ABSTRACT. This study aimed to evaluate cassava genotypes to identify the ones with the best nutritional values for ruminant diets. Nine genotypes were used: Amansa Burro (BGM 549), Aramaris (BGM 116), Brasília, Cambadinha (BRS Guaíra), Curvelinha, Engana Ladrão (BGM 1269), Trouxinha (BGM 1468), BRS Gema de Ovo, and BRS Dourada. A completely randomized block experimental design with nine treatments (genotypes) and three blocks (replicates) were employed. The roots were analyzed for dry matter production (DMP) in tonnes per hectare, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), starch, and in vitro dry matter digestibility (IVDMD). The multivariate analysis was carried out using Ward’s hierarchical agglomerative clustering based on Mahalanobis distance. The groups formed were evaluated by Scott-Knott test. The group formed by genotype Engana Ladrão was chosen as the best one for having the highest DMP t ha-1 and IVDMD values and the lowest NDF and ADF contents.

ABSTRACT. This study examined the influence of the external markers chromium oxide (CO), titanium dioxide (TD), isolated, purified and enriched lignin (LIPE®) and isolated, purified, enriched lignin in nanoparticles (NANOLIPE®) as well as the internal markers indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in diets with inclusion of passion fruit by-product for dairy heifers on the estimation of fecal output and nutrient digestibility. Sixteen Holstein × Zebu crossbred heifers at an average live weight of 363 ± 28 kg were randomly distributed in a completely randomized design where they received diets in which Tifton 85 (Cynodon sp.) hay was replaced with passion fruit by-product (0, 12, 24 and 36%, as-fed basis). The CO, LIPE®, NANOLIPE® and iNDF markers did not differ from the total collection method (p > 0.05) in the estimation of fecal output and nutrient digestibility. The TD and iDM markers overestimated, while iADF underestimated fecal output. Under the presented conditions, we recommend using the CO, LIPE®, NANOLIPE® and iNDF markers to estimate fecal output and nutrient digestibility in diets with inclusion of passion fruit by-product for dairy heifers.

ABSTRACT The objective of this study was to evaluate the effect of guava agroindustrial waste (GAW) on ruminal parameters (pH, N-NH3, and microbial protein), volatile fatty acid (VFA), and morphometry of the rumen and intestine of sheep. A total of forty Santa Inês sheep (120 days old and 21.3±2.62 kg) were used. The animals were fed diets with 0, 7.5, 15, 22.5, and 30% inclusion of GAW. The pH, ammonia nitrogen, microbial protein, and VFA were evaluated in the ruminal fluid, alongside the morphometric characteristics of the rumen and intestine. The inclusion of GAW linearly increased fasting and postprandial pH, N-NH3 only showed a quadratic effect for fasting animal, whereas MP presented a quadratic effect for pre- and post-prandial animals. There was a quadratic effect for papilla width, with a maximum value of 393.33 μm at the level of 34.43% GAW in the diet. The papilla absorption area showed a linear effect, in which increasing levels of GAW in the diet had a smaller area of papillae absorption. The inclusion of GAW in the diet of Santa Inês sheep favored pH neutrality, reduced N-NH3 and ruminal MP concentrations, decreased the thickness of the rumen muscular layer, and increased the intestinal mucosa, favoring greater absorption of nutrients.

ABSTRACT This study was conducted to evaluate the effect of substituting Tifton 85 hay (Cynodon sp. cv. Tifton 85) with levels of cocoa (Theobroma cacao) byproduct (0, 8, 16, and 24%, diet dry matter basis) in the diet of 16 Holstein × Gir heifers with an average body weight of 363.0±27.7 kg on their nutrient intake, digestibility, and protein balance. The experimental period was 17 days, and the sample collection period was five days. There was no effect of cocoa byproduct on nutrient intake. However, the byproduct affected the digestibility of dry matter, crude protein, neutral detergent fiber, and acid detergent fiber, all of which decreased as the level of inclusion of the byproduct in the diet was increased. Nitrogen balance was negatively affected by the inclusion of 24% cocoa byproduct. It is recommended to use cocoa byproduct up to the level of 16% to replace Tifton 85 grass hay in diets for dairy heifers.

