The study aimed to examine the effects of harvesting three maize hybrids at different maturity stages on the ruminal fermentation kinetics, fermentation end-products (volatile fatty acid, ammonia and methane) output, and digestibility of maize plant fractions, as well as the degradability of the resulting silage. Three hybrids were compared (Maximus VIP3, Defender VIP and Feroz VIP) harvested at three grain maturity stages (milk (R3), dough (R4) and dent (R5) grain), while silage samples were collected only at the dent grain stage (R5). Grain digestibility tended to decrease as the maturity stage progressed (p < 0.05), while the whole-plant digestibility increased with increasing maturity for the three evaluated hybrids (p < 0.05). The gas production of whole-plant at 24 h of incubation was higher for the Maximus hybrid than for the others (p < 0.05), with average values of 188, 196 and 207 mL g−1 dry matter at stages R3, R4 and R5, respectively. For the in situ ruminal degradation kinetics of silage, instantly degradable dry matter and fiber potential degradability were greater with Maximus maize forage than with the other two hybrids. From the perspective of in vitro results, the Maximus VIP3 hybrid seems to be the most suitable for silage production when harvested between the dough and the dent grain stage of maturity.

This study aimed to evaluate the contents of hemicellulose, cellulose, and lignin, as well as the rates of dry matter degradability in forage and pre-dried silage of different winter cereals harvested at preflowering. The experiment was conducted by the Animal Production Center (NUPRAN), Department of Agricultural and Environmental Sciences, State University of Midwest (UNICENTRO). It is located in Guarapuava -PR, Brazil. The study was part of the Master's Degree in Crop Production. As experimental materials, we used black oat (Avena strigosa) cv. EMB 139 and cv. IAPAR 61; white oat (Avena sativa) cv. IPR and 126 hp. URS Taura; barley (Hordeum vulgare) cv. BRS Brau and cv. BRS Cauê; wheat (Triticum aestivum) cv. BRS Umbu and cv. BRS Tarumã; rye (Secale cereale) cv. Temprano and cv. BRS Serrano; and triticale (X Triticosecale) cv. IPR and 111 hp. BRS Saturn. Dry matter degradability was measured by an in situ technique, arranged in a completely randomized block design with three replications (animal), subdivided in subplots. Treatments were the plots and subplots digestion times. The incubation times were 0, 6, 12, 24, and 48 hours. To that end, we used two 24-month rumen fistulated steers with 350 kg average weight. A similarity was observed in the results of both forage and pre-dried silage degradability, displaying the same trends. Barley cv. BRS Brau had the highest hemicellulose content in its composition; however, IPR 111 triticale was showed the highest degradability potential, both for green forage and pre-dried silage. Key words: Chemical composition. Ruminal disappearance. Neutral detergent fiber. Hibernal forages. Lignin. ResumoO objetivo do trabalho foi avaliar os teores de hemicelulose, celulose e lignina, bem como a taxa de degradabilidade da matéria seca (MS), da forragem e da silagem pré-secada, de diferentes cereais de estação fria colhidos em estádio de pré-florescimento. O experimento foi conduzido pelo Núcleo de Produção Animal (NUPRAN

O trigo (Triticum aestivum) apresenta grande potencial tanto para a produção de forragem quanto para a produçãode grãos. Desta forma, o objetivo, com o desenvolvimento do trabalho, foi avaliar a produção e a qualidade final degrãos do trigo de duplo propósito cv. BRS Umbu manejado sob diferentes sistemas de corte, sendo: T1 – sem corte(testemunha), T2 – um corte e T3 – dois cortes. A produção de fitomassa verde foi influenciada pelo manejo decortes sendo o tratamento de dois cortes o responsável pelo menor valor (4.726 kg ha-1). A produção de fitomassaseca, produção total de palha e produção de grãos sofreu efeito negativo com os cortes sucessivos, sendo o tratamentosem corte o responsável pelas maiores médias (13.096 kg ha-1, 7.860 kg ha-1 e 5.236 kg ha-1, respectivamente).Na avaliação de desempenho agronômico dos grãos, para todas as avaliações foi observado superioridadenas médias (P<0,05) para o tratamento sem cortes, inclusive para o peso hectolitro e o peso de mil grãos. Já nacomposição bromatológica dos grãos ficou evidente que o manejo de cortes influenciou apenas as médias de matériamineral, ficando o tratamento sem corte com a média de 0,66 % na MS, um corte com média de 0,93% na MSe dois cortes com a média de 1,12 % na MS. Neste contexto, não se recomenda o manejo de mais do que um cortesucessivo para o trigo cv. BRS Umbu.

This study aims to evaluate the nutritive value of Ajuga iva (A. iva) harvested from three distinct altitude regions in Tunisia (Dougga, Mograne, and Nabeul). The chemical composition, phenolic concentration, gas production, and in vitro dry matter (DM) digestibility were determined. The highest concentrations of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were for A. iva cultivated in Nabeul. In contrast, the highest crude protein (CP) concentration was observed in that cultivated in Mograne, and the lowest (p < 0.01) CP concentration was noted in that cultivated in Dougga. Additionally, the cultivation regions affected the concentrations of free-radical scavenging activity, total flavonoids, and total polyphenols (p < 0.01). The highest free-radical scavenging activity was observed with A. iva cultivated in Dougga and Mograne. The highest (p < 0.05) gas production rate and lag time were observed in A. iva cultivated in Mograne and Nabeul regions. DM digestibility differed between regions and methods of determination. The highest (p < 0.01) DM degradability, determined by the method of Tilley and Terry and the method of Van Soest et al., was for A. iva cultivated in Mograne and Dougga, while the lowest (p < 0.01) value was recorded for that cultivated in the Nabeul region. Likewise, metabolizable energy (ME) and protein digestibility values were higher for A. iva collected from Mograne region than that collected from the other sampling areas. In conclusion, the nutritive value of A. iva differed between regions. Therefore, care should be taken when developing recommendations for using A. iva in an entire region. Season- and region-specific feeding strategies for feeding A. iva are recommended.

