desirable alternatives to the conventional growth promoters could also help optimise the ruminant production. This paper examines the opportunities and obstacles which may affect the development of more desirable and sustainable animal production systems for the future.

Resumo em Inglês:

Some arguments currently used to support breed conservation are examined. The central point is that we cannot conserve all breeds because we do not have financial resources enough to keep everything (mainly in developing countries) and in many cases we do not have special reasons to conserve breeds. A breed is a human product and it should not be confused with specie. A breed can be generated or transformed. We can create synthetic breeds with the best characteristics of several breeds. Selection is not exhausting genetic variability (there are several experiments showing that), and genetic variability within breeds is large. We need reasons to keep breeds in danger in extinction. A breed is a tool, and we can decide to keep it when it is useful because it is specially adapted to some environments (although in this case it should not be in danger of extinction), it can be useful in crossbreeding to shorten the way of obtaining response to selection, or it has some extreme values for traits that may be useful in the future (in this case we have to define clearly which traits and how we expect the future to be). We can add cultural reasons when we have money enough to spend in culture.

Resumo em Inglês:

Oocytes in cattle are formed during embryogenesis and develop within individual follicles in the cortex of the ovary. Dormant primordial follicles become active and undergo progressive development at regular intervals commencing during the late fetal stage and continuing throughout adulthood. Once activated, follicles and oocytes in a cohort either grow to maturation and ovulation or undergo atresia, ultimately depleting the ovaries of germ cells. It takes an estimated 100 days for a follicle and its oocyte to reach the mature ovulatory stage. Within an individual, number of follicles in one ovary is similar to number in the other ovary; however, there are large differences among individuals in total number of follicles present in both ovaries. In follicles that are recruited into the preovulatory pool, the fluid filled antrum enlarges and growth can be monitored by ultrasonography. Preovulatory follicles grow in waves rather than in a continuous stream, and number of follicles detected in a wave is related positively to number of microscopic follicles populating the ovarian cortex. Number of follicles in a wave is highly repeatable and the estimated heritability of number of follicles in heifers is approximately 0.35. Monitoring preovulatory follicle numbers by ultrasonography can be used to identify females that produce more embryos following superovulation or more natural twin births. Number of follicles in a wave can be influenced by energy balance and exogenous hormones, and quality of oocytes within those follicles can be influenced environmental factors, hormones and vitamins. The potential exists to increase genetic progress through repeatedly harvesting oocytes from preovulatory follicles of genetically superior females.

Resumo em Inglês:

Genetic diversity among breeds of cattle allows producers to select animals for specific environments or market conditions. Reproductive efficiency is a multi-component trait that is largely influenced by environmental influences such as health and nutritional status; however, there are clearly genetic components to reproductive efficiency, and breed differences in a number of indicator traits associated with fertility and cow productivity have been identified. Historical indicators of fertility include scrotal circumference, age at puberty, and postpartum interval. Both age at puberty and postpartum interval are laborious traits to collect in heifers and cows because they require many days of detection of behavioral estrus. In recent years, the addition of ultrasonography to management practices has allowed for the collection of female traits such as follicle diameter, antral follicle counts, and fetal age that are not as labor intensive. These additional diagnostic traits provide novel phenotypes for the identification of genetic markers of fertility and cow productivity, which would be the ultimate goal. Genetic markers of the number of follicles in the bovine ovary have the potential to identify heifers that will be highly productive cows. Furthermore, identifying and understanding the genes that control various reproductive traits and the response to stressors, such as temperature and nutrient availability, could improve production efficiency by improving management and breeding decisions in a wide range of production environments.

Resumo em Inglês:

Livestock genomics is aimed at dissecting the genetic control of variation in economically important trait, such as disease resistance and product yield/quality. Unraveling the genetic control of such complex traits remains very challenging but farm animals are now well placed to bridge the gap between human biology and traditional model species. Livestock species share with model species the benefits of controlled breeding, while their biology is often much closer to that of humans. Livestock genetics can exploit the abundant genetic variation between divergent breeds as well as segregating variation within breeds, thus getting the best of both worlds. Large numbers of QTL have been detected for a variety of traits but for only a handful has the functional DNA mutation been discovered. The main challenge is how to exploit this information for sustainable animal breeding. The proposed applications for Marker Assisted Selection (MAS) vary from selecting on individual known mutations to using genome-wide SNP data for genome-wide selection. Molecular markers are also important tools to assess genetic variation within and between populations. Sustainable animal breeding should meet the needs of the current generation without compromising the needs of future generations. This contribution will discuss the status of molecular genetics in livestock and how this could support sustainable animal breeding.

