Suchergebnisse

This study aimed to evaluate the effect of cutting height and harvest time on forage yield and quality in elephant grass (Pennisetum purpureum Schum.) cv. Pioneiro. Experimental plots were arranged in a randomized block split-plot design. The treatments consisted of four residual heights (30, 40, 50, and 60 cm)and three successive harvest times (January, March, and May 2011). There was a significant interaction between residual height and harvest time for the proportion of stems (P<0.05) and leaves (P<0.01) in the forage. A similar result was observed for fresh (P<0.01) and dry (P<0.01) forage yield at the first and third harvests. There was a quadratic relationship between dry forage yield and residual height, with a maximum yield of5738 kg ha-1ataresidual height of 50.17 cm in the second harvest. The increase in residual height from 30 to 60 cm, regardless of harvest time, reduced neutral detergent fiber (NDF)and acid detergent fiber (ADF) and increased crude protein content. Forage yield and quality were highest at 40-50 cm residual heights.

We aimed to evaluate nutritional quality, fermentation profile, aerobic stability, and dry matter losses in corn (Zea mays) and wheat (Triticum aestivum 'BRS Umbu') silages. Treatments included uninoculated and inoculated (Lactobacillus plantarum and Pediococcus acidilactici, 1.0 × 105 UFC g-1) wheat silage, corn silage from a conventional hybrid and a transgenic hybrid. Nutritional quality and fermentation profile variables were tested in a completely randomized design. Means were compared using Tukey's test at 5% significance. An aerobic stability trial was conducted in a factorial design with two silages (wheat × inoculated wheat; conventional hybrid corn × transgenic hybrid corn) and two temperatures (ambient temperature × controlled temperature at 24°C). Data were submitted to ANOVA and means were analyzed by the F test at 5% probability. Inoculation of wheat silage increased dry matter, organic matter, and total carbohydrates, but reduced crude protein by a dilution effect. Regarding the fermentation profile, inoculation reduced acetic acid and butyric acid content, whereas it increased propionic acid in wheat silage. Bt corn hybrid silage showed higher dry matter and lower neutral detergent fiber, whereas transgenic corn silage showed lower content of acetic acid, propionic acid, alcohol, and ammonia. Conversely, Bt hybrid silage showed higher butyric acid. Transgenic corn silage showed higher temperature than the conventional hybrid silage during aerobic exposure. Inoculated wheat silage experienced larger deterioration and dry matter losses during the aerobic stability trial. Temperature control worsened aerobic stability in all treatments, increasing dry matter losses and heating.

The goal of this work was to evaluate the growth dynamics and chemical characteristics of the upper and lower strata of summer perennial grasses under a four cuts system. The experiment was conducted in a randomized block design, composed of 28 treatments in a factorial arrangement of 7x4, with four repetitions. The cultivars evaluated were Star Grass, Coast-cross, Tifton 68, Tifton 85, Jiggs, Roxinha and Quicuio. Each cultivar was cut when it reached 95% light interception. The cultivars Jiggs and Tifton 68 had the highest (P &lt; 0.05) accumulation of dry biomass ha-1 during the four cuts, with productions of 21,348 and 21,016 kg ha-1, respectively. The ash content varied (P &lt; 0.05) among species and times of cutting for both strata. Cellulose contents were significantly different in the upper stratum, with the highest concentrations found in cvs. Quicuio and Tifton 68 (39.12% and 38.07%, respectively). We found the highest levels of lignin (P &lt; 0.05), for both strata, in cv. Quicuio. Cultivars Jiggs and Tifton 68 were the most appropriate for a management system of four cuts, displaying good chemical composition and high productivity.

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 pre-flowering. 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.

<p>O experimento foi conduzido no Núcleo de Produção Animal (NUPRAN) da Universidade Estadual do Centro Oeste (UNICENTRO), com o objetivo de avaliar o efeito da colheita da planta de milho em diferentes estádios reprodutivos e com diferentes processamentos de grãos sobre a digestibilidade da matéria seca, digestibilidade da fibra em detergente neutro e desempenho animal. O delineamento experimental foi inteiramente casualizado, composto por 4 tratamentos com 4 repetições, onde cada repetição constou de uma baia contendo dois novilhos, totalizando 16 unidades experimentais. Durante a confecção da silagem, foram coletadas amostras homogêneas e representativas das plantas picadas, parte destinada a análise bromatológica antes de sofrer fermentação e outra parte foi inserida em silos "bags", acomodando estes no perfil de cada silo, sendo considerados como unidades experimentais. O experimento teve duração de 84 dias após abertura dos silos, sendo 14 dias para adaptação dos animais, seguidos de 4 períodos de 21 dias. Assim, silagens colhidas em estádio de grão pastoso apresentaram melhores valores de digestibilidade <em>in vitro </em>da matéria seca e digestibilidade da fibra em detergente neutro. A utilização da silagem de milho colhida em estádio R5 possibilitou maior desempenho animal com consequente melhor transformação da matéria seca consumida em ganho de peso diário.</p>

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.

