Abstract The presence of PUFA (polyunsaturated fatty acids) in cow milk, including conjugated linoleic acids (CLA) isomers, makes milk susceptible to lipid oxidation, and may lead to the formation of volatile products responsible for a rancid smell. Consequently, including natural antioxidants in the diet of dairy cattle can assist in preventing lipid oxidation. In this study, soybean oil (a source of PUFA) and different ethanolic extracts of Brazilian propolis were included in the cows' feed, and the antioxidant activity and lipid oxidation of the animals' milk was assessed. Antioxidant activity was analyzed using the DPPH method, potassium ferricyanide reduction and chelating ability. Total phenolic compounds and flavonoids were also determined. Lipid oxidation was assessed by determining conjugated dienes and the production of aldehydes (propanal, pentanal, hexanal and octanal). Increased antioxidant activity was seen in the samples of milk from cows receiving propolis. Similarly, the addition of ethanolic extract of propolis to the diet of dairy cattle increased milk protection for two treatments with propolis against lipid oxidation in terms of production of propanal and hexanal. These results confirm the positive effect of applying this natural additive to the diet of lactating cows, improving the nutritional quality of the milk produced.

ABSTRACT The objective of this study was to evaluate the effect of adding ground soybeans and antioxidants to diet of buffaloes on intake, ruminal microbial production, total and ruminal digestibility of nutrients, and ruminal fermentation parameters. Four crossbred buffaloes with a mean weight of 506±29 kg were distributed in a 4×4 Latin square. Four diets were tested: control; diet with ground soybeans; diet with ground soybeans and supplementation with yerba mate; and diet with ground soybeans and supplementation with yerba mate and vitamin E. The addition of ground soybeans had negative effects on intake of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber, as well as ruminal digestibility of neutral detergent fiber and total carbohydrates but did not influence total digestibility of nutrients. Yet, the ground soybeans diet increased the concentration of butyrate and microbial production in the rumen. The diet with ground soybeans supplemented with yerba mate decreased the concentration of acetate and increased the concentration of propionate and increased the efficiency of synthesis and the production of microbial protein in the rumen. There was a positive additive effect of vitamin E in the presence of yerba mate, enhancing the synthesis and production efficiency of microbial protein. Thus, the addition of ground soybeans and antioxidants to diet of buffaloes improves the efficiency of microbial protein synthesis and increases the production of butyrate, without, in general, altering the total digestibility of nutrients.

The present study tested brown propolis in crude or extract form as a feed supplement for feedlot lambs to identify the type that most improves in vivo nutrient digestibility. Digestibility was assessed by both total fecal collection and internal markers and the results obtained by these techniques were compared. The completely randomized design was used to compare feed intake and nutrient digestibility of 24 male lambs aged seven months among four dietary treatments (crude brown propolis, propolis ethanol extract, monensin sodium, and control). Methods of feces collection were compared using a completely randomized split-plot design, with experimental diets corresponding to the main factor and the methods to estimate fecal production as the sub-factor. The diets had a roughage:concentrate ratio of 50:50, with Tifton-85 bermudagrass hay (Cynodon spp.) as roughage, and ground corn, soybean meal and minerals as concentrate. The lambs fed diets with crude propolis had higher feed intake than those fed diets containing monensin sodium. The different diets did not affect dry matter, organic matter, crude protein, neutral detergent fiber, or acid detergent fiber digestibility, but crude propolis supplementation provided higher ether extract digestibility than monensin sodium. Nutrient digestibility, as indicated by indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber, was lower than that found with the fecal collection method. The addition of brown propolis has the same effect as monensin, but neither maximized nutrient availability in the diet of feedlot lambs at 7 months of age. Digestibility assessment using the internal markers indigestible neutral detergent fiber, indigestible acid detergent fiber and sequentially-determined indigestible acid detergent fiber is not an efficient method compared with total feces collection.

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.

