RESUMO.A presente revisão de literatura tem como objetivo apresentar como a cana de açúcar é utilizada na recria de novilhas leiteiras. Algumas características relacionadas à cultura da cana de açúcar, tais como a facilidade de seu cultivo, a execução da colheita justamente na época de estiagem, possibilidade de auto armazenamento ou conservação a campo, persistência da cultura e a grande produção obtida em nossas condições tornaramna um alimento de grande interesse dos criadores. Fêmeas em recria necessitam de um ganho de peso que garanta uma idade ao primeiro parto aos vinte e quarto meses de idade. Serão relatados os sistemas de recria de novilhas, os aspectos importantes ligados à nutrição de novilhas, limitações do uso da cana de açúcar para bovinos, composição e a produtividade da cana de açúcar. Os resultados de diferentes trabalhos de pesquisa sugerem várias formas de utilização da cana de açúcar para a obtenção de resultados satisfatórios como a cana in natura, cana com ureia, a silagem de cana, cana hidrolisada e o bagaço da cana de açúcar. Apesar da baixa digestibilidade da cana de açúcar e do menor ganho de peso das novilhas quando comparadas com outros tipos de alimentações como, por exemplo, a silagem de milho, a cana de açúcar mostrou-se ser uma alternativa viável para recria de novilhas leiteiras em propriedades pouco tecnificadas. Palavras chave: Bovinos leiteiros, novilhas, formas de utilização de cana de açúcarSugar cane in feeding of milker heifers: Review ABSTRACT. This review aims to present how sugarcane is used in the rearing of dairy heifers. Some characteristics related about the culture of sugarcane, such as ease of cultivation, implementation of crop in the dry season, the possibility of self-storage or conservation field, persistence of culture and great production obtained in Brazilian conditions They made it a food of great interest to breeders. Females in growing need an average weight gain that guarantees an age at first calving at twenty-four months old. Will be reported the dairy heifer's systems, important aspects of heifers' nutrition, limitations of use of sugarcane for cattle, composition and productivity of sugarcane. The results of different research papers suggest several ways of using sugarcane to obtain satisfactory results as in natural cane, cane with urea, silage cane, hydrolyzed cane and bagasse from sugarcane. Despite the low digestibility of sugarcane and less weight gain for heifers as compared to other feeds, for example, silage corn, sugarcane proved to be a viable alternative for rearing dairy heifers little technicality properties.

Possible advantages of reducing length of dry period includeincreased income from milk production, simplified dry cow management,decreased metabolic disorders, and alleviation of overcrowdeddry cow facilities. There is abundant data to support a 60-ddry period to maximize milk yield the next lactation. The greatmajority of data is from studies using farm records. In these data sets, cows with less than 6- to 8-wk dryperiods probably were not intended to have short dry periodsand consequently were not managed for short dry periods. Additionally,recommendations from observational data may be biased due tointeractions, e.g., between milk yield and length of dry period.Some experiments specifically designed to compare 30- and 60-ddry periods indicate that shorter dry periods are possible withoutsacrificing milk production the next lactation. There is a paucityof data to determine the effects of shortening the dry periodon milk composition, metabolic disorders, and reproductive performance.The limited amount of information that is available indicatesthat shortening the dry period will probably not have negativeeffects on these parameters and may have slight beneficial effects.In some cases, the beneficial effects may have resulted, inpart, due to negative effects on milk production. Cows withlonger calving intervals and older cows may be more likely toavoid negative effects of shortening dry periods on subsequentmilk yield. Shortening the dry period by initiating milkingafter a dry period but prior to parturition does not increasemilk yield or improve animal health sufficiently to warrantconsideration. Several studies indicated complete eliminationof the dry period results in a 20 to 25% decrease in milk yieldthe following lactation. However, these studies have utilizedlow cow numbers and cows with extremely low milk production.As milk yield and persistency of lactation increases, eitherthrough genetic selection or administration of exogenous agentssuch as bST, the likelihood of successfully shortening or eliminatingthe dry period should increase. Future studies to increase ourknowledge of factors affecting mammary epithelial cell proliferationand apoptosis should yield strategies to reduce the length orcompletely eliminate the dry period.

RESUMO.Nos últimos 25 anos, pesquisas em todos os aspectos da nutrição de ruminantes foram intensificadas. Previsões apontam que em 2050 a produção mundial e o consumo de carne será quase o dobro da atual, podendo chegar a 455 milhões de toneladas por ano. Tais projeções são o resultado do crescimento da população humana, estimada em nove bilhões em 2050 e, pelo aumento do poder de compra e qualidade de vida, também aumentará a demanda por proteína animal. Pesquisas relevantes sobre eficiência alimentar, processos de digestão e absorção, o desenvolvimento de novas técnicas de avaliação de alimentos e o conhecimento aprofundado da microbiota ruminal permitem a maximização da utilização dos nutrientes pelos animais, reduzindo também a eliminação de resíduos no meio ambiente, outra área de grande preocupação atual. Em detrimento de tamanha importância, o objetivo desse texto é realizar uma breve explanação sobre o "Estado da Arte da Nutrição de Ruminantes". Dada a vasta possibilidade de pesquisa, foram selecionados alguns temas atuais de relevância global, principalmente com aplicação em bovinos, como a utilização de beta-agonistas, utilização de óleos essenciais e/ou funcionais, e a utilização de técnicas de biologia molecular para o estudo da microbiota ruminal. Palavras-chave: Beta-agonistas, óleos essenciais, óleos funcionais, microbiologia ruminalThe state-of-the-art of ruminant nutrition ABSTRACT. Over the last 25 years, researches in all aspects of ruminant nutrition were intensified. Forecasts indicate that in the year 2050 the world production and consumption of meat will be almost the double of the current volume, reaching 455 million tons per year. These projections are the result of human population growth, estimated at nine billion by the year 2050, and by the increasing of the purchasing power and quality of life will also increase the demand for animal protein. Relevant researches about feed efficiency, digestion and absorption processes, the development of new techniques for evaluating food and in-depth knowledge of ruminal microflora allow to the maximum use of nutrients for animals, also reducing the disposal of waste in the environment, another area of great concern. With a theme with such importance, the aim of this paper is to perform a brief explanation about the "State of Art of Ruminant Nutrition". Given the vast potential of research, we selected some current issues with global significance, especially with use in bovines, as the use of beta-agonists, use of essential /or functional oils and the use of molecular biology techniques to study the microflora rumen.Keywords: Beta-agonists, essential oils, funcional oils, ruminal microbiology El estado del arte de la nutrición de los rumiantesEn los últimos 25 años, las investigaciones en todos los aspectos de la nutrición de rumiantes se intensificaron. Previsiones indican que en 2050 la producción y el consumo mundial de carne será casi el doble del actual, pudiendo llegar a 455 millones de toneladas

The study was conducted in order to determine which bromatological aspect and kinetic parameters of materials from the silage from the pineapple plant . Four treatments were used: 1 - Pineapple silage compaction under 600 kg / m³ , 2 - Pineapple silage compaction under 700 kg / m³ , 3 - Pineapple silage compaction under 900 kg / m³ , 4 - Pineapple silage under compression 1000 kg / m³ . After ensiling the material from the plantation were evaluated bromatological aspects and kinetic passage of particles. For the kinetics of passage of particles was used as an indicator to mark the chromium fiber. Pass rates were determined by the recovery in the faeces of the animal. Bromatological parameters were not significant difference between treatments. Treatment with 900 kg/m3 compaction proved to be more efficient by providing a potentially digestible and consequently a higher indigestible fraction lower compared to the other treatments.