ABSTRACT The objective of this study was to examine serum retinol and some mineral (zinc, iron, calcium, phosphorus, magnesium, and copper) levels in seven Mangalarga Marchador colts aged 329.48 days, reared on pasture in the city of Montes Claros, MG, Brazil, during the dry season. Equines were evaluated for four periods of 45 days during the total study period of five months. The foals had access to Panicum maximum cv. Tanzania pasture, while water and mineral salt lick were provided ad libitum. Blood samples were taken to determine serum retinol and levels of minerals, along with pasture samples to quantify beta-carotene in the grass. The results indicated that retinol levels varied (2.87 to 1.97 µg/dL) and remained below the standard levels. The levels of zinc, iron, calcium, and phosphorus did not vary significantly with average values of 36.79 µg/dL, 77.32 µg/dL, 10.33 mg/dL, and 9.99 mg/dL, respectively. However, zinc and calcium remained below standard concentrations of 60-120 µg/dL and 10.8-13.5 mg/dL, respectively, since the beginning of the study. On the other hand, copper and magnesium levels decreased over time (97.76 to 77.56 mg/dL and 2.86 to 2.21 µg/dL, respectively), but showed normal levels for horses during the research. Beta-carotene in grass showed a downward trend over time from 38.53 to 0.09 mg/kg of dry matter. The results also indicated a significant relationship between serum retinol and serum copper levels. Vitamin A supplementation is necessary whenever foals are fed pastures during the dry season.

Resumo Este experimento teve como objetivo avaliar o consumo e a digestibilidade aparente da matéria seca, proteína bruta, frações fibrosas, energia e balanço do nitrogênio do feno de Andropogon gayanus colhido em três diferentes idades (56, 84 e 112 dias). O delineamento estatístico utilizado foi o inteiramente casualizado com três tratamentos e seis repetições. As digestibilidades aparentes da matéria seca, das frações fibrosas e da energia bruta foram maiores para os fenos colhidos aos 56 e 84 dias (P<0,05). O feno de A. gayanus colhido aos 56 dias apresentou maiores valores de consumo e digestibilidade aparente da proteína bruta (5,22 g/UTM/dia; 55,69%, respectivamente) (P<0,05) em relação aos demais tratamentos que não diferiram entre si (P>0,05). Os valores de consumo e digestibilidade aparente apontam as idades de 56 e 84 dias como as melhores dentre as estudadas para o corte do capim A. gayanus para fenação.

Abstract The aim of this study was to evaluate the voluntary intake and apparent digestibility of dry matter, crude protein, fiber fractions, energy, and the nitrogen balance of Andropogon gayanus hay at three different stages (56, 84 and 112 days). The statistical design was completely randomized, with three treatments and six replicates. Dry matter, fiber fractions, and energy apparent digestibility were higher (P<0.05) for hay harvested at 56 and 84 days. Crude protein intake and apparent digestibility of A. gayanus hay harvested at 56 days of growth were greater (P<0.05) than the hay harvested at 84 and 112 days. The A. gayanus hay showed the best voluntary intake and digestibility at 56 and 84 days of age.

RESUMO Estudo colaborativo foi conduzido para avaliação do teor de proteína bruta (PB) em diferentes amostras de alimentos em sete diferentes laboratórios de análise de alimentos de instituições integrantes do Instituto Nacional de Ciência e Tecnologia de Ciência Animal (INCTCA). Foram utilizadas amostras de quatro alimentos (cana-de-açúcar, silagem de milho, farelo de soja e milho grão) e quatro compostos que foram assumidos como padrões para aferição da exatidão das estimativas (ureia, fosfato de amônia monobásico, ácido etileno diamínico tetra-acético e sulfato de amônio). Cada laboratório analisou as amostras durante seis dias, consecutivos ou não, sendo realizadas três repetições por amostra em cada dia de avaliação. As variâncias entre laboratórios e dentro de laboratórios (repetibilidade) representaram 34,5 e 10,3 % da variação total. A avaliação das recuperações de nitrogênio a partir dos padrões permitiu evidenciar que 25% das observações apresentaram vícios significativos de recuperação (P<0,001). A avaliação global das amostras propiciou variações significativas (P<0,001) em função: do dia de análise, interação do material com o laboratório e entre laboratórios. Adicionalmente, verificou-se que a variação dos resultados entre laboratórios correspondeu de 43,6 a 68,2% da variação aleatória total, ao passo que a repetibilidade (variação intra-laboratorial) representou de 11,9 a 42,8% da reprodutibilidade. Os teores de PB estimados pelos laboratórios participantes são dependentes do efeito de interação do material avaliado e do laboratório, possível reflexo das várias diferenças entre os procedimentos utilizados por cada laboratório.