Intake and total and ruminal digestibility, ruminal characteristics and microbial synthesis efficiency in bovine and bubaline fed sugar cane silages treated with microbial additive Lactobacillus buchneri (inoculate) and the addition of: cassava byproduct meal at 250 g/kg; soybean hulls at 250 g/kg; and urea at 33 g/kg, in natural matter were evaluated. The forage:concentrate ratio was 600:400 g/kg. Bubaline body weight (BW) was 403±49 kg and bovine BW was 492±10 kg. The experimental design consisted of two 4 × 4 Latin squares in a 4 × 2 factorial arrangement. The average DM intake did not differ between species, and the diet with urea showed lowest intake (13 g/kg BW). Among the diets, the one with soybean hulls addition increased the total digestibility of DM, organic matter (OM) and neutral detergent fiber (NDF), while addition of urea reduced the DM, OM and non-fibrous carbohydrates (NFC) total digestibility in both species. Bovines have higher ruminal digestibility of NFC in the diet with addition of inoculate, inoculate + soybean meal and inoculate + urea diets than bubaline. Ruminal liquid pH was higher for bubaline (6.61) than bovines (6.48). Diets with addition of cassava byproduct and soybean hulls presented higher ruminal short chain fatty acids concentrations. Ruminal ammonia concentration (N-NH3) did not differ between species and the treatment with urea presented the highest value of N-NH3 (17.25 mg/100 mL). Liquid passage rate was higher for bubaline (12.9%/h) than bovines (9.9%/h). Bubaline has higher microbial synthesis efficiency than bovine: 35.1 vs 24.6 g of N-microbial/kg OM of the total rumen digestibility, regardless of the diet.

The objective of this study was to evaluate the sugarcane silage in relation to chemical composition, pH, total losses, aerobic stability, in vitro digestibility of dry matter (IVDDM) and effective degradability (ED) of bovine and buffaloes under the following treatments (on a dry matter (DM) basis): sugarcane silage control (control), with addition of 3.3% urea; with addition of Lactobacillus buchneri (inoculate); with inoculate + 3.3% urea; with inoculate + 25.0% soybean hull, and with inoculate + 25.0% cassava byproduct meal. The experiment was analyzed through a completely randomized design with three replications, and for DM ED, a double 4 × 4 Latin square with a 4 × 2 factorial arrangement was used. The sugarcane variety was the RB-855156 (precocious). The urea increased the protein level and reduced neutral and acid detergent fiber and lignin fractions. Treatments with inoculate + cassava byproduct and inoculate + soybean hull increased DM levels. Bovines presented higher IVDDM than buffaloes. pH values varied from 3.1 to 4.0. Mean total losses observed were 7.8%. Treatments with inoculate + cassava and inoculate + soybean hulls resulted in larger aerobic stability with 61 and 81 hours, respectively, in relation to silages control (24 h) and control with 3.3% urea (33 h). A higher DM ED was verified for silages with inoculate + control and inoculate + soybean hulls at 2%/h passage rates and higher neutral detergent fiber ED for the treatment of control + inoculate + soybean hulls at 2 and 5%/h. Silages treated with urea, L. buchneri or agricultural byproduct plus inoculate presented better quality pattern.

In order to evaluate the use of oilseeds in the diet of goat kids, two experiments were performed. Experimental treatments consisted of four different total mixed diets, all containing oat hay, ground corn, soybean meal and mineral supplement, and differing in oilseeds inclusion (dry matter basis), according to the treatments: 1) control (without oilseeds), 2) diet containing 7.87% flaxseed, 3) diet with 7.30% sunflower seed, and 4) diet containing 8.00% canola. In the first experiment (to evaluate the performance), 28 ¾ Boer + ¼ Saanen castrated goat kids (22.66 kg to 30.88 kg BW) were allotted in a randomized design in feedlot. There was no difference between treatments for intake of dry matter, organic matter, crude protein and ether extract, total weight gain, average daily gain, feed conversion or days in feedlot (61 days). In the second experiment (to evaluate the digestibility), four goats (47.42 ± 1.83 kg BW) were allotted in a 4 × 4 Latin square. The inclusion of sunflower seeds in the diet increased the intake of neutral detergent fiber. The digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, total carbohydrate and total digestible nutrients were not influenced by the addition of oilseeds in the diets. There was higher ether extract digestibility for goats receiving dietary canola. The inclusion of flaxseed (7.30%), sunflower (7.87%) and canola (8.00%) seeds in the diets of ¾ Boer + ¼ Saanen goats does not improve performance, but can be used without changing intake, digestibility and energy value of diets.

