Forty-six barrows fitted with steered ileo-cecal valve cannulas were used in four experiments to evaluate the effects of supplementing swine diets with microbial phytase or beta-mannanase on the apparent ileal (AID) and/or apparent total tract digestibility (ATTD) of amino acids, N, Ca, P, DM and energy. In Exp. 1, the addition of phytase to low CP corn-soybean meal based diets increased the AID of Ca (P < .01), P (P < .001), and all amino acids (P < .10) measured except Leu, Ser, Pro, Met, His and Tyr. In Exp. 2, the addition of microbial phytase to corn-soybean meal, corn-soybean meal-wheat middlings, or corn-soybean meal-meat and bone meal based diets resulted in increased AID of Ca and P, but had no effect (P > .1) on amino acid digestibilities. Diet type affected all digestibility measurements, but did not affect the efficacy of supplemental phytase. In Exp. 3, the addition of microbial phytase to corn-wheat-soybean meal, corn-wheat-cannola, or sorghum-corn-soybean meal based diets led to an increased ( P <.05) AID of P, Asp, Thr, Ser, Ala, Tyr, Phe, Lys and Arg. In Exp. 4, the addition of beta-mannanase to corn-soybean meal based swine diets led to an increased AID of DM and ATTD of energy. In addition, the AID of all amino acids measured were increased numerically, with many of these values approaching significance. The results of these studies demonstrate that supplementing pig diets with phytase or beta-mannanase, results in an increased digestibility of certain dietary components due to the breakdown of anti-nutritive compounds in the diet. / Ph. D.

A marker model of fecal kinetics using chromic oxide (Cr) or ytterbium chloride (Yb) is being developed for grazing horses. The model consists of removal of feces at a constant rate from a single compartment, the prefecal mass. It was tested in experiments on stall-fed horses in the context of digestion balance trials. Following the preliminary work of Holland et al., (1998), three improvements in experimental design were tested. First, the rate constants were determined from both the administration and post-administration curve of the one-compartment model. Second, markers were administered three times a day to reduce diurnal variation in fecal marker concentration. Third, yttrium (Y) and Yb were tested were tested as internal markers, for the estimation of digestibility of hay and supplements, respectively. Eight horses were fed Diet 1 (orchardgrass/alfalfa mixed, OG) or Diet 2 (tall fescue/alfalfa mixed, TF) in Exp.1, and Diet 3 (OG plus fat-and-fiber supplement, OGFF) or Diet 4 (OG plus sugar-and-starch supplement, OGSS) in Exp.2. Balance-marker experiments were conducted for 17 and 20 d, with 7 and 10 d of dietary accommodation in Exp.1 and 2, respectively. Chromic oxide and Yb were administered orally and fecal samples were collected every 8 h for 8 d. Dry matter, Cr, Yb and Y were measured in feeds and feces. In balance experiments, estimates of DMD (D_E) using Y, were determined precisely (SE 1 to 3 %) for hay and hay and supplement diets. Linear relationships, correlations and calibration curves were determined, validating Y as a marker. Mean daily fecal Cr data (C_t) at time t (days) including a delay (d) were fitted to a single exponential, with one rate constant (k), rising to an asymptote (C_a): C_t = C_a - C_a·e^-k(t-d) Diets 1 and 2 had two sets of C_tdata, total collection (a) and fecal grab data (b), and each set was used in model development. Diets 3 and 4 had two sets of C_t data (both using fecal grab data), Cr marker dilution (3Cr and 4Cr) and Yb marker dilution (3Yb and 4Yb). For pooled data, delays of 3 to 6 h (Diets 1a, 1b, 2a and 2b) and delays of 5 to 7 h (Diets 3Cr, 4Cr, 3Yb and 4Yb) gave best fits (highest estimates of R²). The delays introduced to the Cr model for both 3Cr and 4Cr diets did not correspond to the preliminary study (Holland et al., 1998), where a 2 h delay gave the best fit in the model for horses fed hay and supplement. The present estimates may more realistically relate to mouth-to-cecum transport times, because the marker was administered three times a day instead of once, and the initial part of the tracer curve was more precisely defined. The results showed that fecal Cr kinetics could be calibrated precisely (SE 1 to 3 %) to predict fecal DM output of horses fed Diets 1b, 2b, 3a but not 4a. Similarly, fecal Yb kinetics could be calibrated to predict fecal DM output of horses fed Diet 3b but not 4b. The rate constants yielded turnover times (TT) that were longer with hay and supplement diets, than with hay alone, and which contrast with previous findings in the horse. However, the longer TT were similar to slower rates of marker excretion in sheep fed concentrates instead of all-roughage diets, suggesting that the lower fiber content retarded the rate of propulsion of digesta through the digestive tract. For two of the eight models of fecal kinetics, the rate constants of the post-administration curve were not well determined by the data, and rate constants from the administration curve were used. In future experiments, more frequent fecal sample collection during the post-administration period may improve rate constant determination. Improvements in diurnal variation of fecal marker concentration were obtained by dosing three times a day. But discrepancies between Cr and Yb concentration means of diurnal samples and combined samples showed incomplete mixing, the major source of tracer error. Therefore more frequent marker administration and fecal samples should be tested in future experiments to achieve more thorough mixing in the prefecal mass for modeling fecal kinetics, and in the small intestine for estimating digestibility. / Master of Science