Resumo em Inglês:

Most livestock are not indigenous to Brazil. Several animal species were considered domesticated in the pre-colonial period, since the indigenous people manage them as would be typical of European livestock production. For over 500 years there have been periodic introductions resulting in the wide range of genetic diversity that for centuries supported domestic animal production in the country. Even though these naturalized breeds have acquired adaptive traits after centuries of natural selection, they have been gradually replaced by exotic breeds, to such an extent, that today they are in danger of extinction To avoid further loss of this important genetic material, in 1983 Embrapa Genetic Resources and Biotechnology decided to include conservation of animal genetic resources among its priorities. In this paper we describe the effort to genetically characterize these populations, as a tool to ensure their genetic variability. To effectively save the threatened local breeds of livestock it is important to find a niche market for each one, reinserting them in production systems. They have to be utilized in order to be conserved. And there is no doubt that due to their adaptive traits, the Brazilian local breeds of livestock can play an important role in animal production, to meet society needs.

Resumo em Inglês:

Quantitative genetics can be used to understand how traits will respond to artificial selection regimes, and therefore, it can be an important tool in the development of selective breeding programs for animal improvement. In order to predict the response to selection, the traditional approach in quantitative genetics partitions phenotypic variation into a heritable genetic component that contributes to the response and a non-heritable environmental component that does not. However, there is an increasing recognition that environmental variation contributed by the social environment provided by conspecifics can ultimately originate from genetically heritably traits in a population of interacting individuals, blurring the distinction between genetic and environmental variation. The presence of these 'social effects' on trait expression means the environment can provide a source of heritable variation that can contribute to trait evolution. Under some conditions, such as when there is competition, the social effects of genotypes on the phenotypes of other individuals may oppose their direct effects on their own phenotypes and, as a result, the evolution of social effects can oppose the evolution of direct genetic effects and thereby can impede the response to selection. Furthermore, when the social effects of genotypes are uncorrelated with their direct effect, the heritable variance contributed by social effects will not contribute to a response to selection on individuals, meaning that a major part of the genetic variance in a population can be unavailable to selective breeding. These constraints can be overcome by using populations of related individuals or through group selection approaches that allow for the social effects to contribute to a response to selection.

Resumo em Português:

Os pequenos ruminantes, ovinos e caprinos, foram das primeiras espécies domesticadas e, desde sua origem produziram múltiplos benefícios ao homem. Nos dois últimos séculos a produção ovina foi progressivamente especializando-se e adaptando-se as peculiaridades geográficas de cada região aonde são criadas. Atualmente, as mudanças nos hábitos e atitudes dos consumidores, juntamente com o desenvolvimento desenfreado das fibras sintéticas, o aumento da população, as crises nos mercados da lã e o incremento dos preços dos cordeiros, fizeram com que a carne ovina tenha aumentado sua importância relativa, frente aos ingressos ovinos totais à nível mundial. Por outro lado, os sistemas de produção variam enormemente de um país para outro como reflexo da diversidade das condições ambientais, que determinam uma grande variabilidade de raças, sistemas de alojamento, níveis de intensificação produtiva e, finalmente, da demanda do mercado e qualidades. Entretanto, entre todas as carnes, a carne de cordeiro é a que apresenta maior comércio internacional (16% da produção mundial é exportada), o que explica a possibilidade de que convivam, em um mesmo mercado, produtos ovinos muito diferentes. Portanto, existe um novo interesse pela produção de carne na espécie ovina, e também na caprina, que inclui a atenção e a busca da qualidade. Este interesse dos produtores e da indústria deveria se ver refletido em um aumento dos interesses dos pesquisadores para os pequenos ruminantes, espécies nas que existe uma notável falta de conhecimentos, em particular no que se relaciona com a produção de cordeiros e cabritos para carne. Nesta apresentação, salientamos as relações entre a qualidade da carcaça e a aceitabilidade da carne e analisaremos o efeito sobre a qualidade de alguns fatores como a raça e a espécie, a dieta e o sistema de produção, o peso de sacrifício, raça e tempo de maturidade, com ênfase especial no que se relaciona com a aceitabilidade dos consumidores.