SUMMARY A collaborative study was conducted to evaluate the crude protein (CP) content in feeds in seven feed analysis laboratories from institutions linked to the National Institute of Science and Technology in Animal Science (INCT-CA). Were evaluated four samples of different feeds (sugarcane, corn silage, soybean meal and corn grain) and four nitrogen compounds assumed as standards (urea, monobasic ammonium phosphate, ethylene diamine tetraacetic acid and ammonium sulfate) to measure the accuracy of the estimates. Each laboratory analyzed the samples for six days, consecutive or not, with three replicates per sample per day of evaluation. The variances among laboratories and within of laboratories (repeatability) represented 34.5 and 10.3% of the total variation, respectively. The evaluation of nitrogen recovered from the standards showed that 25% of observations presented a significant bias (P<0.001). The overall assessment of the samples demonstrated significant variations (P<0.001) in function of the day of analysis, interaction of material with laboratory, and among laboratories. Additionally, it was found that the variation among laboratories corresponded of 43.6 to 68.2% of the total of random variation, while the repeatability (intra-laboratory variation) represented of 11.9 to 42.8% of reproducibility. The CP contents estimated are dependent of the interaction effect of the evaluated material and laboratory, which reflect the differences between the procedures utilized by each laboratory.

The objective of this study was to evaluate the flow of nitrogenous compounds, protein degradability, rumen degradation of total carbohydrate and organic matter and microbial efficiency in heifers subjected to diets containing corn silage, sugarcane or Tifton. For this purpose, the 2,6-diaminopimelic acid (DAPA) technique was adopted and analytical procedures for amino acids by HPLC were adapted. Six rumen-fistulated Holstein-Zebu heifers with 480 kg of initial BW and at 24 months of age kept in individual tie stalls were assigned to two 3 × 3 Latin squares. Omasal digesta dry matter and microbial dry matter flows were determined using the isolated, purified and enriched lignin (LIPE®) and DAPA markers, respectively. Isolated bacteria from rumen showed on average 5.84 g/100 g microbial N, 0.25 g/100 g DAPA in dry matter and 44.61 DAPA:N ratio. The forage sources did not influence the flows of nitrogen compounds, except for total omasal flow and non-ammonia N in relation to N intake for the corn silage diet, for which there was an upward trend compared with the other diets. The degradation of the organic matter and total carbohydrates did not differ, averaging 6.1 kg/day and 5.2 kg/day, respectively. The studied forage sources do not influence the flows of nitrogen compounds, except for total omasal flow and non-ammonia N in relation N intake for the corn silage diet, for which there is an upward trend compared with the other diets. Protein degradability and microbial efficiency are similar between evaluated diets.

This study was carried out to evaluate intake, nutrient digestibility and body weight gain of foals on diets of concentrate and legume hay. Treatments were: lucerne hay (Medicago sativa), Campo Grande stylo hay (20% Stylosanthes macrocephala and 80% Stylosanthes capitata) and Mineirão stylo hay (Stylosanthes guianensis cv. Mineirão). Fifteen weaned foals at 160 Kg body weight (BW) were used. The experiment was entirely randomized with three treatments and five replicates. Dry matter intake was estimated at 30 g of dry matter (DM)/kg BW and was comprised of 40% concentrate meal and 60% hay. Fecal production and nutrient digestibility were calculated by the LIPE® marker methodology. There was no difference between Lucerne hay and Campo Grande stylo hay intake, but intake of Mineirão stylo hay was lower than that of Lucerne hay. Body weight gain and nutrient digestibility coefficients were similar for foals fed different diets. Intake was similar for Campo Grande and Lucerne hay, and led to similar body weight gain in diets with concentrate. Mineirão stylo hay, at 137 days of growth, was not palatable for the foals.

