Twenty-seven animals (½ Angus - ½ Nellore) were fed for four months with one of the following diets: without addition of essential oils (E0.0), with 3.5 (E3.5) or 7 (E7.0) g/animal/day of an essential oil blend (oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange). Chemical composition, fatty acid profile and meat color were evaluated in Longissimus muscle. In addition, the effects of aging (one, seven and 14days) on the meat water holding capacity, texture and lipid oxidation were evaluated. Essential oils had no effect on chemical and fatty acid composition, meat color, water holding capacity or texture, but an inclusion of 3.5g/day decreased lipid oxidation. The addition of 7.0g/animal/day had a pro-oxidant effect on meat during aging and resulted in higher values for lipid oxidation at 14days of aging. Aging significantly affected thawing losses and texture. A dose of 3.5g/animal/day could be recommended in feedlot animals, but greater doses could have a pro-oxidant effect.

ABSTRACT

The effect of corn substitution by glycerine and essential oils on animal performance, apparent digestibility and red and white blood cells of crossbred bulls finished in feedlot was evaluated. Thirty bulls with average weight of 311±28.8 kg and 22±2 month-old were allocated in three diets: CON (without glycerine or essential oils), GLY (with glycerine) and GEO (with glycerine and essential oils). The bulls were fed a diet of sorghum silage, cracked corn, soybean meal, urea, limestone and mineral salt. Three grams of cashew and castor oil/animal/day were included in GEO diet. Animals were kept in feedlot for 115 days and slaughtered at average weight of 467±40.6 kg. No differences (P<0.05) among diets regarding final body weight, average daily gain and feed conversion were reported. Ether extract intake was higher (P<0.05) in CON diet compared to the others. Dry matter, organic matter and crude protein digestibility was higher (P<0.05) in GLY diet compared to CON. Acid detergent fibre digestibility was higher (P<0.05) in CON compared to GLY diet. Nonfibrous carbohydrate, fibrous carbohydrate and ether extract digestibility were similar (P>0.05) among diets. No effect of glycerine and essential oil addition on total blood cholesterol, triglycerides, haemogram, leukogram and plasmatic proteins was observed. Corn replacement by glycerine and essential oils addition did not affect (P>0.05) carcass weight, dressing and conformation, carcass length and cushion thickness.

No abstract

This work was realized to evaluate the effect of natural additives as propolis or essential oils addition on animal performance, feed intake, apparent digestibility and carcass characteristics of bulls finished in feedlot. Thirty bulls (½ Aberdeen Angus vs. ½ Nellore) were randomly assigned in one of three diets (control-CON, propolis-PRO and essential oils-OIL) and kept in feedlot (individual pen) during 55 days. CON diet consists of 45% corn silage, 40% concentrate (cracked corn, soybean meal, limestone and mineral salt) and 15% glycerine. The PRO group received same diet that control plus 3 grams to animal day-1 of propolis dry added to the concentrate. The OIL oils group received same diet that control and 3 grams to animal day-1 of essential oils (cashew and castor oils) added to the concentrate. Final weight, average daily gain, feed efficiency and hot carcass weightwere better for bulls supplemented with essential oils and propolis than for bulls fed control diet. The feed intake, apparent digestibility, carcass conformation and tissue composition were unaffected by the additives addition. The addition of propolis and essential oils in the diets of bulls finished in feedlot improve animal performance and carcass weight.

This study evaluates the effects of three diets: a control (CON), containing sodium monensin (MON) and containing propolis extract (PRO). The performance of 33 feedlot-finished bulls, 11 for each diet, and carcass characteristics were examined. The 27 months old bulls, with initial liveweight 400±2.33 kg, were kept in a feedlot for 84 days, till 484±6.76 kg at slaughter. The roughage and concentrate ratio of the diets was 52:48 on DM basis. Maize silage was used as roughage and maize, soyabean meal, urea, mineral salt and limestone were used as concentrate. The average final weight (501 kg), hot carcass weight (275 kg) and average daily gain (1.17 kg) were higher (P<0.05) for bulls fed with PRO than for those on the CON (472, 259 and 0.87 kg, respectively), or MON (480, 259 and 0.94 kg, respectively) diets. Dry matter conversion was better (P<0.05) for bulls fed with PRO (8.04) than those on the CON (10.9) or MON (9.72) diets. Carcass characteristics such as conformation, carcass length, leg length, cushion thickness, Longissimus muscle area, Longissimus muscle area/100 kg of liveweight, fat thickness, colour, texture and marbling were not influenced (P>0.05) by the treatments.

ResumoO objetivo deste trabalho foi avaliar a inclusão de glicerina sobre o desempenho animal, eficiência alimentar e digestibilidade em novilhas suplementadas em pastagem de Brachiaria brizantha cultivar Marandu. O período experimental foi de 102 dias, sendo os primeiros 14 destinados à adaptação às dietas e às condições experimentais. Foram utilizadas 36 novilhas mestiças com peso inicial médio de 226 + 12 kg e 13 meses de idade distribuídas em delineamento inteiramente casualizado com quatro tratamentos e nove repetições: G00 = controle; G2,8 = 2,8%; G6,1 = 6,1% e G9,0 = 9,0% de glicerina na matéria seca (MS) total na dieta. As novilhas foram pesadas a cada 28 dias para avaliação do ganho médio diário. A ingestão de MS foi estimada a partir da produção fecal, com uso de óxido crômico (Cr 2 O 3 ) como indicador externo e da MS indigestível (MSi) como indicador interno. A digestibilidade aparente foi estimada a partir da produção fecal determinada pelo óxido crômico. A adição de glicerina na dieta determinou redução linear (P < 0,05) no peso final e ganho médio diário das novilhas. A ingestão diária de MS do suplemento, da pastagem e total foi semelhante (P > 0,05) entre os tratamentos. A ingestão de extrato etéreo aumentou de forma linear (P < 0,05) conforme houve acréscimo de glicerol na dieta. A ingestão de carboidratos apresentou redução linear (P < 0,05) em função dos níveis de glicerol às dietas. A inclusão de glicerina não teve efeito (P > 0,05) sobre os coeficientes de digestibilidade da MS, PB, MO, FDN, CNF e CT. A inclusão de glicerina às dietas aumentou de forma linear (P < 0,05) a digestibilidade do extrato etéreo. O uso de glicerina de baixa pureza não é recomendado, pois determina redução no desempenho animal. Palavras chave: Desempenho animal, bovinos, eficiência alimentar, glicerina AbstractThis work was carried out to study the effect of levels different addition of glycerine on animal performance, feed efficiency and digestibility of heifers supplemented in Brachiaria brizantha cultivar Marandu pasture. The experimental period was 102 days. The first 14 days was the period of adaptation of heifers to experimental diets and management. It was used 36 crossbred heifers with an average initial

A maioria dos animais de produção é alimentada à vontade, ou seja, tem livre acesso ao alimento na maior parte do tempo. Para que a produção seja eficiente é necessário elevar o nível de consumo voluntário, pois em geral, quanto mais o animal come, mais ele produz e se torna mais eficiente. A amplitude da ingestão é direcionada pela exigência nutricional e uma estimativa aproximada de quantidade de alimento que um animal vai ingerir pode ser calculada pela exigência de proteína, energia e outros nutrientes para a mantença e produção. No entanto, há vários fatores que podem interferir com a concordância entre exigência e ingestão, como o volume do alimento, que pode ser um fator determinante no nível de ingestão alcançada, especialmente nos ruminantes.