Resumo em Espanhol:

Los pequeños rumiantes, ovinos y caprinos, fueron una de las primeras especies que se domesticaron y desde sus orígenes han producido múltiples beneficios al hombre. En los dos últimos siglos la producción ovina se fue progresivamente especializando, dependiendo del área geográfica. Actualmente, los cambios en los hábitos y actitudes de los consumidores, junto con el desarrollo imparable de las fibras sintéticas, el aumento de la población, las crisis en los mercados laneros y el incremento de los precios de los corderos, han hecho que la carne ovina haya aumentado su importancia relativa, frente a los ingresos ovinos totales a nivel mundial. Por otra parte, los sistemas de producción varían enormemente de unos países a otros como reflejo de la diversidad de las condiciones ambiéntales, que determinan una gran variabilidad de razas, sistemas de alojamiento, niveles de intensificación productiva y, al final, de la demanda del mercado y calidades. No obstante, entre todas las carnes, la carne de cordero es la que tiene un mayor comercio internacional (el 16% de la producción mundial es exportada), lo que explica la posibilidad de que convivan, en un mismo, mercado, productos ovinos muy diferentes. Así pues, hay un nuevo interés por la producción de carne en la especie ovina, y también en la caprina, que incluye la atención y la búsqueda de la calidad y el desarrollo de las marcas de calidad: Este interés de los productores y de la industria, debería verse reflejado en, igualmente, un aumento del interés de los investigadores hacia los pequeños rumiantes, especies en las que existe una notable falta de conocimientos, en particular en todo lo relacionado con la producción de corderos y cabritos para carnicería. En esta ponencia, haremos una incidencia especial en las relaciones entre la calidad de la canal y la aceptabilidad de la carne, y analizaremos el efecto sobre la calidad de algunos factores como la raza y la especie, la dieta y el sistema de producción, el peso al sacrificio, raza y tiempo de maduración, con un énfasis especial en todo lo relacionado con la aceptabilidad de los consumidores.

Resumo em Inglês:

Small ruminants have been one of the first domesticated species and from their origins have produced multiple benefits to humans. In the last two centuries, world sheep production has become more and more specialised upon geographical areas. But, recent changes in consumer attitudes, together with the increment in artificial fibre industries and human world population, some crisis related with the international wool market and some increments in lamb prices, have provoked that lamb meat has increased its relative importance inside the global sheep income. Also, sheep production systems vary considerably across the world, and reflect the different local environmental conditions, which determine, to a large extent, breeds, housing, levels of intensification and, at the end, local market requirements and qualities. However, among all the meats, sheep meat remains the most internationally traded (16 % of total world production is exported), which explains the potential existence of different lamb products in the same market. Then, the new requirements have created a higher interest for meat production, including its quality and quality marks. This interest from producers and the industry should be reflected in a proportional higher interest from the researches towards sheep and goat, where it exists, in general, important lacks of knowledge and, in particular, in lamb and kid meat Science. In the present speech we will made a special incidence on the relationship between carcass quality and lamb acceptability and on some factors like breed and species, diet and production system, slaughter weight and ageing time and their importance on the variation of the carcass and meat quality, including consumer acceptability.

Resumo em Português:

Um experimento foi conduzido com o objetivo de verificar os efeitos de diferentes relações flúor:fosforo na alimentação sobre o desempenho de frangos de corte. Foram utilizados 1.000 pintos de corte de 1 dia distribuídos em um delineamento inteiramente casualizado, com quatro tratamentos e cinco repetições de 50 aves por boxe. Os tratamentos consistiram de quatro fontes de fósforo com relações flúor:fósforo de 1:40, 1:60, 1:80 e 1:100. O experimento foi dividido em três fases experimentais: 1 a 21, 22 a 42 e 43 a 49 dias de idade. Em cada fase, avaliou-se o consumo de ração, o ganho de peso e a conversão alimentar. Ao final do experimento, foram abatidas duas aves de cada repetição para coleta da tíbia e de músculos do peito para análise das concentrações.