Realizou-se um ensaio metabólico para avaliar a lignina purificada de eucalipto (LIPE®), como indicador na determinação da digestibilidade da proteína bruta e matéria seca de alimentos para frangos de corte. Os tratamentos corresponderam a uma dieta basal e outras oito dietas contendo os alimentos-teste. Os alimentos foram: milho, milho expandido, farelo de soja, farelo de soja expandido, glúten de milho 22%, glúten de milho 60%, farinha de carne e ossos e farinha de penas e vísceras. Os alimentos protéicos e os com menor teor de proteína substituíram 25 e 40% da dieta basal, respectivamente. Foram utilizados 270 pintos de corte, linhagem Ross, de ambos os sexos, dos 21 aos 31 dias de idade. Utilizou-se um delineamento experimental inteiramente ao acaso em esquema fatorial 9×3 (rações × métodos), com três repetições. Os coeficientes de digestibilidade (CD) da proteína e da matéria seca e os valores da proteína bruta digestível e da matéria seca digestível de sete das nove dietas, calculados pelos métodos da coleta total de excretas e dos indicadores óxido crômico e LIPE®, foram semelhantes. Com os alimentos-teste, farelo de soja expandido e farinha de penas e vísceras, o uso de óxido crômico resultou em CD e valores de proteína e matéria seca digestível mais altos, quando comparado com o uso da LIPE® e da coleta total de excretas que foram semelhantes entre si. Pode-se considerar que a proteína bruta digestível e matéria seca digestível dos alimentos, calculada pelos três métodos, foram equivalentes. A LIPE® pode ser validada como indicador de digestibilidade da proteína e matéria seca de alimentos para frangos de corte.

A metabolism experiment was carried out to evaluate the use of LIPE® as an external indicator of dry matter and protein digestibility in broilers. The treatments corresponded to a basal diet and eight other different diets. The foods used were: corn grain, expanded corn, soybean meal, expanded soybean meal, gluten meal 22% crude protein; gluten meal 60% crude protein, meat and bone meal and feather meal. The basal diet was replaced with 40% or 25% of the food containing more energy or protein, respectively. Two hundred and seventy broiler chickens were used from 21 to 31 days old. A completely randomized design in a 9x3 factorial arrangement (nine forms of rations x three methods) with three replicates was used. The digestible dry matter and protein and metabolizable energy of the food was calculated by the total fecal collection method and by the indicator methods of chromic oxide and LIPE®; the three methods were further compared. Chromic oxide use resulted in higher values of coefficient of digestibility for expanded soybean meal and feathers and viscera meal when compared to the use of LIPE® and total feces collection which were similar. The results validated the LIPE® as an external protein and dry matter digestibility index of the feed of broiler chicks evaluated.

Neste trabalho, determinou-se o valor nutritivo de quatro alimentos energéticos (fubá de milho, sorgo, farelo de arroz integral e quirera de arroz) para juvenis de surubim. Os coeficientes de digestibilidade aparente da matéria seca (MS), proteína bruta (PB) e energia bruta (EB) foram avaliados pela metodologia de substituição do alimento numa ração-referência usando-se 0,1% de óxido crômico como indicador externo. Utilizaram-se 240 alevinos com 30 g de peso médio distribuídos em tanques apropriados para coleta de fezes. O delineamento foi inteiramente casualizado com quatro dietas, cada uma com quatro repetições. O coeficiente de digestibilidade aparente da matéria seca do fubá de milho foi de 62,3%; do farelo de arroz, 59,7%; da quirera de arroz, 40,4%; e do sorgo, 38%. Os coeficientes de digestibilidade da proteína bruta, nesta ordem, foram 87,4; 83,8; 85,3; e 81,1%; e os da energia bruta, 62,4; 66,4; 46,9 e 47,8%. Entre os alimentos avaliados, o que possui maior digestibilidade da matéria seca, proteína bruta e energia bruta é o farelo de arroz e o de menor digestibilidade, o sorgo.

It was determined, in this work, the nutritional value of four energetic feeds (corn meal, sorghum, whole rice bran, and ground rice) for surubim juveniles. Apparent digestibility coefficients of dry matter (DM), crude protein (CP), and gross energy (GE) were evaluated by food replacement methodology in a reference-feeding using 0.1% of chromic oxide as an external marker. It was used 240 fingerlings with an average weight of 30 g distributed in tanks fitted for faeces collection. A complete random design with four diets, each one with four replicates, was used. Apparent digestibility coefficient of dry matter for corn meal was 62.3%; for rice bran, 59.7%; for ground rice, 40.4%, and for sorghum, 38%. Digestibility coefficients for crude protein were, in this order, the following: 87.4, 83.8, 85.3 and 81.1% and digestibility coefficient for gross energy were: 62.4, 66.4, 46.9 and 47.8%. Among the evaluated feeds, the one with the highest digestibility of dry matter, crude protein, and gross energy is the rice bran and the one with the lowest digestibility is the sorghum.

