RESUMO -Mudanças no hábito de consumo da população em busca de uma alimentação mais saudável exige maiores cuidados para se produzir de forma limpa e sustentável. O rabanete (Raphanussativus L.), apesar de ser uma cultura olerácea consumida em menor escala, vem se destacando como uma alternativa de cultivo promissora para os olericultores do país. O uso isolado ou combinado de fertilizantes orgânicos é uma opção de adubação para uma produção mais saudável e menos agressiva ao meio ambiente. Nesse sentido, a produção sequencial de olerícolas em uma mesma área, pode aumentar o teor de matéria orgânica no solo, viabilizando cultivos subsequentes sem a necessidade de uma nova adubação. Com o objetivo de avaliar a produtividade e a qualidade das raízes de rabanete em cultivo subsequente de alface produzidas com adubação orgânica foi conduzido um experimento no campo experimental da Universidade Estadual de Goiás, Câmpus de Ipameri-GO, em delineamento experimental de blocos casualizados, em esquema fatorial 3 x 4, com 4 repetições, tendo como fatores as cultivares de rabanete (RedJewel F1; Variedade nº 25 e a cv. Vip Crimson) e residuais de fontes de matéria orgânica utilizadas para o cultivo de alface: (testemunha sem matéria orgânica, esterco bovino, cama de aviário, esterco de suíno). As variáveis quantitativas analisadas foram: PT (Peso total das plantas); MFF (Massa fresca das folhas); MSF (Massa seca das folhas); NF (Número de folhas por planta); CP (Comprimento do caule); DR (Diâmetro da raiz); MFR (Massa fresca da raíz) e MSR (Massa seca da raiz). Foram determinadas as porcentagens de raízes rachadas e isoporizadas levando em consideração as plantas colhidas dentro da área útil para a determinação dos parâmetros qualitativos. Não houve correlação positiva entre as cultivares estudadas sob os diferentes tratamentos. O efeito residual de diferentes fontes de adubos orgânicos não foi satisfatório para a produção de rabanete em cultivo sucessivo de alface.Palavras chave: adubação alternativa, Raphanus sativus L., sucessão de cultivo, sustentabilidade. PRODUCTIVITY AND QUALITY OF RADISH ROOTS CULTIVATED UNDER DIFFERENT RESIDUAL SOURCES OF ORGANIC MATTER

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Despite its low NDF digestibility, sugarcane is an option for feeding dairy cattle in tropical regions. We evaluated the effect of sugarcane silages inoculated with CCMA 0170 (LH; an epiphytic bacteria isolated from sugarcane) or with NCIMB 40788 (LB; a commercial strain isolated from temperate grasses) on dairy cow performance and feeding behavior. The microbial inoculums were previously grown in the laboratory to obtain 5 log cfu/g of fresh forage. Nine tons of each inoculated silage and a noninoculated control silage (CON) were harvested from the same field and stored for at least 35 d in experimental 20 × 2.1 × 0.4 m bunker silos. Fifteen Holstein cows in late lactation (336 ± 175 days in milk at the start of the experiment) received the treatments in five 3 × 3 Latin squares with 21-d periods. The diets contained 20% of DM of sugarcane silage and 41% of DM of corn silage. Milk yield was increased from 18.0 kg/d for CON to18.8 kg/d for LH, but LB did not elicit a detectable increase in milk yield (18.1 kg/d). The daily yields of fat, protein, lactose, and total solids were increased by LH. Daily DMI and total tract apparent digestibility of nutrients did not differ among treatments. Both inoculated silages reduced acetate and increased butyrate proportions in ruminal VFA, but only LH silage reduced the acetate to propionate ratio (3.0 vs 3.3). First meal duration was shorter for CON compared to LH and LB. The proportion of daily intake between 0700 and 1300 h tended to be increased, and the proportion between 1900 and 0700 h was reduced by LH. The inoculation of sugarcane silage with affected rumen fermentation profile and feeding behavior of late lactation dairy cows, increasing the yield of milk solids.