Objetivou-se avaliar cepas bacterianas tolerantes a produtos à base de própolis pelas técnicas de isolamento, caracterização morfológica e bioquímica, em dietas com relação volumoso: concentrado de 100:0 e 50:50. Para dietas volumosas foram avaliados os produtos LLOSC1 e LLOSB3 e, para dietas 50:50% os produtos LLOSC1, LLOSD1, LLOSA2 e LLOSC3, diferentes quanto aos teores alcoólicos (1, 2 e 3) e as concentrações de própolis (A, B, C e D). O líquido ruminal foi incubado anaerobiamente a 39°C durante 6 dias em meio contendo LLOS. Após o isolamento, as cepas foram submetidas à coloração de Gram e o crescimento bacteriano foi monitorado por espectrofotômetro. Foi avaliado o crescimento das cepas na presença dos substratos: arabinose, celulose, glicose, celobiose, xilose, frutose e lactose. Em dietas volumosas as cepas tolerantes a LLOSC1 e LLOSB3 foram semelhantes na degradação dos carboidratos, exceto lactose no qual LLOSC1 foi superior às cepas tolerantes a LLOSB3. Para dieta 50:50 de volumoso:concentrado, destacaram-se os produtos LLOSC3 e LLOSA2, que selecionaram maior número de cepas capazes de degradar a maioria dos carboidratos testados. Os resultados sugerem que a tolerância à própolis foi maior nas cepas Gram-positivas, com níveis metabólicos de crescimento diversos.

It was aimed in this work to evaluate bacterial strains tolerant to products based on propolis (LLOS) through the isolation, morphological and biochemical characterization techniques in diets with roughage:concentrate ratio 100:0 and 50:50. For roughage diets, the products LLOSC1 and LLOSB3 were evaluated, and for 50:50% diets, the products LLOSC1, LLOSD1, LLOSA2, and LLOSC3, which differed in alcoholic concentrations (1, 2 and 3) and propolis (A, B, C and D) concentrations. The ruminal liquid was anaerobically incubated at 39°C for 6 days in medium containing LLOS. After isolation, the strains were submitted to Gram staining and the bacterial growth was monitored by photospectrometer. It was evaluated the strain growth in the presence of the following subtracts: arabinose, cellulose, glucose, cellobiose, xylose, fructose, and lactose. In roughage diets, strains tolerant to LLOSC1 and LLOSB3 were similar to carbohydrates degradation, except lactose in which LLOSC1 was superior to strains tolerant to LLOSB3. For diets with 50:50 roughage:concentrate ratio, the products LLOSC3 and LLOSA2 stood out because they selected the highest number of strains able to degrade most of the tested carbohydrates. The results suggest that tolerance to propolis is higher in Gram-positive strains with several growth metabolic levels.

