Redução do nível de proteína bruta da ração com suplementação de aminoácidos sintéticos para leitões na fase inicial Effects of reducing dietary crude protein levels for piglets supplemented with synthetic amino acid

Avaliou-se o efeito da redução do nível de PB e do farelo de soja, com suplementação de aminoácidos, na ração sobre o desempenho, a excreção de N, o peso dos órgãos e a incidência de diarréia em leitões na fase inicial. As dietas continham quatro níveis de PB (21,0; 19,5; 18,0 e 16,5%) e foram suplementadas com os aminoácidos lisina, metionina e treonina. No experimento I, oito suínos machos castrados (PV = 22,0 kg), mestiços (LD x LW), foram alojados individualmente em um delineamento em blocos casualizados com parcela subdividida no tempo, para determinação do balanço de N. O consumo de N e a excreção nas fezes não foram afetados pelos tratamentos, porém, houve decréscimo linear da excreção na urina com a redução da PB dietética. No experimento II, 60 animais (PV = 8,5 kg) foram alojados em delineamento de blocos casualizados, em esquema fatorial 4 x 3 (quatro dietas e três épocas de abate), com cinco blocos e um animal por unidade experimental, para avaliação do peso relativo do fígado, baço e pâncreas e da morfometria intestinal nas três primeiras semanas pós-desmame. Não houve diferenças significativas entre os tratamentos, exceto para a profundidade de criptas na primeira semana, que apresentou efeito cúbico. No experimento III, 60 animais (PV = 8,0 kg) foram alojados em delineamento de blocos casualizados, com cinco blocos e três animais por unidade experimental, para estudo do desempenho e da incidência de diarréia. Não houve diferenças significativas para os parâmetros avaliados, porém observou-se redução na incidência de diarréia nos animais que receberam rações contendo 16,5% de PB. A redução do nível de PB de 21 para 16,5% na dieta de leitões na fase inicial é viável para redução da excreção de N na urina e da incidência de diarréia, pois não afeta os parâmetros fisiológicos e de desempenho de leitões dos 10 aos 25 kg PV.<br>The effects of reducing dietary CP and soybean meal levels on performance, N excretion, organs weight and diarrhea incident were evaluated in pigs supplemented with amino acids. The diets contained four levels of CP (21.0, 19.5, 18.0, and 16.5%) and were supplemented with synthetic amino acid (lysine, metionine and treonine). In experiment I, eight crossbred (LD x LW) castrated males (initial weight = 22 kg) were individually allotted to a randomized block design, with split plot arrangement to determine N balance. No significant changes in amount of N ingested and excreted in the feces were observed among the treatments. However, the treatments linearly decreased N excreted in the urine, as dietary CP decreased. In experiment II, 60 pigs (initial weight = 8.5 kg) were assigned to a randomized blocks design with 4 x 3 factorial arrangement (four diets and three slaughter ages), with five blocks and one animal per unit experimental, to evaluate the relative weights of liver, spleen and pancreas and intestinal morfometry during the first three post weaning weeks. No significant differences on these parameters were observed across the treatments, whereas crypt depth changed in the first post weaning week, that showed cubic effect. In experiment III, 60 animals (initial weight = 8,0 kg) were allotted to a randomized blocks design, with five blocks and three animals per experimental unit, to evaluate the performance and diarrhea incidence. No significant differences on these parameters were observed across the treatments. Pigs fed diet with 16.5% CP showed decreasing diarrhea incidence. Reducing the dietary CP levels from 21 to 16.5% for pigs in the nursery phase decreased N excretion in the urine and diarrhea incidence with no changes on performance and physiologic parameters of piglets from 8 to 25 kg BW

Desempenho e excreção de nitrogênio de leitões dos 9 aos 25 kg alimentados com dietas com diferentes níveis de lisina digestível e proteína bruta Performance and nitrogen excretion for pigs from 9 to 25 kg submitted to the diets with different levels of digestible lysine and crude protein