The overall objective of this study was to evaluate the effects of feeding hulless barley and supplementing a xylanase enzyme on production performance and nutrient utilization of lactating dairy cows. In study 1, we evaluated production performance, milk fatty acid composition, and nutrient digestibility in high-producing dairy cows consuming diets containing corn and hulless barley in different proportions as the grain source. We hypothesized that a plausible reduction in production performance would be explained by an altered rumen function, which would be reflected in a reduction of the proportion of de novo fatty acids in milk fat. The inclusion of hulless barley grain as the energy source in diets for lactating dairy cows resulted in similar production performance and nutrient utilization as corn grain. We concluded that hulless barley is as good as corn grain as an energy source and increasing NDF concentration in hulless barley-based diet is not necessary. In study 2, we evaluated production performance, nutrient digestibility, and milk fatty acid composition of high-producing dairy cows consuming diets containing hulled or hulless barley as the grain source. We hypothesized that rumen function is altered when cows are fed low-forage diets containing barley grains, and this altered rumen function would be reflected in lower production performance and a reduction of fatty acids synthesis in the mammary gland. Contrary to our expectations, feeding hulled barley or hulless barely based diets with different forage to concentrate ratios to lactating dairy cows resulted in similar production performance and nutrient utilization. We concluded that both hulled or hulless barley grains are good energy sources for sustaining high milk production and there is no need to increase NDF concentration in diet when using barley grain as the grain source. In study 3, we evaluated the effects of supplementing a xylanase enzyme on production performance and nutrient digestibility of lactating dairy cows fed diets containing corn or sorghum silage as the forage source. We hypothesized that supplementing a xylanase enzyme product in diets containing corn or sorghum silage increases NDF digestibility, and production performance of lactating dairy cows would also be improved due to enhanced fiber digestion. Supplementation of xylanase for 19 d did not affect cow performance and nutrient utilization. Supplementation of xylanase may require a longer period of time to show any response in production performance and nutrient digestibility. We concluded that supplementing xylanase to cows fed corn or sorghum silage-based diets did not improve fiber digestion. But for feeding hulled or hulless barley grains to lactating dairy cows, increased NDF concentration in diets is not necessary and hulless barley is good as corn grain for feeding lactating dairy cows as the grain source. / Ph. D. / The overall objective of this study was to evaluate the effects of feeding hulless barley and supplementing a xylanase enzyme on production performance and nutrient utilization of lactating dairy cows. Barley starch is fermented faster than corn starch and can possibly reduce ruminal pH. Reduced ruminal pH can compromise cow production performance and cause some health problems. In study 1, we evaluated production performance, milk fatty acid composition, and nutrient digestibility in high-producing dairy cows consuming diets containing corn or hulless barley as the grain source. We hypothesized that a plausible reduction in production performance and milk fat percentage would be reduced by feeding hulless barley as the grain source in the diet. According to our results, the inclusion of hulless barley grain as the energy source in diets for lactating dairy cows resulted in similar production performance and nutrient utilization as corn grain. We concluded that hulless barley is as good as corn grain as an energy source and increasing fiber concentration in hulless barley-based diet is not necessary. In study 2, we evaluated production performance, nutrient digestibility, and milk fatty acid composition of high-producing dairy cows consuming diets containing hulled or hulless barley as the grain source. We hypothesized that rumen function is altered when cows are fed low-forage diets containing barley grains, and this altered rumen function would be reflected in lower production performance and a reduction of milk fat percentage. Contrary to our expectations, we did not observe any differences in cow production performance among all treatments. We concluded that both hulled or hulless barley grains are good energy sources for sustaining high milk production and there is no need to increase fiber concentration in diet when using barley grain as the grain source. In study 3, we evaluated the effects of supplementing a xylanase enzyme on production performance and nutrient digestibility of lactating dairy cows fed diets