Objetivou-se avaliar o efeito da administração de produtos à base de monensina sódica ou de própolis LLOSB3 e LLOSC1 em duas concentrações (B e C, em que B foi menos concentrado que C) e duas extrações alcoólicas (1 e 3, em que 1 foi menos concentrado que 3) sobre o consumo, a digestibilidade total e parcial e as características ruminais em bubalinos alimentados com dieta à base de forragem. Foram utilizados quatro búfalos castrados mestiços com 459,3 ± 44,5 kg em delineamento quadrado latino 4 x 4, com quatro dietas (controle, monensina, LLOSC1 e LLOSB3) e quatro períodos. A dieta continha 80% de volumoso (silagem de milho e feno de capim-tifton) e 20% de concentrado, com 11,1% de PB e 66% de nutrientes digestíveis totais (NDT). Os consumos de matéria seca (MS) e nutrientes não diferiram entre os aditivos testados. A adição de LLOSC1 propiciou maiores coeficientes de digestibilidade total em relação ao controle para MS (62,8% vs 59,4%), FDN (58,6% vs 54,3%), carboidratos totais (65,1% vs 61,5%) e NDT (65,8 vs 62,3%). A dieta com monensina não diferiu da controle e aquela com LLOSB3 foi semelhante a todas as outras. Aumento no fluxo e maior digestibilidade de PB nos intestinos foram verificados com o uso dos aditivos em relação à dieta controle. Após a alimentação, às 2,18 horas, não houve diferença na concentração de nitrogênio amoniacal no rúmen entre dietas e o valor máximo foi de 21,26 mg/100 mL. Menor valor de pH ruminal (6,48) e maiores concentrações de acetato e de butirato foram verificados para LLOSB3. A taxa de passagem de líquido não diferiu entre as dietas, porém, maior volume ruminal foi verificado com o uso dos aditivos. O aditivo LLOSC1 é superior à monensina em aumentar a energia digestível para bubalinos alimentados com dietas à base de forragem.

The objective of this work was to study the effect of the administration of products based on sodium monesin or propolis LLOSB3 and LLOSC1 in two concentrations (B and C, in which B was less concentrated than C) and two alcoholic extractions (1 and 3, in which 1 was less concentrated than 3) on intake, total and partial digestibility, and ruminal characteristics in buffaloes fed diet based on roughage. It was used four castrated crossbred buffalo with average weight of 459.3 ± 44.5 kg in 4 x 4 experimental Latin square design with four diets (control, monensin, LLOSC1 and LLOSB3) and four periods. The diet had 80% roughage (corn silage and Tifton hay) and 20% concentrate, with 11.1% CP and 66% of total digestible nutrients (TDN). The intake of dry matter (DM) and nutrients did not differ among tested additives. The addition of LLOSC1 provided higher total digestibility coefficients in relation to the control for dry matter (62.8% vs. 59.4%), NDF (58.6% vs. 54.3%), total carbohydrates (65.1% vs. 61.5%) and TDN (65.8 vs. 62.3%). The diet with monensin did not differ from the control and the diet with LLOSB3 was similar to all other diets. Increase in the flow and higher digestibility of CP in the intestines were found with the use of additives in relation to the control diet. After feeding at 2.18 h, there was no difference in the concentration of ammoniacal nitrogen in the rumen among diets and the maximum value was 21.26 mg/100 mL. The lowest value of ruminal pH (6.48) and higher concentrations of acetate and butyrate were found for LLOSB3. The passage rate of liquid did not differ among diets, however greater ruminal volume was found with the use of additives. The additive LLOSC1 is superior than monensin in increasing digestible energy for buffalo fed diets based on roughage.

Avaliaram-se os efeitos da utilização de produtos contendo própolis em duas concentrações (B e C) e duas extrações alcoólicas (1 e 3) e de monensina sódica em dieta à base de forragem sobre o consumo, a digestibilidade total e parcial e as características ruminais em bovinos. Utilizaram-se quatro bovinos da raça Holandesa, castrados, com peso corporal de 221 ± 21 kg, canulados no rúmen, em delineamento experimental quadrado latino 4 × 4. As dietas experimentais foram constituídas de 72,5% de volumoso e 27,5% de concentrado e apresentaram 14,4% de PB e 67% de nutrientes digestíveis totais (NDT), diferindo apenas quanto à presença de aditivos. Os consumos médios de matéria seca e nutrientes, não foram afetados pelas dietas, exceto o de NDT, que foi maior nos animais alimentados com a dieta controle. O fornecimento dos aditivos, principalmente própolis, reduziu a digestibilidade total de matéria seca, proteína bruta e NDT. A digestibilidade total da fibra em detergente neutro (FDN) foi semelhante entre aditivos e menor que nos animais controle. A inclusão de própolis refletiu em menor pH ruminal e maiores produções de acetato e AGV totais e a monensina propiciou a menor razão acetato:propionato. A adição dos aditivos avaliados tem efeito negativo sobre a concentração e consumo de energia digestível de dietas à base de forragem fornecida para bovinos em crescimento.