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Twenty Holstein cows at 168 ± 87 d in milk (mean ± SD) were assigned to a 4 × 4 Latin square design with a 2 × 2 factorial arrangement to evaluate the effects of 2 storage lengths (30 or 90 d) and the presence of sodium benzoate (control or 0.2% as fed) on the nutritive value of reconstituted sorghum grain silages (RSGS). For each treatment, dry ground sorghum grain was rehydrated to 35% moisture and ensiled in 200-L plastic drums. The treatments were RSGS stored for 30 d without sodium benzoate ( 30CON), RSGS stored for 30 d with sodium benzoate (30 BEN), RSGS stored for 90 d without sodium benzoate (90 CON) and RSGS stored for 90 d with sodium benzoate (90 BEN). Diets contained 16.3% RSGS. Silages stored for 90 d had higher concentrations of 1,2-propanediol, soluble protein, and ammonia nitrogen than did those stored for 30 d. Sodium benzoate reduced ethanol and ethyl-ester formation. Silages stored for 90 d had higher starch (89.3 vs. 86.9%) and protein (57.1 vs. 54.0%) digestibility compared with silages stored for 30 d. The ruminal acetate-to-propionate ratio tended to be lower in RSGS stored for 90 d than in RSGS stored for 30 d (3.75 vs. 3.34). Milk yield increased from 30.0 kg/d in cows fed RSGS stored for 30 d to 31.2 kg/d in cows fed RSGS stored for 90 d, without a change in dry matter intake (23.5 kg/d on average). Hence, feed efficiency and milk N efficiency also had tendencies to increase in cows fed RSGS stored for 90 d. Sodium benzoate did not alter cow performance but slightly increased plasma glucose (65.2 vs. 63.6 mg/dL). In conclusion, increasing the storage period of RSGS from 30 to 90 d improved starch and protein digestibility, milk yield, and feed efficiency.

Whole-plant corn silage (WPCS) is a major source of forage for dairy cattle in Brazil. Improved kernel processing may be especially advantageous when feeding corn hybrids with vitreous endosperms. Two experiments were conducted to evaluate the effects of the theoretical length of cut (TLOC) and ensiling time on WPCS particle size and kernel processing with two types of forage harvesters. In the first trial, the plant was harvested by a pull-type forage harvester (PTFH) at TLOCs of 3, 6 and 9 mm. In the second trial, the harvesting was performed by a self-propelled forage harvester (SPFH) at TLOCs of 6, 12 and 18 mm, with a roll gap of 3 mm. The WPCS were stored for 0, 35 and 140 days. In the PTFH trial, the TLOCs of 3 and 6 mm did not affect the WPCS particle size distribution and mean particle length (MPL). However, the TLOC of 9 mm increased the MPL. The increase in the TLOC with the SPFH led to a higher MPL and percentage of long particles. The ensiling time increased the MPL and long particles only for the WPCS harvested by the SPFH. The strategy of reducing the TLOC with the SPFH increased the percentage of kernels smaller than 4.75 mm. Furthermore, the TLOC of 6 mm led to the best kernel processing with the SPFH. The ensiling time reduced the particle size of the kernel fractions for both forage harvesters. The corn silage processing score was improved with 140 days of ensiling with the SPFH. These findings suggest that increasing the ensiling time and a low TLOC in SPFHs (6 mm) may be good strategies to increase kernel damage and starch digestibility in WPCS.

The aim of this study was to evaluate the feed quality of reconstituted corn grain silage (RCGS), treated with chemical additives and stored for 15, 30, or 60 d in 5-L plastic buckets. Dry ground corn was rehydrated to 350 g·kg−1 and treated with either polysorbate 80 (2 L·t−1) (POL), propionic acid 28% (2 L·t−1) (PRO), Mycoflake™ (2 L·t−1-blend polysorbate 80 and propionic acid) (MYC) or nothing (CON). The effect of the length of storage was combined in a factorial arrangement with the additives. Ammonia-N increased from d-15 of storage. A treatment × storage length interaction was observed for ethanol content at d-60 of storage, and all treatments had lower ethanol concentration than CON. There was an interaction for butyric acid content at d-30 and d-60 of storage; CON showed higher butyric acid concentration than treated silages. Aerobic stability increased from d-15 to d-30. At d-15 of storage, the PRO and MYC treatments decreased the DM losses. The length of storage increased the ruminal in situ degradability of starch, and DM and MYC increased the DM degradability in 3.6 percentage units at 12 h of incubation, compared with POL. In conclusion, increasing the length of storage of the RCGS from d-15 to d-60 improved the starch and DM degradability. Mycoflake increased the availability of nutrients, and the length of storage enhanced the aggregation of particles; further, polysorbate 80 (Tween 80) might be further studied as a potential antimicrobial agent in silages.