containing corn or sorghum silage as the forage source. We hypothesized that supplementing a xylanase enzyme product in diets containing corn or sorghum silage increases fiber digestibility, and production performance of lactating dairy cows would also be improved due to enhanced fiber digestion. Supplementation of xylanase for 19 d did not affect cow production performance and nutrient digestion. The effects of supplementation xylanase may require a longer period time to detect. We concluded that supplementing xylanase to cows fed corn or sorghum silage-based diets did not improve fiber digestion. For feeding hulled or hulless barley grains to lactating dairy cows, increased fiber concentration in diets is not necessary and hulless barley is good as corn grain for feeding lactating dairy cows as the grain source.

Este trabalho foi desenvolvido com a finalidade de testar alterações nas metodologias in vitro de produção de gases (diferentes proporções de inóculo) e incorporação de 32P (velocidade de centrifugação, número de lavagens e diferentes tipos de inóculos) para adequá-las às condições climáticas e às especificidades da microbiota dos ruminantes mantidos no clima tropical brasileiro. Além dessas técnicas utilizadas, foram feitas determinações de análise bromatológica com posterior análise de nutrientes digestíveis totais, degradabilidade ruminal in situ e digestibilidade in vitro a partir da técnica dos dois estágios. Os substratos testados foram divididos em, fibrosos (feno de alfafa e capim colonião), concentrados (milho grão e farelo de soja) e fermentado (silagem de milho). O delineamento experimental utilizado foi inteiramente casualizado, todos os substratos foram avaliados para cada uma das variáveis com pelo menos três repetições no tempo. Cada variável foi comparada por análise de variância considerando a hipótese de nulidade dentro dos substratos. As correlações entre as metodologias foram testadas quando biologicamente significantes e compatíveis. A técnica de incorporação in vitro de 32P, obteve resultados satisfatórios (P<0,05) em relação à velocidade de centrifugação e número de lavagens. Os diferentes tipos de inóculos testados (100% fase líquida do rúmen, 50% fase líquida e 50% fase sólida) não apresentaram diferença significativa (P>0,05). As diferentes proporções do inóculo testado na técnica in vitro de produção de gases (A contendo 100% de fase líquida e 0% de fase sólida; inóculo B, 75% de fase líquida e 25% de fase sólida; inóculo C, 67% de fase líquida e 33% de fase sólida; inóculo D, 50% de fase líquida e 50% de fase sólida) apresentaram diferença significativa (P<0,01); os fatores analisados permitiram a interpretação de que usando o inóculo com maior porcentagem de fase sólida, o processo fermentativo foi mais parecido ao potencial de produção de gases. Para a técnica in vitro de incorporação de 32P sugere-se usar uma velocidade de centrifugação de 39.907g, 4 lavagens e um inóculo com apenas a fase líquida do conteúdo ruminal. É sugerido que para a técnica in vitro de produção de gases pode ser usado um inóculo contendo 50% de fase sólida e 50% de fase líquida do conteúdo ruminal. / This study was developed to test the adaptations in in vitro methodologies of gas production (different proportion of solid phase in the inoculum) and 32P incorporation technique (centrifugation speed, number of washings and different kinds of inoculum) to adequate them to the climate condition and to the microbiota specifications of the ruminants kept in the Brazilian tropical climate. Besides these techniques, bromatological analysis determinations were made with further total digestible nutrients and also, in situ rumen degradability and in vitro digestibility from the two-stage technique. The tested substrata were divided in fibrous (Panicum grass and Lucerne hay), concentrated (soybean meal and corn grain) and fermented (corn silage). The experimental design was completely randomized, where all the substrata were evaluated for each of the variables with at least three repetitions. Each variable was compared for analysis of variance considering the hypothesis, within substrata. The correlations between methodologies were tested when biologically significant and compatible. The 32P in vitro incorporation technique obtained satisfactory results (P<0,05) in relation to the centrifugation speed and the number of washings. The two different kinds of tested inocula (100% rumen liquid phase, and 50% both liquid and solid phase) showed no significant difference (P>0,05). The different inoculum proportion tested for in vitro gas production (inoculum A containing 100% liquid phase and 0% solid phase; inoculum B, 75% liquid phase and 25% solid phase; inoculum C, 67% liquid phase and 33% solid phase; and inoculum D, 50% both liquid and solid phases) showed significant difference; the analyzed factors allowed the interpretation that using the inoculum with higher solid phase percentage, the fermentation process was more similar to the gas production potential. In the in vitro 32P incorporation technique it is suggested to use a centrifugation speed of 39,907g, 4 washings and an inoculum with only liquid phase from the rumen. It is suggested that for the in vitro gas production technique can be used an inoculum containing 50% of solid phase and 50% of liquid phase.