It was evaluated the effects of using products containing propolis in two propolis concentrations (B and C) and two alcoholic extractions (1 and 3) and sodium monensin in forage based diet on intake, total and partial digestibility and ruminal characteristics in cattle. It was used four Holstein castrated bovines, with body weight of 221 ± 21 kg, implanted with ruminal cannulla, in a 4 × 4 Latin square experimental design. The experimental diets were composed of 72.5% roughage and 27.5% concentrate and had 14.4% crude protein and 67% of total digestible nutrients (TDN), only differing to the presence of additives. The average intake of dry matter and nutrients did not differ among diets, except for the intake of TDN that was higher for animal fed control diet. The supply of additives, mainly propolis, reduced the total digestibility of dry matter (DM), crude protein (CP) and total digestible nutrients (TDN). The total digestibility of neutral detergent fiber was similar among additives and it was lower than the control animals. The inclusion of propolis reflected in lower pH and production of acetate and total volatile fatty acids and monensin resulted in lower acetate:propionate ratio. The addition of the evaluated additives has negative effect on the concentration and intake of digestible energy of roughage based diets for growing cattle.

Este trabalho foi conduzido com os objetivos de avaliar a ingestão e a digestibilidade da matéria seca e dos nutrientes e estimar o valor energético de rações com 0; 25; 50; 75 ou 100% de casca do grão de soja em substituição ao milho moído na dieta de cabritos. As rações foram compostas de feno de aveia, milho moído e/ou casca do grão de soja, farelo de soja e suplemento mineral. Foram utilizados cinco cabritos da raça Saanen (32,44 ± 4,00 kg) alojados em gaiolas de digestibilidade em delineamento quadrado latino 5 × 5. Foram realizadas coletas totais de fezes utilizando-se sacolas de lona. Cada período foi composto de 12 dias (sete dias para adaptação à ração e cinco dias para coletas). As ingestões de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), carboidratos totais (CT) e nutrientes digestíveis totais (NDT) não foram alteradas pela inclusão de casca do grão de soja nas rações. No entanto, para a ingestão de extrato etéreo, FDN e amido, houve efeito linear dos níveis de casca do grão de soja. Para as digestibilidades da MS, MO, PB, CT, FDN, amido e para os NDT, foram observados efeitos quadráticos e a digestibilidade do extrato etéreo não foi alterada. A inclusão de casca do grão de soja em níveis de até 75% nas rações de cabritos melhora a digestibilidade e o valor energético das dietas, mantendo-se a viabilidade econômica.

The objective of this study was to evaluate the dry matter and nutrient intake and digestibility and to estimate the energy value of diets with the inclusion of soybean hulls (0, 25, 50, 75 and 100%) replacement of ground corn in the diet of kids goats. The rations consisted of oat hay, ground corn and/or soybean hulls, soybean meal and mineral supplement. Five Saanen kid goats (32.44 ± 4.00 kg), housed in digestibility cages, in a 5 × 5 Latin square design were used. Total feces were collected with canvas bags. Each period consisted of 12 days, seven days to adapt to the rations and five days for collections. The intake of dry matter (DM), organic matter (OM), crude protein (CP), total carbohydrates (TC) and total digestible nutrients (TDN) were altered by the inclusion of soybean hulls in the rations. However, for the intakes of ether extract, NDF and starch there was a linear effect. Quadratic effects were observed for the digestibility of DM, OM, CP, TC, NDF, starch and the TDN but the ether extract digestibility was not altered. The inclusion of the soybean hulls up to 75% in the rations of kid goats improved digestibility, resulting in higher energy value with economic viability.

