81 research outputs found

    Increased dietary protein in the second trimester of gestation increases live weight gain and carcass composition in weaner calves to 6 months of age

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    Genetically similar nulliparous Polled Hereford heifers from a closed pedigree herd were used to evaluate the effects of dietary protein during the first and second trimester of gestation upon fetal, placental and postnatal growth. Heifers were randomly allocated into two groups at 35d post AI (35dpc) to a single bull and fed High (15.7%CP) or Low (5.9%CP) protein in the first trimester (T1). At 90dpc, half of each nutritional treatment group changed to a High or Low protein diet for the second trimester until 180dpc (T2). High protein intake in the second trimester increased birthweight in females (P = 0.05) but there was no effect of treatment upon birthweight when taken over both sexes. Biparietal diameter was significantly increased by high protein in the second trimester with the effect being greater in the female (P = 0.02) but also significant overall (P = 0.05). Placental weight was positively correlated with birth weight, fibroblast volume, and relative blood vessel volume (P < 0.05). Placental fibroblast density was increased and trophoblast volume decreased in the high protein first trimester treatment group (P <0.05). There was a trend for placental weight to be increased by high protein in the second trimester (P = 0.06). Calves from heifers fed the high protein treatment in the second trimester weighed significantly more on all occasions preweaning (at one month (P = 0.0004), 2 mths (P = 0.006), 3 mths (P = 0.002), 4 mths (P = 0.01), 5 mths (P = 41 0.03), 6 mths (P = 0.001)), and grew at a faster rate over the 6 month period. By 6 mths of age the calves from heifers fed high nutrition in the second trimester weighed 33kg heavier than those fed the low diet in the second trimester. These results suggest that dietary protein in early pregnancy alters the development of the bovine placenta and calf growth to weaning

    On the Representability of Complete Genomes by Multiple Competing Finite-Context (Markov) Models

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    A finite-context (Markov) model of order yields the probability distribution of the next symbol in a sequence of symbols, given the recent past up to depth . Markov modeling has long been applied to DNA sequences, for example to find gene-coding regions. With the first studies came the discovery that DNA sequences are non-stationary: distinct regions require distinct model orders. Since then, Markov and hidden Markov models have been extensively used to describe the gene structure of prokaryotes and eukaryotes. However, to our knowledge, a comprehensive study about the potential of Markov models to describe complete genomes is still lacking. We address this gap in this paper. Our approach relies on (i) multiple competing Markov models of different orders (ii) careful programming techniques that allow orders as large as sixteen (iii) adequate inverted repeat handling (iv) probability estimates suited to the wide range of context depths used. To measure how well a model fits the data at a particular position in the sequence we use the negative logarithm of the probability estimate at that position. The measure yields information profiles of the sequence, which are of independent interest. The average over the entire sequence, which amounts to the average number of bits per base needed to describe the sequence, is used as a global performance measure. Our main conclusion is that, from the probabilistic or information theoretic point of view and according to this performance measure, multiple competing Markov models explain entire genomes almost as well or even better than state-of-the-art DNA compression methods, such as XM, which rely on very different statistical models. This is surprising, because Markov models are local (short-range), contrasting with the statistical models underlying other methods, where the extensive data repetitions in DNA sequences is explored, and therefore have a non-local character

    Carcass characteristics of feedlot-finished Zebu and Caracu cattle

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    This study analyzes the chemical carcass characteristics and carcass losses in 86 cattle, both castrated and non-castrated, with an average initial weight of 329 kg and an average age of approximately 20 months, including 12 Gyr, 20 Guzerat, 20 Nellore, and 20 Caracu among the herds selected for weight determination at 378 days of age, as well as 14 Nellore cattle that were not selected. The diet contained a roughage-to-concentrate ratio of 60:40 in terms of dry matter (DM), with 14.8% crude protein as a percentage of DM and corn silage as roughage. A completely randomized 5 × 2 factorial experimental design was used, including five breeds and two sex classes. The following values were determined: losses due to the trimming of commercial cuts and cooking; shear force; the temperature and pH of the meat; and the chemical composition of the Hankins and Howe section (HH section). The castrated animals exhibited greater losses from the front trimmings compared with the non-castrated cattle. There were no differences in the final pH values of the carcasses among the breeds, although the noncastrated animals exhibited higher values than the castrated ones, likely because non-castrated animals were more susceptible to stress. The final pH remained within the range considered optimal for all of the carcasses studied. No differences were observed in the shear force among the breeds or between the two sexes. When appropriately managed, zebu breeds are capable of producing tender meat, thus meeting the demands of the consumer market

    República de Nicaragua /

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    Relief shown by shading.Prime meridian: Paris.Includes relief profile of "Canal Interoceánico de Nicaragua" and statistical table of administrative divisions and capitals of Nicaragua.Insets: Puerto de Corinto -- Puerto de San Juan del Norte.In lower right margin: 13.LC copy sectioned in 2 sheets

    República del Ecuador

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    Différenciation, croissance et développement du tissu adipeux

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