Foram estudados os efeitos da suplementação com proteinados sobre a degradabilidade da matéria seca (MS), proteína bruta (PB), fibra em detergente neutro e fibra em detergente ácido (FDN e FDA) em bovinos de corte em pastagem de Brachiaria brizantha cv. Marandu. Foram utilizados quatro bovinos Nelore com 395 ± 9 kg, fistulados no rúmen para avaliação da degradabilidade e da cinética da fase líquida e das partículas. Dois bovinos com fístulas esofagianas foram usados para a colheita de extrusas. Suplementos com 50, 40 e 30% de proteína bruta (PB) foram fornecidos na proporção de 400 g/animal/dia em comparação à suplementação controle, com apenas sal mineral. A oferta de suplemento proteinado não influenciou a degradabilidade potencial da MS, PB e FDN, mas promoveu aumento de 36,85% para 48,97% na degradabilidade efetiva da MS e de 22,06% para 30,05% na degradabilidade da FDN. Os suplementos com 40 e 30% de proteína bruta foram superiores ao controle, pois promoveram maior degradabilidade efetiva da PB e maiores taxas de saída das partículas. A taxa de passagem da fase líquida foi 11,4% maior nos animais que receberam os suplementos em relação aos do grupo controle. A degradabilidade efetiva da FDA não foi afetada pelo consumo dos suplementos e variou de 12,19% (controle) a 16,75% (suplemento com 30% de PB). Os resultados deste estudo mostram a importância da suplementação protéica para animais em pastagem de baixa qualidade e também do nível de N dos suplementos.

The effects of protein supplementation on degradability of dry mattter (DM), crude protein (CP) and neutral detergent fiber (NDF) and acid detergent fiber (ADF) were evaluated in beef cattle grazing Brachiaria brizantha cv Marandu. It was used four Nelore steers (395 ± 9 kg) fitted with ruminal cannula to evaluate kinetics and degradability of the liquid phase and of the particles. Forage samples were collected in other two steers with esophageal cannula. Supplements with 50, 40, and 30% of crude protein (CP) were given at the proportion of 400 g/animal/day when compared to control suplementation with only salt and mineral. The offer of protein supplement did not change potential degradability of dry matter, crude protein and neutral detergent fiber but promoted an increase from 36.85% to 48.97% on effective degratability of dry matter and from 22.06% to 30.05% on neutral detergent fiber degradability. Supplements with 40 and 30% of crude protein were higher than the control because they promoted higher efffective degradability of crude protein and higher particle exit rates. The liquid passage rate was 11.4% higher for the animals which received supplementation when compared to the control. The effective degradability of ADF was not affect by consumption and it ranged from 12.19% (control) to 16.75% (supplement with 30% of crude protein). The results of this work show the importance of protein supplementation to animals on pasture of low quality and also the N level of the supplements.

Avaliaram-se os efeitos dos níveis de nitrogênio de suplementos proteicos sobre as concentrações de nitrogênio amoniacal (N-NH3) e ácidos graxos voláteis (AGV) e o pH em bovinos de corte em pastagem de capim-marandu (Brachiaria brizantha, cv. Marandu). Foram realizadas estimativas da síntese microbiana, do aporte de proteína nãodegradável no rúmen (PNDR) e proteína endógena e das suas contribuições no pool de proteína metabolizável (PM). Quatro bovinos Nelore com 395 ± 9 kg, fistulados no rúmen, foram utilizados nas medidas dos parâmetros ruminais e nas avaliações da degradabilidade, da cinética ruminal e das estimativas de síntese microbiana em um delineamento quadrado latino 4 ×4. Suplementos com 30, 40 ou 50% de proteína bruta (PB) foram fornecidos na quantidade de 400 g/animal.dia para comparação a um grupo controle, sem suplementação proteica. Os animais foram mantidos em pastagens de Brachiaria brizantha, cv. Marandu, distribuídos em quatro piquetes com área de 1,0 ha cada, com oferta do suplemento e retirada das sobras, realizada diariamente. As concentrações de N-NH3 nos animais que receberam o suplemento com 50% PB foram superiores às observadas naqueles sob suplementação com 40% PB e no grupo controle, mas foram semelhantes às observadas no grupo sob suplementação com 30% PB. As concentrações de AGV no grupo sob suplementação com 30% PB foram superiores às observadas no grupo controle e semelhantes às obtidas com suplementação com 40 e 50% PB. O pH não diferiu entre os grupos. A estimativa de oferta de proteína microbiana e de PNDR foi maior para os animais sob suplementação com proteína em relação à observada no grupo controle.

