RESUMO.O objetivo deste trabalho foi avaliar a produtividade de massa seca e massa verde, altura de inserção da espiga, número de espigas por planta, altura das plantas e a relação espiga, colmo e folha de seis variedades de milho indicadas para a região semiárida brasileira (BR 5033 -Asa Branca, BR 5028 -São Francisco, BRS 4103, BRS Caatingueiro, BRS Assum Preto e Gurutuba), visando à produção de silagem. O experimento foi conduzido nas dependências da Embrapa Semiárido, adotando-se o delineamento experimental de blocos casualizados com seis tratamentos e quatro repetições. , assim como a relação espiga, colmo e folha atestam a possibilidade de utilização das variedades avaliadas para a produção de silagem na região semiárida brasileira.Palavras-chave: forragem, matéria seca, nutrição, ruminantes, Zea mays.ABSTRACT. Agronomic characteristics of maize varieties for silage production in the submédio São Francisco river valley. The objective of this study was to evaluate the dry and fresh matter yield, height of ear insertion, number of ears per plant, plant height and the ear stem ratio, indicate the possibility of using the evaluated varieties for silage production in the Brazilian semi-arid.Key words: forage, dry matter, nutrition, ruminants, Zea mays. IntroduçãoA cultura do milho está difundida por toda região Nordeste do Brasil, sendo um dos principais produtos agrícolas da região, onde ocupa uma área de, aproximadamente, 3 milhões de hectares (IBGE, 2007), participando na formação da renda agrícola, na ocupação funcional de parcelas consideráveis da população rural e, principalmente, pela sua contribuição na alimentação animal, em que entra como componente básico.A área plantada no Nordeste produziu, nos últimos oito anos, média de 3.322.041 toneladas de grãos ano -1 revelando-se abaixo da média nacional (9.148.306 toneladas ano -1 ), onde se observou que nesta região a produção média por hectare é de aproximadamente 1,5 toneladas ha -1 , enquanto a média nacional é de 3,9 t ha -1 (AGRIANUAL, 2009), o que pode ser atribuído à particularidade climática local, ao grau tecnológico adotado em sua produção e ainda à escolha de genótipos inadequados,

ABSTRACT. Productive performance for silage production of five forage sorghum genotypes (BRS Ponta Negra, BRS 655, BR 601, BRS 506 and BRS 610) was evaluated through the yield of dry matter, digestible dry matter, and fresh matter, plant height, percentage of lodged and broken plants, and anatomical fractions in Brazilian semi-arid region. BRS 506 and BRS Ponta Negra varieties achieved the highest fresh forage yields (89.4 and 76.2 ton. ha -1 ), and BRS 506, stood out for dry and digestible dry matter yield (25.2 and 12.1 ton. ha -1 , respectively). Regarding the participation of the plant fractions, BRS 655 and BRS 610 genotypes showed a higher percentage of panicles (50.2 and 41.0% respectively), while BRS 506 stressed out the stem participation (84.6%), and BRS Ponta Negra, the leaf participation (17.9%). Among the materials evaluated for silage production, stood out the BRS 506 and BRS Ponta Negra genotypes. The results obtained for production of dry and digestible dry matter, and the ratio of plant fractions indicates the possible use of these genotypes on silage production in the Brazilian semiarid.Keywords: forage, dry matter, nutrition, ruminants, Sorghum bicolor (L.) Moench.Características agronômicas de cultivares de sorgo forrageiro para produção de silagem no Submédio do Vale do São Francisco RESUMO. O objetivo deste trabalho foi avaliar a produtividade de matéria seca, matéria verde e matéria seca digestível, altura das plantas, percentual de plantas acamadas e quebradas e a participação das frações anatômicas da planta de cinco genótipos de sorgo forrageiro para a região semiárida brasileira (BRS Ponta Negra, BRS 655, BR 601, BRS 506 e BRS 610), visando à produção de silagem. As variedades BRS 506 e BRS Ponta Negra apresentaram maiores produtividades de matéria verde (89,4 e 76,2 t ha -1 ). A variedade BRS 506 destacou-se pela produtividade de matéria seca e matéria seca digestível (25,2 e 15,7 t ha -1 , respectivamente). Quanto à participação das frações da planta, os genótipos BRS 655 e BRS 610 apresentaram maior percentual de panícula (50,2 e 41,0%, respectivamente), enquanto a variedade BRS 506 apresentou 84,6% de participação do colmo e a variedade BRS Ponta Negra, 17,9% de participação das folhas. Entre os materiais avaliados para produção de silagem destacaram-se as variedades BRS 506 e BRS Ponta Negra. Os resultados obtidos para produção de matéria seca e matéria seca digestível, assim como a relação das frações da planta atestam a possibilidade de utilização dos genótipos avaliados para a produção de silagem na região semiárida brasileira.Palavras-chave: forragem, matéria seca, nutrição, ruminantes, Sorghum bicolor (L.) Moench.