Resumo em Inglês:

A mechanistic model that predicts nutrient requirements and biological values of feeds for sheep (Cornell Net Carbohydrate and Protein System; CNCPS-S) was expanded to include goats and the name was changed to the Small Ruminant Nutrition System (SRNS). The SRNS uses animal and environmental factors to predict metabolizable energy (ME) and protein, and Ca and P requirements. Requirements for goats in the SRNS are predicted based on the equations developed for CNCPS-S, modified to account for specific requirements of goats, including maintenance, lactation, and pregnancy requirements, and body reserves. Feed biological values are predicted based on carbohydrate and protein fractions and their ruminal fermentation rates, forage, concentrate and liquid passage rates, and microbial growth. The evaluation of the SRNS for sheep using published papers (19 treatment means) indicated no mean bias (MB; 1.1 g/100 g) and low root mean square prediction error (RMSPE; 3.6 g/100g) when predicting dietary organic matter digestibility for diets not deficient in ruminal nitrogen. The SRNS accurately predicted gains and losses of shrunk body weight (SBW) of adult sheep (15 treatment means; MB = 5.8 g/d and RMSPE = 30 g/d) when diets were not deficient in ruminal nitrogen. The SRNS for sheep had MB varying from -34 to 1 g/d and RSME varying from 37 to 56 g/d when predicting average daily gain (ADG) of growing lambs (42 treatment means). The evaluation of the SRNS for goats based on literature data showed accurate predictions for ADG of kids (31 treatment means; RMSEP = 32.5 g/d; r2= 0.85; concordance correlation coefficient, CCC, = 0.91), daily ME intake (21 treatment means; RMSEP = 0.24 Mcal/d g/d; r2 = 0.99; CCC = 0.99), and energy balance (21 treatment means; RMSEP = 0.20 Mcal/d g/d; r2 = 0.87; CCC = 0.90) of goats. In conclusion, the SRNS for sheep can accurately predict dietary organic matter digestibility, ADG of growing lambs and changes in SBW of mature sheep. The SRNS for goats is suitable for predicting ME intake and the energy balance of lactating and non-lactating adult goats and the ADG of kids of dairy, meat, and indigenous breeds. The SRNS model is available at http://nutritionmodels.tamu.edu.

Resumo em Português:

Atendendo ao crescente interesse na produção e consumo de carne de caprinos e à cada vez maior necessidade de recorrer a metodologias rápidas que proporcionem a predição da composição corporal e qualidade da carcaça, realizamos uma revisão dos últimos trabalhos realizados com recurso à técnica dos ultra-sons. Após uma breve resenha histórica sobre a evolução do uso do método na caprinicultura, são referidos os princípios da técnica e a sua aplicação aos caprinos (operador, identificação de pontos anatómicos de medida, diferentes medidas corporais e na carcaça, tipos de aparelhos e sondas e acondicionamento animal). São posteriormente analisados os resultados das principais pesquisas recentemente efectuadas. Finalmente são discutidas as expectativas futuras para o uso da técnica de ultra-sons na avaliação in vivo de caprinos, com referência a diferentes procedimentos para a obtenção de modelos de predição.

Resumo em Inglês:

Considering the increasing interest in the production and meat goat consumption and the necessity to appeal the rapid methodologies that provide to predict the body composition and quality of the carcass, we carry through a revision of the last works using ultrasound technology. After a brief history description about the evolution of the use of ultrasound methods in goats, the main important principles of the technique and its application in goats are refereed (operator, anatomical point's identification for measurements, different body and carcass measures, types of probes and equipment and animal handling). The most recent results of works in goats to predict carcass composition were mentioned. Finally the future expectations for the use of ultrasound technology to evaluate in vivo goats are discussed with a reference of different procedures to obtain the prediction models.