Este trabalho objetivou verificar se o prebiótico a base de parede celular de Saccharomyces cerevisiae reduz coliformes totais, Escherichia coli e Salmonella spp da pele, fezes e da carcaça de bovinos terminados em confinamento. Para tanto, 18 novilhos, ½ sangue Angus foram submetidos a três tratamentos diários durante 105 dias: controle (n=6), Lev4g (dieta com 4 g de levedura por animal dia-1, n=6) ou Lev 7g ( dieta com 7 g de levedura por animal dia-1, n=6). Nos dias 29 e 90 após a entrada no confinamento, coletou-se amostras de fezes, swab de pele, água e alimento para contagem de Escherichia coli e coliformes totais e isolamento de Salmonella spp. No dia do abate, realizou-se coleta nas carcaças para identificação de Salmonella spp e quantificação de Escherichia coli, coliformes totais, mesófilos. Notou-se redução de Escherichia coli e coliformes totais nas amostras de fezes (P=0,0001 e 0,001 respectivamente) e de Escherichia coli, coliformes totais e aeróbios mesófilos na carcaça (P=0,06; 0,10 e 0,05 respectivamente) nos grupos tratados. Houve ausência de Salmonella spp. em todas as coletas realizadas. Concluiu-se que a suplementação reduziu a excreção fecal e consequentemente, a contaminação da carcaça pela Escherichia coli, mesófilos e coliformes totais dos animais confinados, sendo uma medida sanitária benéfica e livre de resíduos para melhorar a qualidade microbiológica da carne.

This study aimed to evaluate the performance, carcass characteristics, serum parameters, the residual depletion in the beef and the economic viability of termination steers with salinomycin in the diet. Were confined 32 animals fed with diet consisting of corn silage and concentrate (50:50) or not added salinomycin (120 mg animal d-1). The design was completely randomized with 8 repetions. The use of salinomycin improved weight gain (1.582 vs 1.304 kg) and feed conversion (6.16 vs 7.25 kg kg-1). There were no significant changes in feed intake (9.52 vs 9.25 kg animals d-1) in serum parameters, nor in the apparent digestibility of the diet. The 16-hour grace period before slaughter expressed salinomycin concentrations below 0.25 µg kg-1 in the organs and edible tissues below the values allowed by law. Animals finished with salinomycin showed better hot carcass weight (287.76 vs 275.81 kg) and better economic results, an increase of R$ 84.20 per animal in the profit margin. The use of salinomycin for feedlot steers promoted improvements in the production and economic performance without harming the health of animals and consumers, because they were not detected significant residues in edible tissues

The use of diets without roughage in beef feedlot has become common in recent years due to practicality, feasibility and availability of inputs. However, the introduction of roughage that does not harm the operation of the feeding management can bring health benefits to animals and economic gain. This study aimed to evaluate the productive and economic performance of steers finished in feedlot, fed three levels of sugar cane bagasse pellets (SBP) in diets without long-fiber. The treatments consisted of 0%, 7% and 14% of SBP in a mixture of concentrate, comprising 80% whole corn grain plus 20% of a protein core. The experimental design was completely randomized with four replications. The diet with 0% of SBP promoted lower dry matter intake and weight gain. Feed conversion was similar between treatments, with an average of 6.21 kg-1. The lower dry matter digestibility was found in the diet with 14% of SBP. The introduction of SBP did not change the rumination, averaging 1.9 hours day-1. Animals fed 7% of SBP showed higher fat thickness. Due to the numerical differences between treatments for feed conversion in housing and daily cost of food, the profit margin was maximal in the diet with 0% of SBP, with values of R$ 338.1; R$ 311.6 and R$ 305,1 per animal, respectively 0%, 7% and 14% of SBP. The introduction of SBP promoted improvements in production performance, but did not improve the economic results of steers finished in feedlot.