Dois experimentos foram conduzidos para avaliar níveis de PB e lisina digestível (LISD) na dieta sobre o desempenho e a excreção de nitrogênio (N) de leitões na fase inicial. No experimento 1, 80 suínos machos castrados e fêmeas (peso inicial de 9,1 &plusmn; 1,2 kg e final de 21,5 &plusmn; 4,8 kg), mestiços Landrace &times; Large White, foram distribuídos em blocos casualizados em esquema fatorial 2 &times; 4, composto de dois níveis de PB (16 e 18%) e quatro níveis de LISD (0,7; 0,9; 1,1 e 1,3%) com cinco repetições e dois animais por unidade experimental durante 35 dias. Foram avaliados o ganho de peso médio diário (GPMD), o consumo médio diário de ração (CMDR) e a conversão alimentar (CA). No experimento 2, 32 suínos machos castrados (25,0 &plusmn; 1,3 kg), provenientes do experimento 1 foram alojados individualmente em gaiolas próprias para estudos de metabolismo (unidade experimental) durante 11 dias para determinação dos teores de N ingerido (NI), N nas fezes e N na urina. As rações foram formuladas com milho, farelo de soja e leite em pó modificado e suplementadas com vitaminas e minerais. Os aminoácidos metionina e treonina foram corrigidos de acordo com os níveis de lisina, segundo o conceito de proteína ideal. Não houve efeito da interação LISD &times; PB sobre nenhuma variável estudada. Os níveis de LISD tiveram efeito quadrático sobre o GMDR e a CA, que foram melhores nos animais alimentados com as dietas com níveis de 1,04 e 1,09% de PB. Os níveis de N nas fezes sofreram efeito linear crescente dos níveis de LISD e PB, enquanto os níveis de N na urina foram afetados de forma quadrática pelos níveis de LISD, com melhor resultado no nível de 1,03% LISD na ração. O CMDR e o nível de N nas fezes não foram influenciados pelos níveis de LISD e PB. O nível de 1,05% LISD em dietas com 16 e 18% PB proporciona melhor desempenho e menor excreção de N nos dejetos de suínos.<br>Two experiments were conducted to evaluate dietary levels of crude protein (CP) and digestible lysine (LYSD) on the performance and nitrogen (N) excretion of piglets in the initial phase. In experiment 1, 80 barrows and females (initial weight of the 9.1 kg &plusmn; 1.2 kg and final weight of the 21.5 &plusmn; 4.8 kg), crossbred (Landrace x Large White), were distributed to a randomized blocks in factorial scheme 2 x 4 (two levels of CP 16 and 18% - and four levels of LYSD (0.7; 0.9; 1.1 and 1.3%) with five replications and two animals per experimental unit, during 35 days. The average daily weight gain (ADG), average daily feed intake (ADFI) and feed:gain ratio (F:G) were evaluated. In experiment 2, 32 barrows (25.0 &plusmn; 1.3 kg), from experiment I, were individually allotted in metabolic cages (experimental unit), during 11 days, to evaluate the ingested N, N in feces and N in urine . The diets were formulated with corn, soybean meal and modified powder milk, supplemented with vitamins and minerals. The amino acids methionine and threonine were corrected in function of the lysine levels, following the ideal protein concept. No interaction LYSD x CP was observed for neither studied variable. Average daily gain and F:G showed a quadratic effect for the LYSD levels and were better in the animals fed diets with levels of 1.04 and 1.09%, respectively. The levels of N in the fezes showed crescent linear effect with the LYSD and CP levels, while the N levels in the urine showed quadratic effect with LYSD levels, with lower excretion for the level of 1.03% in the ration. No influence was observed for LYSD and CP level on ADFI and N in fezes. The level of 1.05% LYSD in diets with 16 and 18% CP provide best performance and lower excretion of de N in dejects of the swine

Pan-cancer analysis of whole genomes

Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation; analyses timings and patterns of tumour evolution; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity; and evaluates a range of more-specialized features of cancer genomes