Resumo em Espanhol:

Tres isoformas de MyHC han sido caracterizadas en músculo esquelético de equinos adultos a nivel proteico: tipo I, IIA y IIX. La distribución de estas MyHCs definen tres tipos puros de fibras que contienen una sola isoforma (tipo I, IIA y IIX) y dos tipos de fibras híbridas que expresan dos isoformas (I+IIA y IIAX). Las fibras híbridas IIAX existen en los músculos locomotores como una población estable y significativa. Dependiendo de la naturaleza del estímulo, la respuesta adaptativa puede tomar diferentes formas: hipertrofia, remodelación sin hipertrofia y respuesta mixta, cuando se combina la remodelación con la hipertrofia. Los equinos pueden aprovechar diferentes sustratos energéticos, algunos de los cuales son utilizados en forma inmediata tras la ingesta, mientras que otros son almacenados en el hígado, músculos y tejido adiposo para ser usados en otro momento. El glucógeno muscular y la glucosa pueden ser degradados por la vía aeróbica (oxidativa) o la anaeróbica lactacida (glucolítica), mientras que en ejercicios de resistencia la utilización de ácidos grasos se realiza a partir de la degradación de triglicéridos almacenados en el tejido celular subcutáneo. El metabolismo oxidativo mide la función de los sistemas cardiovascular y respiratorio. En cambio, el metabolismo anaeróbico solo involucra al tejido muscular.

Resumo em Inglês:

Three isoforms of MyHc have been characterized in the skeletal muscle of adult equines at the proteins level: types I, IIA and IIX. The distribution of these MyHCs defines three pure kinds of fibre which contain a single isoform (I+IIA and IIAX). The hybrid fibres IIAX exist in the locomotive muscles as a permanent and significant population. The adjusting response may take different forms depending on the nature of the stimulus: hypertrophy, reorganization (restructuring) without hypertrophy and a combined answer, when restructuring joins hypertrophy. The equines may take the most of different energetic subtrates, some of which are used immediately after the ingest, while others are stored in the liver, the muscles or adipose tissue in order to be used later. The muscular glycogen and the glucose may be degraded aerobically through the aerobic pathway or through the anaerobic pathway, while in the endurance exercises the use of fatty acids is accomplished from the degradation of fat stored in the subcutaneous cellular tissue. The oxidative metabolism measures the function of the cardiovascular and respiratory systems. On the contrary, the anaerobic metabolism involves only the muscular tissue.

Resumo em Português:

Nos últimos anos a equideocultura deu um salto qualitativo, havendo hoje, no mercado, animais de alto valor e geneticamente superiores. Isso é possível, em grande parte, devido aos avanços na área da genética animal, os quais permitem identificar, não apenas anomalias, mas também diversos genes de interesse econômico. Com o auxílio da citogenética pode-se identificar indivíduos com alterações no número ou na estrutura dos cromossomos, o que em muitos casos afeta principalmente a reprodução. Também a confirmação de genealogia, anteriormente feita por tipagem sangüínea e atualmente por testes de DNA, tem papel extremamente importante, não apenas por garantir a ascendência dos animais, mas também porque um pedigree confiável pode permitir ao criador identificar a origem de problemas genéticos em seu rebanho e reduzi-los ou mesmo, eliminá-los. Ainda com as ferramentas da biologia molecular, podemos hoje, identificar indivíduos que apresentam genes desejáveis ou indesejáveis, o que nos permite selecioná-los precocemente, reduzindo assim, os custos do produtor e aumentando o valor agregado dos animais. Entre tais genes podemos destacar os que identificam portadores ou afetados por mutações genéticas indesejáveis como: SCID (Síndrome da Imunodeficiência Combinada), HYPP (Parilisa Hipercalêmica), HERDA (Astenia Dérmica Regional Hereditária Eqüina), etc. Também a identificação dos genes que determinam a cor ou padrão da pelagem já pode ser feita direta ou indiretamente (por meio de marcadores genéticos), como é o caso dos genes para as pelagens Overo, Tobiano, etc. Com os avanços no estudo do genoma eqüino muito mais estará disponível em breve, o que certamente só trará maiores contribuições à equideocultura mundial.