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SUMMARYPearl millet (Pennisetum glaucum (L.) R.) could play an important role as a feed source for ruminants in arid and semi-arid zones of the world owing to its high yield and drought tolerance. The current paper assessed the agronomic characteristics, ensilability, intake and digestibility of five Brazilian pearl millet cultivars (IPA Bulk1BF, BRS 1501, CMS-03, CMS-01 and BN-2) in a typical Brazilian northeastern semi-arid climate. Forage was harvested at the dough stage of grain maturity (growth stage 86 according to the BBCH scale) and ensiled under laboratory and farm conditions. Apparent digestibility of the silages was determined using 25 Santa Inês male lambs. The cultivars CMS-01, CMS-03 and BN-2 out-performed the others in terms of dry matter (DM) and digestible DM yield/ha. At DM partitioning among plant tissues, the cultivar IPA Bulk1BF had a greater DM associated with panicles and one of the greatest concentrations of organic matter, lactic acid and in vitro dry matter digestibility among the five cultivars. The cultivar BRS 1501 had greater butyric acid concentration as well as one of the highest pH values. Silage produced from BN-2 not only contained greater acetic acid concentration, but also showed one of the greatest total volatile fatty acid concentrations. There were no differences in feed intake and digestibility of nutrients and fibre fractions across all cultivars. Silage made from BN-2 resulted in greater urinary excretion of nitrogen than those produced from BRS 1501. Under the conditions of the present study, the results obtained for production of DM and digestible dry matter, and the ratio of plant fractions, indicates the possible use of these cultivars for silage production in the Brazilian semi-arid region.

SUMMARYIn the near future, ruminants may be forced to consume low-quality water since potable drinking water will become increasingly scarce in some regions of the world. A completely randomized design trial was completed to evaluate the effect of increasing concentrations of total dissolved salts (TDS) (640, 3187, 5740 and 8326 mg TDS/l) in drinking water on the performance, diet digestibility, microbial protein synthesis, nitrogen (N) and water balance using 24 Red Sindhi heifers (200 ± 5 kg) that were fed Buffel (Cenchrus ciliaris) grass hay and concentrate in a ratio of 50 : 50. After a 15-day diet adaptation period, the digestion study was completed over a 5-day period and the performance trial was completed over a 56-day period. Dry matter intake, average daily gain, feed:gain, intake and digestibility of most feed components were unaffected by the concentration of salt in the water. However, intake and digestibility of neutral detergent fibre declined linearly as TDS inclusion rate increased. Further, the inclusion of TDS resulted in a linear increase in the intake of drinking water and total (food plus drinking) water intake. Similarly, TDS inclusion levels resulted in a linear increase in total water excretion, with urine being the major route of water excretion. In contrast, increasing concentrations of TDS caused a linear decrease in creatinine and allantoin excretions. Finally, increasing the inclusion rate of TDS resulted in a linear decrease in N retention and a linear increase in urinary N excretion, which may pose a considerable challenge for farmers with respect to the reduction and management of nutrient losses.