The objective of this dissertation was to evaluate the effects of exogenous enzymesupplementation to gestation-lactation diets on the digestibility of nutrients in mature swinefemales and the associated implications on energy metabolism during gestation and lactationphysiologic states. Three experiments were performed to evaluate the effects of commerciallyavailable enzyme products or pure enzymes on the digestibility of nutrients. Crossover designs intwo periods during gestation (early and late gestation) and lactation were studied to obtain anincreased number of observations from the surgically cannulated sows.Experiment 1 evaluated the effects of two enzyme products supplemented to a practicalcorn soybean meal diet fed to second parity crossbred sows. One of the enzyme productscontained both protease and cellulase activities, and the other xylanase activity, both productswere produced by microbial fermentation. No effects (P andgt; 0.10) were observed during eitherperiods during gestation. During lactation, effects of both enzyme products were observed fordigestibility of nutrients. Protease/cellulase supplementation increased ileal digestibility of grossenergy (P andlt; 0.09). Xylanase supplementation produced higher ileal digestibilities of dry matter,nitrogen and gross energy (P andlt; 0.02), improvements that were maintained for the total tractdigestibilities (P andlt; 0.05).Experiment 2 evaluated pure exogenous enzymes added to a practical corn soybean mealdiet fed to multiparous crossbred sows. Alpha-galactosidase and protease were supplementedeither alone or in combination to a control diet and compared to a non-supplemented diet duringperiods in gestation and lactation. The observed increases in ileal digestibilities in lactation inExperiment 1 for dry matter, nitrogen and gross energy were observed as tendencies (P andlt; 0.15)during lactation on Experiment 2.Experiment 3 evaluated a semipurified diet (with soybean meal as the only proteinsource) supplemented or not with an enzyme product containing protease and cellulase activitiesfrom microbial fermentation. Multiparous crossbred sows were fed the semipurified diet for twoperiods during gestation and two weeks during lactation. Effects of the enzyme product (P andlt;0.10) on nutrient digestibility were observed during gestation. Apparent digestibilities ofnitrogen were greater for the supplemented diet. In addition, there were observed tendencies (P andlt;0.15) for higher ileal digestibilities of dry matter and gross energy for the supplemented dietduring gestation. No effects (P andgt; 0.10) were observed during lactation period for any of theresponse variable tested. However, tendencies (P andlt; 0.15) of higher DM and GE total tractdigestibilities were observed in lactation for the supplemented diet.According to the results observed in the three experiments, the supplementation ofexogenous enzymes to gestation and lactation diets has the potential to increase the ilealdigestibilities of dry matter, nitrogen, and gross energy, especially during the lactation period.

This diploma thesis discusses the fundamental aspects in dog's nutrition. In this diploma thesis is also compared the digestibility of in vivo and in vitro dry matter and organic matter of granulated dog food.

