Four rumen-cannulated primiparous lactating cows were studied in a 4 × 4 Latin square design experiment to evaluate the effects of propolis-based products (PBP) with different concentrations of propolis and alcohol levels on total digestibility, (TD), ruminal digestibility (RD), intestinal digestibility (ID), pH, ruminal ammonia-nitrogen production (NH3-N), rumen microbial synthesis, and blood parameters. The feed consisted of 591.9 g/kg corn silage and 408.1 g/kg concentrate (dry matter [DM] basis), and treatments differed with regard to the inclusion (via ruminal cannula) or exclusion of PBP as follows: control (without the PBP), PBP B1 (3.81 mg of phenolic compounds/kg of ingested DM), PBP C1 (3.27 mg of phenolic compounds/kg of ingested DM), and PBP C3 (1.93 mg of phenolic compounds/kg of ingested DM). Inclusion of PBP reduced the RD of dietary crude protein (CP). Treatment PBP C1 reduced ruminal NH3-N production, while PBP B1 increased the ID of CP relative to that in the control. These findings indicate that propolis had a positive effect on rumen nitrogen metabolism. Rumen pH, efficiency of microbial protein synthesis, and blood parameters were not affected by addition of PBP, but there were significant effects on the other parameters when the treatments containing propolis were contrasted. Higher TD of DM (0.717 vs. 0.685), OM (0.737 vs. 0.703), and CP (0.760 vs. 0.739), as well as higher NDF (0.622 vs. 0.558) and TDN (0.747 vs. 0.712) were observed when comparing PBP C1 with C3. Inclusion of propolis in diets for dairy cows have positive effects on protein metabolism in the rumen. Variation in the amounts of phenolic compounds in the different PBP may explain the diverse effects on the digestive parameters evaluated.

Objetivou-se avaliar o efeito de produtos à base de própolis (PBP) sobre o desempenho, digestibilidade, produção microbiana e características de carcaça de bovinos confinados. Foram utilizados 27 bovinos com 353 ± 28 kg de peso corporal em um delineamento inteiramente casualizado dividido em três tratamentos: duas dietas contendo PBP em diferentes dosagens (PBP1 = 0.018 mg g-1 e PBP2 = 0.036 mg g-1 de flavonoides totais em crisina) e dieta controle (CON) sem adição de própolis. Para a determinação da digestibilidade total, a matéria seca indigestível foi usada como marcador interno, enquanto a produção microbiana foi estimada pelos derivados de purina na urina, coletadas pelo método spot. As características de carcaça avaliadas foram: peso de carcaça quente, rendimento de carcaça quente, conformação, área de olho de lombo, espessura de gordura, coloração, textura, marmoreio, pH, espessura de coxão e percentagens de músculo, osso e gordura. As variáveis estudadas foram submetidas à análise de variância com 5% de probabilidade. A adição da própolis não teve efeito sobre a digestibilidade da MS e nutrientes (exceto para FDA, que foi maior) e eficiência de síntese microbiana. As características de carcaça não foram afetadas pelos tratamentos experimentais. As dosagens utilizadas nos PBP devem ser revistas e dosagens mais elevadas devem ser testadas.

The objective was to evaluate the effect of propolis-based products (PBP) on performance, digestibility, microbial production and carcass characteristics of feedlot young bulls. Twenty-seven crossbred young bulls were used, with 353 ± 28 kg of body weight in a completely randomized experimental design, divided in three treatments: two diets with PBP with different dosages (PBP1= 0.018 mg g-1 and PBP2= 0.036 mg g-1 of total flavonoids in chrysin) and control diet (CON). To determine total digestibility, the indigestible dry matter was used as an internal marker, while microbial production was estimated from purine derivatives in urine, collected by the spot method. The evaluated carcass characteristics were: hot carcass weight, dressing percentage, conformation, Longissimus muscle area, fat thickness, colour, texture, marbling, pH, cushion thickness and percentages of muscle, bone and fat. The studied variables were subjected to analysis of variance with 5% probability. The addition of propolis had no effect on DM and nutrients digestibility (except the ADF, which was higher) or efficiency of microbial synthesis. Carcass characteristics were not affected by the experimental treatments. The PBP in the used dosages should be reviewed and higher dosages should be tested.

O objetivo deste estudo foi quantificar o ácido alfa-linolênico [LNA, 18:3 (n-3)], avaliar a composição centesimal das folhas e caules de linho (Linum usitatissimum L.) submetidos à secagem e colhidos em diferentes estágios de desenvolvimento (40, 80 e 120 dias), e determinar o potencial antioxidante das folhas colhidas aos 80 dias através do teste com o radical DPPH. As folhas obtiveram maiores teores de cinzas, proteína e lipídios totais em relação aos caules. Tanto as folhas quanto os caules apresentaram razões de AGPI/AGS e n-6/n-3 dentro dos valores considerados adequados para a alimentação. Os caules colhidos nos diferentes tempos não apresentaram diferenças significativas (P<0,05), quanto ao teor de LNA. As folhas colhidas aos 80 dias apresentaram a maior concentração de LNA, correspondendo a 1,262,36 mg/100g de folhas desidratadas. Os diferentes extratos (metanólico, butanólico, acetato e aquoso) foram eficientes na inibição do radical DPPH, com destaque para as frações butanólica e acetato, sendo os valores de IC50 de aproximadamente 42ppm para as duas frações. Tais resultados evidenciaram a atividade antioxidante e potencial nutritivo das folhas e caules de linho para futuro uso na alimentação animal e humana.

The objective of this study was to quantify the alpha-linolenic acid [LNA, 18:3 (n-3)] and to evaluate the proximate composition of leaves and stems of flax (Linum usitatissimum L.) dried and harvested at different stages of development (40, 80 and 120 days), and to determine the antioxidant potential of the leaf harvested at 80 days using the test of DPPH radical. The leaves had higher levels of ash, protein and total lipids when compared to the stems. Both the leaves as the stems had ratios of PUFA/SFA and n-6/n-3 within the values considered suitable for food. Stems in the different stages showed no significant difference (P<0.05) of LNA content. Leaves harvested at 80 days showed the highest concentration of LNA, corresponding to 1,262.36 mg/100g dried leaf. The different extracts (methanol, butanol, acetate and water) were efficient in the inhibition of DPPH radical, with emphasis on the butanolic and acetate fractions and the values of IC50 were approximately 42 ppm. These results highlight the nutritional potential and antioxidant activity of leaves and stems of flaxseed for future use in the animal and human feeding.