Ionóforos são antibióticos amplamente utilizados nas composições de dietas de ruminantes, com o objetivo de diminuir o consumo de matéria seca e aumentar a eficiência alimentar, dificultando o desenvolvimento da acidose ruminal e gerando melhor aproveitamento de nutrientes, por ação principalmente sobre as bactérias gram- positivas. Entretanto, essa utilização é uma preocupação pelo surgimento de resistência bacteriana aos antibióticos, que reflete na medicina humana. Meio a situação, surgem estudos com os óleos essenciais (OEs) que buscam a substituição dos antibióticos, promovendo efeitos similares, devido suas propriedades antimicrobianas, similares às funções dos ionóforos. O objetivo do trabalho foi analisar os resultados da comparação entre os dois aditivos na dieta. O efeito dos OEs variam de acordo com sua fonte, podendo causar diferentes impactos no consumo de alimentos pelo animal, porém estudos realizados concluíram que independente da dosagem e da fonte os óleos provocam resultado positivo no ganho médio diário (GMD), levando a eficiência alimentar (EA) a não sofrer impactos pelo aumento do consumo de matéria seca (CMS). Colocando- se os OEs em substituição à monensina, a observação do aumento do CMS se mantém, porém não são observadas alterações no GMD, também é notado um aumento na incidência de abcessos hepáticos o que gera a necessidade de novos estudos para compreensão. O fornecimento dos OEs na alimentação terá repercussão similar a monensina (principal ionóforo utilizado), porém com um maior CMS.

The objective of the present study was to evaluate whether sorghum silage exposure to air for 8, 16 or 24 hr before re‐ensiling reduces silage quality and animal feed efficiency. Sorghum was ensiled in 52 metal drums (13 for each exposure time) with 200‐L capacity, and after 112 days, 39 drums were opened and silage was exposed to air for 8, 16 or 24 hr. Thirteen silos were not opened and considered control treatment. Subsequently, silage was re‐ensiled, and after 56 days, all silos were opened to determine silage quality variables. In addition, the silage was offered to sheep to determine animal feed efficiency. The experimental design was completely randomized with five replications per treatment, and orthogonal polynomials were used to determine linear or quadratic effects of the exposure time. The non‐fibrous carbohydrate (NFC) (minimum of 278 g/kg), in vitro dry‐matter digestibility (IVDMD) (minimum of 570 g/kg) and lactic acid (1.51 g/kg for each hour) decreased with longer exposure. The pH (0.011 for each hour), ammonia nitrogen (0.057 g/kg for each hour), acetic acid (maximum of 17.9 g/kg) and aerobic stability (maximum of 62.4 hr) increased with longer exposure. Although silage exposure reduced NFC and IVDMD and increased pH and ammonia nitrogen, animal feed efficiency was not compromised. These results indicate that sorghum silage exposure for up to 24 hr does not compromise its use.

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This study aimed to evaluate the agronomic performance of 30 sorghum genotypes planted in two seasons. In the agronomic performance evaluation, 15 superior genotypes were selected and submitted to nutritive value and nutrient accumulations evaluations. The genotypes were planted on 20 December 2017 and 5 February 2018 and submitted to three and two cuts. Agronomic and nutritional characteristics were evaluated in all cuts and considered as the average values per season. The hybrids forage accumulation 6,941 kg/ha in the first and 3,370 kg/ha in the second planting season. The plant leaf proportion varied from 41.1 to 55.9% among all hybrids in the two seasons. The whole plant crude protein contents were 111 and 121 g/kg DM in the first and second planting seasons. The in vitro dry matter digestibility varied from 579 to 679 g/kg DM among all hybrids. The agronomic and nutritional characteristics were better in first compared to second planting due to better climatic conditions. The hybrids 16F26008, 16F26014 and 16F26007 had superior characteristics. The females (ATF54A*{ATF54B*[(Tx623B*ATF54B)6-1]}-263-C-1)A and (ATF54A*{ATF54B*[((Tx623B*ATF54B)6-1]}-207-C-1)A and the males TX2784 and TX2785 produced superior hybrids.

This study aimed to evaluate the silage quality, ingestive behaviour, and sheep energy partition fed corn and sorghum silages, with or without inoculation with Lactiplantibacillus plantarum and Lentilactobacillus buchneri. Whole plants of one dent corn hybrid (DCS), one flint corn hybrid (FCS), and one forage sorghum hybrid (SS) were ensiled with or without an inoculant containing L. plantarum and L. buchneri (4 × 105 CFU g−1), totalling six treatments (3 × 2 factorial scheme). The treatments were ensiled in metal drums with 200 L capacity. The lactic acid concentrations in the inoculated FCS and DCS were higher by 13.4% and 12.8%, respectively, than those in the non‐inoculated plants. In contrast, the lactic acid concentration in the inoculated SS was 23.1% lower than that in the non‐inoculated SS. Furthermore, there were differences in pH and acetic acid concentrations only in SS, which were 2.3% and 45.2% higher, respectively, in inoculated silage than in non‐inoculated silage. In inoculated DCS and SS, propionic acid concentrations were 1.7 times higher (for both silages), and 1‐propanol was 3.7 and 1.8 times higher compared than those in non‐inoculated silages. There was a main effect of the inoculant on 1,2‐propanediol concentrations, which were 37.5% higher in inoculated silages than in non‐inoculated silages. However, ingestive behaviour, heat and methane production, and silage net energy concentrations were not affected by inoculant use. Fermentative modifications caused by inoculation with L. plantarum and L. buchneri in whole plant corn or sorghum silage did not modify sheep energy partition.

Este trabajo investiga las interrelaciones entre la regulación y los as-pectos económicos y ambientales en una comunidad de agricultores familiares en la región conocida como Zona da Mata Mineira, en el estado brasileño de Minas Gerais. El estudio es producto de una acti-vidad de extensión realizada entre 2016 y 2018, y tuvo como objetivo asesorar a los pequeños productores en el proceso de adecuación legal de la producción. Durante este período se realizaron cerca de cinco reuniones entre investigadores y comuneros, en las que se analizaron las dificultades encontradas por los pequeños productores en relación con el referido proceso. Las experiencias reportadas fueron confron-tadas con el régimen legal regulatorio para la actividad acuícola en Brasil, tomando como categorías de análisis los atributos de norma-tividad y facticidad del sistema legal. Se concluyó que la regulación ambiental en el área de la acuicultura en Brasil, diseñada para grandes productores, carga de manera desproporcionada a los pequeños pro-ductores, generando un desequilibrio económico injustificado. Como aporte a la teoría, se propone, en definitiva, la formulación de un con-cepto de regulación jurídica inclusiva, cuyos rasgos distintivos inclu-yen la participación social y la promoción de la alfabetización jurídica como derecho fundamental.

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