RESUMOO consumo de forragem fo i avaliado em novilhas de corte exclusivamente em pastagem de azevém (Lolium multijlorum Lam.) ou recebendo farelo de arroz integral (FAI) com ou sem adição de ionóforo. Foi usado o óxido de cromo como indicador da produção fecal. O delineamento experimental fo i o inteiramente casualizado, com medidas repetidas no tempo, com três tratamentos e três repetições de área. Os animais foram considerados as unidades experimentais nas avaliações de consumo. O consumo de pasto pelas novilhas fo i similar nos diferentes sistemas alimentares, ocasionando taxa de lotação semelhante. O fornecimento de farelo de arroz integral, com ou sem monensina, aumenta o consumo de matéria seca total. A adição de ionóforo ao FAI aumenta o desempenho individual das novilhas, sendo o seu uso recomendado quando existe o objetivo de reduzir a sua idade ao primeiro acasalamento. Palavras-chave: Angus, Lolium multiflorum Lam., monensina, óxido de cromo. ABSTRACTThe forage intake was evaluated in beef heifers exclusively in Italian ryegrass (Lolium multiflorum Lam.) pasture or receiving rice bran with or without addition o f ionophore. Chromic oxide was used as a fecal production indicator. The experimental design was completely randomized with repeated measures on time, three treatments and three area replicates. The animals were considered experimental units fo r intake evaluations. The pasture intake by heifers was similar at different feeding systems causing similar stocking rate. The supply o f rice bran with or without monensin increased the total dry matter intake. The individual heifers performance was increased with ionophore addition to rice bran. Ionophore is recommended when there is a goal to reduce the age o f beef heifers at their first mating. INTRODUÇÃOO consumo voluntário de forragem é o principal fator que influencia a produtividade dos sistemas em pastejo, sendo influenciado por características relacionadas ao animal, à planta, ao suplemento fornecido, ao ambiente e ao manejo imposto ao pasto. O consumo total de matéria seca é menor em ruminantes mantidos exclusivamente em pastejo, em relação aos que recebem suplementos, e é esperado melhor desempenho de bovinos de alta produção quando há inclusão de suplementos em sua dieta, permitindo que esses expressem seu potencial genético. ROSA et al. (2013), no entanto, não observaram mudança na ingestão total de matéria seca, independente do estádio de desenvolvimento do pasto, quando novilhas receberam grão de milho ou gordura extrusada em pastagem de azevém (Lolium multiflorum Lam.).Dentre os suplementos que podem ser utilizados para animais em pastejo em azevém, destaca-se o farelo de arroz integral (FAI), por sua abundância regional. No Rio Grande do Sul, na safra 2011/12, estima-se que tenham sido produzidas aproximadamente 680 mil toneladas desse subproduto. Respostas anteriores, obtidas com o uso do FAI na recria de novilhas de corte, em pastagem de inverno, mostram que, quando associado à polpa cítrica (1:1), proporcionou incrementos de 21,92% ...

Under conditions of high temperature, humidity, and incidence of solar radiation, dairy cows use behavioral changes as a strategy to decrease the metabolic heat production at pasture. The objective of this study was to evaluate the behavioral and physiological responses of Gyr and Girolando (5/8 Holstein 3/8 Gyr, and ½ Holstein ½ Gyr) dairy cows submitted to environments with and without shade. The experiment was conducted at Embrapa Cerrados (Technology Center for Dairy Zebu breeds—CTZL), Brasilia, Distrito Federal—Brazil, with 48 Gyr and Girolando cows total in the lactation group, with low to medium milk production, in full sun or shade with Eucalyptus urograndis (267 plants/ha−1). The physiological and behavioral characteristics evaluated were panting score, superficial temperature, and time spent grazing, ruminating, and lying down. Other traits included skin and coat thickness, hair diameter, density and length, and predominant coat color. In addition, body measurements, such as body length, the height of withers, chest circumference, and shin circumference, were measured. Shaded cows had 34% longer rumination times than cows in full sun (p = 0.01). With a temperature-humidity index ranging from 79 to 83, the rumination time was 1.7 times higher in cows under shade (p = 0.01) during a 24-h period of observation. There were no significant differences in the grazing time between the environments, but lying time was 23% longer in cows under the sun (p = 0.01). The panting score was not influenced by the environment (p = 0.17). Girolando cows had a 35% higher panting score than Gyr cows (p = 0.01) regardless of the environment. The panting score increased two and a half times during the afternoon compared with the morning (p = 0.01). The surface and rectal core temperatures had significant differences between treatments and time of the day. Body measurements were not different between cows in both environments, but there was a difference between breeds. The use of trees in pastures with a silvopastoral system for dairy zebu cows is indicated to improve grazing behavior, as well as time spent ruminating and lying down.

ContentsThe aim of this work was to investigate the methylation and hydroxymethylation status of mesenchymal stem cells (MSC) from amniotic fluid (MSC-AF), adipose tissue (MSC-AT) and fibroblasts (FIB-control) and to verify the effect of trichostatin A (TSA) on gene expression and development of cloned bovine embryos produced using these cells. Characterization of MSC from two animals (BOV1 and BOV2) was performed by flow cytometry, immunophenotyping and analysis of cellular differentiation genes expression. The cells were used in the nuclear transfer in the absence or presence of 50 nM TSA for 20 hr in embryo culture. Expression of HDAC1, HDAC3and KAT2A genes was measured in embryos by qRT-PCR. Methylation results showed difference between animals, with MSC from BOV2 demonstrating lower methylation rate than BOV1. Meanwhile, MSC-AF were less hydroxymethylated for both animals.MSC-AF from BOV2 produced 44.92 ± 8.88% of blastocysts when embryos were exposed to TSA and similar to embryo rate of MSC-AT also treated with TSA (37.96 ± 15.80%). However, when methylation was lower in FIB compared to MSC, as found in BOV1, the use of TSA was not sufficient to increase embryo production.MSC-AF embryos expressed less HDAC3 when treated with TSA, and expression of KAT2A was higher in embryos produced with all MSC and treated with TSA than embryos produced with FIB. The use of MSC less methylated and more hydroxymethylated in combination with embryo incubation with TSA can induce lower expression of HDAC3 and higher expression of KAT2A in the embryos and consequently improve bovine embryo production. K E Y W O R D Sadipose cells, amniotic cells, bovine cloning, DNA methylation, histone acetylation

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RESUMOFoi estudado o desempenho de bezerras de corte em pastagem de azevém (Lolium multiflorum Lam.), com animais exclusivamente em pastejo ou recebendo farelo de arroz integral (FAI) em nível de 0,8% do peso corporal, associado ou não à monensina. O método de pastejo foi contínuo com número variável de animais. O delineamento experimental foi o inteiramente ao acaso, com medidas repetidas no tempo, com três tratamentos e três repetições de área. O uso de FAI associado ou não à monensina não expressou alteração na área pélvica das bezerras, na taxa de lotação e no ganho de peso por área. As bezerras que receberam FAI, com ou sem monensina, apresentaram maior ganho diário de peso corporal, peso corporal, escore de condição corporal e relação peso corporal:altura. O fornecimento de suplementação energética para bezerras de corte é uma alternativa viável em sistemas de produção que visam à redução da idade ao primeiro acasalamento.