O objetivo do estudo foi avaliar o efeito da inclusão de doses de S. cerevisiae na dieta sobre a digestibilidade da fibra, o consumo de matéria seca, a cinética e o ambiente ruminal de bovinos Nelore alimentados com feno de Tifton-85 (Cynodon spp.), recebendo ou não suplementação energética. Foram utilizados 36 novilhos Nelore canulados no rúmen, com aproximadamente 24 meses de idade e 400 kg de peso corporal (PC) ao início do experimento, em delineamento experimental de blocos casualizados, com seis repetições por tratamento. Os tratamentos foram obtidos em arranjo fatorial 3x2, a partir da combinação de três níveis de inclusão de S. cerevisiae (0, 8 e 40 x109 UFC/animal/dia; CNCM I-1077, Lallemand&reg;) em duas dietas a base de feno de Tifton-85, com ou sem suplementação energética (0 e 0,8% do PC). Foram realizadas coletas de líquido ruminal para mensuração de pH, ácidos graxos de cadeia curta (AGCC) e N-amoniacal, além de esvaziamento total de conteúdo ruminal para determinação do volume, massa total e tamanho do compartimento ruminal. Amostras das fases líquida e sólida da digesta ruminal foram retiradas para as análises dos componentes da digesta e população de microrganismos ruminais através da técnica de PCR em tempo real. A inclusão de levedura aumentou linearmente o consumo de matéria seca (P = 0,03) e de FDN (P = 0,01), no entanto não houve efeito sobre o pH ruminal (P = 0,30). A suplementação energética aumentou a concentração ruminal de AGCC totais (P &lt; 0,01). Em relação à digestibilidade in situ da FDN, a inclusão de levedura promoveu aumento linear para as quatro forrageiras após 24 h de incubação (P = 0,02). A inclusão também aumentou a massa ruminal de MS (P = 0,02) e FDN (P = 0,02), mas não a de FDN indigestível (P = 0,33). Não houve efeito da levedura sobre a população das bactérias celulolíticas mais abundantes no rúmen (F. succinogenes, R. flavefaciens e R. albus) (P = 0,72). Como conclusão, a inclusão de levedura na dieta de bovinos Nelore aumenta a digestibilidade ruminal da fibra, porém o aumento da digestibilidade da fibra não pôde ser explicado por mudanças na população de bactérias celulolíticas no rúmen. / The objective of the study was to evaluate the effect of inclusion of dietary S. cerevisiae on fiber digestion, dry matter intake, kinetics and ruminal environment of Nellore cattle fed with Tifton-85 hay (Cynodon spp.), receiving or not energetic supplementation. Thirty-six rumen cannulated Nellore steers, approximately 24 months old and 400 kg body weight (BW) were used at the beginning of the experiment, in a randomized complete block design with six replicates per treatment. The treatments were obtained in a 3x2 factorial arrangement, by combining three inclusion levels of S. cerevisiae (0, 8 and 40 x109 CFU/animal/day; CNCM I-1077, Lallemand&reg;) in two diets based on Tifton-85 hay, with or without energetic supplementation (0 and 0.8% of BW). Ruminal fluid samples were collected to measure pH, short chain fatty acids (SCFA) and ammonia nitrogen, as well as the rumen evacuation to determine the volume, total mass and size of the rumen compartment. Samples of the solid and liquid phases of the rumen digesta were taken for analysis of the digesta components and population of ruminal microorganisms through the real-time PCR technique. The yeast inclusion linearly increased the dry matter intake (P = 0.03) and NDF (P = 0.01), however with no effects on rumen pH (P = 0.30). Energy supplementation increased the rumen concentration of total SCFA (P &lt; 0.01). The yeast inclusion linearly increased in situ digestibility of NDF of the four forages after 24 h of incubation (P = 0.02). The yeast inclusion also increased the ruminal mass of DM (P = 0.02) and NDF (P = 0.02), but not the indigestible NDF (P = 0.33). There was no yeast effect on a population of the most abundant cellulolytic bacteria in the rumen (F. succinogenes, R. flavefaciens and R. albus) (P = 0.72). In conclusion, the inclusion of yeast in the diet of Nelore cattle increases the rumen digestibility of the fiber, however, it could not be explained by changes in the population of cellulolytic bacteria in the rumen.