This study aimed to assess the chemical composition of the forage and pre-dried silage from twelve winter cereals harvested at pre-flowering. We used black oat (Avena strigosa) cv. EMB 139 and cv. IAPAR 61; white oat (Avena sativa) cv. IPR and 126 hp. URS Taura; barley (Hordeum vulgare) cv. BRS Brau and cv. BRS Cauê; wheat (Triticum aestivum) cv. BRS Umbu and cv. BRS Tarumã; rye (Secale cereale) cv. Temprano and cv. BRS Serrano; and triticale (X. Triticosecale) cv. IPR and 111 hp. BRS Saturno. Plants were harvested at pre-flowering, when they were pre-dried and ensiled. The analysis of variance evidenced nutritional differences between species and cultivars. Triticale cv. IPR 111 showed notorious chemical characteristics in relation to the other treatments, highest protein content (113.7 g kg-1) and lower content of NDF and ADF (657.9 and 380.9 g kg-1, respectively). Among the pre-dried silages, barley cv. BRS Cauê had the highest level of NDT (614.7 g kg-1). Triticale cv. IPR 111 was shown as a high-quality nutritional food as forage and kept these characteristics after conservation. On the other hand, the pre-dried silage of barley cv. BRS Cauê showed the highest potential for nutrient degradability.

ABSTRACT. The objective of the experiment was to evaluate the nutritional composition, dry matter (DM) recovery and aerobic stability of winter cereal silages under different storage periods. The materials used were wheat (Triticum aestivum cv. BRS Gralha Azul), barley (Hordeum vulgare cv. BRS Brau), white oat (Avena sativa cv. URS Guará), black oat (Avena strigosa cv. Embrapa 139) and triticale (X Triticosecale IPR 11), in three storage periods: 60, 120 and 180 days. The experiment was conducted in a 5x3 factorial, completely randomized design, consisting of five forage species and three storage periods, with five replicates. In nutritional assessment, barley silage presented low values of acid detergent fiber (ADF; 331.2, 355.2 and 378.5 g kg DM -1 for 60, 120, 180 days, respectively), high total digestible nutrients (TDN; 558.2, 544.7 and 531.6 g kg DM -1 for 60, 120, 180 days, respectively), high DM recovery and aerobic stability. Wheat and triticale showed a decrease in DM recovery with the increase in storage length, although showed high aerobic stability. The storage period had a different effect on forages; however, storage period above 60 days provided no benefits for the variables evaluated.Keywords: storage, aerobic deterioration, DM recovery.Composição nutricional e estabilidade aeróbia de silagens de cereais de inverno com diferentes tempos de estocagem RESUMO. O objetivo do experimento foi avaliar a composição nutricional, a recuperação de matéria seca (MS) e a estabilidade aeróbia de silagens de cereais de inverno submetidas a diferentes tempos de estocagem. Os materiais utilizados foram o trigo (Triticum aestivum cv. BRS Gralha Azul), cevada (Hordeum vulgare cv. BRS Brau), aveia branca (Avena sativa cv. URS Guará), aveia preta (Avena strigosa cv. Embrapa 139) e triticale (X Triticosecale cv. IPR 11), em três tempos de estocagem: 60, 120 e 180 dias. O delineamento experimental foi inteiramente casualizado em arranjo fatorial 5x3. Na avaliação nutricional, a silagem de cevada apresentou baixos teores de fibra em detergente ácido (FDA; 331; 355 e 378 g kg MS -1 , para 60, 120 e 180 dias, respectivamente) e altos de nutrientes digestíveis totais (NDT; 558; 544 e 531 g kg MS -1 para 60, 120 e 180 dias, respectivamente), além de alta recuperação de MS e estabilidade aeróbia. O trigo e o triticale apresentaram decréscimo na recuperação de MS com o aumento dos dias de estocagem, embora tenham apresentado alta estabilidade aeróbia. O tempo de estocagem influenciou de maneira distinta as forrageiras, no entanto, tempos de estocagem acima de 60 dias não proporcionaram benefícios para as variáveis avaliadas.Palavras-chave: armazenamento, deterioração aeróbia, recuperação de MS.

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

The use of nitrogen fertilizers in corn crops for silage can improve both production and, theoretically, nutritional quality, especially carbohydrate and protein fractions, thereby optimizing animal production. Thus, the aim of this study was to evaluate the effect of increasing levels of nitrogen fertilization in carbohydrate and protein fractionation on the resulting corn silage (Zea mays L.). Nitrogen fertilization was carried out in the urea form (45-00-00) in V5 stage, at the following doses: T1: 0kg N ha-1; T2: 45kg N ha-1; T3: 90kg N ha-1; and T4: 135kg N ha-1. Crops were harvested at R4 stage and submitted to ensiling in experimental PVC silos. The chemical composition of the resulting silage was evaluated after silo opening. There was no statistical difference (P<0.05) in the average contents of gross protein (GP), as well as its C fraction, showing that increasing nitrogen doses in coverage linearly increased GP and linearly decreased its C fraction. For total carbohydrates, there was a linear decreasing behavior due to such consumption with the highest levels of nitrogen applied. Increased nitrogen fertilization dose in corn also linearly enhanced pH in the resulting silage. Therefore, nitrogen increases in coverage can alter carbohydrates and GP fractionation of corn silage, with increases in soluble fiber, GP, and pH, and reduction in the protein indigestible fraction.