Avaliaram-se os coeficientes de digestibilidade (CD) parcial e total dos nutrientes, o pH, a concentração de nitrogênio amoniacal (N-NH3) do líquido ruminal e a eficiência de síntese microbiana em bovinos alimentados com rações contendo 0; 8; 16 e 24% de resíduo de cervejaria fermentado (RCF). O resíduo de cervejaria foi conservado em silo de superfície (5.000 kg). Foram utilizados quatro bovinos da raça Holandesa com peso corporal de 480 ± 100 kg, portadores de cânula ruminal e duodenal, distribuídos em delineamento quadrado latino 4 × 4. O consumo médio de MS pelos animais foi de 1,7% do peso corporal (PC). Os coeficientes de digestibilidades total e ruminal dos nutrientes não diferiram entre os níveis de RCF utilizados nas rações. Os níveis de RCF nas rações tiveram efeito linear crescente sobre o coeficiente de digestibilidade intestinal de matéria seca e carboidratos totais, calculado em porcentagem do que chegou ao compartimento. Não houve efeito dos níveis de RCF nas rações sobre o pH e a concentração de N-NH3 do líquido ruminal. Os níveis de RCF nas rações não influenciaram a eficiência de síntese microbiana em g N-Mic/kg de matéria orgânica aparentemente degradável no rúmen (MOADR) e da matéria orgânica verdadeiramente degradável no rúmen (MOVDR). A inclusão de até 24% do RCF na MS em rações para bovinos não altera os processos de fermentação ruminal e digestão dos nutrientes.

The objective of the present study was to evaluate the partial and total digestibility coefficient (DC) of the nutrients, ruminal pH, ammonia nitrogen (N-NH3) concentration in the ruminal fluid and microbial efficiency synthesis in bovines fed rations containing 0, 8, 16 and 24% of brewers grains. The brewer grains were ensiled in surface silo (5,000 kg). Four Holstein cattle (480 ± 100 kg of body weight) fitted with ruminal and duodenal cannulas, were distributed to 4 × 4 Latin square design. The mean DM intake of animals was 1.7% BW. Total and ruminal DC of the nutrients did not differ among the levels of BG used in the rations. The levels of BG in the rations showed a linearly increased on the intestinal DC dry matter and TC, as % of that reached the compartment. There was no effect of levels of BG in rations on pH and N-NH3 concentration in the ruminal fluid. The levels of RCF in diets did not affect the microbial efficiency synthesis in g N-Mic/kg of rumen apparent degradable organic matter and rumen truly degradable organic matter. The inclusion of up to 24% of BG (%DM) cattle feed does not alter the processes of rumen fermentation and digestion of nutrients.

Quatro novilhos da raça Holandesa (450 kg) portadores de cânula ruminal e duodenal, recebendo dietas com níveis de proteína degradável no rúmen (PDR) de 50, 60, 65 e 70%, associadas a uma fonte de amido de alta degradabilidade ruminal (farinha de varredura de mandioca), foram distribuídos em quadrado latino 4 × 4 para se avaliarem as digestibilidades total e parcial dos nutrientes, a concentração de amônia e o pH ruminal. Foi utilizada, como indicador do fluxo duodenal e fecal, a cinza insolúvel em ácido. Não foi observado efeito do nível de PDR sobre o coeficiente de digestibilidade total, digestibilidade ruminal e digestibilidade intestinal da matéria seca, matéria orgânica, fibra em detergente neutro, carboidratos não-estruturais e energia bruta. O aumento do nível de PDR na dieta elevou o coeficiente de digestibilidade total e ruminal da proteína bruta e reduziu a digestibilidade intestinal desse nutriente como porcentagem do digerido. Não houve efeito dos níveis de PDR no pH ruminal, no entanto, maior concentração ruminal de amônia foi observada para as dietas com maior teor de PDR. Os resultados obtidos indicaram que o aumento no teor de PDR acarretou maior produção de nitrogênio na forma de amônia, independentemente da presença da fonte de amido de alta degradabilidade ruminal, contudo, o aporte de proteína intestinal foi semelhante para todas as dietas.