Objetivou-se avaliar os efeitos da inclusão de quitosana e óleo de soja nas dietas de vacas leiteiras no terço médio da lactação, sobre o consumo e digestibilidade aparente total da matéria seca e nutrientes, fermentação e síntese de proteína microbiana ruminal, produção e composição do leite, concentrações de parâmetros sanguíneos e os balanços de energia e de nitrogênio. Foram utilizadas 24 vacas da raça Holandesa, sendo quatro canuladas no rúmen e 20 não canuladas, com 581,2 ± 73,6 kg de PC, DEL médio de 174,7 ± 53,1 e produção de leite inicial de 36,14 ± 5,32 kg de leite por dia, que foram distribuídas em seis Quadrados Latinos balanceados e contemporâneos, para receber uma das quatro dietas experimentais, obtidas pela combinação dos fatores quitosana (aproximadamente 150 mg/kg de peso corporal) e óleo de soja (3,3% da MS da dieta): C controle; Q quitosana; O óleo de soja e QO quitosana associada ao óleo de soja. Foi observada interação entre os fatores avaliados para o consumo de MS, MO, PB, FDN, CNF e NDT. O consumo foi reduzido pela inclusão de quitosana nas dietas sem óleo, enquanto que, na presença deste, a quitosana não influenciou o consumo. A inclusão de óleo de soja reduziu o consumo de MS, MO, PB, FDN, CNF e NDT e aumentou o consumo de EE, independentemente da inclusão de quitosana na dieta. A inclusão de quitosana aumentou os coeficientes de digestibilidade (CD) da MS, MO e PB e não alterou o CDFDN. O CDEE foi alterado positivamente pela inclusão de óleo de soja na dieta. Tanto a inclusão de quitosana quanto a de óleo de soja aumentaram o colesterol total sérico. Na ureia plasmática foi observada interação, onde a concentração maior foi observada na dieta Q em relação a C, não diferindo entre as dietas contendo óleo de soja (O e QO). As concentrações de AST foram influenciadas positivamente pela suplementação de óleo de soja nas dietas. Observou-se interação para eficiência de utilização da energia e do nitrogênio, onde observou-se aumento pela inclusão quitosana nas dietas sem óleo de soja e reduziram quando da inclusão em dietas contendo óleo. As inclusões de quitosana e de óleo de soja não influenciaram a síntese de proteína microbiana ruminal. A inclusão de óleo de soja aumentou a concentração de propionato e reduziu acetato e consequentemente a relação C2:C3, no rúmen. A produção de leite não foi influenciada pela inclusão de quitosana na dietas sem óleo de soja e foi reduzida quando esta foi realizada em dietas contendo óleo de soja. A eficiência de conversão da MS consumida em leite foi reduzida nas dietas contendo óleo e aumentada nas dietas sem óleo de soja, pela inclusão de quitosana. Assim, considerando principalmente o desempenho produtivo dos animais, a inclusão de quitosana nas dietas de vacas leiteiras no terço médio de lactação é viável, desde que esta não esteja associada a suplementação com fontes de lipídeos. / The aim of this study was to evaluate the effects of addition of chitosan in the diets of dairy cows in lactation, containing or not soybean oil, over intake, and total apparent digestibility of dry matter and nutrients, ruminal fermentation and microbial protein synthesis, milk yield and composition, concentrations of blood parameters and energy and nitrogen balances. 24 Holstein cows were used , four rumen cannulated and 20 non-cannulated with 581.2 ± 73.6 kg of BW, DIM average of 174.7 ± 53.1 and 36,14 ± 5,32 kg per day of initial milk wield which were distributed in six Latin squares balanced and contemporary to receive one of four diets, that were obtained by a combination of factors chitosan (approximately 150 mg / kg body weight) and soybean oil (3.3% of diet DM): control (C) , chitosan (Q), soybean oil (O) and chitosan associated with soybean oil (QO). Diets The consumption was reduced by the addition of chitosan in the diets without oil, whereas the presence of this, the chitosan does not affect the intake. The addition of soybean oil reduced the intake of DM, OM , CP, NDF , NFC and TDN and increased consumption of EE, regardless of the addition of chitosan in the diet . The addition of chitosan increased the digestibility coefficients (DC) of DM, OM and CP and did not alter the NDFDC . The EEDC was changed positively by addition of soybean oil in the diet. Both the addition of chitosan as soybean oil increased the total serum cholesterol. In plasma urea interaction, where the highest concentration was observed in the diet Q over C , did not differ between diets containing soybean oil (O and QO) was observed. AST concentrations were affected by supplementation of soybean oil in the diets. Observed interaction for efficient use of energy and nitrogen, which showed increase by adding chitosan in diets without soybean oil and reduced upon addition in diets containing oil. The experimental diets did not affect the synthesis of rumen microbial protein. The addition of soybean oil increased the concentration of propionate and acetate and thus reduced the ratio C2:C3 rumen. Milk production was not affected by the addition of chitosan in the diets without soybean oil, and was reduced on diets containing soybean oil. The conversion efficiency of DM intake in milk was reduced in diets containing oil and increased in diets without soybean oil, adding the chitosan. Thus, considering mainly the productive performance of the animals, the addition of chitosan in the diets of dairy cows in mid lactating is feasible, provided that this is not associated with supplementation with lipid sources.