The effects of nitrogen levels of protein supplements were evaluated on the concentrations of ammonical nitrogen (N-NH3), volatile fatty acids (VFA's) concentrations and pH in beef cattle grazing Brachiaria brizantha cv. Marandu. The microbial protein synthesis, ruminal undegradable protein (RUP) and endogenous crude protein (ECP) and their contributions to the pool of metabolizable protein (MP). Four Nelore steer, 395 ± 9 kg, fitted with ruminal cannulas, were used to evaluate ruminal parameters, degradability, ruminal kinetics and microbial synthesis in a 4 ×4 Latin square design. The animals were supplied with 400g/head/day of supplements containing 30, 40, and 50% crude protein (CP) for comparison with a control group without protein supplementation (C). The animals grazed Brachiaria brizantha cv Marandu, distributed in four one-hectare paddocks where the supplements were offered and the orts removed daily. The N-NH3 levels in the animals that received 50% CP were higher than those observed in animals receiving 40% CP and C, but were similar to the levels observed in the animals supplemented with 30% CP. The VFA concentrations in the group supplemented with 30% PB were higher than the control treatment (C) and similar to those obtained with 40 and 50% CP supplementation. The pH did not differ among the groups. The microbial synthesis and RUP were greater for the animals that received protein supplementation compared to the control treatment.

Objetivou-se avaliar o consumo, a cinética digestiva e a digestibilidade de nutrientes em equinos consumindo rações suplementadas com óleo de soja. Foram utilizados 15 equinos em delineamento experimental inteiramente casualizado com três dietas e cinco repetições. As dietas experimentais foram formuladas a partir de uma dieta controle (sem inclusão de óleo de soja) acrescida 8,5% ou 19,5% de óleo de soja. O ensaio teve duração de 34 dias: 30 de adaptação dos equinos às dietas e quatro de coleta de fezes. A cinética da fase líquida da digesta no trato digestivo foi estimada pela LIPE® (lignina isolada, purificada e enriquecida) na forma líquida. A LIPE® foi fornecida no 30º dia, em dose única, e as amostras de fezes foram coletadas nos tempos 0, 2, 4, 8, 12, 16, 20, 24, 30, 36, 42, 48, 54, 60, 66, 72 e 78 horas após o fornecimento. O consumo de matéria seca das dietas reduziu com a inclusão de óleo de soja. O coeficiente de digestibilidade aparente do extrato etéreo aumentou nas dietas hiperlipidêmicas, enquanto o de digestibilidade da celulose reduziu com a inclusão de 19,5% de óleo de soja. O coeficiente de digestibilidade dos demais nutrientes, exceto o de proteína bruta, e a cinética da digesta no trato gastrointestinal não foram alterados. A inclusão de óleo de soja em dietas práticas para equinos possibilita reduzir o consumo de matéria seca e aumentar a concentração energética, desejável em equinos atletas.

The objective of this study was to evaluate intake, digestive kinetics and nutrient digestibility in horses fed diets supplemented with soybean oil inclusion. Fifteen horses were used in a randomized complete design with three diets and five replications. The experimental diets were formulated from a control diet (without soybean oil) with the addition of 8.5% and 19.5% soybean oil. The experiment lasted for 34 days, 30 days for the horses to adapt to the diets and four days for feces collection. The kinetics of the liquid phase of the digesta in the digestive tract was estimated by LIPE® (Purified Enriched Isolated Lignin) in liquid form. LIPE® was given on the 30th day, in a single dose, and the feces samples were collected at 0, 2, 4, 8, 12, 16, 20, 24, 30, 36, 42, 48, 54, 60, 66, 72 and 78 hours after administration. Dry matter intake of the diets decreased with soybean inclusion. The apparent digestibility coefficient of the ether extract increase in the high fat diets, while the cellulose digestibility decreased with the inclusion of 19.5% soybean oil. The coefficient of digestibility of the other nutrients, except crude protein, and the kinetics of the digesta in the gastrointestinal tract were not altered. Including soybean oil in practical diets for horses enables dry matter intake reduction and increase in the energetic concentration, which is desirable in athletic horses.

