This study aimed to evaluate mechanical and chemical methods of forage dehydration in the production of black oat pre-dried silage (Avena strigosa Schreb) under different dehydration times. The experiment was conducted in a randomized block experimental design with five replications and arranged in a 2 x 6 factorial scheme. We assessed two methods of dehydration, mechanical and chemical, over six dewatering times, being made at 0, 3, 6, 9, 12, and 15 days after cutting or application of glyphosate. Harvest took place at 88 days after emergence, at pre-flowering. We evaluated dry biomass production at harvest, dry matter losses during dehydration in the field, losses during ensiling, gauging effluent output, and pre-dried silage chemical composition. There was an interaction between dehydration method and harvest time for most of the production characteristics. Chemical dehydration showed an enhanced dry matter recovery at the field level, however, unsuitable for pre-dried silage. The longer the dehydration period, the lower the losses for both analyzed methods; nevertheless, the chemical method reached unsatisfactory DM contents to produce good quality silage. Key words: Avena strigosa Schreb. Bromatology. Winter cereals. Conserved forage. Dry matter recovery. ResumoObjetivou-se avaliar a interferência dos métodos mecânico e químico de desidratação da forragem na confecção de silagem pré-secada de aveia-preta (Avena strigosa Schreb), sob diferentes tempos de desidratação. O experimento foi realizado em delineamento de blocos ao acaso, com 5 repetições, em esquema fatorial 2 x 6, sendo dois métodos de desidratação, mecânico e químico, sobre seis tempos de desidratação, sendo 0, 3, 6, 9, 12 e 15 dias após o corte ou aplicação do herbicida glifosato. A colheita se deu aos 88 dias após emergência, em estádio de pré-florescimento. Foram avaliadas produção de fitomassa seca no momento da colheita, perdas de fitomassa seca durante a desidratação à campo, perdas durante a ensilagem, com aferição da produção de efluentes, além da composição bromatológica da silagem pré-secada. Houve interação entre método de desidratação x época de colheita, para a maioria

This study aimed to evaluate the production, the physical and nutritional composition of forage and silage, as well as the profitability and aerobic stability of different winter cereals harvested at the stage of floury grain. The experimental design was a 2x7 factorial randomized block design, with two forms of foods (fresh forage and silage) and seven genotypes, with four replications. The genotypes used were the white oat (Avena sativa) cv. URS Taura; barley (Hordeum vulgare) cv. BRS Brau and cv. BRS Cauê; wheat (Tricticum aestivum) cv. CD 1440; rye (Secale cereal) cv. BR 01; and triticale (X Triticosecale) cv. IPR 111 and cv. BRS Saturno. The materials were harvested during the stage of floury grain. In forage evaluation, rye showed the highest (P < 0,05) dry biomass production (7,100 kg ha-1), but with a higher percentage of stem (46.7%) in dry matter, implying higher ADF (44.69%) in relation to other cereals. The forage of the white oats cv. URS Taura and triticale cv. IPR 111 provided the best nutritional quality compared to the other evaluated cereals, but in the resulting silage, only triticale remained with forage-like characteristics. It was clear the superiority of barley cv. BRS Cauê, wheat cv. CD 1440 and rye cv. BR 01 regarding the maintenance of aerobic stability (160 hours), while the other silages lost their stability within 32 hours. Rye cv. BR 01 and triticale IPR 111 presented the highest production of recovered dry biomass (5,402 and 5,352 kg ha-1 respectively), barley cv. BRS Cauê and oat URS Taura provided higher cost of production per kg-1 dry biomass, both with R$ 0.29 and higher cost per kg of recovered dry biomass R$ 0.45 and 0.37 respectively. There are several factors to consider when choosing the winter species for silage production, and future studies can fully elucidate these factors.

Effect of monensin sodium associative to virginiamycin and/or essential oils on the performance of feedlot finished steersEfeito associativo da monensina sódica à virginiamicina e/ou óleos essenciais sobre o desempenho de novilhos terminados em confinamento respectively in the same weightings. The daily carcass gain and carcass overall gain were higher in associations MO+VI and MO+EO+VI and provided an average gain of 16.67 kg more compared to MO and MO+EO. In the parameters feed efficiency, dry matter intake and nutrient expressed in kg day -1 and percentage of live weight were not observed differences (P> 0.05) between treatments. Data on apparent digestibility, feeding behavior and carcass characteristics did not show statistical difference between treatment, except for fat thickness which was higher when associated with any of the additives to the MO, and farm weight was higher in associations containing VI. Associating MO+VI or MO+EO+VI proved to be best in this work compared to MO+EO or only MO in the diets of steers in termination. Key words: Ionophores. Antibiotics. Plant extracts. Performance enhancers. Os dados referentes à digestibilidade aparente, comportamento ingestivo e características de carcaça também não apresentaram diferença estatística entre os tratamentos, exceto para espessura de gordura que foi superior quando associado qualquer um dos aditivos à MO, e peso de fazenda que foi superior nas associações que continham VI. A associação de MO+VI ou MO+OE+VI mostraram-se melhores no presente trabalho em relação a MO+OE ou somente MO nas rações dos novilhos em terminação. Palavras-chave: Ionóforos. Antibióticos. Extratos vegetais. Melhoradores de desempenho.