Em um delineamento em Quadrado Latino 4X4 balanceado, foram utilizados quatro potros, filhos do mesmo garanhão, com idade entre 10 e 12 meses e peso médio de 270 kg (dp ± 9,80 Kg). Foram analisados os efeitos, por regressão simples polinomial, da inclusão dos níveis de 5, 10, 15 e 20 % de óleo de soja, no concentrado, sobre aceitabilidade, coeficiente de digestibilidade aparente da matéria seca (CDAMS), matéria orgânica (CDAMO), proteína bruta (CDAPB), extrato etéreo (CDAEE), fibra insolúvel em detergente neutro (CDAFDN), em detergente ácido (CDAFDA) e sobre a concentração plasmática de colesterol total (COL) e suas frações nas lipoproteína de densidade muito baixa (VLDL-C), lipoproteína de densidade baixa (LDL-C), lipoproteína de densidade alta (HDL-C) e triglicérides totais (TRG). O aumento do nível de inclusão de óleo afetou (p<0,05) o CDAMO, CDAFDN e CDAFDA, apresentando uma resposta quadrática, com diminuição da digestibilidade após o valor esperado de 10,7%, 9,5% e 10,5% EE na dieta, respectivamente. Observou-se resposta linear (p<0,05) dos tratamentos sobre a concentração plasmática de colesterol e LDL-C, apresentando diminuição 0,65 mg/dL de colesterol e 0,58 mg/dL de LDL-C para cada 1% de aumento no EE no concentrado. A inclusão de óleo de soja afetou a digestibilidade da dieta, principalmente na fração parede celular e diminuiu a concentração plasmática de colesterol e HDL-C. / In a balanced 4x4 Latin Square design, 04 foals from the same stallion were used. They aged between 10 and 12 months and their average weight was 270±9.80 kg. The effects of soybean oil inclusion at the concentrated on acceptability, coefficient of apparent digestibility to dry matter (CADAMS), organic matter (CADOM), crude protein (CADCP), ethereal extract (CADEE), neutral detergent fiber (CADNDF), acid detergent (CADADF) and the plasma concentrations of total cholesterol (COL) and the fractions in Very Low Density Lipoprotein (VLDL - C), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C) and total triglycerides (TRG), at the following levels of 5, 10, 15 and 20%, were analyzed by simple polynomial regression. Increase in the level of oil inclusion affected (P<0.05) CADOM, CADNDF and CADADF, showing a quadratic response. For those parameters, digestibility was decreased after inclusion of 10.7%, 9.5% and 10.5 of EE% in the diet, respectively. There was a linear response (P<0.05) to the treatments on the cholesterol plasma concentration and LDL-C; each 1% of increase in EE on the diet caused a decreased of 0.65 mg/dL on cholesterol and 0.58 mg / dL on LDL-C. The inclusion of soybean oil affected the digestibility of the diet, mainly on cell wall fraction, and decreased the concentration of plasma cholesterol and HDL-C.