Four ruminally and duodenally cannulated Holstein steers (450 kg) were fed diets with rumen degradable protein (RDP) levels of 50.0 60.0 65.0 and 70.0% associated with a high ruminal degradability starch (cassava by-product meal) were allotted to a 4 × 4 Latin square design for the evaluation of total and partial digestibility of the nutrients, ruminal ammonia concentration and pH. The acid insoluble ash was used as a marker of the duodenal and fecal flow. No effects were observed on the level of RDP on total digestibility coefficient, ruminal digestibility and intestinal digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fiber, non structural carbohydrates and gross energy. The increase of the RDP levels in the diet increased the coefficients of total and ruminal digestibility of crude protein and reduced the intestinal digestibility of this nutrient as a percentage of the digested. There was no effect of RDP levels on the ruminal pH, however, higher ammonia concentration was observed for the diets with higher level of RDP. The results indicated that the increase in the level of PDR cause a higher production of nitrogen in the ammonia form, independently of the presence of the source of high ruminal degradability starch, however the contribution of intestinal protein was similar for all the diets.

Avaliaram-se os efeitos do ionóforo (monensina sódica) e do probiótico (Saccharomyces cerevisiae + selênio + cromo) em rações com 50:50% de volumoso:concentrado sobre os coeficientes de digestibilidade total (CDT) e parcial dos nutrientes. Foram utilizados três búfalos da raça Murrah e três bovinos da raça holandesa, com peso médio de 477 ± 47 e 518 ± 56 kg, respectivamente, portadores de cânula ruminal e duodenal, distribuídos em delineamento experimental com dois quadrados latinos 3 <FONT FACE=Symbol>´</FONT> 3 e arranjo fatorial 3 <FONT FACE=Symbol>´</FONT> 2. O indicador dos fluxos fecal e duodenal foi a cinza insolúvel em ácido. Não houve interação dieta <FONT FACE=Symbol>´</FONT> espécie animal para os CTD dos nutrientes, porém a adição de ionóforo à ração teve efeito positivo sobre os CDT de MS, PB, EE e amido e a adição de probiótico aumentou os CDT do amido, da FDN e da FDA. As adições de ionóforo e probiótico propiciaram maior fermentação ruminal da FDN e FDA e maiores coeficientes de digestibilidade intestinal (CDI) do amido. Observaram-se maiores CDT da PB e do amido para os bovinos e maior CDT da FDN para búfalos. Houve interação rações <FONT FACE=Symbol>´</FONT> espécie somente sobre os coeficientes de digestibilidade ruminal (CDR) e CDI de MS, PB e EE. Para ambas as espécies, a adição de ionóforo foi efetiva em aumentar a fermentação ruminal da MS, reduzir a degradação ruminal da PB e elevar o CDI da PB. A adição do probiótico também reduziu a degradação ruminal da PB em bubalinos, porém em menor escala que o ionóforo. Independentemente da presença ou não dos aditivos nas rações, os bubalinos apresentaram maior CDR da MS e sem a adição de aditivos, maior CDR da PB e menor CDI da PB que os bovinos.