Monensin is an ionophore antibiotic, the inclusion of which in the feed of beef cattle favors the best use of feed nutrients, via ruminal modulation. However, there are concerns regarding the residence of residues in the carcass from metabolism of monensin. The objective of this study was to evaluate the productive performance, carcass characteristics, serum parameters, tissue residual depletion and economic benefit of finishing of young bulls in confinement with monensin in the ration. Thirtysix animals were confined, and given 50% corn silage feed and 50% more concentrated feed. The experimental design was completely randomized, with two treatments (with or without monensin) and 10 replicates for the control group and eight for the monensin group. The use of monensin reduced the dry matter intake in relation to live weight (2.36% vs 2.55%), and improved feed conversion (8.61 vs 10.06 kg kg −1 ); the animals presented higher live weight (511 vs 494 kg), higher warm carcass weight (285 vs 272 kg) and an increase in fat thickness (4.97 vs 4.25 mm) compared to control animals. These increases in performance gave higher economic results, with a profit margin of R$ 122.84 per animal. A waiting period of 16 h before slaughter resulted in monensin concentrations below 0.25 µg kg −1 in edible organs and tissues, values well below those permitted by legislation. The use of monensin for young bulls in confinement promoted improvements in productive and economic performance, without leaving residues in edible tissues. ResumoA monensina é um antibiótico ionóforo, cuja inclusão na alimentação de bovinos de corte favorece o melhor aproveitamento dos nutrientes da ração, via modulação ruminal. Porém há preocupações no que tange a permanência de resíduos na carcaça, provenientes da metabolização da monensina. Assim, objetivou-se avaliar o desempenho produtivo, as características de carcaça, os parâmetros séricos, a depleção residual tecidual e a economicidade da terminação de tourinhos em confinamento com monensina na ração. Foram confinados 36 animais com ração 50% de silagem de milho mais 50% concentrado. O delineamento experimental foi inteiramente casualizado, com 2 tratamentos (com ou sem monensina) e 10 repetições para o grupo controle e 8 para o grupo com monensina. O uso de monensina reduziu o consumo de matéria seca em relação ao peso vivo (2,36 vs 2,55%), melhorou a conversão alimentar (8,61 vs 10,06 kg kg -1 ), os animais apresentaram maior peso vivo (511 vs 494 kg), maior peso de carcaça quente (285 vs 272 kg) e aumento na espessura de gordura (4,97 vs 4,25 mm) comparativamente aos animais da ração controle. Tais acréscimos em desempenho conferiram maiores resultados econômicos, com margem de lucro de R$ 122,84 por animal. O período de carência de 16 horas antes do abate apresentou concentrações de monensina inferiores a 0,25 µg kg -1 nos órgãos e tecidos comestíveis, valores muito abaixo dos permitidos na legislação. O uso de monensina para tourinhos em confinamento promoveu melhorias no desempenho produt...

The goal of this study was to evaluate the effects of successive harvests, with or without application of foliar fungicide, on the morphometric characteristics, yield and nutritional value of rye forage harvested at the hard dough grain stage, aiming at silage production. The preventive control of foliar diseases was carried out with the fungicide OrkestraTM SC®, in a single application, at early flowering, for both harvesting systems. The first harvest was conducted at the full vegetative stage and the second, at the hard dough grain stage. The system with two harvests resulted in higher cumulative yield compared with the single-harvest system (40,680 and 9,029 kg ha-1 fresh and dry biomass with two harvests, against 8,816 and 5,375 kg ha-1 fresh and dry biomass). Fungicide application promoted a reduction in neutral detergent fiber content in both systems, with values of 753.9 against 790.6 g kg-1 for the single-harvest system and 734.4 against 773.3 g kg-1 for the two-harvest system, with and without fungicide, respectively. For lignin content, the application of the fungicide reduced values (97.2 against 110.3 g kg-1) only in the two-harvest system. Rye management with a harvest at the vegetative stage increases the cumulative dry biomass yield without negatively affecting the harvest yield at the hard dough grain stage, and without drastic changes in the nutritional value of the plant. Even under adverse conditions, fungicide application positively interferes with plant cell wall components