O concentrado em substituição à parte da forragem na alimentação, principalmente por grãos de cereais ricos em amido, a fim de suprir as necessidades energéticas do animal, pode exceder a capacidade digestiva do intestino delgado e atingir o ceco e cólon, acarretando em mudanças na microbiota e causando distúrbios gastrointestinais. O objetivo desse estudo foi avaliar o efeito da suplementação do óleo essencial carvacrol sobre a digestibilidade aparente dos nutrientes da dieta, resposta glicêmica e insulinêmica pós-prandial, pH fecal, perfil plasmático de triglicerídeos, colesterol total, frações de colesterol ligado à lipoproteína de alta densidade (HDL-C), colesterol ligado à lipoproteína de baixa densidade (LDL-C) e colesterol ligado à lipoproteína de muito baixa densidade (VLDL-C). Foram utilizados oito animais da raça Mini-horse, machos, castrados, com idade de 42±6 meses, peso médio de 135±15 kg, alimentados com dieta contendo alta proporção de concentrado: volumoso, constituída de 60% concentrado comercial peletizado e 40% de feno de gramínea, cuja variação foi a inclusão de um produto contendo 7% de carvacrol, onde os tratamentos foram inclusão de controle, 100, 200 e 300 ppm de óleo essencial contendo 7% de carvacrol. O delineamento experimental utilizado foi em quadrado latino duplo 4x4 com medidas repetidas no tempo e os dados obtidos foram submetidos à análise de variância com nível de significância de 5%. Os resultados dos coeficientes de digestibilidade MS, MO, PB, EE, MM, FDN e FDA foram respectivamente, P= 0,48; P= 0,66; P= 0,58; P= 0,64; P= 0,55; P= 0,58; P= 0,46; valores de pH fecal observados foram adequados (pH = 6,38) para o equilíbrio da microbiota, não sendo observado efeito de tratamento (P=0,84). Na avaliação da área abaixo da curva (AAC), não foi observado efeito de tratamento (P= 0,48) para os valores de glicose. A resposta plasmática de insulina apresentou efeito quadrático para AAC (P=0,05) nos tempos (90, 150 e 210 minutos). Na avaliação de gordura plasmática não foi encontrado efeito de tratamento para triglicérides o valor de (P=0,37), para colesterol total e frações HDL, LDL e VLDL os valores foram respectivamente, P= 0,85; P= 0,57; P= 0,94; P= 0,37. A inclusão de óleo essencial na dieta não promove efeito sobre a digestibilidade, resposta glicêmica, perfil plasmático de gordura plasmática e pH das fezes. A inclusão de óleo essencial promove efeito sobre a resposta insulinêmica. / The concentrate to replace part of the forage in the diet, mainly cereal grains rich in starch, in order to meet the energy needs of the animal, may exceed the digestive capacity of the small intestine and reach the cecum and colon, resulting in changes in the microbiota and causing gastrointestinal disorders. The aim of this study was to evaluate the effect of supplementation of carvacrol as essential oil on the apparent digestibility of nutrients, glucose and insulin responses postprandial fecal pH, plasma levels of triglycerides, total cholesterol and its fractions high density lipoprotein (HDL-C), low density lipoprotein (LDL-C) very low density lipoprotein (VLDL-C). Were used eight animals, Mini-horse breed, geldings, aged 42±6 months, average weight 135±15 kg, fed a diet containing high relation concentrate:roughage, consisting of 60% commercial concentrate and 40 % of grass hay, which variation was the inclusion of essential oil containing 7% carvacrol, with the treatments divided according to the level of inclusion: 0 (control), 100, 200 and 300 ppm. The experimental design was 4x4 latin square with repeated measures over time and the data were subjected to analysis of variance with a significance level of 5%. The results of the digestibility coefficients of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), mineral matter (MM), neutral detergent fiber (NDF) and acid deterge nt fiber (ADF) were, respectively, P=0.48; P=0.66; P=0.58; P=0.64; P=0.55; P=0.58 and P=0.46. Faecal pH values were found suitable (pH=6.38) to the balance of microorganisms, and there was no effect of treatment (P=0.84). In evaluation of the area under the curve (AUC), weren´t observed effects of treatment (P=0.48) values for glucose. The response of plasma insulin showed a quadratic effect for AUC (P=0.05) in times 90, 150 and 210 minutes. In the evaluation of plasma lipids wasn´t found effect treatment of the triglyceride value (P=0.37) for total cholesterol, and HDL-C, LDL-C and VLDL-C values were respectively (P=0.85; P=0.57; P=0.94 and P=0.37). The inclusion of essential oil in the diet does not promote effect on digestibility, glycemic response, plasma levels lipids and plasma pH of feces. The inclusion of essential oils promotes effect on the insulin response.