Resumo em Inglês:

In the last few years the horse breeding industry is achieving significant progresses producing animals of high commercial value and genetically superior. It was possible, mainly due to the progresses in the area of the animal genetics, which allow identifying, not only anomalies, but also several genes of economical interest. With the aid of the cytogenetics, individuals with alterations in the number or in the structure of the chromosomes can be identified, which in many cases affect mainly the reproduction. Also the genealogy confirmation, previously done by blood type and now by DNA tests, has extremely important role, not just for guaranteeing the origin of the animals. Due to a reliable pedigree, the breeder can identify the origin of genetic problems and can reduce or even eliminate them. With the tools of the molecular biology, today, we can identify individuals that present desirable or undesirable genes, allowing us to select them early, reducing the costs of the producer and increasing the joined value of the animals. Among those genes we can detach the ones that identify carriers or affected animals for undesirable genetic mutations such as: SCID (Severe Combined Immunodeficiency Disease), HYPP (Hyperkalemic Periodic Paralysis), HERDA (Hereditary Equine Regional Dermal Asthenia), etc. Also the identification of the genes that determine the coat color or coat pattern can already be made directly or indirectly (through genetic markers), as it is the case of the genes for the coat colors Overo, Tobiano, etc. With the progresses in the study of the equine genoma much more will be available soon, which will certainly bring larger contributions to the world horse breeding industry.

Resumo em Inglês:

In 1989, the National Research Council (NRC) Subcommittee on Horse Nutrition defined three categories of exercise: light, moderate or intense. In the 6th revised edition of "The Nutrient Requirements of Horses" (NRC, 2007), there are four categories for exercising horses: light exercise, moderate exercise, heavy exercise and very heavy exercise. Light exercise is described as 1 to 3 hours/week of mostly walking and trotting. Many horses kept for recreational riding would be included in the light exercise category. Moderate exercise consists of 3 to 5 hours/week of mostly trotting with some walking, some cantering and possibly some jumping or other type of more difficult activity. Horses used for horse shows, ranch work and frequent recreational riding would fit into the moderate exercise category. Heavy exercise is described as 4 to 5 hours/week of trotting, cantering, galloping and some jumping, cattle work, etc. Horses engaged in three day eventing, polo, endurance racing or other competitive events would be in this category. The very heavy exercise category includes racehorses and a few other horses that compete at the elite level of endurance or three day eventing. The NRC (2007) provides recommendations for nutrient intakes by mature exercising horses and for yearlings and two year olds that are receiving regular exercise. Many of the recommendations are similar to those in the 1989 publication, but others have been increased or decreased. For example, crude protein recommendations for exercising horses are generally lower than in the last edition. However, lysine requirements are relatively similar and the publication suggests that protein quality should be emphasized more than in the past. The 2007 NRC contains more information about the factors that influence the requirements for each nutrient, making it easier for users to develop diets for individual horses.

Resumo em Inglês:

An experiment was conducted to evaluate the effect of different fluorine:phosphorus ratios in the diet on performance of broiler chickens. One thousand broiler chickens with one day old were allotted to a completely randomized experimental design with four treatments with five replications of fifty broilers per experimental unit. The treatments was composed by four phosphorus sources with fluorine: phosphorus ratios of 1:40, 1:60,1:80, 1:100 and fed during three experimental phases: 1-21, 22-42 and 43-49 days. In each phase, feed intake, weight gain and feed conversion were evaluated. At the end of experiment, two birds per replication were slaughtered and their tibias and samples of muscle tissue from breast were collec.

Resumo em Português:

A criação industrial de frangos de corte tem sido eficiente na produção de proteína animal, no entanto geram resíduos com alto conteúdo de N, P, K, minerais traço, e alta carga de bactérias. A rápida degradação microbiana destes resíduos ocasiona volatilização de amônia, odores, e pó fino, além de atrair insetos e roedores. Esta apresentação discutirá os métodos mais efetivos para aproveitamento destes recursos e minimizar o possível impacto ambiental. Estes procedimentos incluem planejamento, capacitação do pessoal, zoneamento das áreas para dispor dos resíduos finais nas glebas, isolamento da granja, nutrição com precisão, praticas de manejo da cama e galpão, e correto manejo das aves mortas. A cama de frangos tem sido utilizada na alimentação animal e geração de energia. Adicionalmente serão apresentadas novas tecnologias visando à redução de emissões de amônia, odores e pó fino, ou a redução na solubilidade de fósforo.