O trabalho foi realizado visando avaliar a influência da suplementação de probióticos ou fitase sobre o consumo diário de matéria seca (CMS), o ganho de peso diário (GPD) e a conversão alimentar (CA) de 24 potros da raça Mangalarga Marchador (16 machos e 8 fêmeas), com 241,6 ± 23,2 dias de idade e 216,7 ± 27,8 kg de peso vivo (PV). O experimento teve duração de 28 dias: os 23 iniciais para adaptação à dieta e ao manejo e os cinco finais para coleta de fezes. A dieta foi composta por pastagem de Cynodon e concentrado comercial (1,2 kg/100 kg PV), além de água e sal mineral à vontade. Os tratamentos foram: dieta basal (controle); dieta basal + 5 g/dia de leveduras vivas (10(9) UFC/g de Saccharomyces cerevisiae); dieta basal + 2 g/dia de bactérias (10(8) UFC/g de B. bifidum, E. faecium, L. acidophilus, L. plantarum) e leveduras vivas (10(5) UFC/g de S. cerevisiae) e dieta basal + fitase (1.250 FTU/dia). Para estimativa do consumo de matéria seca, foram utilizados o indicador externo LIPE® e a técnica de digestibilidade in situ. O delineamento foi inteiramente casualizado, em fatorial 4 × 2, e as médias comparadas pelo teste Student, considerando o efeito da covariável PV inicial para porcentagens de CMS por PV. O consumo de matéria seca total dos grupos variou de 2,4 a 2,8% PV, de modo que os animais sob suplementação com bactérias e leveduras vivas apresentaram menor CMS total e de volumoso. Todos os animais tiveram GPD médio de 0,33 kg/dia e o grupo sob suplementação com bactérias e leveduras vivas teve conversão alimentar do volumoso 32,42 a 43,83% menor que a observada no grupo controle e naquele sob suplementação com fitase. A fitase, na dosagem de 205 FTU/kg de MS da dieta basal, não influenciou os parâmetros avaliados. O probiótico composto por bactérias e leveduras vivas melhorou a eficiência alimentar do volumoso e pode ser utilizado como estratégia nutricional para manutenção da condição corporal de potros durante o período seco.

The objective was to assess the effect of probiotic or phytase supplementation on dry matter intake (DMI), average daily gain (ADG) and feed conversion (FC) in 24 Mangalarga Marchador foals (16 males, 8 females), with 241.6 ± 23.2 days of age, and 216.7 ± 27.8 kg of body weight (BW). The study lasted 28 days, the first 23 days for diet and handling adaptation, and the last five days for feces collection. The basal diet consisted of Cynodon pasture and pelleted concentrate (1.2 kg/100 kg BW), as well as water and mineral salt ad libitum. Treatments groups were assigned as follows: basal diet (control); basal diet + 5 g/day of live yeast culture (10(9) CFU/g of S. cerevisiae); basal diet + 2 g/day of live bacteria (10(8) CFU/g of B. bifidum, E. faecium, L. acidophilus, L. plantarum) and yeast culture (10(5) CFU/g of S. cerevisiae); and basal diet + 1250 FTU/day of phytase. Pasture DMI was estimated with an external marker (LIPE™) associated with cecal in situ digestibility of dry matter. All foals were randomized, by replicated, using a 4 × 2 factorial, and results were compared using Student t-test, taking into consideration the effect of initial BW as covariate for the percentage DMI per BW. Among foals, DMI varied from 2.4 to 2.8% BW, with foals supplemented with live bacteria and yeast having lower DMI (total diet and forage). All animals had an ADG of 0.33 kg/day, and foals supplemented with live bacteria and yeast had FC 32.42 to 43.83% lower than foals supplemented with phytase or fed only basal diet. The phytase dose of 205 FTU/kg DM in the basal diet had no effects. Probiotic composed of live bacteria and yeast culture improved feed efficiency of forage and can be used as a nutritional strategy to maintain body condition in foals during the dry season.