The objective of this work was to evaluate the silage quality, fermentation profile, intake, and digestibility of six sorghum cultivars for sheep feeding. 'SF 15', 'IPA 2502', 'BRS 655', 'BR 601', 'BRS 506', and 'Sudão' were cultivated in randomized complete block designs with five replicates, harvested, and ensiled when plants reached the soft-dough grain stage. Silage quality was determined in laboratory silos. Intake and apparent digestibility were determined during 22 days, using 24 Santa Inês lambs (35.5±2.21 kg) randomly distributed in the treatments. Silage from 'IPA 2502' had the lowest contents of dry matter, neutral detergent fiber, and acid detergent fiber; the highest nonfibrous carbohydrate and total digestible nutrient contents; and the greatest dry matter degradability. Silages from 'BR 601' and 'BRS 506' showed the highest values of crude protein, whereas those of 'SF 15' and 'Sudão' had the highest levels of fibrous fractions. Lambs fed silage from 'IPA 2502' consumed more dry matter and nonfibrous carbohydrates, and their crude protein digestibility was also greater than that from the consumption of other cultivar silages. 'IPA 2502' stands out for its nutritional characteristics, which resulted in better animal performance.

RESUMO.-Avaliou-se o efeito da inclusão da silagem da raiz de mandioca sobre os parâmetros ruminais e o balanço de compostos nitrogenados em bovinos de origem leiteira. Utilizou-se cinco animais, canulados no rúmen, não lactantes e com peso corporal médio de 389 kg. Os animais foram distribuídos em um quadrado latino cinco x cinco, sendo cinco dietas com níveis de inclusão (0,00; 3,62; 7,23; 10,84 The effect of inclusion of cassava root silage on ruminal parameters and nitrogenous compounds in dairy cattle was evaluated. Five cattle cannulated in the rumen and with average body weight of 389 kg were distributed into a Latin square 5x5, with five levels of inclusion (0.00, 3.62, 7.23, 10.84 and 14.54% of the diet dry matter) of cassava root silage and five periods (10 days for adaptation and five days for data collection). The nitrogen excretion in urine and feces were not affected (P>0.05) by inclusion of cassava root silage in the diet. The total nitrogen intake (CNT) and nitrogen balance (NB) showed an increasing quadratic and linear behavior, respectively. The lowest CNT (142.14g/day) was obtained with the inclusion of 5.82% silage cassava root. The concentration of urea (U) and urea nitrogen (UN) in plasma and urine did not change (P>0.05). There was a quadratic behavior (P<0.05) in excreta of U and NU in the urine, with minimum point of 131.13 and 61.20g/day respectively, at the level of 7.27% inclusion of the cassava root silage. No interaction (P>0.05) was between the levels of cassava root silage and the collection time of rumen contents for the short-chain fatty acids, pH and ammonia nitrogen (NH3-N). Only the N-NH 3 protein showed quadratic behavior, according to the inclusion levels, with the minimum point (12.62mg/100ml of rumen contents) at the level of 5.98%. The level of 7.23% of cassava root silage in the diet was more efficient with the use of nitrogen compounds. The diets contribute similarly to the production of short chain fatty acids, without disturbing the rumen pH.

-The objective of this study was to evaluate the daily intake and total apparent digestibility of dry matter, organic matter, crude protein, gross energy, ether extract, neutral detergent fiber, acid detergent fiber, total and non-fibrous carbohydrates, total digestible nutrients, energy intake and nitrogen balance of silages of six maize varieties with early or super early cycles recommended to Northeast Brazil. Twenty-four male castrated lambs were lodged in metabolic cages.A completely randomized design with six treatments and four replications was used, with means compared by Tukey test at 5%. There were no differences among varieties for any of the evaluated variables regarding intake and apparent digestibility.Concerning the intake of digestible energy, metabolizable energy and the ratio content of digestible and metabolizable energy, significant differences were observed between varieties and BRS Assum Preto showed highest values of metabolizable energy (2.650,8 kcal/day). All of the treatments presented positive nitrogen balance and did not differ among themselves.The varieties asessed can be an additional option to the semiarid regions in Brazil.