The effects of the ionophore (sodic monensin) and of the probiotic (Saccharomyces cerevisiae + selenium + chrome) were evaluated in rations with 50:50% of forage:concentrate ratio on the total (TDC) and partial [ruminal digestibility coefficients (RDC) and intestinal (IDN)] nutrients digestibility coefficients. Three Murrah buffalos (Bubalus bubalis) and three steers Holstein (Bos taurus), with an of 477 ± 47 kg and 518 ± 56 kg of average weight respectively, and with ruminal and duodenal cannulas were used; the animals were designed into two 3 <FONT FACE=Symbol>´</FONT> 3 latin squares and in a 3 <FONT FACE=Symbol>´</FONT> 2 factorial arrangement. The acid insoluble ash was the internal marker for fecal and duodenal flow. No interaction of diet and animal species for TDC of nutrients was observed, although the ionophore addition in the ration showed a positive effect on TDC for DM, CP, EE and starch and the probiotic addition increased TDC of starch, NDF and ADF. The ionophore and probiotic addition provided higher ruminal fermentation of NDF and ADF and higher IDC of starch. It was observed higher TDC of CP and starch for bovine and higher TDC of NDF for buffaloes. There was interaction of rations <FONT FACE=Symbol>´</FONT> species only on RDC and IDC for DM, CP and EE. The ionophore addition was effective to increase the ruminal fermentation of DM, to reduce ruminal degradation of CP and to increase IDC of CP for both species. The probiotic addition also reduces ruminal degradation of CP in buffaloes, but in lower scale than ionophore. For buffaloes, the presence or absence of additives in rations caused higher RDC of DM, the absence of addictives in ration caused higher RDC and lower IDC of CP than in bovine.

Foram avaliados dois níveis de suplementação com sal mineral proteinado (290 e 400 g.an-1.dia-1), em comparação ao sal mineral, em 90 novilhos Nelore, mantidos em pastagem de grama estrela roxa (Cynodon plectostachyus Pilger) no inverno. O consumo do suplemento foi ajustado pelo teor de cloreto de sódio adicionado à mistura. Quando considerado o período de adaptação (28 dias) na análise estatística, não foi observada diferença no ganho médio diário (GMD) entre os tratamentos, ao passo que, quando desconsiderado, a suplementação com 400 g.an.-1.dia-1 resultou em maior GMD (0,15 kg.dia-1), em comparação aos demais tratamentos (0,06 e 0,05 kg.dia-1 para o sal proteinado, com consumo de 290 g.an.-1.dia-1, e sal mineral, respectivamente). A qualidade e disponibilidade da forragem foram semelhantes entre os tratamentos, com médias de 4366 kg de matéria seca.ha-1, 2145 kg de matéria verde seca.ha-1 e 353 kg de folhas.ha-1. Houve redução na proporção de folhas e colmos e aumento na proporção de material morto, em função dos períodos experimentais. Os valores médios para composição química da pastagem foram de 3,5% de PB, 1,6% de PB digestível, 48,1% de FDA e 48,4% de DIVMS. A pastagem de grama estrela roxa apresentou baixo valor nutritivo entre os meses de maio e outubro, sendo necessária a suplementação protéica para que os animais pudessem manter ou ganhar peso neste período.

Two levels of protein and mineral supplements (290 and 400 g.an.-1.day-1) were evaluated and compared with the mineral supplement in 90 Nelore steers on star grass pasture (Cynodon plectostachyus Pilger) during the winter. The supplement intake was ajusted by the concentration of sodium clore into the mixture. Considering the first 28 days (adaptation period) in the statistical analysis, there was no difference in average daily gain (ADG). Taking out this period of adaptation, the ADG was better for the protein and mineral supplement with intake of 400 g.an.-1.day-1 (0.15 kg per animal a day), when compared with the other supplements (0.06 and 0.05 kg per animal a day, respectively for intake of 290 g.an.-1.day-1 of protein mineral supplements and mineral salt). The forage quality and availability were similar for the different treatments, with average levels of 4366 kg dry matter.ha-1, 2145 kg green dry matter.ha-1, and 353 kg of leaves.ha-1. The proportion of leaves and stems were reduced and the dead material proportion rose during the experimental periods. The chemical composition of forage had values of 3.5% of CP, 1.6% of digestible CP, 48.1% of ADF, and 48.4% of IVDMD. The sta grass pasture presented poor nutritional quality during beetwen the months of may and october, so the protein supplement is necessary to the animals mantain or gain weight during this period.