Resumo em Inglês:

The broiler industry produces efficiently animal protein, but generates residues with high contents of N, P, K, trace minerals, and high bacterial charge. The rapid microbial decomposition of these residues cause ammonia volatilization, nuisance odor, fine particulate matter, and attract insects and rodents. This presentation will discuss the more effective methods to utilize these resources and minimize potential environmental impact. These procedures include planning, personnel training, zoning of areas used to dispose the final residues in crop lands, farm isolation, precision nutrition, litter and house management practices, and appropriate mortality disposal. Broiler litter has been used for animal feeding and power generation. Additionally, new technologies to reduce ammonia, odor and fine particle emissions, or reduction of P solubility will be presented.

Resumo em Português:

Com a introdução de óleo vegetal na cadeia produtiva do biocombustível no Brasil, é esperado o aumento da demanda por plantas oleaginosas e oferta de fibras vegetais resultantes da extração do óleo. Considerando a alimentação animal como elo entre a produção de biodiesel e a pecuária, propomos o estudo da utilização de subprodutos destes empreendimentos na alimentação visando aumentar a produtividade e diminuir a emissão de gases de efeito estufa pelos animais, gerando créditos de carbono e atendendo ao interesse da iniciativa privada. A técnica de produção de gases in vitro tem sido utilizada no LANA-CENA/USP com a finalidade de estudar o efeito de alimentos que possuem metabólitos secundários bioativos, na fermentação ruminal e degradabilidade da matéria orgânica (MOVD), bem como, no estudo da produção de metano. Resultados recentes mostraram que a substituição total do farelo de soja por tortas de algodão, dendê, mamona e pinhão manso proporcionou menor produção total de gases; e que a produção de metano foi significativamente afetada pela inclusão das tortas, sendo que o farelo de soja apresentou produção de metano de 15,3 mL/g MOVD. Diversos trabalhos mostram que as tortas e farelos apresentam características nutricionais adequadas para inclusão na dieta de ruminantes, entretanto, estudos criteriosos desses materiais enquanto matérias-primas para ração animal são necessários para avaliar possíveis efeitos deletérios devido à presença de metabólitos bioativos. Através de análises de cromatografia de alta resolução, podem ser identificadas essas substâncias que, em condições tropicais podem não apresentar a mesma toxicidade. A introdução de tortas com elevado teor de gordura nas dietas de ruminantes pode auxiliar na mitigação de metano entérico, e a produção de algumas oleaginosas pode contribuir com o seqüestro de carbono pelos solos de Cerrado na recuperação de pastagens, reduzindo a necessidade de desmatamentos.

Resumo em Inglês:

With the introduction of vegetable oil in the bio-fuel productive chain in Brazil, the increase in the demand of oleaginous plants is expected as well as the offer of the resulting vegetable fibers from the extraction of the oil. Considering the animal feeding as link between the biodiesel production and the livestock, we propose the study of the use of by-products of these enterprises in the feeding system seeking to increase the productivity and to reduce the emission of greenhouse gases from the animals, generating carbon credits and assisting to the interest of the private initiative. The in vitro gas technique has been used at LANA-CENA/USP with the purpose of studying the effect of feeds containing secondary bioactive metabolites upon the ruminal fermentation and organic matter degradability (MOVD), as well as, in the study of methane production. The total substitution of the soybean meal for meals of cotton seed, palm oil, castor oil plant and jatropha provided less total gas production and the production of methane was affected significantly by the inclusion of the meals, with soybean meal presenting methane production of 15.3 mL/g MOVD. Literature data also show that meals from biodiesel production present appropriate nutritional characteristics for inclusion in the diet of ruminant, however, discerning studies of those materials while raw materials for animal ration are necessary to evaluate possible harmful effects due to the presence of bioactive metabolites. Through analyses of high resolution chromatography, those metabolites may be identified. The introduction of meals with high fat content in the diets of ruminant can aid in the mitigation of enteric methane, and the production of some oleaginous plants can contribute with the sequestering of carbon for the Cerrado soils in the recovery of pastures, reducing the need of deforestations

Resumo em Inglês:

Providing feed is a major input cost in beef production, hence improvements in the efficiency of feed utilisation will reduce the cost of production. Residual feed intake (RFI) is a measure of feed efficiency, and is defined as the difference between an animal's actual feed intake and its expected feed intake based on its size and growth. It is independent of the level of production, and the lower the value the more efficient the animal is. This paper examines the current state of knowledge on RFI. Available information indicates that postweaning RFI is moderately heritable, and that selection for low RFI will result in progeny that consume less feed for the same level of production as progeny of high RFI cattle. Under ad libitum feeding, RFI is phenotypically independent of growth traits. There is a weak genetic relationship between RFI and fatness but additional studies are needed to assess the magnitude of this relationship in different breeds, sexes, ages and feeding regimes. Residual feed intake is believed to represent inherent variation in basic metabolic processes which determine efficiency. Economic analyses of genetic improvement schemes that incorporate testing of individuals for RFI have yielded substantial economic benefits over and above existing schemes that do not include RFI testing. Selection for low RFI has an additional benefit of reducing greenhouse gas emissions by cattle.

Resumo em Inglês:

Glycerol, also known as glycerin, is a colorless, odorless, hygroscopic, and sweet-tasting viscous liquid. It is a sugar alcohol with high solubility index in water and has a wide range of applications in the food, pharmaceutical, and cosmetic industries. The use of glycerol in diets for dairy cattle is not novel; however, this interest has been renewed due to the increased availability and favorable pricing of glycerol as a consequence of recent growth in the biofuels industry. Experimental evidence supports the use of glycerol as a transition cow therapy but feeding rates are low, ranging from 5 to 8 % of the diet DM. There is a paucity of research that examines the use of glycerol as a macro-ingredient in rations for lactating dairy cows. Most reports indicate a lack of effect of addition of glycerol to the diet when it replaces corn or corn starch. Recent feeding experiments with lactating dairy cows indicate replacing corn with glycerol to a level of 15% of the ration DM does not adversely effect milk production or composition. Milk production was 37.0, 36.9, 37.3, 36.4 ± 0.6 kg/d and feed intake was 24.0, 24.5, 24.6, 24.1 ± 0.5 kg/d for 0, 5, 10 and 15% glycerol treatments respectively and did not differ (P > 0.05) except for a modest reduction in feed intake during the first 7 days for the 15% glycerol treatment. Glycerol fed to dairy cattle is fermented to volatile fatty acids in the rumen and early reports indicated that glycerol is almost entirely fermented to propionate. In vitro data indicates glycerol fermentation increases the production of propionate and butyrate at the expense of acetate. Rumen microbes appear to adapt to glycerol feeding and consequently, cows fed glycerol also require an adaptation period to glycerol inclusion. Debate exists regarding the fate of glycerol in the rumen and although most reports suggest that glycerol is largely fermented in the rumen, the extent of rumen digestion may depend on level of inclusion in the diet. Data are lacking regarding the rates of rumen fermentation of glycerol at intake levels for high producing dairy cattle. Current data indicates that glycerol can be included in diets fed to dairy cattle at macro ingredient levels; however, additional information is needed to permit a full appreciation of the feeding value of glycerol and the resulting impact on cow health and productivity.

Resumo em Inglês:

This review summarizes recent developments on the utilization of specific fatty acids to modulate bovine energy metabolism, with emphasis on the periparturient dairy cow. A number of experiments have assessed the effects of polyunsaturated fatty acids on bovine hepatic energy metabolism using in vitro and in vivo models. Treatment of hepatocytes with specific fatty acids altered energy metabolism in vitro. For example, linolenic acid seemed to decrease hepatocyte triacylglycerol accumulation. This effect was confirmed in vivo, using parenteral infusions of emulsions derived from different fat sources to feed-restricted non-lactating cows. Additionally, polyunsaturated fatty acids can increase whole body response to insulin, potentially enhancing antilipolytic effects of insulin and muscle protein anabolism in the bovine. There is limited literature on the effects of feeding fat sources rich in omega-3 polyunsaturated fatty acids, such as fish oil and linseed oil, on metabolism of periparturient dairy cows. Available research has yielded conflicting results which need further clarification. On the other hand, specific isomers of conjugated linoleic acid consistently induce milk fat depression and are able to decrease energy export in milk by periparturient dairy cows. Nonetheless, research is still needed to assess whether these effects will ultimately benefit productivity and health status of periparturient dairy cows. Limitations of available methods to protect fatty acids from ruminal biohydrogenation are also addressed.